430 FXUS66 KSEW 031010 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 310 AM PDT Thu Sep 3 2026 .SYNOPSIS... Upper level low off the coast today will remain in the vicinity through Sunday. The low will move east Monday. Weak upper level trough over the area Tuesday and Wednesday. && .SHORT TERM /TODAY THROUGH SATURDAY/... Upper level low weatherpersons woe. Satellite imagery shows upper level low offshore about 200 miles northwest of Hoquiam. Showers spinning around the low covering most of the area west of Puget Sound. Temperatures at 3 am/10z were in the 50s. Upper level low offshore today drifting south moving into Western Oregon Friday morning. Showers rotating around the low moving through the area at times through this evening. Air mass somewhat unstable with increasing instability in the afternoon. Lapse rates at 00z Friday near 7C/km, lifted indexes between 0 and -3 and convective temperatures in the mid 60s. Chance of thunderstorms along the coast this morning with a chance of thunderstorms over the entire area this afternoon. Thunderstorm and shower chances decreasing quickly this evening as the air mass stabilizes and the low moves south. Highs today in the 60s. Lows tonight in the mid 40s to lower 50s. Upper level low over Oregon Friday wobbles back to the north over Western Washington Saturday. Shower chances increasing again Friday night into Saturday especially for the Cascades and Southwest Washington. Highs Friday in the 60s and Saturday in the 60s and lower 70s. Lows in the mid 40s to lower 50s. Felton && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... What is left of the low hanging out west of the Cascades Saturday night and Sunday keeping a chance of showers in the forecast mainly over the Cascades. Low kicking out to the east Monday with a weak upper level trough developing over the area Tuesday and Wednesday. Little in the way of moisture with the trough. Low level flow light bringing up the possibility of some morning fog both days. Highs in the mid 60s to mid 70s. Lows in the upper 40s and 50s. Felton && .AVIATION... South to southwest flow aloft for at least the first half of the day today before shifting more southeasterly to southerly as an an upper low digs southwards along the Washington coast. Although some terminals have seen their winds go light and variable, majority are reporting south to southeasterly with speeds running 5-10 kts. HQM is the exception where speeds linger in the 10-15 kt range. Widespread VFR conditions this morning although isolated spots of MVFR can be found along the coast and over the islands. With showers over the western half of the CWA and slowly moving eastward, locations under heavier precip could see cigs dip into MVFR briefly, however cells of this nature are scattered. This limits the degree of confidence for TAF inclusion at this time. Lingering moisture from both precip from yesterday and approaching showers may allow for a brief drop in cigs early this morning into high-end MVFR as well. Locations more prone to lower cigs /HQM, OLM, PWT/ could see cigs fall even lower into brief periods of IFR. By late morning/early afternoon, widespread VFR conditions are expected to return thanks to increasing instability. That said, there is a risk for isolated thunderstorms this afternoon and early evening, however latest model guidance might be overestimating potential. Will not rule out development, but would assign only a 10-20 pct chance of occurring...most locations leaning toward the lower end of that range while locations in the SW interior /HQM, OLM/ leaning toward the upper end. Cigs area-wide likely to lift to mid-cloud levels tonight. KSEA...VFR conditions are expected to continue for much of the TAF period, with the exception mentioned above as high-end MVFR conditions may briefly emerge around 15Z and linger into the late morning. As per current radar, showers are east of the terminal, but likely to start entering the area around 13-14Z. After the first wave passes through, scattered showers will linger in the forecast. Given their scattered nature, confidence is shaky regarding any direct impacts to terminal, and VCSH seems like the best bet for now. Above thunderstorm discussion applies, with SEA falling into the lower end of expectations. South to southeasterly winds 5-10 kts turning more southwesterly this afternoon. Speeds generally will remain consistent. 18 && .MARINE... A Small Craft Advisory continues this morning for the eastern Strait of Juan de Fuca, Admiralty Inlet, and northern inland waters as breezy southerly winds persist in these areas. An additional Small Craft Advisory for the coastal waters will also remain in place throughout the morning hours, this one for a mix of breezy winds and heightened seas. Winds and seas will continue to ease together slowly through the day and into Friday as broad low pressure lingers over the region. Northerly winds develop Saturday and continue into early next week. Showers remain in the forecast today with a 10 to 15% chance of thunderstorms for all waters Thursday afternoon. Seas 8 to 10 feet early this morning, steadily falling below SCA criteria by mid to late morning. Seas further ease to 4 to 6 feet by tonight and remain there through the weekend. 18 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 11 AM PDT this morning for Admiralty Inlet-Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm- Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm-East Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland Waters Including The San Juan Islands. && $$

