769 FXUS66 KSEW 252102 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 202 PM PDT Tue Aug 25 2026 .SYNOPSIS... Dry and warm conditions will peak this afternoon ahead of a pattern change tonight that will bring the return of onshore flow, cooler temperatures, and chances for precipitation to the area. Thunderstorm chances increase Thursday across the Olympics, northern Interior, and North Cascades. Upper level troughing will continue to influence the region over the weekend, maintaining cooler and cloudier conditions across western Washington. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... Upper level ridging over the Intermountain West will maintain southerly flow aloft across western Washington today, bringing the warming and drying trend to a peak. Temperatures across the region are well on their way to reaching the mid to upper 80s, with some areas in the Cascade foothills and valleys reaching the lower 90s. This corresponds to widespread Moderate (orange) HeatRisk across the lowlands from the Puget Sound metro areas northward through Bellingham, with some pockets of Major (red) HeatRisk in the Cascade valleys. Along the coast, low level flow has switched to onshore, bringing in cooler and more moist air under the marine layer with highs closer to the mid 60s to lower 70s. Onshore flow will continue to increase throughout the afternoon and evening today, bringing in a push of cooler and more moist air. This will also help to scour out any lingering haze from wildfire smoke. The onshore flow will bring a return to cooler and more seasonable temperatures, morning clouds, and afternoon sunshine to most areas over the next several days across western Washington, though areas along the coast may have a hard time breaking out of marine stratus. Continued troughing will also bring increased chances for light precipitation and isolated thunderstorms, though rainfall amounts look to be minimal through the week. An upper level trough will swing inland to the north on Thursday, bringing the highest chances for thunderstorm activity over the next week. The Olympic Peninsula and North Cascades will see the best chances for isolated thunderstorms on Thursday with potential rain shadowing over the northern interior and islands, though storm chances peak at around 10-20%. Storms and rain showers with this system are expected to bring light rainfall amounts of generally up to a tenth of an inch of rain to the region. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Ensembles continue to show high chances for troughing to remain over the Pacific Northwest into next week, bringing continued chances for light rain and isolated thunderstorms over higher terrain. The details remain fairly uncertain at this time, but seasonal temperatures, cloudy mornings, and afternoon sun breaks are expected through early next week. 15 && .AVIATION... Southerly flow aloft will persist as upper level ridging continues to move eastward. Marine stratus will persist along the coast through this afternoon with MVFR to IFR conditions continuing. It is unlikely that the coast will fully clear out this evening. Smoke and haze will continue aloft, mainly affecting slant- wise visibility in the mid and upper levels. The back edge of the smoke looks to move east of the Cascades tonight. Winds remain SW 5 to 10 knots, with gusts up to 20 knots through around 06Z Wed for terminals west of the interior. Tonight, after 06Z, the marine push will make farther progress inland. An extensive mix of IFR/MVFR ceilings and patchy fog is expected to reach peak coverage around sunrise, then gradually erode during Wednesday. Southwesterly winds will slowly east this evening to around 5 kt or less by early Wednesday morning. Winds increase again to around 5-10 kt during the day Wednesday. KSEA...Patchy smoke at around 6000 ft agl is expected to push eastward tonight. VFR will persist through this evening with SW winds remaining at 5 to 10 knots. Onshore flow is expected to bring a marine push late tonight into Wednesday morning, with stratus beginning to develop around 10-12Z. MVFR ceilings are expected from 13Z to around 17Z, with clouds lifting and scattering to VFR, which will follow through Wednesday evening. 62 && .MARINE... Surface high pressure will continue over the coastal waters today with a thermal trough along the coast shifting inland this afternoon. Increasing onshore flow tonight and into Wednesday will result in small craft westerlies through the Strait of Juan De Fuca. Weak systems crossing over the coastal waters will continue the onshore flow pattern through the remainder of the week with continuous pushes each afternoon and evening down the Strait of Juan De Fuca. Chances for isolated thunderstorms over the waters increases on Thursday with the passage of a frontal system, which may locally produce gusty outflow winds and lightning. Seas generally remain around 4 to 6 feet through the weekend. Mazurkiewicz/15 && .FIRE WEATHER... Elevated fire weather concerns will continue into the afternoon today as easterly flow promotes additional drying and very low relative humidities in the mid to lower 20s along the western Cascade gaps. A pattern change on track for later today into Wednesday will bring the return of moist onshore flow, excellent overnight relative humidity recoveries, cooler temperatures, and chances of light precipitation to western Washington at times through much of the second half of the week. Overall, expect upper level troughing to help mitigate fire weather concerns for most areas. The exception will be in any isolated thunderstorm activity through the week, particularly on Thursday across the mountains and northern interior. While the exact details on thunderstorm activity remain uncertain at this time, lightning from any storms that do develop may lead to new fire starts mainly over the mountains and gusty, erratic outflow winds could impact ongoing fires within the vicinity of any storms. 14/15 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory from 5 PM this afternoon to 2 AM PDT Wednesday for Central U.S. Waters Strait Of Juan De Fuca- East Entrance U.S. Waters Strait Of Juan De Fuca. && $$

