548 FXUS66 KSEW 090258 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 758 PM PDT Tue Sep 8 2026 .SYNOPSIS... An upper ridge offshore will bring dry, warmer conditions through Wednesday. Troughing develops over the Pacific Northwest Thursday with an upper low bringing cooler conditions and precipitation potential into the weekend. && .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/... Mostly clear skies prevail across Western Washington this evening. Forecast trends look on track for a smidge of warming tomorrow as an upper ridge nudges into the region before a cooler, unsettled stretch finishes off the week as a trough settles over the Pacific Northwest. Previous discussion follows with updates to marine and aviation portions. 27 Mostly sunny conditions today with a few clouds mainly over the higher elevations. An upper ridge offshore builds into Western Washington on Wednesday, resulting in warmer temperatures and continued dry conditions. Highs on Wednesday are expected to range in the 70s to low 80s. The ridge begins to flatten Wednesday night as troughing develops on Thursday. Widespread clouds Thursday AM will result in cooler conditions. Increasing onshore flow may also result in the development of weak convergence by late Thursday over central Puget Sound and into the Cascades. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Troughing further develops over the Pacific Northwest on Friday with a continued cooling trend late in the week. Ensembles are in general agreement that an upper low moves southwards offshore Friday before moving inland over WA/OR during the weekend. Rain potential increases as the upper low moves inland, particularly Saturday into Saturday night. There is also a 10 to 15 percent probability for thunderstorms Saturday afternoon. Some uncertainty in the ensembles as to how quickly the troughing moves eastwards Sunday into Monday. However, lingering precipitation is likely at least over the Cascades on Sunday before a slow warming trend begins early next week with ridging offshore. JD && .AVIATION... VFR conditions will continue across western Washington through tonight with mostly clear skies. Models are hinting at some marine stratus development early Wednesday morning, but the most likely area remain the coast, with less than a 20-25% chance elsewhere. Some patchy valley fog may develop for the more sheltered terminals as well (OLM, PAE). Low clouds and fog will dissipate quickly again tomorrow morning, through high clouds will begin to build in from the north. Winds remain northerly 10 kt or less through the period. KSEA...VFR conditions prevail through the TAF period. Northerly winds between 3-6 kts overnight, increasing slightly tomorrow afternoon at around 4 to 8 kt. 62/21 && .MARINE... High pressure will continue to build over the coastal waters through early Thursday. Northwesterly winds will prevail over the coastal waters, but will increase moreso Wednesday night as a weak frontal system from the north tightens the pressure gradients. Northwest winds over the far outer coastal waters could reach up to around 20 kt (30-50% chc), with better chances of seeing Small Craft Advisory winds being through portions of the Strait of Juan de Fuca (60-90% chc). Winds look to slowly ease Thursday night. Another weather system may move over the waters late Friday into Saturday, but no headline winds are anticipated at this time. Seas around 3 to 5 feet will gradually build through Wednesday, reaching 7 to 10 feet by Thursday afternoon. This will also bring steep seas as short period waves from the stronger winds over the coastal waters begin to dominate. Seas will ease to around 5 to 6 feet by Friday, then further easing into the weekend. 62/21 && .FIRE WEATHER... Dry, warm weather continues through Wednesday. Given the recent cool conditions, this will generally return fire weather conditions back to seasonal levels of concern, with localized elevated conditions Wednesday. Light offshore flow Tuesday night into Wednesday will yield moderate RH recoveries along the ridges of the Cascades and Olympics. Daytime RH values will approach the low to mid 20 percent range Wednesday over the Cascades and nearby valleys. However, this period of warmer, dry conditions will remain short-lived as onshore flow returns later Thursday for increasing RH values. Cooler conditions, along with precipitation chances, then continues over the weekend. JD && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$

943 FXUS66 KPQR 090541 AFDPQR Area Forecast Discussion National Weather Service Portland OR 1041 PM PDT Tue Sep 8 2026 Updated aviation discussion. && .SYNOPSIS...Drier and warmer conditions persist through Thursday with temperatures gradually warming and peaking Wednesday with the development of low-level offshore flow. Cooler temperatures return on Friday through the weekend, along with increasing chances for rain. Forecast uncertainty then increases by the start of next week. && .DISCUSSION...Now through Monday...Satellite imagery early this afternoon shows mostly clear skies across NW OR and SW WA. Ensemble guidance remains in good agreement that upper heights over the PacNW will raise into Wednesday as the upper low from previous days continues moving eastward into the Northern Plains and high pressure over the desert SW slowly spreads into the Western US. In addition to these two synoptic features over CONUS, a tropical/sub-tropical low off the coast of California along with an upper level high over the NE Pacific will create a col over the Pac NW. This col will help to maintain rather benign conditions through the middle of the week. At the surface, a thermal trough will push north from CA, bringing weak offshore flow (east winds over terrain and the coast and north winds for the interior lowlands). This overall setup will bring continued dry weather as well as a brief warming trend into Wednesday. Daytime temperatures are expected to rise into the upper 70s to around 80 degrees for the interior lowlands today and low to mid 80s on Wednesday. Coastal communities will also be warmer due to the offshore flow, in the upper 60s to low 