513 FXUS66 KPQR 031059 AFDPQR Area Forecast Discussion National Weather Service Portland OR 359 AM PDT Thu Sep 3 2026 .SYNOPSIS...Another frontal system will bring widespread rain, breezy winds from the south, and a 20-30% chance for thunderstorms today. Any passing thunderstorms may produce lightning, heavy rain, gusty erratic winds, small hail, and/or a funnel cloud. Chances for lingering showers continue through the weekend with cooler than average temperatures. Drier conditions early next week. && .SHORT TERM...Today through Friday night...Observations over the past 24 hours show rainfall totals across the forecast areas around 0.30 to 0.75 inches, with higher elevations picking up 0.75 to 1.25 inches. Current radar observations this morning shows more showers streaming into the area. So, it looks like our region is in store for another round of widespread showers today, with similar 24 hour rainfall totals expected. The upper-level low which brought the rain yesterday will move overhead of the Pacific Northwest. This will lead to cooler temperatures aloft and a general increase in overall atmospheric instability. Model guidance is showing CAPE values anywhere between 100-500 J/kg across the region. This instability, along with good lift and moisture from the overall upper-level low, will support a 20-30% chance for thunderstorms starting late this morning through at least tonight. Model soundings are showing minimal shear across the region. This means that long lived cells are not likely, which means that "storm mode" for today will likely take the form of "pop-corn" showers and thunderstorms. If a thunderstorm does pass over an area, it may produce lightning, heavy downpours, gusty and erratic winds, small hail, and/or a funnel cloud. Given that even cooler air aloft is expected today, an isolated cold-core funnel cloud can`t be ruled out (5-10% chance). By Friday, the upper-level low continues to sit overhead, maintaining chances for lingering showers and another 15-20% chance for afternoon thunderstorms. These systems will continue to bring the first substantial rainfall of the season. Models are still calling for 48 hour totals (Wed morning-Fri morning) exceeding at least 1 inch of rainfall. While this wet weather won`t be a "fire season ender," it will definitely slow down fire season. /42-10 .LONG TERM...Saturday through Wednesday...Over the weekend, the majority of ensemble members continue to show broad upper-level troughing over the Pacific Northwest. However, there is uncertainty with whether or not we remain dry or continue with lingering showers. While 75% of ensemble members suggest showers continuing over the region Saturday-Sunday, the other 25% keep us dry. What we can say with higher confidence is that this upper-level low will maintain below-average 500 mb heights and keep high temperatures slightly cooler than average for this time of year. Early next week, the majority of ensemble members show the upper low weakening and beginning to move eastward. This would favor drier conditions, but there remains uncertainty with how much high pressure will re-build over our area, and how warm/dry we get. /42-10 && .AVIATION...Through 12Z Friday...Current radar imagery as of 11Z Thursday show showers slowly moving eastward. These showers are currently bringing MVFR to IFR conditions to the coast. As a result, expect these conditions to persist along the coast through the majority of the TAF period. As for inland locations, rain showers will gradually fill in through 14Z Thursday, along with a mixture of VFR and MVFR conditions. Across the airspace there is a 15-40% chance of MVFR conditions at any given hour during the TAF period. Also, any stronger showers could temporarily reduce flight conditions to IFR or lower through 16Z Thursday. Lastly, there is a 20-35% chance for thunderstorms across the airspace starting around 17Z Thursday through around 03Z Friday. Any thunderstorms that develop will have the potential to produce lightning, small hail, and gusty/erratic winds. Southerly winds will continue through the TAF period with gusts of 20-30 kt through 00Z Friday, with the highest gusts along the coast. Winds will weaken beyond 00Z Friday, but still remain mostly southerly. KPDX AND APPROACHES...Generally VFR conditions with intermittent MVFR conditions as showers re-develop. This is resulting in a 25-40% chance of MVFR