293 FXUS66 KPQR 251735 AAA AFDPQR Area Forecast Discussion...UPDATE National Weather Service Portland OR 1035 AM PDT Tue Aug 25 2026 Updated Aviation discussion .SYNOPSIS...A weak upper level disturbance will bring slightly cooler high temperatures in the mid to upper 80s across the interior lowlands. Southerly winds are expected as troughing sets up over the northeast Pacific. Temperatures continue to trend cooler into the weekend with mid to upper 70s possible Saturday. .SHORT TERM...Now through Wednesday night...Troughing over the Gulf of Alaska is expected to slowly drift southeast while a shortwave over the northeast Pacific gets swung toward the PacNW today. This will lower heights aloft and in turn, decrease 850 mb temperatures to around 16-18 C but will still support high temperatures in the mid to upper 80s across the interior lowlands and 60s along the coast. Winds will also shift onshore across the entire area. Winds shift to the west by the evening, bringing a strong marine push to the coast and eventually the interior valleys later tonight. Any lingering wildfire smoke should shift back east of the Cascades by Wednesday. The upper level trough over the northeast Pacific will slowly shift eastward toward the PacNW heading into Wednesday. Upper level heights will continue to drop as the center of the trough moves toward Vancouver Island. Wednesday likely starts out with marine stratus covering the interior lowlands which will also impact afternoon highs which are expected to top out in the low 80s across the interior. -19 .LONG TERM...Wednesday through Sunday...Confidence remains high heading into the latter half of the week and into the weekend. Cluster analysis is heavily favoring troughing over the PacNW and western Canada with several embedded impulses reinforcing this pattern for several days. Temperatures continue to trend downward into the weekend. Models continue to show only weak signals for precipitation with a chance coming on Thursday as a front moves through the area and a better shot on Saturday as a slightly stronger front is expected. Beyond Saturday, the upper level pattern begins to flatten out and temperatures warm back into the 80s. -19 && .AVIATION...Through 18Z Wednesday...Dry, southwest flow aloft today as upper level ridge of high pressure shifts east. Satellite imagery this morning shows marine stratus entrenched along the coast, slowly retreating from the Coast Range valleys. Wildfire smoke from the Austin fire has been streaming aloft over PDX, but is expected to shift farther east later this afternoon as a strong marine push of westerly winds arrives. Expect a mix of MVFR to IFR CIGs to persist along the coast much of the day. There is around a 60% chance of conditions improving to VFR at KAST briefly this afternoon between 21-00z. VFR expected across inland terminals through at least 10z Wednesday. There is around a 30-50% chance that marine stratus with MVFR CIGs pushes inland after 12-14z Wed morning. Expect southwest winds to become slightly more westerly this afternoon before easing later this evening. KPDX AND APPROACHES...VFR conditions expected with smoke aloft gradually drifting eastward this afternoon. With a stronger marine push tonight, marine stratus could push inland with around a 30-50% chance of MVFR CIGs after 14z Wednesday. SSW winds around 4-7 kt expected to become westerly after 22z. /DH && .MARINE...Winds shift to the south as a weak disturbance passes over the region. Winds across much of the waters expected to be 5-15 kt with gusts up to 20 kt within 20 nm of the coast. The notable exception will be the inner waters north of Cape Falcon north to Cape Shoalwater where winds are expected to be 15-20 kt with gusts to 25 kt late this morning through the evening. A Small Craft Advisory has been issued for zone PZZ251 and the Columbia River Bar from 10 AM to 7 PM today. Isolated SCA criteria gusts are possible outside the advisory. The next pattern shift looks to occur Thursday night into Friday, when troughing moves into the Pacific Northwest. This will bring a return to northwesterly flow with low to moderate chances for light rain showers. Seas otherwise continue at 3-6 ft through this weekend. -19/36 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 7 PM PDT this evening for PZZ210-251. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

697 FXUS66 KMFR 251712 AFDMFR Area Forecast Discussion National Weather Service Medford OR 1012 AM PDT Tue Aug 25 2026 ...New Aviation Section... .AVIATION (18Z TAFs)... Marine layer is stronger today and may provide little relief through the daytime hours for KOTH with IFR/MVFR being common through this cycle. For inland TAF sites, other than high clouds, we are expecting typical summer time diurnal breezes with VFR conditions. There is one thing to consider for KRBG, there is a very small chance (~15% for MVFR) for some low clouds overnight, but confidence was not high to include at this time. This would occur close to sunrise if the low clouds do develop and may be added in subsequent TAFs. -Guerrero && .PREV DISCUSSION... /Issued 439 AM PDT Tue Aug 25 2026/ Updated AVIATION Discussion... AVIATION...25/12Z TAFs...IFR/LIFR conditions under marine stratus will persist along the coast and over the waters through this morning. Conditions will gradually improve to MVFR by this afternoon as the marine layer peels back to the immediate coast, but full clearing is not expected today. LIFR/IFR conditions will return again around sunset. Inland terminals will remain VFR through the TAF period with some mid and high level clouds streaming through the region. Gusty afternoon/evening winds are expected today, strongest east of the Cascades and in the Shasta Valley. These winds will ease after sunset. PREV DISCUSSION... /Issued 345 AM PDT Tue Aug 25 2026/ KEY MESSAGES... * Hot temperatures continue today, trending cooler through the week into the weekend. * Weather pattern largely influenced by upper level troughing, resulting in gusty winds in the afternoons/evenings. * Heightened fire weather concerns today through Thursday due to gusty winds and low RH. Fire weather concerns highest for Shasta Valley and portions of the East Side. DISCUSSION...Southwest flow persists over the region today with persistent high pressure over the the Desert Southwest and low pressure just offshore of British Columbia. The upper level pattern doesn`t change too much compared to yesterday. Low pressure off the BC coast will drop southward this afternoon and this will be enough to push some drier air into the mid-levels as well as shift the instability slightly eastward today. This will shift any thunderstorm chances into Nevada and Idaho. There could be enough/marginal moisture for some cumulus buildups over the Warners this afternoon, but, along with the lack of instability, it`s not sufficient enough for thunderstorm development today. Despite a few degrees of cooling today west of the Cascades, it`ll be another hot day across the region with high temperatures (mid- upper 90s West/mid-upper 80s East) peaking around 5 to 7 degrees above normal for late August. Low pressure offshore this afternoon will be the main weather maker for much of the week as it moves closer to shore today, then gradually inland into the Pacific Northwest Wednesday and Thursday...a pattern quite similar to that of last week. With this