70s today and low to mid 70s on Wednesday. There`s around a 5-10% chance that coastal cities off the immediate coast could reach 80 degrees on Wednesday if offshore flow continues into Wednesday afternoon/early evening. Ensemble members remain in good to excellent agreement on the weather pattern for Thursday into Saturday. On Thursday, a weak trough begins pushing south into the PacNW, lowering heights and pushing the surface thermal trough south. This will allow temperatures to lower back to near to slightly below normal for early September (upper 70s for the interior lowlands), though dry conditions will continue. On Friday, ensemble members indicate another, more robust low will develop over far western Canadian and drop south into the PacNW for the end of the week and the start of the weekend. Uncertainty still exists on the exact track, strength and timing of this low with 80% of members suggesting the trough will deepen along the coast while the other 20% suggest the trough will deepen a little more inland over eastern WA and eastern OR. As Sunday approaches, the majority of ensemble models, around 60-70%, indicate the trough will move east of the Cascades by Sunday morning where the other 30-40% suggest the trough will linger longer into the day on Sunday with around 10-15% keeping the trough over the PacNW into Monday. Even with the uncertainty, nearly all members indicate rain will return to the area sometime between Friday night and Sunday, though the exact track will determine how much rain and where it will fall. Friday night into Saturday has the highest confidence with the latest NBM deterministic forecast now indicating a 40-50% chance of rain late Friday into Saturday night across the entire forecast area. Part of the reason for the lower probabilities is likely more to do with the timing of when the trough will push through the area as opposed to whether it will actually rain or not. There`s a 70-80% chance that any location, within our CWA, will receive at least 0.01 inch of rain in the 48 hours ending at 5 AM Monday. When looking at probabilities of reaching or exceeding 0.25 inch in the same 48 hour period, there`s a 30-50% chance for locations west of the Cascades with a 45-65% chance over the Cascades, including the foothills. Temperatures will also fall fairly dramatically. Daytime temperatures will be anywhere from 6-10 degrees cooler on Friday than Thursday with another 2-6 degrees of cooling on Saturday. However, the forecast temperature spread increases Saturday into Sunday as the uncertainty in the weather pattern increases. The 10th to 90th percentile spread for the interior lowlands on Saturday is from the low 60s to mid 70s increasing to the mid 60s to low 80s on Sunday. If you have outdoor plans this weekend, keep an eye on the forecast and plan accordingly for the rain potential. Even with the 10-15% of ensemble members keeping the upper trough over the region on Monday, members indicate it would weaken and limit precipitation chances. The rest of the members indicate dry and warmer conditions for Monday, which is reflected in the deterministic NBM with precipitation chances less than 10% with temperatures in the 70s for the interior lowlands. -42/03 && .AVIATION...Through 06z Thursday...High pressure over the region will continue to support widespread VFR conditions across the airspace beneath largely clear skies. Light offshore flow tonight will limit chances for low cigs to around 20% along the coast, but if east winds are lighter than expected, lowered cigs will be more likely. Favored east-southeast winds along Youngs Bay at KAST may also result in restricted vis within fog/mist overnight despite the offshore orientation, however confidence in occurrence is low. North to northwest winds build to 5-10 kt inland and 8-12 kt with gusts to 20 kt along the coast by 18-20z Wed with high confidence in widespread VFR conditions. KPDX AND APPROACHES...VFR conditions expected through the period. Diurnal northwest winds at 3-5 kt overnight will build to 6-8 kt by 18-20z Wed. High cloud coverage increases late. -36 && .MARINE...High pressure offshore will maintain predominately northerly winds across the coastal waters through the week. A strengthening pressure gradient today will bring stronger northerlies with gusts up to 25 kt as there is an 80% chance of wind gusts exceeding 21 kt by this evening. As a result, Small Craft Advisories remain in effect until 6 AM Wednesday beyond 10 NM south of Cape Falcon. Breezy north winds continue through Thursday, but should remain 20 kt or less. Seas of around 4 to 5 ft with a dominant northwest swell at 10-11 seconds will gradually build to around 6 ft by this evening as wind chop increases with the northerly winds. A weak low pressure system is expected to approach the coastal waters from the north late Friday into Saturday. /DH && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 6 AM PDT Wednesday for PZZ272-273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

252 FXUS66 KMFR 090813 AFDMFR Area Forecast Discussion National Weather Service Medford OR 113 AM PDT Wed Sep 9 2026 .KEY MESSAGES... * Today will be the warmest day of the week, with daytime highs 5 to 15 degrees above normal expected. * A shortwave trough weakens the high pressure and temperatures trend a few degrees less warm on Thursday. Gusty winds and dry humidities will bring elevated fire weather concerns east of the Cascades Thursday afternoon. * On Saturday, a low pressure system will bring cool temperatures and chances for rain showers to area. Also expect low chances (15-25%) for thunderstorms from the coast to the Southern Oregon Cascades. Gusty winds are likely east of the Cascades. * Dry weather and mild temperatures are expected Sunday into early next week. && .DISCUSSION...An upper level ridge remains in place today and temperatures will peak with highs around 5 to 15 degrees above normal. The National Blend of Models and model guidance continues to indicate highs in the mid 80s to upper 80s for areas east of the Cascades and in the 90s for inland valleys west of the Cascades. Along the southern Curry