conditions at any given hour during the TAF period. There is a 20-35% chance for thunderstorms starting around 18Z Thursday through around 00Z Friday. Southerly winds will continue with gusts of 20 kt through 00Z Friday. Winds will weaken beyond 00Z Friday, but still remain mostly southerly. /42 && .MARINE...Current observations show seas around 9-11 ft at 8-10 seconds with southerly gusts up to 30 kt. These conditions are expected to continue through tonight as a fresh west/northwest swell overnight into Thursday maintains conditions. Due to the continued sea state and breezy winds, a Small Craft Advisory is in effect through at least tonight. There`ll also be 15-30% chance for thunderstorms through Thursday with the best relative chances Thursday afternoon. Any of these storms will be capable of producing gusty/erratic winds, small hail, and lightning. While relatively active weather with lingering rain showers will continue into the weekend, marine conditions will subside by Friday with seas holding in the 4-6 ft range by Friday afternoon. Similar conditions persist into early next week while winds occasionally gust to 15-20 knots. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 11 PM PDT this evening for PZZ210- 251>253-271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

822 FXUS66 KMFR 031106 AFDMFR Area Forecast Discussion National Weather Service Medford OR 406 AM PDT Thu Sep 3 2026 .KEY MESSAGES... * Temperatures remain 15 to 25 degrees below normal for today. * Showers and thunderstorms will continue today with a moderate to heavy rain developing east of the Cascades. * Shower chances will persist through Monday as an upper level low remains overhead. * Normal September weather returns Tuesday and Wednesday of next week. && .DISCUSSION... The upper level wave is still situated offshore as of this morning as the cold front has progressed eastwards. In addition, we`re watching some thunderstorms off the Oregon coast this morning in the SE quadrant of the upper level low. The SPC HREF is pretty confident these thunderstorms will continue through the morning hours and perhaps move onshore around Douglas and Coos Counties later this evening. The SPC HREF probability of cloud to ground lightning is about 10 to 20 percent while the NBM is going with 20 to 30. There is also a relatively low 10 percent chance over all other locations this afternoon as the sun should get some heating in above this cooler airmass. This will create some potential instability over the region this late afternoon and early evening. The bulk of the rain will fall east of the Cascades through the day and this is an unusually large amount of rain in the ensemble forecast for this time of year. This is showing up in the extreme forecast index(EFI) product again with EFI values around 0.8 to 0.9 and some 0.95 over the Warners with a shift of tails of 2 over south central Oregon. This could be due some embedded convective elements in some ensemble members. There are no 2026 burnscars over the Warner Mountains, or we would go with a flash flood watch. However, this should be beneficial rain for locations east of the Cascades. It will remain cool on the eastside with temperatures changing very little through the day due to extensive cloud cover and rain. Medford and some of our west side valleys should warm a bit with breaks in the clouds between the showers. However, we`ll still remain 15 to 25 degrees below normal for this time of year. Klamath Fall`s normal high is 82 and we`re forecast a high of 57 and Medford`s normal is 88 and we`re forecasting 67 this afternoon. It`s pretty much rinse and repeat from Friday into Monday as the low wobbles around the Pacific Northwest keeping shower chances going with some low thunderstorm probabilities. However, QPF values will be lower compared to what was observed Wednesday and what is still left to observe through today, Thursday. The one thing does change are temperatures gradually warming up into the weekend as more sun must be reaching the ground in between the showers. By Tuesday and Wednesday of next week, things will continue to warm up and return to climatological normals for mid September. The ensemble forecasts hint at another system arriving around Friday. It actually looks like its the remnants of hurricane Marie currently spinning off the coast of Mexico at the moment. About 50% of the members show low amounts of QPF hitting us while the other 50% and dry. So still a lot to get sorted over the next few days and it`s looking drier than what we went through on Wednesday. -Smith && .AVIATION... A cold front is graudally moving east of the Cascades tonight with showers filling in behind the front by Thursday. This will result in a mix of MVFR and VFR ceilings, along with local IFR, in showers overnight and Thursday. Rainfall may also result in reduced visibilities at times, especially tonight and Thursday morning. Conditions will trend towards mainly VFR late Thursday afternoon and evening, except for continued MVFR along the coast. A chance for thunderstorms (15-25%) is also expected on Thursday, mainly along the coast, into the Umpqua Basin as well as along the Cascades and eastward. Thunderstorm chances are highest in the late morning and afternoon. && .MARINE...Updated 300 AM PDT Thursday, September 3, 2026... South winds will remain gusty, strongest from Cape Blanco northward, and steep combined seas will continue across all the waters through Thursday night. Conditions improve further on Friday, with winds shifting to the north, then remain relatively calm through the weekend and into early next week. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory until 2 AM PDT Friday for PZZ350-356-370-376. && $$