trough, temperatures will gradually trend cooler over the remainder of the week, eventually settling into the 80s area wide (except for the coast) for the weekend behind the trough passage. Persistent onshore flow will bring the nightly return of marine layer intrusions along the coast, and eventually into the Umpqua Basin Thursday morning. Expect periods of increased mid and high level cloud cover as shortwaves pass through into southwest flow ahead of this trough today and Wednesday. Aside from the cooler temperatures, the main concern with this trough will be increased afternoon winds each day through Thursday. This will bring heightened fire weather concerns each afternoon/evening as daily winds increase and RHs remain fairly low. Fire weather concerns diminish some Friday onward as RHs trend higher, but with no precipitation expected anytime soon, fire danger remains very high across the region. Please remember to do your part and prevent a spark. One less spark, one less fire. The mid-levels will be too dry to support any thunderstorm development this week, and while no widespread precipitation is expected through the forecast period, some of the guidance is showing some tropical moisture being swept into the westerlies on Friday. Current guidance brings this moisture into central CA/northwestern Nevada, which could clip the southeastern portions of the forecast area or remain just south, depending on how it interacts with the trough passing inland at the same time. Overall, the thunderstorm threat is minimal, but it`s something worth watching this week. Broad troughing will remain over the western CONUS over the weekend and into early next week. Dry conditions will continue with temperatures near to a few degrees below normal. MARINE...Updated 130 AM PDT Tuesday, August 25, 2026...Relatively calm conditions with light winds and low seas are expected through the week. Southerly winds will persist through Wednesday, then turn northerly on Thursday. North winds increase on Friday south of Cape Blanco, but wind driven seas likely hold off until the weekend. FIRE WEATHER...Updated 300 AM PDT Tuesday, August 25, 2026... Southwest flow will persist over the region through much of the week. The upper level pattern will largely be dominated by an upper level trough over the eastern Pacific that will move closer to shore today, then inland into the Pacific Northwest Wednesday and Thursday. This pattern is quite similar to that of last week, when gusty winds combined with low daytime RHs and brought critical fire weather conditions. This will again be possible today through Thursday as this trough brings gusty winds in the afternoons/evenings. With low daytime RHs expected, near critical conditions are possible each day, with critical conditions also possible in the Shasta Valley and portions of the East Side. Another day of gusty south winds is expected in the Shasta Valley today, which could lead to a period of overlap with gusty winds/low RH, but there is uncertainty on whether the duration requirement is there. For the East Side today, gusty southwest winds will be present, but not quite strong enough and RHs won`t be quite low enough for critical conditions to be met. Wednesday and Thursday, however, RHs will trend lower across the East Side as a dry front gradually moves inland. These two days seem most likely for gusty winds/low RH to overlap and result in critical conditions. By Friday, RHs trend upward and remain elevated enough through the weekend to lower the concern for critical fire weather conditions. It`ll remain breezy through the weekend, but winds generally trend weaker compared to this week. Meanwhile, onshore flow will generally maintain moderate to good recoveries with nightly marine pushes for coastal zones. The exception to this could be Thursday morning when poor recoveries are possible along the Warners and southern portions of the Fremont- Winema National Forest. Thunderstorms drop out of the forecast today. Mid-level moisture is marginal enough for some cumulus buildups over the Warners, but along with the lack of instability, it`s not sufficient enough for thunderstorm development today. We`ll be keeping an eye on the potential for some tropical moisture to get swept into the westerlies later in the week. Current guidance keeps this south of the area, but it`s possible it could clip the southeastern zones (285/625) depending on the interaction with the incoming trough. Stay tuned for updates. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. PACIFIC COASTAL WATERS...None. && $$

551 FXUS66 KEKA 250715 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1215 AM PDT Tue Aug 25 2026 .KEY MESSAGES... * Gradual cooling this week with inland temperatures returning to near or slightly below seasonal normals. * Increasing Relative Humidity and a deeper marine layer will diminish the fire danger this week. && .SYNOPSIS...An upper level trough approaching the Pacific Northwest is expected to start bringing cooler temperatures and a deeper marine layer to the area. The near coastal areas are expected to start cooling today and Wednesday with more cooling late in the week farther inland. && .DISCUSSION...An upper level trough is in place off the Pacific Northwest. This is expected to stall here with shortwaves occasionally rotating around it. The first one is expected to start some minor changes to the weather. This is expected deepen the marine layer and potentially bring some drizzle to the coast this morning. Areas in the "near coastal" zone are expected to see some cooling today with more marine influence. The coast may see brief periods of clearing this afternoon, although generally the status at the immediate coast is expected to be stubborn. Additional shortwaves continue to move around the trough to the northwest of the area. This may bring some subtle changes to the weather each day, but overall the pattern is expected to remain fairly persistent through the work week. The northerly winds will start to increase slightly Thursday, especially along the Mendocino Coast. Next weekend some offshore flow and brief warmup is possible before the trough takes hold again. MKK && .AVIATION...IFR with locally LIFR conditions are in place this morning. The marine layer is gradually getting deeper and this should keep the CIGS and VIS from getting too low this morning. There may some drizzle at times, but this isn`t expected to drop conditions significantly. Ukiah is expected to remain clear, although a clouds will be pushing north from Sonoma county so a few hours of clouds around sunrise are not out of the question. This afternoon CIGs are expected to lift to MVFR conditions at the coast, but clouds likely remain in place for the majority of the afternoon. Tonight clouds are expected to