432 FXUS66 KSEW 122144 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 244 PM PDT Tue May 12 2026 .SYNOPSIS... A lingering ridge of high pressure will bring one more day of warm temperatures to western Washington today with the potential for an isolated thunderstorm or two. A transition to onshore flow and cooler conditions will take place on Wednesday along with a chance of some precipitation. Cooler and unsettled conditions will continue into the weekend as a trough of low pressure over the Northeast Pacific sends a series of weak frontal systems across the area. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... Lingering upper level ridge has continued to bring warm conditions across the area this afternoon, with high temperatures in the mid to upper 70s, along with some locations in the Cascade foothills in the lower 80s. The ridge will shift eastward tonight with an incoming trough offshore. With southerly flow aloft and associated moisture with this incoming trough, we could see an isolated thunderstorm or two, particularly over the Southern portion of the Cascades this evening as orographics give the instability a boost (20-30% chance) The main hazard associated with any thunderstorm is frequent lightning, brief erratic winds, and heavy downpours. Again, could see an isolated thunderstorm or two move towards the interior, but confidence is low at the moment. Otherwise, we will see some scattered showers develop and move northward later tonight and through Wednesday morning and fill in through the interior. We`ll see the upper level low track over the area on Wednesday, keeping showers and unsettled weather in the forecast with significantly cooler temperatures. High temperatures on Wednesday will be in the upper 50s and lower 60s - almost a 15 degree temperature difference from the day before. A shortwave will cross over the area on Thursday with a slight warm up with temps in the lower 60s, with shower chances being mainly confined to the Cascades. Will likely be a dry day for the interior locations. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A series of troughs look to cross over western Washington over the weekend and into early next week. A trough on Friday will help favor some instability over the area once again, resulting in a slight chance of thunderstorms mainly over the North Cascades. Cooler temperatures in the upper 50s to lower 60s look to stay around for much of the weekend, with chances of precipitation in the forecast through at least Monday. Conditions look to dry out by Tuesday with temps warming into the mid/upper 60s. Mazurkiewicz && .AVIATION... High pressure across the region today with VFR conditions area- wide. Increasing southwest flow aloft later today. Winds become southerly this afternoon and increase a bit, with some gusts to 15-20 kt possible late this afternoon. There is a 60-80% chance of showers passing through the terminals east of Puget Sound/Cascades starting this afternoon through the overnight period. There is also a 20% chance of thunder in the Cascades, generally from Mt. Rainier southward. Expect mostly MVFR ceilings overnight. Winds to remain out of the southwest Wednesday, with a couple spots becoming breezy later in the day. KSEA...VFR during the day, becoming southerly this afternoon. Speeds increase to 8-12 kt later afternoon with gusts to 20 kt through evening. Showers likely arrive after 06z Wednesday through the terminal area, decreasing through the day Wednesday. && .MARINE... High pressure over the waters today, with the next system approaching. Winds increase a bit over the waters, especially through the Strait of Juan de Fuca. Small craft advisory winds are likely (70-80%) in the central Strait zone this evening and tonight. A more widespread round of onshore winds increases tomorrow through the day, bringing higher end advisory winds to 30 kt through the Strait. There remains lower (20-30%) chance of isolated gale gusts in the central Strait tomorrow, but confidence isn`t high in this. Otherwise, seas building over the coastal waters with a mix of a longer period and shorter period wave groups will bring confused seas that may be more hazardous than the wave heights (5-7 ft) would otherwise suggest. Otherwise, onshore flow continues through the Strait of Juan de Fuca later this week with northerly winds over the coastal waters. Another round of building seas to 8-9 ft over the coastal waters around Saturday from a distant disturbance. Cullen && .HYDROLOGY... The daily hydrology discussion has ended until the start of the next rainy season; it will only be updated during this time as needed. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory from 6 PM this evening to 5 AM PDT Wednesday for Central U.S. Waters Strait Of Juan De Fuca. && $$

618 FXUS66 KPQR 122157 AFDPQR Area Forecast Discussion National Weather Service Portland OR 257 PM PDT Tue May 12 2026 .SYNOPSIS...The arrival of a weather system tonight facilitates a notable pattern change towards cooler/slight wetter conditions. This is kicked off by the potential (15-35%) for a period of high-based thunderstorms this evening into early Wednesday morning, mainly I-5 corridor and eastward. After rain decreases on Wednesday, showers linger at times through the end of the week, mainly over the Cascades and coast/coast range. Then another low from the Gulf of Alaska increases precipitation chances(30-60%) to start the weekend while maintaining near to slightly below normal temperatures. && .DISCUSSION...Today through Monday...Broad southerly flow is in place this afternoon with mid to high cloud cover streaming across the region. Still, the added clouds haven`t been robust enough to suppress temperatures too much, and as of 1500 this afternoon we`re running about 3-8 degrees warmer across the Willamette Valley and Portland metro than we were at this time yesterday. Enjoy the conditions this afternoon if you`re a fan of warmer weather, we likely won`t see temperatures in the 70s and 80s for the remainder of the week. The feature responsible for the added high cloud cover and above normal temperatures is an approaching negatively tilted shortwave trough which we`ll have to watch closely this evening and overnight as it takes aim at the Pacific Northwest. While it`s mainly beneficial from a precipitation/moisture standpoint once we get to Wednesday morning, this approaching feature will result in a period of increasing high-based instability this evening through a good chunk of tonight with a 15-35% chance of thunderstorms of the nocturnal variety. To add more of a challenge, any thunderstorms that do develop, will likely not be surface based and can be tough for models to properly resolve. The primary question of thunderstorm coverage and frequency remains, but there has been some added clarity with the latest CAMs (Convective Allowing Models) this morning. Out of the available CAMs, the 12/18z NAMNEST and 12z UW WRF are the most bullish, with storm development starting around 6-8pm in Lane County and rapidly spreading north along the Willamette Valley through SW WA and across Cascades by 9-11pm. This presents more of a "worse case" scenario in regards to convection but the NAMNEST at least should be taken with a grain of salt as it can sometimes run "hot" when it comes to these set-ups; the UW-WRF does add some credence to the scenario it`s depicting however. Otherwise, the remainder of the high resolution ensemble space keeps development a bit delayed (10pm-midnight), more sporadic over the lower elevations, and further north/east largely placing activity in around the I-5 corridor in the north Willamette valley/SW Washington eastward into the Cascades. As the night goes on, the instability fueling convection continues to progress eastward eventually bringing and end to thunderstorm chances by the sunrise Wednesday. Just chances for plain old rain and showers follow. Later Wednesday morning into the early afternoon, the axis of the shortwave trough will shift east of the