coast, northeast winds will result in a Chetco warming effect in the Brookings area with highs in the 80s. Over upper slopes and ridges, moderate to locally poor are expected this morning and again tonight/Thursday morning. On Thursday, a shortwave trough moves into British Columbia, weakening the high pressure over the area. Temperatures will trend slightly less warm but sill remain well above normal across inland areas. Westerly to northwesterly winds will increase across the area Thursday afternoon, strongest for areas east of the Cascades. Gusty winds and low humidities will result in elevated fire weather conditions east of the Cascades Thursday afternoon. On Friday, models and ensembles continue to show a low pressure center will shift southward and approach the coast late Friday and Friday night. This low will then move inland over the area on Saturday. Temperatures will trend cooler on Friday with near normal highs across the area. Then, temperatures trend below normal on Saturday. Additionally, as the low moves overhead on Saturday, showers will develop across the area, with best chances from the Cascades west. The National Blend of Models supports a 50-70% chance of showers from the Cascades west and a 20-50% chance for showers east of the Cascades. Additionally, there is a chance (15-25%) for thunderstorms on Saturday, mainly from the coast inland to the Southern Oregon Cascades. This low quickly shifts east of the area on Sunday. So, expect dry weather with lingering cooler than normal temperatures. Model guidance then supports a broad upper level trough remaining over the region early next week with dry weather and near normal temperatures. && .AVIATION...09/06Z TAFs...VFR prevails area wide, and this should continue for the next 24 hours. Offshore flow should keep most areas VFR tonight into Wednesday morning, though localized MVFR/IFR in fog or low stratus are possible in sheltered valleys for a few hours around sunrise. Guidance is also showing about a 40% chance of fog/low ceilings at North Bend (KOTH). We`ve prevailed SKC in the TAF due to the persisting offshore NE winds. There could be some lower ceilings/fog in the Coquille Basin or at the beaches. && .MARINE...Updated 100 AM PDT Wednesday, September 9, 2026...Gusty north winds and steep wind seas can be expected area wide into early Wednesday morning. Winds briefly diminish Wednesday but steep seas will linger for most the waters. Then, gusty north winds increase on Thursday, with a a potential for steep to very steep seas south of Cape Blanco and steep seas from Cape Blanco northward. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Friday for PZZ356-370. Small Craft Advisory until 5 AM PDT Wednesday for PZZ350. Small Craft Advisory from 5 PM Wednesday to 5 AM PDT Friday for PZZ350-376. Hazardous Seas Warning until 5 AM PDT Wednesday for PZZ376. Hazardous Seas Watch from Thursday afternoon through late Thursday night for PZZ376. && $$

247 FXUS66 KEKA 081901 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1201 PM PDT Tue Sep 8 2026 .KEY MESSAGES... * Above normal temperatures likely through Thursday, including along the coast. * Locally elevated fire danger for the higher elevations today and Wednesday. && .SYNOPSIS...Much warmer temperatures are likely today through Thursday, with warm temperatures even at the coast. Breezy offshore wind will bring locally elevated fire danger today and Wednesday. Cooler temperatures return late this week into the weekend. && .DISCUSSION...Building high pressure today through Thursday will bring much warmer than normal temperatures, both to the interior and the coast. Today, temperatures are forecast to be in the high 80s to the mid 90s for most interior valleys, while the immediate coast could break 70. Wednesday and Thursday, the ridge strengthens, bringing near or slightly above triple digit temperatures to most of the interior valleys. This includes valleys close to the coast which may not have experienced temperatures this high so far this year, including Garberville and the Eel River valley. Interior valleys are likely to see overnight lows also trend upwards into the 50s or low 60s. Temperatures this low is providing enough cooling at night to lower the HeatRisk which has also kept conditions below advisory criteria. Still, interior areas will see widespread Moderate HeatRisk which corresponds to a moderate risk for heat-releated illness to those without proper cooling. Drink plenty of water and stay safe out there! Coastal areas also continue to warm as offshore flow continues to inhibit coastal stratus formation with 70s possible at the immediate coast and 80s possible just a few miles inland on Wednesday. Offshore flow weakens Wednesday night into Thursday, which may support more coastal stratus to form or move onshore. Currently, stratus is likely to clear again by the afternoon and relatively light sea breezes will still support a pleasant day in the mid to high 60s. Subtropical moisture from the remnants of Hurricane Marie arriving Wednesday will complicate the forecast somewhat. Instability continues to be modeled near zero with a less than 5% chance for MUCAPE over 100 J/kg. Still, cloud cover could bring slightly lower high temperatures than currently expected Wednesday, along with a few virga showers. Troughing rebuilds late this week into the weekend, returning near normal temperatures and coastal stratus by Friday. By this weekend, much of the interior is forecast to be in the 70s and 80s with the coast in the low 60s. A weak front may bring light rain to Del Norte and northern Humboldt Counties on Saturday, but confidence remains low. There is around a 50% chance for any measurable rain for Del Norte and 20% for northern Humboldt. Chances for a tenth of an inch are around 20% in Del Norte County. /JB && .AVIATION...