push back inland at the coast, but again expect CIGS won`t get too low. MKK && .MARINE...Winds have diminished along the coast and some local areas have become southerly. These have reached 10 to 15 kt near Pt St George and Crescent City. These local southerly winds will diminish this morning and northerly winds return late this afternoon and tonight. South of Cape Mendocino these may reach 10 to 15 kt with generally 5 to 10 kt farther north. In addition to the local wind driven waves there is a small southerly swell. Currently it is around 2 feet at 14 seconds. This is expected to reinforced with another southerly swell around 2 feet at 17 seconds. Winds are expected to remain fairly steady through Wednesday night. Thursday or Thursday night the northerly winds are expected to increase again to around 15 to 25 kt by Friday afternoon. These are expected to continue to increase over the weekend to 20 to 30 kt. MKK && .FIRE WEATHER...The current weak ridging pattern will give way to a weak troughing regime, bringing cooler temperatures and helping recovery RH values overnight. Minimum daytime RH values will also improve. Trinity Lake county will still have minimum RH values in the upper teens to 20`s Tuesday but will continue to improve as the work week progresses and the offshore low pressure system approaches BC and Washington coast gradually bringing the marine air farther inland as it deeps. Winds will generally remain light and terrain driven, aside from southwesterly afternoon breezes. && .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

385 FXUS66 KMTR 251944 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1244 PM PDT Tue Aug 25 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1242 PM PDT Tue Aug 25 2026 - A shallow marine layer will keep coastal conditions near normal through Thursday - Seasonably warm and very dry conditions continue above 1000 feet and across the far interior through Thursday - Pattern change Friday into the weekend brings cooler temperatures and moderate potential for tropical moisture && .SHORT TERM... Issued at 1242 PM PDT Tue Aug 25 2026 (This evening through Wednesday night) Regional satellite imagery is showing stratus retreating to the immediate Pacific coastline with abundant sunshine expected across the interior this afternoon. Meanwhile, passing high clouds also persist and are moving northeastward across region. Thus, interior temperatures will warm into the 80s to mid 90s and up to around 105 deg F in the warmest interior parts of Monterey County. Persistent onshore and a shallow marine layer will keep temperatures near seasonal averages near the coast. Breezy onshore winds are forecast to develop by this afternoon and evening, with gusts up to 20 to 35 mph along the coast and in the favored valleys and passes. Tonight, expecting stratus to return inland late this evening and into the interior valleys by Wednesday morning. However, the inland extent may be less than previous days as the marine layer compresses slightly. For Wednesday, a slight up tick in temperatures as the ridge builds further west across the Desert Southwest. As such, temperatures will be some 5-10 degrees F above average with 10-20 degrees F above average in the far interior and higher elevations above 1000 feet. We are still expecting warm and very dry conditions above the marine influences with little to no overnight humidity recoveries through Thursday. See the FIRE WEATHER section for the implications for local fire weather concerns. && .LONG TERM... Issued at 1242 PM PDT Tue Aug 25 2026 (Thursday through next Monday) Afternoon temperatures will be slightly cooler on Thursday as a trough of low pressure approaches the West Coast, however 850 MB temperatures will remain between 23-26 degree C. The cooling trend will become more noticeable Friday and moreso into the upcoming weekend and early next week as the trough deepens over the Pacific Northwest. Thursday night into Friday, we are expecting mid/upper level tropical moisture to advect northward across the Bay Area and Central Coast. This will definitely increase high cloud cover and also result in an increased potential for high-based rain showers and/or thunderstorms. However, the lack of instability looks to be the limiting factor for thunderstorms. We are monitoring this closely at this time. Expecting breezier conditions with the deepening trough off of the West Coast. Gusts are forecast to be between 25 to 35 mph near the coast and in the favored valleys, gaps, and passes by Friday and into the weekend. By Monday, temperatures are forecast to be some 5-15 degrees F below seasonal averages which matches with the CPC`s 6-10 Day Temperature Outlook. && .AVIATION... (18Z TAFS) Issued at 1206 PM PDT Tue Aug 25 2026 Stratus quickly dissipated out of the remaining terminals and widespread VFR prevails this afternoon. Onshore winds should remain moderate throughout the day and ease to gentle overnight. Rather tricky stratus forecast this TAF period. Model guidance is trying to indicate a widespread compressed marine layer tonight into tomorrow, but it is not convincing when compared to observations. Per the OAK sounding this morning, the marine layer was measured at a depth of around 1700 feet. Closer to Monterey Bay, the marine layer is around 1200 feet. That being said, highest confidence for IFR to LIFR ceilings at HAF, MRY, and SNS around sunset. Low confidence on whether SJC will develop a ceiling as it depends on how deep the marine layer decides to be tonight. The other Bay Area terminals can expect IFR to low-end MVFR ceilings to arrive around or after sunset. Vicinity of SFO...VFR with northwest breezes increasing to fresh through the afternoon and diminishing to gentle overnight. If the stratus pattern from this morning holds, IFR ceilings may develop shortly after sunset and dissipate by late Wednesday morning. The current TAF relies a bit on persistence from last night, but overall low to medium confidence on the exact timing. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR through the day as northwest winds remain around 10-12 kt. Stratus is expected to bring IFR ceilings around 7-8 PM PDT this evening as winds become light. Ceilings may drop to LIFR overnight which will reduce visibility due to either mist or fog. Stratus should clear by late Wednesday morning. && .MARINE... (Tonight through next Sunday) Issued at 1206 PM PDT Tue Aug 25 2026 Moderate northwest breezes become fresh to strong Wednesday and persists through the week. Wind driven seas remain moderate into the weekend. A long period southerly swell around 15 to 17 seconds continues to build by the end of the week. && .FIRE WEATHER... Issued at 1202 AM PDT Tue Aug 25 2026 Near-critical fire weather conditions continue through Thursday for elevations above 1000 feet as warm and dry conditions continue across the region. Humidity recoveries remain poor to very poor in the higher elevations, with nocturnal drying expected within the Santa Lucia range. Breezy conditions will develop each afternoon and evening, but not for a long enough period to trigger any fire weather products. Specifically regarding the Timber Fire vicinity, observational data suggests that southwesterly winds from the Pacific Ocean over the ridgetops are helping to moisten the air, with nocturnal drying being observed as the winds diminish and even turn faintly offshore overnight. This has led to an unusual situation where daily maximum relative humidity values have been observed during the daytime. Smoke transport from the Timber Fire will continue to peak in the afternoon and evening with the plume spreading towards the Salinas area. Friday into the weekend, a pattern change should allow for some relief as an upper level trough comes into the region bringing cooler temperatures and a deeper marine layer. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 9 AM PDT Thursday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory from 9 PM this evening to 9 AM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10- 60 NM. && $$ SHORT TERM...RGass LONG TERM....RGass AVIATION...Navarrete MARINE...Navarrete 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

301 FXUS66 KOTX 252106 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 206 PM PDT Tue Aug 25 2026 .KEY MESSAGES... - Moderate to Major HeatRisk continues Wednesday with highs in the mid to upper 90s. - Breezy winds Wednesday into Thursday bringing elevated fire weather conditions. - Cooler temperatures and potential for mountain showers Friday and Saturday. && .SYNOPSIS... Hot temperatures persist through Wednesday with highs in the mid to upper 90s. The heat begins to break down Wednesday into Thursday with breezy winds regionwide and thunderstorm chances over the mountains. Temperatures cool below normal for the weekend with showers possible over the mountains. && .DISCUSSION... Wednesday: A ridge of high pressure maintains influence over the Inland Northwest through Wednesday, keeping temperatures warm in the mid to upper 90s. A Heat Advisory remains in effect through Wednesday evening for the Lewiston-Clarkston Valley, where temperatures will climb into the upper 90s to triple digits. Westerly winds pick up through the Cascade gaps Wednesday afternoon and evening as an approaching system pushes cool marine air onshore west of the Cascades. Combined with afternoon humidity values in the low to mid 20s, these breezy winds will result in elevated fire weather conditions across Central WA. In addition to breezy and dry conditions across Central WA, there is potential (around a 15 percent chance) for isolated showers and thunderstorms across the Northern Mountains and North ID Wednesday afternoon as mid- level moisture increases, temperatures cool aloft, and a weak shortwave disturbance supplies synoptic scale lift. Convective- allowing models aren`t overly enthusiastic with most only indicating a cell or two developing over the course of the evening, so confidence is not high that storms will materialize, but the potential is there. Any storms that do develop may bring gusty outflow winds due to a dry sub-cloud layer. Thursday: A trough and associated cold front will sweep across the region late Wednesday night into early Thursday, tightening the pressure gradient across the Northwest and bringing gusty westerly winds by Thursday afternoon. Sustained winds of 15-25 mph with gusts of 30-40 mph are expected. Temperatures Thursday will be 9-12 degrees cooler compared to Wednesday, but humidity values will still be low in the 20-25 percent range. The combination of stronger winds with low relative humidity values will be enough to create elevated to locally critical fire weather conditions. A Fire Weather Watch has been issued for the Okanogan Valley and Waterville Plateau Thursday afternoon and evening where the strongest winds and lowest RH values are expected. Friday through Tuesday: Below normal temperatures return for the weekend with chances for mountain showers. Winds will be breezy at times, but the cooler temperatures look to keep relative humidity levels above critical thresholds. /Fewkes && .AVIATION... 18Z TAFs: VFR conditions expected for much of the region. The caveat will be smoke impacts from fires burning in the Cascades, notably the Little Giant Fire. Smoke is expected to gradually clear out from KEAT through the late morning and afternoon hours with VFR conditions forecast to return by evening. There is a 15% chance for thunderstorms to develop over the Northeast Blue Mountains by the late afternoon on Tuesday (after 21Z). Afternoon convection on Tuesday looks to weaken quickly as it moves off the higher terrain and is unlikely to be a threat to KLWS, but expect towering cumulus to be in the area. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in VFR conditions for all terminals apart from KEAT, where MVFR to IFR conditions are possible through the late morning and afternoon before clearing out in the evening. ----------------------- 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 61 93 60 86 54 81 / 0 10 0 0 0 0 Coeur d`Alene 62 95 61 86 53 80 / 0 10 10 0 0 0 Pullman 55 90 53 82 47 78 / 10 10 0 0 0 0 Lewiston 66 97 65 89 59 85 / 20 10 0 0 0 0 Colville 50 93 50 86 44 81 / 0 10 10 0 0 0 Sandpoint 61 93 59 84 50 78 / 0 20 20 0 0 0 Kellogg 59 95 58 83 52 78 / 0 20 20 0 0 0 Moses Lake 58 93 57 87 52 83 / 0 0 0 0 0 0 Wenatchee 68 95 65 85 60 84 / 0 0 0 0 0 0 Omak 64 95 58 88 52 84 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Heat Advisory until 9 PM PDT Wednesday for Lower Garfield and Asotin Counties. Air Quality Alert until further notice for Chelan, Okanogan, and Douglas Counties. Fire Weather Watch from Thursday afternoon through Thursday evening for Okanogan Valley (Zone 703)-Waterville Plateau (Zone 706). ID...Heat Advisory until 9 PM PDT Wednesday for Lewiston Area. && $$