area leading to a decreasing precipitation the remainder of the day. The added cloud cover, westerly flow, and cooler airmass likely pushes high temperatures down into upper 50s to mid 60s for much of the area, almost 10-20 degrees lower than the day prior across the inland valleys. Looking towards Thursday and Friday, a more zonal flow pattern emerges keeping temperatures near to below normal, and shower chances in place across the coast, coast range/Willapa Hills, and Cascades. Then late Friday into early Saturday most deterministic and ensemble guidance shows another shortwave trough dropping down from the Gulf of Alaska into the region. This likely increases chances for precipitation across the area and nudges high temperatures even lower into mainly the 50s to near 60 Saturday afternoon. For those dreaming of a return to daytime temperatures back in the 60s and 70s hope is not lost as there is moderate confidence in a ridge of high pressure beginning to build back overhead by early next week. -99/42 && .AVIATION...Mainly VFR conditions Tuesday across NW OR and SW WA except for along the coast. MVFR marine stratus continues along the coast south of KAST under southwesterly surface flow. There could be a few hours of lifting to VFR at KONP or fluctuations between MVFR and VFR ceilings between 22z Tue - 03z Wed. Across inland areas, westerly winds are increasing to around 8-10 kts. Winds will then ease and become more south to southwesterly after 06z Wed. An upper level low pressure system approaches the region Tuesday night with a surface front pushing ahead. The front will move through the region between 06-15z Wed. Ahead of the front, there is a slight chance (15-25%) of scattered showers and thunderstorms 03-09Z Wed for all inland TAF locations. The chance for these showers or thunderstorms aren`t high enough at any one location to add them to the TAFs at this time, but any strong shower or thunderstorm could produce heavy rain, small hail, lightning, and gusty and erratic winds. A more stratiform band of showers then pushes inland along and behind the front, beginning along the coast around 06-09z Wed then moving east and reaching inland terminals by 09-12z Wed. This band will be mainly east of the Cascades by 18z Wed with scattered showers continuing through the afternoon. There`s a 60-80% chance of MVFR ceilings south of KSLE and a 30-60% chance at KSLE and north between 09-14z Wed. Winds increase along and behind the front around 09-12z along the coast and 12-15z inland. Expect winds around 8-12 kts with gusts up to 20-25 kts at times. KPDX AND APPROACHES...VFR conditions with high clouds into Tuesday night. There is a slight chance (15-25%) of scattered showers and thunderstorms from 03Z-09Z Wed. Then a more stratiform band of rain will impact the terminal beginning around 10-14z Wed with a 30-45% chance of MVFR ceilings. Scattered showers continue behind this with occasional chances of MVFR conditions in showers. Winds becoming west to southwest up to 8-10 kt, then becoming lighter and more variable after 02z Wed. Winds become southwest again and increase to 8-12 kts with gusts up to 20 kts after 11-14z Wed. -03 && .MARINE...Relatively benign conditions expected through the week with predominately westerly winds, mainly under 10 kts. An upper level trough and associated front moves through the waters on Wednesday, which bring a 40-55% chance of occasional small craft gusts up to 25 kt across all waters. This will mainly be when the front is passing between 4 AM - 12 PM Wednesday. Not expecting gusts to last long enough over any specific area to issue a small craft advisory at this time, though we will continue to monitor conditions. Winds remain westerly but decrease once again Wednesday night. Seas generally below 8 ft around 10-12 seconds through the majority of week, but could see seas close to 10 ft by Friday/Saturday. -42/03 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

964 FXUS66 KMFR 122134 AFDMFR Area Forecast Discussion National Weather Service Medford OR 234 PM PDT Tue May 12 2026 .KEY POINTS... * Strong gusty winds today - gusts of 25-35 mph common across the region with gusts 40-45 mph possible across the highest terrain east of the Cascades. * Heightened fire weather concerns today - strong winds and low RHs east of the Cascades and in the Shasta Valley. Also, hot, dry and unstable conditions are expected across northern California and East Side. * Isolated showers/thunderstorms possible this evening over the Siskiyous and Cascade Crest, shifting north of the area tonight. * Hottest day of the forecast period is today, with a cooling trend back to seasonal normals expected for Wednesday onward. Below normal temperatures are possible over the weekend. * Light rain (<=0.10") expected tonight into early Wednesday mainly along the coast and north of the Rogue-Umpqua Divide. && .DISCUSSION...Low pressure is approaching the region this afternoon, inducing southerly flow over the forecast area and tightening pressure gradients. This is resulting in strong gusty winds across the region with gusts of 20-30 mph fairly common away from the coast. It`s another warm day today with temperatures running about 5 to 8 degrees warmer than this time yesterday. Increasing cloud cover should limit the warming trend some, but expect another afternoon of upper 80s for the West/lower 80s for the East. Due to the strong winds today, we are highlighting some heightened fire weather concerns today, especially east of the Cascades and in northern California where humidities will be lowest this afternoon. Please use extra caution today if using anything with an open flame. With southerly flow over the region, there`s a low chance (10-20%) for isolated showers/thunderstorms later today into the evening. Instability will be most favorable over western Siskiyou/Siskiyou Mountains and along the Cascades Crest. Steering flow is fairly strong today, out of the southwest around 35-45 kts, so anything that develops over the Siskiyous will move into the Rogue/Illinois Valleys. It`s low chance, as moisture is fairly marginal, but still worth mentioning. The thunderstorm threat shifts north of the forecast area tonight. Low pressure will swing inland tonight through early Wednesday. Gusty winds will ease some after sunset, but remain breezy into early Wednesday. 700 mb winds peak (45-55kt) overnight tonight as the low swings inland, but since it`s coming through in the overnight hours, this should limit mixing of the strongest winds down to most places. The higher terrain will likely see stronger gusty winds carry into the overnight hours and straight into Wednesday morning. A cold front will move through the area, bringing some light rain (<=0.10") to the coast and Umpqua Basin. There could be some sprinkles as far south as the OR/CA border, but we don`t expect a soaking rain by any means. Areas east of the Cascades and south of the OR/CA border have a very high chance of remaining dry. The bulk of the precipitation, such that it is, should be winding down around sunrise into early Wednesday morning. Snow levels will lower to around 5000 ft, so there could be some light flurries in the Cascades early Wednesday morning, but winter impacts are not a concern. Some showers could linger into the late morning hours, primarily along the coast and north of the Rogue-Umpqua Divide, but we`ll be on the back side of the trough by Wednesday afternoon so the atmosphere will begin drying out. Wednesday will be noticeably cooler compared to recent days, and we`ll see afternoon highs return closer to seasonal norms (low-mid 70s West/low-mid 60s East). Wednesday night will also be quite cool east of the Cascades, with freezing temperatures returning to the forecast. Zonal flow persists through the end of the week, so afternoon highs will trend a few degrees warmer Thursday and Friday, with overnight lows hovering near seasonal norms. Dry conditions are expected for the remainder of the week, but a weak front on Thursday should bring