(18Z TAFs)...Offshore flow largely kept coastal stratus from forming early this morning and VFR conditions are being observed at all terminals. Offshore flow continues tonight and is likely to prevent widespread stratus formation again, but some patchy ground fog around sunrise may bring periodic and brief LIFR impacts. Any low clouds will lift and scatter shortly after sunrise. /JB && .MARINE...Northerly winds have eased and wind-driven seas have started to subside. Breezy northerly winds return Thursday and are likely to continue south of Cape Mendocino through the weekend. Along with wind driven seas, a long period south swell from Hurricane Marie at around 3 to 5 ft will persist through the week. JB/JJW && .FIRE WEATHER...Much warmer and drier conditions are expected as high pressure rebuilds this week. High temperatures in the interior valleys will climb in the high 90s to just over 100 through Thursday. Afternoon relative humidities will fall into the teens or single digits in the eastern portions of the area. Offshore flow developing overnight will result in poor overnight recoveries for the higher elevations and winds may be locally breezy. Elevated to locally critical fire weather conditions are possible in the highest elevations of Del Norte, Trinity, and Humboldt Counties tonight into Wednesday morning with these breezy winds. Troughing late this week into the weekend will return cooler temperatures and a deeper marine layer. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 6 AM PDT Wednesday for PZZ470. Small Craft Advisory until 6 PM PDT this evening for PZZ475. && $$ 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

411 FXUS66 KMTR 090739 CCA AFDMTR Area Forecast Discussion...Corrected National Weather Service San Francisco CA 1207 AM PDT Wed Sep 9 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 218 PM PDT Tue Sep 8 2026 - Warming and drying trend will bring widespread moderate to major HeatRisk through Thursday - Cooler temperatures, closer to normal, Friday into the weekend && .SHORT TERM... Issued at 1207 AM PDT Wed Sep 9 2026 (Today through Thursday) A northward intrusion of mainly mid and high level tropical moisture from the remnants of Marie continues to move in across the forecast area. The Tuesday evening 5 pm (00z) Vandenberg upper air sounding showed a cloud layer as low as 16,000 feet. Cirrus at ~ 30,000 feet with the subtropical jet stream was evident on the Oakland upper air sounding. Under the mid and high level clouds, it`s currently much drier to the ground with a sliver of coastal dew point temps in the 50s to around 60F to Santa Cruz, otherwise it is drier away from the coastline. Warm temperatures will continue tonight with the incoming cloud layers greatly reducing radiative cooling. Sub-cloud layer dry air does at times tend to stay land-locked over the highly varied terrain of CA, until diurnal mixing, diffusion, wind transport and/or precipitation get going to thoroughly mix in the higher humidity to ground level. KVBX Vandenberg radar does show high based light showers recently. GOES West lightning mapper shows spotty lightning activity to the southwest as well and this lightning is close to the leading edge of a mid-upper level moisture gradient. There`s a history of rain and lightning activity from earlier today well to our south, a signature of favorable thermodynamics and jet stream dynamics west of strong 500 mb ridging even at 590+ heights. This bears close monitoring in the nearest term. No changes to the forecast at this time. A Heat Advisory remains in effect for the entire forecast area until 10 PM Thursday. Strong high pressure will result in warm morning low temperatures and daytime highs in the 90s to lower 100s over much of the forecast area. Along the immediate coastline an afternoon sea breeze may help nudge temperatures back down. This is a complex pattern, please stay tuned to the latest updates. From the earlier forecast discussion: Please remember these tips to help mitigate impacts from heat exposure: -Suspend unnecessary outdoor activities during the extreme heat, but if you must be outdoors, take frequent breaks in the shade or AC and drink cool water. -Know the signs and symptoms of Heat Exhaustion vs. Heat Stroke! Heat Stroke can be deadly if not treated immediately by a medical professional. Call 911 if you suspect someone is suffering from Heat Stroke. -Wear a life jacket, swim near a lifeguard, and check conditions before entering the water if going to a river or ocean to cool off. Rivers and the ocean are extremely cold, and Cold Water Shock can turn into paralysis and drowning if you are not careful. -Use a cool and damp towel on your body if you do not have AC and are feeling hot. Or, take a cool shower or bath. -Do not leave kids or pets in a parked car. -Ensure pets and livestock have access to shade and water. && .LONG TERM... Issued at 1207 AM PDT Wed Sep 9 2026 (Friday through next Tuesday) The main concern is the short term. A late week and weekend cooling trend remains in the forecast. The strong ridge over our forecast area will weaken. Dry weather is forecast. && .AVIATION... (06Z TAFS) Issued at 945 PM PDT Tue Sep 8 2026 Widespread mid-upper clouds will overspread the airspace tonight. Still expecting VFR all terminals. Some HZ/BR may occasionally drop vis 5 to 6 at HAF. Onshore flow will bring gusts Wednesday afternoon/evening. Vicinity of SFO...VFR. Gusts up to 20 kt Wednesday afternoon. SFO Bridge Approach...Similar to SFO minus the gusts. Monterey Bay Terminals...VFR. Still a 20 percent chc for some CIGs SNS by AM, but not high enough to included TAFs yet. && .MARINE... (Tonight through next Monday) Issued at 945 PM PDT Tue Sep 8 2026 High pressure off the Pacific Northwest and low pressure over California maintain gentle to moderate northwesterly breezes through Wednesday. Northerly pressure gradients increase leading to fresh to strong breezes Thursday afternoon into the weekend. Slight to moderate seas will prevail, building to become rough in the outer waters Friday into Saturday. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Heat Advisory until 10 PM PDT Thursday for CAZ006-502>506- 508>510-512>518-528>530. Coastal Flood Advisory until 1 AM PDT Thursday for CAZ006-506- 508-529-530. PZ...None. && $$ SHORT TERM...Canepa LONG TERM....Canepa AVIATION...MM MARINE...MM 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