696 FXUS66 KPDT 252052 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 152 PM PDT Tue Aug 25 2026 .KEY MESSAGES... 1. Very low chances of showers and thunderstorms this afternoon and evening 2. Temperatures today and Wednesday will remain above seasonal normal through Wednesday 3. An upper level low approaching the region will bring increased winds Wednesday increasing fire weather concerns. && .DISCUSSION... Current satellite shows a cumulus field developing over the Elkhorns and Blues as well as over the Eagle Caps down into the Wallowa Valley. Ground observations are showing no rainfall associated with these cells at this time. NBM raw ensembles shows a 5-15% chance of thunderstorms and showers over the eastern mountains and Wallowas this afternoon and this evening. Looking at RAP forecast soundings, there is between 500-650 J/kg of MUCAPE, LIs of -2 to -3, lapse rates of 9-10 C/km and bulk shear nearing 15-20 knots. This is enough instability and lift that we cannot rule out the possibility of a shower or thunderstorm forming over the area. Wednesday models and NBM raw ensembles show a bit more instability in the region decreasing the chances of showers and thunderstorms to under 10%. Models show the ridge of high pressure remaining over the region through Wednesday ahead of the next system. Looking at in house calculations, temperatures are expected to be anywhere from 5 to 10 degrees above seasonal average today, increasing to near 15 degrees today and Wednesday. Looking at HeatRisk probabilities, tomorrow (Wednesday) will be the peak with 70-80% probabilities of areas reaching Moderate HeatRisk (level 2 of 4) across the Columbia Basin and Central OR. There is also a low to medium risk of areas in the Columbia Basin seeing Major HeatRisk (level 3 of 4) with 20-40% probabilities. Moderate HeatRisk affects those who are sensitive to heat, especially those without cooling/hydration, while Major HeatRisk affects anyone without cooling/hydration. Models on Wednesday show the leading edge of the upper level low beginning to make its way onshore. As the low begins to traverse east, the leading edge over the Cascades Wednesday will bring a tightening of the surface pressure gradients. Winds will be increased through the Columbia River Gorge, Kittitas Valley and along portion of the Simcoe Highlands and foothills of the southern Blues. NBM raw ensembles shows 70-80% probabilities that winds will be 20-25 mph with gusts to near 30-35 mph. The increase in the winds will also raise some fire weather concerns on Wednesday. With that, a special weather statement has been issued for isolated areas within the aforementioned places for critical fire weather between 1100-2000 (8PM) Wednesday due to winds and low relative humidity. While not widespread, this will affect a few of the fires already on the landscape as well as any new fire that may occur in these areas. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... VFR conditions to prevail through the period. Very low confidence (10-15%) in smoke impacts to sites. Mostly light winds through the period. Except at sites DLS/RDM/BDN where winds will be 10-15kts with gusts up to 25kts this afternoon. Lawhorn/82 && .FIRE WEATHER... Hot and dry conditions will prevail through Wednesday with elevated fire weather concerns. Wednesday will see an increase in winds as an upper level low makes its way onshore. Sustained winds will be between 20-25 mph with winds gusts between 30-35 mph. Coupled with areas of low relative humidity, a special weather statement has been issued between 1100-2000 (8PM) Wednesday for localized critical fire weather concerns. While not widespread, this will affect a few of the fires already on the landscape as well as any new fire that may occur in these areas. && .Preliminary Point Temps/PoPs... PDT 57 93 56 85 / 0 0 0 0 ALW 65 94 63 87 / 0 0 0 0 PSC 62 96 61 90 / 0 0 0 0 YKM 63 96 60 88 / 0 0 0 0 HRI 64 95 62 88 / 0 0 0 0 ELN 61 91 56 80 / 0 0 0 0 RDM 51 91 49 85 / 0 0 0 0 LGD 58 97 56 90 / 20 0 0 0 GCD 58 96 57 92 / 10 0 0 0 DLS 65 89 63 83 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until noon PDT Wednesday for WAZ026-028>030- 522-523. OR...Air Quality Alert until noon PDT Wednesday for ORZ044-502-503- 507. && $$ DISCUSSION...90 AVIATION...82 FIRE WEATHER...90

997 FXUS65 KREV 252027 AFDREV Area Forecast Discussion National Weather Service Reno NV 127 PM PDT Tue Aug 25 2026 .KEY MESSAGES... * Isolated showers and thunderstorms are possible today, mainly in Churchill, Mineral, and Mono Counties. * Breezy to gusty winds will return Wednesday through Saturday, leading to elevated fire weather conditions. * A weak system will bring increased chances for showers to the Sierra and western Nevada on Friday. && .DISCUSSION... The upper-level pattern today features a strong ridge over the Southwest US, with western NV on its western periphery, experiencing southwesterly flow aloft. A PacNW low is gradually approaching the Washington coast. This setup continues to funnel monsoonal moisture northward along the western flank of the ridge, interacting with embedded shortwave energy. Isolated showers and thunderstorms are expected today over Churchill, Mineral, and S. Mono Counties, with 15-25% chances between 2-8 PM. DCAPE values over 1300 J/kg indicate that any storms that do develop could produce strong outflow gusts (40-45 mph). Breezy SW winds with gusts up to 25-30 mph are expected, contributing to elevated fire weather conditions. Smoke from the Hawk Fire may persist, particularly in the Reno-Sparks area, but improved ventilation is anticipated. Patchy smoke may also creep into NE CA from the Timber Fire. Wednesday and Thursday, the Pac NW low continues its eastward progression, strengthening the upper jet over the region. This will translate to increasing surface winds, with NBM guidance showing gusts up to 25-35 mph across the region, particularly in wind-prone areas of the Sierra and northern Nevada. These elevated winds, combined with low relative humidity, will lead to elevated to critical fire weather conditions. Temperatures will remain above seasonal averages on Wednesday, with NBM highs for western NV valleys in the mid 90s, and Sierra communities in the low 80s. Precipitation chances remain very low (10%) for most of the CWA on Wednesday. However, NBM guidance shows a slight uptick in shower chances for Wednesday evening into Thursday morning, particularly for western Nevada. This appears to be a localized signal and confidence in widespread precip remains low. By Thursday, conditions are expected to be mostly sunny and dry across the CWA, with continued breezy winds, although some models are showing the potential for rain showers Thursday evening south of US-50. Friday onward, the upper ridge will flatten late in the week as troughing strengthens over the Northwest. This pattern shift will bring a weak system through the CWA on Friday. NBM guidance shows a notable increase in precipitation chances for Friday (40-60%). Showers are possible across the Sierra and western Nevada, with a slight chance lingering into Saturday afternoon. Temperatures will see a slight cooling trend on Friday, with valley highs dropping into the upper 70s to upper 80s, and Sierra highs in the upper 60s to upper 70s. Winds will remain breezy on Friday, gradually diminishing through the weekend. Beyond Saturday, the NBM and GFS guidance point to a return of dry and mostly clear conditions for Sunday and Monday, with temperatures