a decent marine push and there could be some drizzle along the coast with that. Over the weekend, broad troughing settles over the Pacific Northwest, which will bring another cooling trend with afternoon highs being somewhat below normal. Shortwaves within this broad trough will provide glancing precipitation chances across northern/northwestern areas Saturday and Saturday night. The overall chance for any widespread wetting rainfall is low at this time, but we`ll have to watch model trends with this trough to see if there are any southward shifts in shortwaves. && .AVIATION...12/18Z TAFs...VFR prevails across the region with some high clouds streaming through. IFR continues along the coast and over the coastal waters, but is gradually breaking up for the more inland locations. Since the flow will be more onshore today, there could be some more persistent cloudy areas along the immediate coast. Expect gusty south to southwest breezes today, especially in NorCal and east of the Cascades, but there will also be some gusty northwest breezes for areas west of the Cascades today. Expect the strongest winds to peak around 25-30 kt today. Southerly flow is in place over the region today and some instability late this afternoon/evening could lead to iso/sct showers (even a thunderstorm?) in some spots from western Siskiyou County up across the Siskiyous to the Cascades (thunder probability is about 10-20% in these areas). With decent mid-level flow anything that gets going could drift over the valleys (mostly Jackson/eastern Douglas), but as far west as Illinois Valley, Grants Pass and even perhaps Roseburg during the evening. Overnight, an upper trough will move onshore with more widespread MVFR clouds and coastal showers spreading inland by Wednesday morning. The showers could reach northern Klamath and Lake counties Wednesday morning, but areas south and east of the mountains will largely remain dry with VFR. Things mostly dry out with a much cooler air mass Wednesday afternoon. -Spilde/BR-y && .MARINE...Updated 815 AM PDT Tuesday, May 12, 2026...Relatively calm conditions are expected today with sub-advisory seas and winds shifting to southwest by this afternoon. An incoming low pressure system will bring showers late tonight into Wednesday, along with increasing west winds and west swell. Despite this, below advisory conditions are expected to persist as seas increase some, but remain swell dominated. Gusty north winds could return Thursday with steep seas possible by Friday. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. PACIFIC COASTAL WATERS...None. && $$

436 FXUS66 KEKA 122057 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 157 PM PDT Tue May 12 2026 .SYNOPSIS...An upper level low will cool temperatures slightly today with some light rain tonight and early Wednesday for the North Coast. Cool temperatures Wednesday with warming again Thursday before a weak shortwave upper level disturbance brings cooler temperatures Friday and Saturday. Warmer weather expected early next week. && .KEY MESSAGES... - Light rain or drizzle forecast for tonight and Wednesday morning for Del Norte and Humboldt counties, mostly dry weather for areas farther east and south. - Breezy winds for Lake County tonight. - Breezes grow more widespread Thursday into this weekend. .DISCUSSION...The approaching upper-level trough is deepening the marine layer, cooling temperatures across the forecast area. The greatest effect of this deepening is near the coast where today is around 10degF cooler than yesterday. Further inland, Trinity county, eastern Mendocino county and Lake county is showing only a few degrees of cooling at most. Tonight into Wednesday morning, the weak frontal boundary will force very light rain for Humboldt and Del Norte counties. Totals of 0.10-0.25" is expected in these counties, with the heaviest rain, up to 0.35",forecasted for the mountains of Del Norte county. Farther south and east, only a trace of rain is forecasted <0.01" for valleys. High temperatures will be notably lower on Wednesday due to cold air advection. This front will also force strong winds tonight into Wednesday, particularly for Lake County as the wind direction aligns with Clear Lake. Gusts of 25mph are possible with a 10% chance of gusts >35mph. Wednesday afternoon through Thursday, high pressure starts to build into the area promoting clear skies as most of the inland areas can expected daytime highs warming into the 80s. Friday and Saturday the upper level flow evolves towards a more zonal setup as a shortwave moves over Washington State. This change forces slightly cooler temperatures Friday with additional cooling on Saturday. Also, more wide spread gusty winds are expected starting on Thursday and increasing Friday and into the weekend. Gusts of 20 to 30 mph are possible with locally higher gusts up to 40mph possible in localized areas. Ensemble predict a return of high pressure on Sunday and return of the inland heat. This will bring some offshore flow for Monday morning leading to a potential clearing of coastal clouds. These offshore winds will be short-lived. This high pressure looks to be a catalyst for a thermal trough pattern leading to breezy winds along the coast, likely help keep the high temperatures on the coast normal. Inland, areas are predicted to warm into the upper 80s to low 90s. Minor heat risk is possible for much of the interior next week if this forecast remains on track. MKK/DS && .AVIATION...An approaching cold front is forcing variable conditions at North Coast terminals today. Overcast ceilings are forecasted to scatter slightly through midday before southerly winds and overcast conditions return this evening. This frontal will be relatively weak and data shows only a 50% likelihood of MVFR ceilings developing over the North Coast terminals from 08Z-15Z (+/-1hr). Conditions Wednesday look to be VFR from 18Z through the daylight hours. Inland terminals will experience gustier winds due to this frontal passage. Winds aloft ~2500ft AGL will be around 35kts out of the NW and have the potential to mix down to terminals, especially those in open or N-S orientated valleys. VFR for inland areas through the TAF period. DS && .MARINE...Light to moderately breezy NW winds will remain for the southern waters. For the waters north of Cape Mendocino, a southerly wind shift will occur this afternoon/evening as a weak cold front enters the area. After this frontal passage, a thermal trough is predicted to develop, which, interacting with an incoming Pacific High pressure will force NW winds by dawn Wednesday. Wednesday through Friday shows these winds increasing with over a 70% chance of gusts over 35kts south of Cape Mendocino and near gale gusts elsewhere. Due to these winds, a Gale Watch has been issued for PZZ475 beginning Wednesday afternoon. The sea state will continue to be dominated by a mid- period westerly swell and short period northerly winds, especially late week. Small craft advisory conditions are expected possible Wednesday afternoon through the end of the week as steep short period seas become dominate. DS && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None. && $$ NOTE: The full forecast discussion is now regularly issued between 10 am/pm and 1 pm/am. Additional updates will be issued as needed. Visit us at https://www.weather.gov/eureka Follow us on Facebook and Twitter at: https://www.facebook.com/NWSEureka https://www.twitter.com/NWSEureka For forecast zone information see the forecast zone map online: https://www.weather.gov/images/eka/zonemap.png