369 FXUS66 KOTX 090754 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 1254 AM PDT Wed Sep 9 2026 .KEY MESSAGES... - A warming and drying trend expected today (Tuesday) through Thursday. - A warming and drying trend expected Wednesday through Thursday. - Gusty winds Thursday afternoon which may result in patchy blowing dust over the Columbia Basin and elevated fire weather in dry grasses. - Cool and showery conditions return Friday through the weekend. && .SYNOPSIS... A warming and drying trend continues today (Wednesday) as higher pressure returns to the region. Winds pick up out of the west Thursday afternoon ahead of the next weather system, then showers and cooler temperatures return Friday through the weekend. && .DISCUSSION... Wednesday: A ridge off the Canadian coast will continue to promote a drying and warming trend for the Inland Northwest through the rest of the day. The early morning contains a chance of fog through the northern valleys in eastern Washington and in the Northern Idaho Panhandle. Visibilities could drop to a half mile or less, impacting the morning commute for people those areas. The ridge will be at its strongest today, with the increase in heights bringing a 6-8 degree increase in high temperatures across the area. Winds from the south will increase over the Columbia Basin, Waterville Plateau, and Okanogan Valley, resulting in a breezy evening for these areas with wind gusts 15-20 mph. Thursday through Friday morning: A low pressure system strengthening over Western Canada and then moving into Central Canada will usher a trough across the region Thursday afternoon and evening. This will bring strong winds, localized blowing dust potential and fire weather concerns, and mountain rain to the region. Of most impact will be winds increasing ahead of the trough moving through the area Thursday morning through evening. For much of the Waterville Plateau, Wenatchee, Columbia Basin, Moses Lake, Spokane/CdA, and Palouse areas, there is a 60-70 percent chance of maximum wind gusts greater than 30 mph. In the Waterville Plateau and Columbia Basin, wind gusts up to 40 mph are possible. This will result in blowing objects and trouble driving, especially for high profile vehicles. Another impactful result of these winds could be localized blowing dust and fire weather concerns throughout areas that have not seen much recent rain and thus have drier soils. For blowing dust, greatest chances will be seen throughout the Waterville Plateau and Lewiston/Pullman areas. Blowing dust can bring visibilities down to a mile or lower, impacting drivers. Hot Dry Windy Index values increase throughout the broader Basin area on Thursday due to the gusty winds moving through, bringing a chance for elevated fire weather concerns. Impacts include rapid fire spread, especially for any existing fires. Localized rain chances will be seen in the Idaho Panhandle Thursday night into Friday morning. There is only a 10 percent chance for accumulations to reach 0.1 inches. However, the moisture over the area will result in a returning chance for fog in sheltered northern valleys on Friday morning. Friday evening through Sunday: Lower heights will remain over the area on Friday as another low spins off the coast of British Columbia. Temperatures will decrease nearly ten degrees between Thursday and Friday. On Friday night, as the low nudges closer to the state of Washington, there is a 10 to 20 percent chance of precipitation in Western Okanogan Valley. As the center of the low tracks just south of Washington through Oregon Saturday into Sunday, chances of precipitation widely increase regionwide. Nearly all of the Inland Northwest has a 20 percent chance and above at seeing 0.10 inches of rain from Saturday night into Sunday afternoon. Ahead of the main low passage on Saturday morning, winds will again increase throughout much of the area as a north-south surface pressure gradient strengthens. Wind gusts through the Basin, Waterville Plateau, and Okanogan Valley could reach 35-40 mph Saturday morning and afternoon. As the low tracks eastward, winds begin to increase in the Idaho Panhandle on Saturday night and continue to be elevated with gusts 20-25 mph through Sunday morning. Ridgetops could see wind gusts up to 35 mph. Impacts with these wind gusts include blowing objects and trouble driving, especially for high profile vehicles. Saturday night into Sunday, chances for isolated thunderstorms increases as the low moves through. Areas from Spokane to Wenatchee and southward have a 10 to 20 percent chance of thunderstorms. Mid to long range models show CAPE values increasing to 200-300 J/kg, and steep 3-6km lapse rates. A heavy caveat to these thunderstorm chances is that they could change should the track of the low pressure change. Even now, many models show the highest chances for thunderstorms outside of our forecast area to the south and east, but it is worth a mention and something we`ll keep an eye on through the week since it could create localized impacts. Monday through Tuesday: By Monday, clusters are divided on where the low will be. About 60 percent of clusters have the low far enough eastward that higher heights will start moving over the area. This will favor a warming and drying trend. 40 percent of clusters have the low closer to the region, which would indicate continuing chances for cooler and showery conditions. /AS && .AVIATION... 06Z TAFS: Expect VFR conditions through the next forecast period, alongside winds light and less than 10kts. Around 07-09Z and lasting through 16Z, patchy and localized fog will develop in northern sheltered valleys in E WA and the ID Panhandle. Potential airports in these areas that could see ceilings and visibilities drop down to IFR and below are 63S, DEW, and SZT. At the main terminals, there is potential for fog at GEG and SFF from 08Z through 16Z. High- res models show some patchy fog along the I-90, but there is little confidence for either terminal to see conditions drop below VFR, so no degradations included in TAFs at this time. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions for all terminals but GEG and SFF. Low confidence in patchy fog at GEG and SFF from 08-16Z. This will be the most impactful alternate scenario and terminals will be closely monitored for any necessary 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 77 51 77 47 69 47 / 0 0 10 0 0 0 Coeur d`Alene 76 49 76 46 69 47 / 0 0 10 10 0 0 Pullman 77 47 76 44 68 43 / 0 0 0 10 0 0 Lewiston 83 53 84 54 75 52 / 0 0 0 20 0 0 Colville 78 44 78 40 72 41 / 0 10 0 10 0 0 Sandpoint 74 45 74 42 67 43 / 0 0 20 10 0 0 Kellogg 74 48 73 47 67 47 / 0 0 10 20 0 0 Moses Lake 82 52 81 47 73 48 / 0 0 0 0 0 0 Wenatchee 83 62 79 52 73 55 / 0 0 0 0 0 10 Omak 82 55 80 47 74 50 / 0 0 0 0 0 10 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$