rebounding slightly but remaining generally near or slightly above seasonal averages. The overall synoptic pattern suggests a more stable, drier regime settling in for the start of next week. -Justin && .AVIATION... VFR conditions are expected at all area TAF sites today and tonight. Surface winds in the region gusting up to between 20-25 kts are forecast between through 03Z tonight. The latest HRRR smoke product does not show much impact from Hawk Fire smoke today compared to the previous days. Not anticipating flight rules to be reduced at this time due to smoke at KRNO, but will continue to monitor in case this changes. There`s a 15-25% chance for isolated showers and thunderstorms in Churchill, Mineral, and S. Mono Counties this afternoon between 25/21Z-26/04Z. Lesser precipitation chances are seen in the NV Basin and Range on Wednesday afternoon. -078/Justin && .FIRE WEATHER... Breezy SW winds with gusts up to around 25-30 mph and RH reductions of 15-25% will support elevated to isolated critical fire weather conditions this afternoon across the Sierra Front and NE CA, including the Hawk Fire. Tuesday night RH recoveries in these areas are forecast to be between 35-50%. Wednesday through Saturday, increased winds with gusts upwards of 35 mph (40 mph in wind prone areas) are expected mainly for the Sierra Front and NE CA. Currently, the day with the most widespread critical fire weather conditions in these areas looks to be Thursday. Please continue to watch for further updates in case fire products need to be issued. -078/Justin && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

977 FXUS66 KSTO 251926 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1226 PM PDT Tue Aug 25 2026 .KEY MESSAGES... - Dry with seasonable high temperatures through the week, with a cool down by the weekend. - Elevated Fire Weather conditions in portions of the Valley and Foothills on Wednesday and Thursday. && .DISCUSSION... Mid level clouds are moving through portions of the Sacramento Valley this afternoon. Cloud coverage has decreased over the last few hours allowing for sunshine to filter in the through the area. Temperatures are starting to reach the upper 80s in the northern Sacramento Valley with low to mid 80s elsewhere. Overall synoptic pattern remains relatively unchanged compared to yesterday; with high pressure in the south and off shore troughing in the PacNW. Ensembles reveal slight changes in the upper level pattern through Thursday, which will allow temperatures to remain seasonable and keep dry conditions in the forecast. The continued dry pattern with daytime humidity values in the the teens to low 20s across portions of the Valley and NE Foothills and Burney Basin will allow for elevated fire weather conditions to develop tomorrow and Thursday. By Friday, offshore troughing is forecast to begin moving inland, which will allow for cooling high temperatures and enhanced onshore flow. High temperatures will begin a gradual cooldown, allowing for mostly Minor HeatRisk to remain in the forecast this weekend and into next week. The slight pattern change will also allow a moisture plume to move through portions of the Sierra, mainly south of HWY50 on Friday embedded within a shortwave of energy. Recent NBM runs have slightly decreased overall confidence in any thunderstorms developing in the higher elevations west of the Sierra Crest on Friday; however some deterministic soundings show enough instability and moisture for us to keep an eye on how the pattern evolves the next few days. Cooler temperatures will continue to prevail as we move into next week as ensembles suggest offshore troughing will remain the driving synoptic feature. Periodic breezy onshore winds will also remain in the forecast as we move into the weekend and into next week. && .AVIATION... VFR conditions prevail across interior NorCal TAF sites next 24 hours. Period of locally breezy southerly winds up to 25 kts in the northern Sacramento Valley from 21Z today thru 04Z Wednesday. Elsewhere, surface wind gusts generally below 12 kts. Mountain TAF sites with west-southwest wind gusts 25 to 30 kts through 03Z Wednesday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

605 FXUS65 KMSO 252014 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 214 PM MDT Tue Aug 25 2026 .DISCUSSION... KEY MESSAGES: - Warmest temperatures today and Wednesday. - Thunderstorms this afternoon south of Interstate 90. Expanding coverage into all of western Montana and north central Idaho on Wednesday. Main threats will be lightning and gusty outflow winds. - Pacific Northwest trough brings gusty winds later this week and cooler temperatures for the weekend. Hot, dry and smoky conditions will continue through Wednesday as high pressure remains anchored over western Montana. Monsoon moisture from the Dessert Southwest will be expanding northwards, increasing the chances for thunderstorms in the afternoon and evening hours. This afternoon, storms will be most likely along and south of Interstate 90. Thunderstorm coverage will expand northwards to the Canadian border by Wednesday afternoon and evening. Due to the very dry low levels of the atmosphere and high cloud bases, little precipitation is expected to accompany storms. Gusty outflow winds will also be a concern with storms, between 30 to 40 mph today and possibly up to 50 mph on Wednesday. The combination of mostly dry storms, lightning and gusty winds will elevate the potential for new fire starts. On Thursday, the high pressure ridge begins to break down as a trough of low pressure approaches from the west. Breezy conditions are anticipated with another round of thunderstorms, mainly across western Montana. A subtle drop in temperatures is anticipated by Friday as a weak cold front moves through the region. Gusty winds, dry conditions and lingering thunderstorms will keep fire weather conditions elevated both days. The weekend will trend significantly cooler with temperatures at or even slightly below normal. There are still a few models showing a more significant low pressure system moving through northwest Montana, but the majority of models solutions are trending more towards an open wave, which decreases the chance of precipitation. There is still potential to see shower and thunderstorm activity in this pattern, but this would be more focused across southwest Montana and Lemhi County. && .AVIATION... High pressure will maintain widespread VFR weather conditions across the region today, though warming temperatures will significantly increase density altitudes, particularly at high-elevation terminals like KBTM. Degraded slant-range visibility aloft is anticipated due to wildfire smoke throughout the afternoon. Some improvement is possible by this evening, however visibility will likely degrade once again late tonight into Wednesday morning. Monsoonal moisture moving northward will introduce isolated to scattered thunderstorms starting around 25/2200z, particularly near KSMN and KBTM. These high-based storms will be capable of erratic convective outflow wind gusts of generally 30 to 40 knots near storm cores. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...Red Flag Warning from 11 AM to 7 PM PDT Wednesday for Palouse/Hells Canyon. && $$