914 FXUS66 KMTR 121900 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1200 PM PDT Tue May 12 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1200 PM PDT Tue May 12 2026 - Cooling trend continues today and Wednesday - Elevated fire weather risk for far interior San Benito and Monterey counties this afternoon and evening - Warming and drying trend resumes Thursday through the weekend && .SHORT TERM... Issued at 1200 PM PDT Tue May 12 2026 (This evening through Wednesday) The satellite imagery shows stratus coverage across the coastal regions and some lingering into the valleys of the Bay Area as a thin layer of high clouds persists over the region, with gradual clearing across the inland and Bayshore regions into the afternoon while the coast remains socked in. Stratus coverage should rebuild this evening and overnight but should not come as far into the southern Salinas Valley or the North Bay valleys as we saw this morning. The large scale weather pattern features a departing ridge moving into the northern and central Rockies while a trough centered on an upper level low around 500 miles to the west of the Oregon Coast moves in, resulting in a gradual cooling trend today into Wednesday and an expansion of the marine layer. The latest readings from the Bodega Bay profiler suggest a marine layer around 1500-2000 feet thick, remaining rather consistent through the next couple of days as the trough passes through the region. High temperatures today will range from the upper 70s to the lower 80s in the inland valleys, the upper 80s to lower 90s in southern Monterey and San Benito Counties, the middle 60s to the middle 70s in the bayshore regions, and the upper 50s to lower 60s along the Pacific coast. Highs might be a few degrees cooler where the stratus is slower to dissipate than the forecast or does not clear out this afternoon. Low temperatures on Wednesday morning range from the upper 40s to the middle 50s across the lower elevations, while Wednesday`s highs will range from the lower 70s to the lower 80s for the inland valleys. As the trough moves through, the increasing pressure gradients will result in breezy and gusty winds starting this afternoon through Wednesday, with the gusts reaching 20 to 30 mph across the coastal and higher elevation regions and the northern Salinas Valley. Isolated favored regions, namely the Mayacama range and the Altamont Pass, may reach gusts of 40 to 45 mph this evening and overnight. Elevated fire weather risks will set up starting this afternoon across a narrow strip of the far interior San Benito and Monterey counties adjacent to the Central Valley. A particularly concerning combination of gusty winds, hot temperatures, low daytime humidities, and poor overnight humidity recoveries across this region will result in a period of elevated fire weather concerns across this strip through the evening hours. Any fires that start in the drier grasses across this region may take hold and spread rather quickly. Our neighbors in Hanford have issued a Red Flag Warning for the adjacent zones across the western edge of Fresno County, but in our area of responsibility. the fire weather concerns are not widespread enough to warrant any products. && .LONG TERM... Issued at 1200 PM PDT Tue May 12 2026 (Wednesday night through next Monday) As the trough moves out, warmer and drier weather will return to the region with highs on Thursday and Friday in the 80s to the lower 90s in the interior valleys, the middle 70s to lower 80s across the Bays, and the lower to middle 60s in the Pacific coast. A second trough coming down from the Gulf of Alaska will interrupt the warming trend this weekend, with inland highs dipping in to the lower 70s to lower 80s on Saturday before bouncing back to the upper 70s to middle 80s for Sunday. Uncertainty in the forecast starts to increase in the early part of next week as the ensemble models struggle to diagnose the interaction between an upper level ridge and trough over the western United States. Model ensemble means from the American GEFS, European ECMWF, and Canadian GEPS models suggest a ridge over the eastern Pacific and a trough over the Rockies should develop by Monday morning, although with significant differences in the strength of both features. However, a peek into the model ensemble clusters reveals a significant minority of the ensemble members (around 30- 40%) show an alternate scenario where more zonal flow or troughing develops over the West Coast, nudging the forecast towards cooler temperatures. Past the 7-day outlook, CPC outlooks into the later part of May show a slight lean towards temperatures above seasonal averages, and precipitation totals near or above seasonal averages. && .AVIATION... (18Z TAFS) Issued at 1059 AM PDT Tue May 12 2026 A deep marine layer produced widespread stratus across the region this morning. Stratus is receding with all sites except HAF and MRY likely to clear by 19/20Z. Winds strengthen by the afternoon/evening with gusts to around 20-30 knots expected along the coastline. A dry cold front will push through tonight with moderate confidence in the timing of cloud cover arrival. Currently kept a later stratus arrival (09/10Z) for most sites but LAMP guidance shows some potential for stratus to return closer to 05/06Z. This cold front will also result in widespread gusty winds along the coast and across the bay shoreline early tomorrow morning. For now, kept tomorrow morning`s gusts limited to HAF, OAK, and SFO but gusts are expected to pick up at the remaining airports after 18Z tomorrow. Vicinity of SFO...Stratus is receding from SFO and should dissipate by 19Z. Gusts are expected to pick up by late this morning with the site to remain gusty through the end of the TAF period. Bumped up the afternoon/evening gusts to 30 knots with around a 10% chance of stronger gusts to 35 knots. We do expect gusts to ease slightly overnight (20-25 knots) but gustier winds (30-35 knots) are expected to return tomorrow afternoon/evening. Moderate confidence that stratus will return around 09Z with some potential for stratus to return as early as 03-06Z. Stratus should clear by late tomorrow morning with VFR conditions through the end of the TAF period. SFO Bridge Approach....Generally similar to SFO. Expect stratus to fill in over the bay this evening and linger through late tomorrow morning. Similar to SFO, gusty winds are expected over the bay with the potential for sustained winds around 20 knots and gusts between 30-35 knots tomorrow afternoon/evening. Monterey Bay Terminals...VFR at SNS through early this evening. IFR- LIFR CIGs are expected to persist at MRY through the TAF period with a continued stream of stratus onshore making it unlikely for MRY to clear this afternoon. Moderate confidence in IFR-LIFR CIGs developing again tonight with LIFR CIGs becoming more likely by early tomorrow morning. Breezy onshore winds are expected this afternoon/evening with gustier onshore winds to develop late tomorrow morning and continuing through the evening. && .MARINE... (Tonight through next Sunday) Issued at 949 PM PDT Mon May 11 2026 Occasional strong gusts continue through tonight across the far northern outer waters. Otherwise, a moderate to fresh northwest breeze will continue over the waters through midweek. Seas subside but remain moderate with 4 to 6 foot seas through midweek. Winds increase and seas build starting mid-week with gale force winds and wave heights in excess of 10 feet likely starting Friday and continuing through the weekend. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 9 AM to 9 PM PDT Wednesday for Mry Bay. Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Thursday for Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory from 9 AM Wednesday to 3 AM PDT Thursday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10- 60 NM-Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory from 3 AM Wednesday to 3 AM PDT Thursday for Pt Pinos to Pt Piedras Blancas 0-10 nm. && $$ SHORT TERM...DialH LONG TERM....DialH AVIATION...Kennedy MARINE...Kennedy Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea

574 FXUS66 KOTX 122353 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 453 PM PDT Tue May 12 2026 .KEY MESSAGES... - Very warm temperatures through Tuesday evening resulting in Minor to locally Moderate HeatRisk. This level of heat primarily affects those who are sensitive to heat. - Cold water temperatures pose a high risk for cold water shock and hypothermia. Wear a life jacket if recreating on or near the water. - Widespread showers, chances for thunderstorms, and gusty winds Tuesday night through Wednesday. Gusty winds may lead to choppy lakes, strong cross winds, and isolated areas of blowing dust where precipitation is limited. && .SYNOPSIS... Isolated dry thunderstorms and gusty winds are expected Tuesday evening through early Wednesday morning. Temperatures turn cooler Wednesday, with strong west to southwest winds, and widespread showers. Breezy winds and chances for mountain showers and thunderstorms linger Thursday through Saturday. Some frost is possible toward the end of the week into the weekend. && .DISCUSSION... Tuesday night through Thursday: An amplified upper-level ridge is currently in place over the Inland Northwest as an upper-level closed low approaches the Pacific Northwest. Models have generally come into better agreement on the trajectory of the upper-level low as it takes on a negative tilt and moves into Oregon late tonight. Ahead of the low, the combination of favorable upper-level diffluence and moisture advecting into the Inland Northwest will support shower and thunderstorm development tonight into early Wednesday morning. Models are showing elevated instability (MUCAPE between 200-600 J/kg) overtop a very dry boundary layer, which brings the risk of dry lightning and gusty outflow winds. The low will move into eastern Oregon Wednesday morning and shift northeast into eastern Washington and north Idaho Wednesday afternoon and evening. Preciptiation will increase in coverage later Wednesday morning through the afternoon. The heaviest precipitation totals are expected across the mountains where 25th to 75th percentile 24 hour amounts between 0.30 to 1.30 inches. Totals across the lowlands vary depending on the track of the low with 25th to 75th percentile amounts between 0.05 inches to 0.30 inches for the Columbia Basin into the Spokane area and northern Palouse. 25th to 75th percentile precipitation amounts are lowest across the Palouse and L-C Valley at 0 to 0.10 inches. Additionally, the passage of the low will tighten cross-Cascade pressure gradients Wednesday afternoon and evening. Modeled surface pressure gradients for YKM-YQL (+17 to +24mb) and PDX-GEG (+9 to +14mb) gradients suggest the potential for stronger westerly winds across much of the Inland Northwest. Winds will begin to increase Wednesday morning and are expected to peak between 10 AM and 5 PM and gradually decrease through the evening. There is high confidence for wind gusts greater than 45 mph from the lee of the Cascades through the Columbia Basin and into the Palouse and Spokane area. The strongest winds will be felt across the Blue Mountains with high confidence for gusts greater than 55 mph. These winds will be strong enough to result in scattered tree damage and power outages, strong cross winds, and choppy lake conditions. If the Columbia Basin precipition totals are below 0.10 inches, patchy blowing dust will also be a concern. However, there is a 70% chance for greater than 0.10 inches, so confidence in this occurring is low. Light mountain showers will persist through Thursday as the region transitions into a brief period of weak ridging. Friday through Monday: Models show a broad upper-level trough in the Northeast Pacific with embedded waves moving into the region Friday and Saturday before the low dives into the PNW Saturday into Sunday. Differences in the specifics of these systems introduces a good amount of uncertainty in the exact forecast, but the main message is that this weekend looks to be cooler with periodic precipitation. The NBM is giving the Cascades a 60% chance and greater for 1 inch of snowfall. Sunday morning will also need to be monitored for frost potential with a 50% or greater chance for temperatures below 36F across much of the Basin, northern valleys, Spokane/CdA area, and the Palouse. /vmt && .AVIATION... 00Z TAFs: VFR conditions are expected, though ceilings trend downwards with increasing chances of showers by the end of the forecast period. CAMs are showing chances of showers and isolated thunderstorm chances moving into the forecast area around 04-06Z. 04Z is the earlier time a couple CAMs show, but confidence increases more around 06Z. Best chances for thunderstorms are in the mountains, northeast Washington, and the northern Idaho Panhandle, and there is not enough confidence to include thunderstorms at any specific terminals. Timing for thunderstorms show best chances from 06-12Z, with widespread rain showers moving in after that. Around 18Z, ceilings begin trending downward, though terminals are still expected to stay at VFR. Around 12Z, ahead of a cold front Wednesday morning, south/southwest winds will increase with sustained winds 20-25kts and gusts 30-35kts from the lee of the Cascades through the Columbia Basin and Palouse. By 18Z, with the passage of the cold front, winds will increase, with sustained winds 25-30kts and wind gusts 35-45kts. These will be the peak winds, and will last through 00Z and into the start of the next TAF period. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions for all TAF sites. High confidence in wind gusts increasing starting 12Z. Low chances in showers and thunderstorms impacting specific terminals between 06-12Z Wednesday. Most impactful alternate scenario would be isolated thunderstorms near any airports, which will be carefully monitored for any amendments. /AS ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https:/www.weather.gov/otx/avndashboard && .Preliminary Point Temps/PoPs... Spokane 53 65 43 64 41 62 / 10 80 50 0 0 10 Coeur d`Alene 53 64 44 62 42 59 / 10 90 80 0 10 20 Pullman 50 62 41 61 40 59 / 10 70 40 0 0 0 Lewiston 56 68 47 68 45 67 / 10 50 20 0 0 0 Colville 49 69 36 67 35 64 / 20 90 70 0 0 10 Sandpoint 52 66 41 61 40 59 / 10 90 90 0 10 20 Kellogg 53 66 42 59 41 59 / 10 90 90 20 10 10 Moses Lake 52 68 43 69 40 67 / 10 90 10 0 0 0 Wenatchee 56 65 48 67 44 65 / 10 90 10 0 0 0 Omak 55 70 42 69 40 66 / 20 100 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Wind Advisory from 8 AM to 11 PM PDT Wednesday for Northeast Mountains. Wind Advisory from 5 AM to 11 PM PDT Wednesday for Moses Lake Area-Spokane Area-Upper Columbia Basin-Washington Palouse- Waterville Plateau-Wenatchee Area. High Wind Warning from 5 AM to 11 PM PDT Wednesday for Lower Garfield and Asotin Counties-Northeast Blue Mountains. ID...Wind Advisory from 8 AM to 11 PM PDT Wednesday for Central Panhandle Mountains-Northern Panhandle. Wind Advisory from 5 AM to 11 PM PDT Wednesday for Coeur d`Alene Area-Idaho Palouse-Lewis and Southern Nez Perce Counties-Lewiston Area. && $$

197 FXUS66 KPDT 122238 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 338 PM PDT Tue May 12 2026 .KEY MESSAGES... - High temperatures in the mid 80s to mid 90s this afternoon. - Isolated thunderstorms along elevated terrain in central and eastern OR this afternoon into the overnight hours - Mountain showers, isolated mountain thunderstorms, and breezy to gusty low elevation winds Wednesday && .DISCUSSION...Satellite imagery this afternoon shows a veil of cirrus over the forecast area, which ha limited heating across northern portions of the forecast area. Meanwhile, breaks in the cirrus have allowed central OR, Yakima valley, and the Gorge to warm into the mid to upper 80s. Otherwise, isolated areas of cumulus have begun to develop across elevated terrain south of the forecast area, but no sign of towering cumulus at this time. Today, the upper ridge will begin to break down and push east, with deep southerly flow developing as a result. Instability across elevated terrain of central and eastern OR will increase as a result (MUCAPE 250-1250 J/kg), introducing a low chance (<15%) of isolated thunderstorms in these areas into the afternoon. CAMs and deterministic guidance are showing a shortwave impulse with a weak moisture plume riding up the southerly flow late Tuesday afternoon through the