394 FXUS66 KPDT 090531 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1031 PM PDT Tue Sep 8 2026 .KEY MESSAGES... - Below-normal temperatures today, then warming to near or above normal Wednesday and Thursday. - Low-medium (20-50%) chance of widespread advisory-level winds through the Cascade gaps Thursday, with locally higher (60-85%) chances for wind-prone portions of north-central Oregon and the Kittitas Valley. - Friday into Monday brings showers and potential convective precipitation. && .DISCUSSION... The upper-level low-pressure system that brought cool temperatures and widespread precipitation to the region over the holiday weekend is ejecting eastward over the ID/MT Rockies, with a dry northwesterly flow aloft in its wake. Meanwhile, water vapor imagery reveals an upper-level ridge of high pressure in the northeast Pacific extending into British Columbia. Farther south, the remnants of Marie are tracking northward towards another area of low pressure that is located off the central California coast. Satellite shows mostly clear skies across the forecast area early this afternoon, aside from a fair weather cumulus field that is developing over the Blue Mountains. Temperatures will be a few degrees below normal today, with predominantly light winds. Looking ahead, ensemble NWP guidance is in excellent agreement that the remnants of Marie will merge with the low off the California coast and retrograde through the week. Heights will rise over the forecast area as the ridge slides east tomorrow, resulting in near- normal or above-normal afternoon high temperatures. The ridge will be suppressed Thursday as a shortwave trough dives south across British Columbia, resulting in strengthening zonal flow aloft. Westerly winds will increase in strength on Thursday, and may result in wind headlines. The NBM indicates a low-medium (20-50%) chance of advisory-level wind gusts (45 mph or greater) through the Cascade gaps, with locally higher (60-85%) chances for wind-prone portions of north-central Oregon and the Kittitas Valley. Aside from the winds, anticipating another day of near-normal to above-normal high temperatures Thursday, and a slight chance (15- 25%) chance of showers across the Blue Mountains and their foothills Thursday afternoon into Thursday night. Leading into Friday shows the trough entering the Pacific NW region traveling east through the region up throughout the weekend, bringing showers and chance for convective precipitation for the Blue Mountain region. Conditions from Friday into Sunday show chance Showers, potential convection and near normal temperatures. While the model clusters, NAM, and GFS are in agreement of when the trough will arrive they are split on the NS position of the trough upon arrival, with the favored position being near the Washington Oregon Border (49.6% confidence). Chances for precipitation greater than a tenth of an inch range from 30% - 62% with a slight chances of thunder at 11%. Monday the clusters show drier and warmer conditions along with a weak ridge pattern (67% confidence) with low confidence in the trough lingering, potentially deepening, bringing more showers and lower temperatures to Western Oregon (33% confidence). && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Light and variable winds (under 10 knots) are forecast for the entirety of this TAF cycle. Clear sky and no visibility obstructions are expected. Occasional gusts above 15 knots in the afternoon around BND and RDM are possible (50% confidence). && .Preliminary Point Temps/PoPs... PDT 47 84 52 83 / 0 0 0 0 ALW 52 84 59 82 / 0 0 0 0 PSC 50 86 53 86 / 0 0 0 0 YKM 53 84 56 82 / 0 0 0 0 HRI 49 86 53 85 / 0 0 0 0 ELN 49 82 54 74 / 0 0 0 0 RDM 41 87 45 83 / 0 0 0 0 LGD 46 84 49 84 / 0 0 0 0 GCD 47 87 49 84 / 0 0 0 0 DLS 56 88 58 82 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...None. OR...None. && $$ DISCUSSION...86 AVIATION...71

242 FXUS65 KREV 081900 AFDREV Area Forecast Discussion National Weather Service Reno NV 1200 PM PDT Tue Sep 8 2026 .KEY MESSAGES... * Warmer and drier conditions expected through Thursday with typical afternoon breezes. * Isolated shower and thunderstorm chances, mainly confined to the Eastern Sierra and Mono County, on Wednesday and Thursday afternoons. * A significant cooling trend and breezy to windy conditions are forecast for Friday through the upcoming weekend. && .DISCUSSION... An elongated area of high pressure will build over the region mid-week, leading to a continued warming trend through Thursday. Today, temperatures across western Nevada valleys will reach the mid-80s to low 90s, with the Lake Tahoe area seeing upper 70s. By Wednesday and Thursday, valley locations are expected to climb into the upper 80s to mid-90s. Isolated shower and thunderstorm chances also return to the forecast Wednesday and Thursday afternoons. There`s less than a 10% chance for Wednesday, increasing to 20-30% for Thursday, mainly south of US-50. The synoptic pattern will undergo a significant change towards the end of the week and into the weekend. We`ll have a closed low moving into the Pacific Northwest by Saturday, progressing eastward. This trough will bring a notable cooling trend and increased winds to the region. Temperatures will begin to drop on Friday, with highs across western Nevada valleys falling into the low 80s to low 90s, and further cooling into the 70s by Saturday and Sunday. Overnight lows will also become noticeably cooler, especially in the Sierra, with some areas potentially seeing lows in the 30s by Sunday night. Gusty winds are expected Friday, continuing through Saturday, as that trough approaches. West/southwest gusts of 35-40 mph on Friday, and gusts 40-45 mph for western Nevada and the Sierra on Saturday. These winds will be accompanied by continued dry conditions, leading to elevated fire weather conditions. We`ll monitor those two days as they gets closer and see if any products are warranted. Then winds Sunday and Monday are expected to diminish as the trough moves eastward, leaving clear skies and cool, dry conditions. -Justin && .AVIATION... VFR conditions prevail today with afternoon wind gusts 10-15 kt between 21-03z this afternoon. Gusts today near KMMH may reach 15-20 kt. HRICH/Justin && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