845 FXUS65 KBOI 252005 AFDBOI Area Forecast Discussion National Weather Service Boise ID 205 PM MDT Tue Aug 25 2026 .KEY MESSAGES... - Isolated afternoon thunderstorms today and Wednesday, mainly forming over the Idaho mountains, and southern Twin Falls County on Thursday afternoon. - A slight warming trend Tuesday and Wednesday, then gradually cooling the rest of the week with breezy conditions. - Scattered showers and thunderstorms over southwest Idaho on Friday and Saturday. Some of the storms may be severe. && .SHORT TERM /Through Thursday Night/... A seasonably strong anticyclone over Arizona and New Mexico is dominating the synoptic pattern over the western CONUS, leaving the interior Northwest in broad and strengthening southwest flow aloft. This also means warm temperatures will continue with little day-to-day change through Thursday. The primary concerns will revolve around the potential for thunderstorms each afternoon, and then increasing winds with low humidity by Thursday. Thunderstorms are most likely near the Nevada border into the western Magic Valley both this afternoon and Wednesday afternoon, with strong gusty winds the primary threat. Isolated thunderstorms are still possible over the central Idaho mountains as well. Drier air will limit any thunderstorm potential over eastern Oregon, including Malheur/Harney and the Oregon Outback, with only low probabilities existing over Baker County. By Thursday, the increase in southwest flow aloft associated with a strengthening trough ejecting eastward across Oregon will bring gusty winds to southeast Oregon and far southwest Idaho. This will combine with the antecedent low RH/dry conditions and warm temperatures to create an elevated wind-driven fire weather threat across these areas. && .LONG TERM /Friday through Tuesday/... A cold front on Friday will drop temperatures down to near normal. Ahead of this cold front, Tropical Storm Iselle will weaken, with its remnant moisture transported over our area in southwesterly flow aloft. As the long range ensemble guidance sees it, PWAT values across southwest Idaho will increase to around the 95th percentile of climatology (highest near the Magic Valley and eastward). The timing of the cold front and moisture advection right now looks favorable for the development of showers and thunderstorms come Friday afternoon, mainly in SW Idaho and the southeastern portions of the Great Sandy Desert. With high PWATs, heavy rain will be a hazard with storms that develop and the flash flood risk will need to be monitored. The cold front and associated upper trough will be quick to push the moisture off to the east come Saturday. The weekend will feature generally dry conditions with temperatures at or below normal. Come Monday/Tuesday, another trough digging down the coast of British Columbia and grazing our area will bring a slight chance of precipitation across higher terrain of southwest Idaho. This fall- like transition pattern looks to continue beyond the long-term period, with the extended outlooks leaning towards above normal precipitation and below normal temperatures.&& .AVIATION /18Z Tuesday through Wednesday/... Issued 1153 AM MDT TUE AUG 25 2026 VFR. Isolated showers and thunderstorms this afternoon, mainly east of a KMYL-KBOI line and near KTWF/KJER. Thunderstorms capable of outflows to 35-45 kt. Surface winds: SE-SW 5-15 kt. Winds aloft at 10kft MSL: SW 10-25 kt KBOI...VFR. A low chance (<10%) of showers and thunderstorms this afternoon after 22z, capable of outflows to 30 kt. Surface winds: Variable, leaning W-NW 5-10 kt this afternoon. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Fire Weather Watch from Thursday afternoon through Thursday evening for IDZ423. OR...Fire Weather Watch from Thursday morning through Thursday evening for ORZ670>672. Air Quality Alert until noon PDT Wednesday for ORZ062. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...JR LONG TERM....NF AVIATION.....NF

361 FXUS65 KLKN 251955 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1255 PM PDT Tue Aug 25 2026 .KEY MESSAGES... * Lingering storm chances in eastern Nevada through Thursday * Vegetation remains dry enough that any cloud to ground lightning strikes could produce fire starts that could spread rapidly * Convective activity is expected to ramp up again later on this week and into the weekend && .DISCUSSION... (This evening through next Monday) WEATHER PATTERN OVERVIEW: The latest round of daytime thunderstorms continues over far eastern and northeastern Nevada today. Given the previous few days, any thunderstorms have a high probability of new fire ignitions from lightning strikes. This pattern will continue through Thursday as the high pressure system shifts west. Starting Friday, a trough in the northwest will combine with the high over Arizona and New Mexico to bring southwest flow and Pacific moisture into the forecast area. The strength of this moisture is still being determined but the current forecast would bring shower and thunderstorm chances to effectively the entire forecast area between Friday and Saturday. Moisture is currently anticipated to linger into early next week, with weaker and more sparse storms Sunday and Monday. FORECAST CONFIDENCE & DEVIATIONS: Moderate confidence in storm chances and associated impacts through Thursday. High confidence in increasing moisture and atmospheric instability for Friday and Saturday but low confidence in moisture strength and extent of impacts. No changes to NBM output. && .AVIATION...Mostly calm day today, with some afternoon gusty winds at KWMC/KBAM/KELY. A stray thunderstorm or two is also possible at KELY and KENV this afternoon. Otherwise, expect light winds under 10KT and VFR conditions. && .FIRE WEATHER...Dry thunderstorm activity is expected Tuesday afternoon for FWZ 438/469/470/425. Storms will initiate in early afternoon and diminish around sunset tonight. The nature of storm activity will be more dry than wet with impacts being dangerous lightning, and erratic gusty winds that will enhance aggressive fire behavior. General motion of storms will be from southwest to northeast at around 20 mph. A very similar setup is forecast for Wednesday afternoon over the same locations. && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...94 AVIATION...94 FIRE WEATHER...99