overnight hours. The combination of the shortwave, moisture, and instability will result in a continued low chance (10-15%) of isolated thunderstorms across the elevated terrain of eastern OR through late this evening, with a slight chance (15-25%) of isolated to scattered thunderstorms will develop throughout tonight along the OR/WA Cascade crest. Otherwise, expect mostly scattered showers along the Cascade crest throughout tonight as well. Temperatures will continue to warm through this afternoon, but locations under the cirrus will only warm into the lower to mid 80s, with areas outside of the cirrus coverage warming into the upper 80s to lower 90s. Wednesday and Thursday: An upper low offshore will kick inland early Wednesday morning, which will transition into an open trough with a slight negative tilt. The trough passage will bring widespread shower chances and cooler temperatures across the region through Wednesday, with a slight chance (15-25%) of isolated to scattered thunderstorms continuing along the Cascade crest and WA Cascade east slopes through late Wednesday morning. Widespread winds 20-35 mph with gusts 35-55 mph will develop across the lower elevations, with winds approaching 40 mph and gusts up to 60 mph across portions of the Simcoe Highlands and the OR Blue Mountain foothills. High wind warnings and wind advisories have been issued for many lower elevation locations in and adjacent to the Columbia Basin. The upper trough will exit the region Wednesday night allowing a broad upper ridge to slide over the PacNW with drier conditions. Light showers will retreat to the WA Cascade crest Thursday, with cooler temperatures persisting across the forecast area. Otherwise, tightened surface pressure gradients will persist into Thursday, bringing breezy winds (15-30mph with gusts up to 40mph) through the Cascade gaps into the Columbia Basin. Friday through Monday: Ensemble cluster guidance is in great agreement through Saturday in a broad upper trough sliding over the PacNW, producing another round of mountain showers with breezy winds in the lower elevations (confidence 60-70%). The upper trough will bring much cooler conditions across the region, with high temperatures lowering into the upper 50s to 60s by Saturday (confidence 45-60%). The cooler airmass in the region will also result in snow levels dropping to the surface across the mountains, resulting a return of snow showers generally above 4kft to 4.5kft Friday night through Saturday. Sunday into Monday, there is some disagreement amongst ensemble members in when a transient upper ridge will slide over the PacNW. A majority of members favor the ridge overhead by Sunday afternoon, with dry conditions developing and persisting into Monday, while remaining members delay the upper ridge arrival to Sunday night. Confidence is low-mod(25-40%) on end time of shower activity Sunday, while moderate (40-50%) for dry conditions Monday. Otherwise, temperatures will remain in the 60s Sunday, with warming into the lower 70s Monday (confidence 35-50%). Lawhorn/82 && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...Mostly VFR conditions to prevail through the period. An upper low approaching the region will produce showers and isolated to scattered thunderstorms starting late this afternoon through tomorrow. There is about a <10% chance of an isolated shower/thunderstorm impacting RDM/BDN later this afternoon, but otherwise shower chances will increase after 06Z and end around 18Z at these sites and site DLS. For sites PDT/YKM/ALW/PSC, shower chances will increase after 12Z, and will continue into the end of the period. After 18Z-20Z, showers will become more periodic. A prob30 for thunder was included at site YKM for the morning period. Winds of 15-25kts with gusts 25-45kts will develop at site DLS this evening, then develop at sites PDT/RDM/BDN/ALW/PSC after 13Z. Strong winds will persist through the end of the period. Lawhorn/82 && .FIRE WEATHER...Dry and warm conditions today but high pressure will breakdown late this afternoon. There is an isolated thunderstorm chance across the mountains in the late afternoon and evening. Breezy to gusty winds in the lower elevations and rain showers will develop early tomorrow morning as an upper low moves inland. Breezy winds will continue Thursday with min RHs in the teens in central OR. Mountain rain/snow showers will develop Friday and early Saturday, while winds will remain breezy. && .Preliminary Point Temps/PoPs... PDT 51 65 44 68 / 0 70 10 0 ALW 55 65 48 68 / 0 80 20 0 PSC 55 70 47 73 / 0 70 10 0 YKM 53 68 43 71 / 10 80 0 0 HRI 53 68 46 71 / 0 70 0 0 ELN 47 61 39 63 / 20 90 10 0 RDM 42 62 32 72 / 40 60 0 0 LGD 50 63 40 68 / 10 80 20 0 GCD 48 65 37 71 / 20 70 0 0 DLS 52 67 48 70 / 40 70 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Wind Advisory from 8 PM this evening to 11 PM PDT Wednesday for WAZ024. Wind Advisory from 5 AM to 11 PM PDT Wednesday for WAZ026>029. High Wind Warning from 5 AM to 11 PM PDT Wednesday for WAZ521. OR...Wind Advisory from 8 PM this evening to 11 PM PDT Wednesday for ORZ041. Wind Advisory from 5 AM to 11 PM PDT Wednesday for ORZ044-510. High Wind Warning from 5 AM to 11 PM PDT Wednesday for ORZ507- 508. && $$ DISCUSSION...82 AVIATION...82 FIRE WEATHER...82

896 FXUS65 KREV 122025 AFDREV Area Forecast Discussion National Weather Service Reno NV 125 PM PDT Tue May 12 2026 .KEY MESSAGES... * Unseasonably warm with gusty winds across NE California and far NW Nevada today. Strong outflow winds also possible this afternoon. * Cooler temperatures Wednesday with renewed wind impacts in the afternoon. * Dry and mild weather expected to end the week with cooler, breezier conditions possible over the weekend. && .DISCUSSION... Persistent western ridging will give one more opportunity to set new daily record highs today before cooler temperatures -- albeit still warmer than normal -- prevail to end the week. Daytime highs nearing or exceeding 80F/90F in Sierra/lower NE CA/W NV valleys, respectively, will yield a minor (2 of 5 risk) to moderate (3 of 5 risk) HeatRisk this afternoon, so be sure to stay hydrated and limit strenuous outdoor activities. Winds will continue to increase across NE California and far NW Nevada with SW gusts reaching 30-40 mph during this afternoon. Impacts should be limited to lakes in this area where choppy waters will make for hazardous conditions for recreation. Father east, there is still the prospect of sudden, strong outflow winds of 40+ mph in the late afternoon and evening today in an area from Mono County extending northward into Pershing County. Model soundings suggest that this area will become increasingly more favorable through the afternoon as a well-mixed boundary layer continues to deepen and midlevels cool/moistens, narrowing the window for strong downdrafts/outflows to 4 PM to 8 PM PDT. Lightning is unlikely given a shallow depth of moist convection, but a few isolated strikes may accompany stronger updrafts. An eastern Pacific low and attendant cold front will pass through the region Wednesday, giving us a ~10F cooldown and gusty W/NW winds in the afternoon. Be prepared for additional impacts to lake recreation and air/ground travel on Wednesday, especially in western Nevada. Dry and mild weather is in store for the end of the week, with cooler, breezier conditions possibly returning this weekend. -Salas && .AVIATION... The main weather concern today will gusty SW winds through the afternoon, posing a risk of minor LLWS impacts for Sierra and Sierra Front terminals. There is a low probability of strong outflow winds of 35+ kts impacting KHTH-KNFL-KLOL between 23Z and 03Z, with an even lower likelihood of isolated lightning near these terminals. Mountain wave turbulence will be possible tonight into Wednesday morning as FL100 winds increase to 30-35 kts. W/NW surface gusts of 20-30kts may renew LLWS impacts Wednesday afternoon. Otherwise, expect VFR conditions to persist. -Salas && .REV Watches/Warnings/Advisories... NV...Lake Wind Advisory from 11 AM to 8 PM PDT Wednesday NVZ004. CA...Lake Wind Advisory until 8 PM PDT this evening CAZ071. && $$