618 FXUS66 KSTO 081947 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1247 PM PDT Tue Sep 8 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Drying and warming trend through Thursday, with areas of Moderate to Major HeatRisk Wednesday and Thursday. - Heat Advisory is in effect 10 am Wednesday - 10 pm Thursday for the Delta, Valley, and foothills. - Cooling temperatures late week into the weekend. - Breezy onshore winds Friday-Saturday followed by gustier north winds Sunday-Monday. && .DISCUSSION... Today-Thursday: A fluctuating weather pattern is setting up across the region today with split flow aloft currently over interior NorCal. Desert Southwest ridging is beginning to creep eastward however; introducing rising heights aloft and the anticipated warming trend through the middle of the week. High temperatures start to climb into the 90s throughout the Valley today, jumping up to the upper 90s to triple digits on both Wednesday and Thursday. With predominantly light to breezy offshore winds accompanying the pattern, overnight low temperatures are expected to remain relatively stagnant in the mid 60s to 70s as well. As result, a Heat Advisory remains in effect from 10 am Wednesday through 10 pm Thursday for the majority of the Delta, Valley, and foothills with widespread Moderate HeatRisk and areas of Major HeatRisk in the forecast through Thursday. Dry weather and periodically breezy north to east winds are also on track to accompany the warming trend over the next few days. Wind gusts generally look to remain around 15-20 mph through Wednesday, strongest overnight and into late Wednesday morning. Lighter north winds are then anticipated into Thursday morning with south to west onshore winds of a similar magnitude increasing by Thursday afternoon. Daytime humidity values in the teens, with some single digits possible, and poor overnight recovery alongside these breezy winds will yield elevated fire weather conditions across the region through Thursday. Friday Into Early Next Week... Ridging and high heights aloft will begin relaxing by late Thursday as a longwave trough starts to drop down from interior British Columbia. This is expected to lead to an abrupt cool down to more seasonable high temperatures by Friday with a trend toward slightly below normal temperatures through the weekend and into early next week. Breezy onshore winds look to return as well with this pattern shift introducing some improvements to daytime humidity and overnight recoveries. There continues to be increasing confidence within ensemble guidance for the aforementioned trough to dig south through the end of the weekend before ejecting eastward into early next week, although some uncertainty regarding the exact trajectory remains. Despite this, periods of breezier onshore winds are currently on track for Saturday before shifting to gusty north to east winds Saturday evening through Sunday. Currently, probabilities for northerly wind gusts greater than 30 mph sit around 20-40% on Sunday, highest along and west of the Interstate 5 corridor. While exact details remain uncertain, some potential for elevated fire weather concerns will be possible late weekend into early next week. && .AVIATION... VFR conditions prevail at TAF sites across the forecast period. Breezy north to east winds are expected at times, although remaining 12 kts or less, with strongest winds through the Valley and Delta in the late morning and afternoon hours, especially after 15z Wednesday. && .STO WATCHES/WARNINGS/ADVISORIES... Heat Advisory from 10 AM Wednesday to 10 PM PDT Thursday for Butte County Below 1000 ft-C. San Joaquin County including Stockton-C. Solano County including Fairfield-C. Stanislaus County including Modesto-C. Yolo/NE Solano including Woodland- Central Colusa County Incl. I-5-Central Glenn Co & Interstate 5- Central Motherlode 1000-3000 ft-E. Diablo Range Above 1000 ft- Eastern Colusa County-Eastern Glenn County-N. Motherlode 1000- 3000 ft-N. Sac Valley in Tehama County-NE San Joaquin Valley Below 1000 ft-SW Solano County including Vallejo-Sac Metro/W. El Dorado/Amador County-Sacramento County Delta-San Joaquin County Delta-Sierra (Tehama-Plumas) 1000-3000 ft-Southern Motherlode 1000-3000 ft-Sutter/Yuba counties below 1000 ft-Tracy Triangle Below 1000 ft-W. Stanislaus County Above 1000 ft & I-5-W. Yolo County including Capay/I-505-Yolo / Solano County Hills. && $$

916 FXUS65 KMSO 081856 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1256 PM MDT Tue Sep 8 2026 .DISCUSSION... KEY MESSAGES: - Rain in northwest Montana diminishes by this evening. - A brief drying and warming trend is expected Wednesday and Thursday. Fog or low clouds are possible each morning. - Chance for frost in high valleys of southwest Montana. - Unsettled with showers on Friday. Growing confidence for a wet and cool system with high elevation snow developing by this weekend Satellite imagery this afternoon shows a trough of low pressure moving east over the Continental Divide. This system brought copious rainfall to much of the Northern Rockies over the Labor Day weekend. Wraparound moisture from this low will continue to supply light rain over the Flathead Valley and the Glacier Park region this afternoon. Precipitation rates will diminish going into this evening. In the wake of the low, upper level flow will turn