180 FXUS66 KSTO 121810 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1110 AM PDT Tue May 12 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Temperatures will trend less hot today and will be noticeably cooler by Wednesday, though still be above normal. - Temperatures trend warmer late week into the weekend, with areas of Moderate HeatRisk returning - Gusty north to east winds are expected for the weekend, coupled with low humidity, bringing elevated fire weather concerns for lower elevations && .DISCUSSION... ....Today... Warm weather but cooler than yesterday is expected with widespread Minor HeatRisk throughout the forecast area. The Valley will see afternoon highs in the 80s and 90s with warmest weather across the lower foothills and northern San Joaquin Valley. This evening will see a trough push our ridging further east and alleviate some of our heat impacts midweek. ...Wednesday through Weekend... As the ridge pulls eastward, we will see cooling on Wednesday returning highs to the 80s and Minor HeatRisk across the Valley. Ensembles continue to trend drier for the trough passage with most locations now remaining dry outside of slight shower chances over Shasta County. Overall, expecting little to no impacts from precipitation over the next several days. Concerns for gusty northerly winds are increasing for the weekend as ensembles are starting to lean more towards an inside-slider type shortwave shifting into the Great Basin. Today`s models trended slightly weaker for Saturday but stronger on Sunday in regards to wind strength but similar affected areas. Current forecast have north winds gusts of 30 to 45 MPH this weekend, strongest on Sunday and along Interstate 5. Additionally, dry conditions develop particularly over the Sacramento Valley, especially north of Interstate 80, with the NBM showing minimum Relative Humidity getting into the teens and upper single digits. Ultimately, this brings elevated fire weather concerns for the Valley and portions of the Delta and will continue to monitor model trends to evaluate strength of winds/drying effect over the Valley. Saturday`s Chances for Wind Gusts > 35 MPH: 40-60% Sunday`s Chances for Wind Gusts > 35 MPH: 60-85% Please continue to practice fire safety and monitor your latest forecast to stay up to date at weather.gov/sacramento && .AVIATION... VFR conditions are expected over the next 24 hours. Breezy south-southwest wind gusts up to 15-25 kts in the Valley and Delta, and up to 25-35 kts over the mountains until around 06z-09z Wednesday. Locally breezy west-northwest winds develop after 18z Wednesday, with gusts up to 15-20 kts across portions of the southern Sacramento Valley, northern San Joaquin Valley and Delta and gusts up to 25-35 kts over the Sierra. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

764 FXUS65 KMSO 121851 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1251 PM MDT Tue May 12 2026 .DISCUSSION... KEY MESSAGES: - Near-record heat today: Highs will reach the 80s to low 90s. Rivers remain dangerously cold and fast; use extreme caution near the water. - Two distinct wind threats Wednesday: 1. Damaging thunderstorm winds: Gusts over 60 mph are possible Wednesday afternoon, mainly from Deer Lodge to Butte and southward. 2. Strong cold front winds: Gusty winds will arrive Wednesday afternoon and evening, creating dangerous conditions for boaters on lakes and increasing fire danger in southwest Montana. - Drastic temperature drop and hypothermia risk: Summer conditions end Wednesday night. Mountain highs will crash into the 40s on Thursday and the 30s this weekend with accumulating snow. Backcountry users must prepare for winter conditions. Frost is possible by Sunday morning. Today (Tuesday):High pressure brings one last day of near-record heat, with highs in the 80s and low 90s. Rapid snowmelt continues to keep rivers dangerously cold. Cold water shock is a severe hazard for anyone on the water today; even strong swimmers can be quickly incapacitated by these temperatures. Wednesday and Thursday (The Big Transition):Weather conditions will change abruptly on Wednesday as a strong cold front moves through. Missoula and Kalispell will likely see their warmest temperatures early in the day before readings begin to fall. The front is expected to reach the Camas Prairie in Idaho by mid- morning, west-central Montana by early afternoon, and the Butte area between 6:00 p.m. and 9:00 p.m. MDT. The Dual Wind Threat: Cold Front: Wind is the primary hazard on Wednesday. While scattered storms are possible, a rapid increase in air pressure behind the front will cause westerly wind gusts of 35 to 45 mph. These winds will create dangerous waves for small boats on Flathead Lake and other area waters. Expect some broken tree branches and isolated power outages. Thunderstorms: Showers and storms will form as early as noon over Lemhi County, moving northeast at 30 to 45 mph. Because the air is so dry, these storms could produce intense, damaging wind gusts. The highest risk is along Highway 93 in the Bitterroot and Missoula Valleys, extending east to the Continental Divide. This will create dangerous cross-winds on north-south highways and increase fire danger in southwest Montana. The Rain/Snow Shift: Rain and snow will focus primarily on the northern two-thirds of the region late Wednesday. Valleys may see up to 0.30 inches of rain, while mountains could receive up to 0.75 inches of liquid. As a cold storm system moves over the area, snow levels will drop to near 5,000 feet. Several inches of new snow are expected in the high country of Northwest Montana by Thursday morning. Backcountry users will encounter slushy snow on high-elevation roads. Combined with winds and temperatures in the 40s, this creates a high risk for hypothermia. Friday through the Weekend (Return to Winter): An unusually strong storm system from the Gulf of Alaska will settle over the Northern Rockies this weekend. Bitterly cold air will drop snow levels to 4,000 feet. Mountain highs will stay in the 30s, while valleys will struggle to reach the 50sabout 15 degrees below normal. Unstable air will trigger widespread showers all weekend. In the valleys, heavy bursts of soft hail (graupel) are possible. Bottom Line for the Weekend: Pack for winter if you are heading outdoors. The combination of wet snow, wind, and near-freezing temperatures is dangerous for those only prepared for spring. By Sunday and Monday morning, temperatures may drop low enough to cause frost, which could damage sensitive plants. && AVIATION...Clear skies and unseasonable heat continue through Tuesday with light winds. A dramatic change arrives Wednesday as a strong cold front brings sharp wind shifts and showers. Thunderstorm wind gusts up to 45 knots are possible at KSMN and over 50 knots at KBTM between noon and 6:00 p.m. Wednesday. Snow in the mountains of Northwest Montana will cause clouds to cover the peaks (mountain obscuration) Wednesday night, especially in the Glacier National Park region. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Wind Advisory from 9 AM Wednesday to midnight MDT Wednesday night for Kootenai/Cabinet Region...Lower Clark Fork Region. Wind Advisory from noon Wednesday to midnight MDT Wednesday night for Bitterroot/Sapphire Mountains...Butte/Blackfoot Region...Flathead/Mission Valleys...Missoula/Bitterroot Valleys...Potomac/Seeley Lake Region...West Glacier Region. Winter Weather Advisory from midnight Wednesday night to 3 PM MDT Thursday for West Glacier Region. Red Flag Warning from noon to 9 PM MDT Wednesday for Deerlodge/West Beaverhead...East Beaverhead. ID...None. && $$

557 FXUS65 KBOI 122317 AFDBOI Area Forecast Discussion National Weather Service Boise ID 517 PM MDT Tue May 12 2026 .UPDATE...Updated aviation discussion. && .KEY MESSAGES... - Record high temperatures this afternoon, where low lying areas will see highs in the 90s. - A cold frontal passage brings very gusty winds, a slight chance of thunderstorms, and cooling conditions Wednesday. - Just above normal temps through Friday before another cooldown this weekend, conditions stay dry and breezy. && .SHORT TERM /Through Thursday Night/... Issued 230 PM MDT TUE MAY 12 2026 High pressure over the area, and mostly clear skies today will allow temps to climb through late this afternoon. Low-lying areas including the Snake Plain and valleys in the Boise Mountains, Weiser Basin, and Malheur County will see temps in the 90s for their afternoon highs. This threatens daily high temp records for many locations in Southwest Idaho and Southeast Oregon. Alongside the hot temps is exceptional dryness. The 18Z sounding revealed a nearly dry adiabatic atmosphere up to 500 mb. There is just enough moisture at this level to produce some altocumulus, and with visible virga there is a slim chance for strong winds near the clouds. Right now, this seems very unlikely given the depth of the dry layer and limited moisture available to convection. Temperatures cool quickly after sunset as the focus shifts to a quickly encroaching upper level low moving inland. This low will carry a strong cold front through most of the intermountain west. The primary hazard for our area as this front moves through is the winds. Late in the morning through the early evening, wind gusts increase to 40-55 mph across open areas and ridges. A Wind Advisory has been issued in the areas expected to see the strongest winds. Outside of the advisory, winds will still gust 30-40 mph throughout the day save for a few very sheltered mountain valleys. Winds will kick up dust, especially along the front, leading to reduced visibilities. In the morning and early afternoon, as the front itself passes, thunderstorms will be possible. Gusts out of thunderstorms could locally enhance the already gusty conditions in parts of the upper Snake Plain. The enhancement could briefly take winds up to 60 mph. Forecasts, however, continue to favor thunderstorm development over the West Central and Central Idaho mountains. Moderate rain and small hail will also be possible in storms. Winds finally begin to weaken after sunset, but remain elevated overnight. Behind the front, temps on Thursday will be seasonal across the area. Winds stay elevated through the day, especially in Central and South-Central Idaho and Central Oregon. While Tuesday is the driest day, afternoon minimum relative humidities remain in the teens for southern areas each day. The coincidence of dry air and gusty winds highlights elevated fire weather conditions, especially Wednesday. && .LONG TERM /Friday through Tuesday/... Issued 230 PM MDT TUE MAY 12 2026 Good model agreement in the overall large scale pattern Friday through Sunday. Dry westerly flow Friday with temperatures around normal. A substantial cool down for the weekend (temperatures 10 degrees below normal) as a shortwave trough moves across the area. Not a lot of moisture expected with this system so there`s only a low end chance (20-30 percent) of precipitation for northern Baker County and portions of the West Central and Boise Mountains. Expect breezy NW winds Saturday and Sunday afternoon, especially across Baker County and the Snake River Plain. Temperatures expected to trend up with dry conditions on Monday. Forecast uncertainty grows Tuesday with some model guidance suggesting another shortwave trough with limited moisture may move across the region. && .AVIATION /00Z Wednesday through Thursday/... Issued 509 PM MDT TUE MAY 12 2026 VFR with some shallow convection near terrain this evening. Isolated storms could produce localized gusty winds. Significant cold front to pass through the area Wednesday morning, with a dramatic shift in wind direction and increase in wind speed. Frontal passage 15-17Z for Oregon sites and 17-20Z for Idaho locations. Surface winds SSE 10-20 kt with higher gusts this evening, becoming SSW 10-20 kt overnight, then WNW 20-30 kt with higher gusts after frontal passage. Periods of LLWS possible near the front. Winds aloft at 10kft MSL: SSW 20-25 kt. KBOI...VFR. Significant cold frontal passage 17-19Z Wednesday, with strong winds expected. Surface winds ESE 10-12 kt with gusts in the evening, becoming WNW 20-25 kt with gusts to 35 kt after 17Z. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Wind Advisory from noon Wednesday to midnight MDT Wednesday night for IDZ012-014>016-028>030. OR...Wind Advisory from noon MDT /11 AM PDT/ Wednesday to midnight MDT /11 PM PDT/ Wednesday night for ORZ063-064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise AVIATION.....MC SHORT TERM...JM LONG TERM....TL

108 FXUS65 KLKN 121850 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1150 AM PDT Tue May 12 2026 .KEY MESSAGES... * High pressure produces warm and dry weather through Wednesday. * Record high temperatures are likely through Wednesday, followed by cooler temperatures. * Gusty winds Wednesday afternoon. * Wind Advisory has been issued for northern Nevada Wednesday. && .DISCUSSION... (This afternoon through next Tuesday) WEATHER PATTERN OVERVIEW: Upper ridge is still on track to keep dry weather with potential for record breaking high temperatures today. High temperatures today is expected to reach above 80s degrees across the region with an 80-100% chance that northern Nevada will see above 85 degrees. Tomorrow, the chances for high temperatures to reach above 80 degrees drop to 40% for northern Nevada (except for West Wendover expected to see 90 degrees). Some breezy winds expected over central Nevada with speeds up to 10-15 mph, gusts 20-25 mph. Wednesday, low pressure to the northwest will weaken the upper ridge and push to a more zonal flow by the evening. Main concerns is high winds across the region with stronger winds in northern Nevada up to 20-25 mph, gusts 35-45 mph which prompted a Wind Advisory for northern Nevada from 10 AM to 11 PM. High winds may cause blowing dust throughout much of the region which may limit visibility. Recent model trends are now showing no chance for showers over northern Nevada, as the low pressure stays to the north. Some clouds may develop as there will be mid-level moisture in the atmosphere, but not enough to produce wetting rains. There is still a 15% chance for some dry thunderstorms over northeastern Elko County Wednesday afternoon. Zonal flow is expected to stay in place over Nevada for the rest of the week and into next week, keeping the upper ridge from building back up. This will aid in starting a cooling temperature trend through the weekend, bringing temperatures down to slightly above normal through Saturday with highs in the 70s, and to near normal by Sunday. Temperatures will start back on a warming trend by Monday, but stay relatively in the 70s. FORECAST CONFIDENCE & DEVIATIONS: High confidence for warm temperatures today with potential record breaking temps. High confidence for strong gusty winds tomorrow prompting a Wind Advisory for northern Nevada. Low confidence for dry thunderstorm activity over northeastern Nevada. Moderate confidence for cooling temperature trend Thursday through the weekend. Adjust winds grids in the NBM to better reflect recent model runs. && .AVIATION...Look for VFR conditions across all terminals over the next 24 hour period. Breezy westerly winds over all terminals (except for KENV) with speeds up to 10-12 kts, gusts 20-25 kts. Tomorrow, westerly winds expected to be stronger across the region with speeds up to 15-20 kts, gusts 30-35 kts with strongest winds over the northern terminals. Mid-level moisture will aid in developing CIG levels between FL120-FL180. No chance for showers to impact the terminals but dry thunderstorms are not ruled out over northeastern Nevada. VFR conditions expected across all terminals, but strong gusty winds may cause blowing dust. && .LKN Watches/Warnings/Advisories... Wind Advisory from 10 AM to 11 PM PDT Wednesday NVZ030-031-033-034-036-038-039. && $$ DISCUSSION...97 AVIATION...97