northwesterly by Wednesday. As it does, a tightening pressure gradient and upper level jet streak approaching the Northern Rockies will bring an increase in westerly winds for Wednesday and Thursday. Expect choppy conditions on area lakes including Flathead Lake both days. A broad trough will traverse the Canadian border on Thursday, pushing a cold front through the Northern Rockies, further enhancing westerly winds. Drier air accompanying increase winds will create elevated fire weather concerns for southwest Montana on Thursday. Daytime high temperatures for Wednesday and Thursday will bounce back to near seasonal norms. More unsettled weather is on the way for the weekend. Model ensembles are on board for low pressure to return. The broad trough along the border will bring some chances for precipitation on Friday, then a secondary, deeper trough arrives on Saturday through Sunday. While ensemble solutions like the change to unsettled weather, actual precipitation amounts are still up in the air. Regardless of precipitation amounts, this system does look cold enough for precipitation to fall in the form of snow in the high elevations (7,000 - 8,000 feet), especially along the Continental Divide including Glacier National Park. && .AVIATION...Rain and low stratus are affecting ceilings and, to a lesser extent, visibility at KGPI this afternoon. Expect light rain to continue through the afternoon and diminish this evening. Low stratus could remain an impact to aviation at KGPI tonight as the lower atmosphere holds onto quite a bit of moisture from recent rains. Low clouds will obscure terrain in northwest Montana this afternoon as well. Elsewhere, high clouds will increase this afternoon due to wraparound moisture from a departing trough of low pressure. Clouds decrease tonight. There will be chances for fog formation at KGPI, and possibly KMSO on Wednesday morning. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

242 FXUS65 KBOI 090813 AFDBOI Area Forecast Discussion National Weather Service Boise ID 213 AM MDT Wed Sep 9 2026 .KEY MESSAGES... - Dry and warmer through Thursday. - Cold front and gusty winds Thursday evening, followed by breezy and cooler weather Friday. - Much stronger cold front late Saturday with gusty winds, showers, and thunderstorms, then windy and much cooler Sunday. - Warming and drying next week. && .SHORT TERM /Through Friday Night/... Yesterday`s weak secondary upper low has moved away leaving our CWA dry and forecast to warm under WNW-ly flow aloft through most of Thursday. Thursday`s highs will be in the upper 70s through 80s, with a couple of spots (e.g., Grand View/ID and Rome/OR) near 90. Meanwhile, an upper trough will be digging southward through western Canada and into the nwrn US. The trough will push a dry surface cold front through our CWA Thursday night with gusty west winds and a couple hours of cloudiness. Friday looks sunny, breezy, and 5 to 10 degrees cooler, and Friday night looks mostly clear and seasonably cool. But the real weather will come Saturday through Sunday (below). && .LONG TERM /Saturday through Wednesday/... Latest models move a deep, compact upper low off the WA coast rapidly inland across OR Saturday, then right through our CWA Saturday night, and into MT Sunday. What makes this unusual is how fast the low moves for a closed system, and for that reason we are expecting a strong cold front to pass through our CWA Saturday evening, with showers, chance of thunderstorms, strong winds, and rapidly falling temperatures. No highlights will issued just yet as the event is still 4 days away, but confidence is growing with models already in good agreement. Showers, possibly heavy, will continue Sunday morning as moisture wraps around the northern and western flanks of the eastward-moving upper low. By late Sunday our western zones should clear, and Sunday night looks clear and cold CWA-wide, except for valley fog early Monday morning. Then sunny and warmer Monday before the next upper trough digs SSW-ward from BC and forms another low off the WA/OR. Tuesday and Wednesday should be dry and warming as models (especially GFS) keep that low off the coast. && .AVIATION /06Z Wednesday through Thursday/... Issued 1157 PM MDT TUE SEP 8 2026 VFR with mostly clear skies overnight. Patchy fog in sheltered mountain valleys overnight through Wednesday late morning. Surface winds: Variable less than 10 kt. Winds aloft at 10kft MSL: W-NW 10-20 kt. KBOI...VFR and mostly clear. Surface winds: SE under 8 kt until mid-morning, then light NW. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...LC LONG TERM....LC AVIATION.....TL

053 FXUS65 KLKN 090701 AAA AFDLKN Area Forecast Discussion...Updated National Weather Service Elko NV 1201 AM PDT Wed Sep 9 2026 .KEY MESSAGES... * Warming trend today and Thursday * Strong, gusty winds Saturday * Turning cooler this weekend * Dry conditions for at least the next several days && .DISCUSSION... (Today through Tuesday) WEATHER PATTERN OVERVIEW: Calm conditions are expected to continue through the next several days as temperatures warm into the upper 80s and low 90s by Thursday. Winds increase Friday ahead of an upper level low entering the Pacific Northwest, with gusts 20 to 30 mph. Winds are expected to be even stronger for Saturday, with gusts of 40 mph currently forecast. Temperatures will also drop starting Saturday as the low center passes through Oregon and Idaho. Sunday is expected to be the coldest day of the forecast, with highs in the 60s and low 70s and overnight lows approaching freezing, especially in Elko County. Temperatures are expected to rebound to seasonal levels to start next week as the low exits to the northeast. FORECAST CONFIDENCE & DEVIATIONS: High confidence in warming temperatures through Thursday. Moderate confidence in strong winds Friday and Saturday. No changes made to the NBM. && .AVIATION... VFR conditions and winds under 10KT expected through the next 24 hours. && .FIRE WEATHER... No fire weather concerns over the next few days. Monitoring strong wind potential for Saturday. No storms are expected. && .LKN Watches/Warnings/Advisories... None. && $$ 94