250 FXUS66 KEKA 030742 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1242 AM PDT Thu Sep 3 2026 .KEY MESSAGES... * A general troughing pattern will bring additional light rain over the region today and periods of unsettled weather over the weekend. * Overnight temperatures for the interior will turn chilly, bringing chances for frost Friday morning and through the weekend. && .SYNOPSIS...Winds have sharply subsided into early this morning, while rainfall turns lighter as the storm system continues east. Light rainfall chances continue today as a weaker area of low pressure moves by. Overnight temperatures for the interior will turn chilly, bringing chances for frost Friday morning and through the weekend. A general troughing pattern will bring additional light rain over the region today and periods of unsettled weather over the weekend. && .DISCUSSION...Winds continue to sharply decline into early this morning. Rainfall has become light and showery for most of Northwest California, as well. A second colder and somewhat unstable area of low pressure will then move by today. This will continue the chances for showers and perhaps a couple of coastal thunderstorms. As the environment attempts to clear out through Friday morning, much cooler overnight lows will develop for the interior. If clouds do clear out and fog does not develop, areas of frost will be likely for the interior. There is still some question on the amount of clearing or even additional light showers, especially with the numerous troughs forecast through the weekend. These will also bring a shot for some isolated thunderstorms. The broad upper low to the north will stall ahead of blocked flow through the weekend, with weaker shortwave disturbances rotating in. More at least weak troughing may redevelop behind it. This gives mixed signals for the extended outlook. There will looks to be some sort warmup early to mid next week, but if it occurs, it should be short lived if the troughs continue moving through. && .AVIATION...(06Z TAFs)...Winds and rain continue to diminish early this morning. Patchy areas of fog may form through the early morning hours, as well. MVFR to IFR ceilings could persist for coastal terminals into mid morning, with periods of LIFR. Ceilings at UKI will likely lower near or below 1500 AGL through the morning with the light rainfall. && .MARINE...Strong southerly winds have diminished over the coastal waters. Wind driven seas up to 9 ft will subside below 5 ft early this morning. A trough from the north will then drive in a steep NW swell at 7 to 9 ft at 11 seconds today and tomorrow. If the swell comes in larger near 10 ft then advisory level conditions will be met. Mariners in small crafts should exercise caution on this day for this potential threat. Otherwise winds will be light for most of the waters through Saturday. Then, northerlies will strengthen some through the weekend, mainly over the southern water south of Cape Mendocino. The northerlies do not look to fully strengthen again until early next week. Hurricane Marie will deliver a long period southerly swell Saturday. Though small, at around 4 ft at 16 seconds, this is a larger than typical swell from this direction. && .BEACH HAZARDS...Hurricane Marie will usher in a long period southerly swell of 3-4 feet at 16 seconds for south facing beaches by Saturday. Thus, there could be a risk of sneaker waves, especially if the swell comes in slightly larger. Sneaker waves are a unique hazard, with up to 30 minutes between waves. Large, unexpected waves can sweep across the beach without warning, sweeping people into the sea from rocks, jetties, and beaches. These sneaker waves can also move large objects such as logs, crushing anyone caught underneath. Even ankle to knee deep water can knock you down and drag you out when a sneaker wave hits. Pay attention and stay above the high water line and any wet sand to stay safe. If the ground is wet, waves have surged there recently. Stay safe and never turn your back on the ocean! && .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

967 FXUS66 KMTR 031152 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 452 AM PDT Thu Sep 3 2026 ...New AVIATION, MARINE... .KEY MESSAGES... Updated at 1010 PM PDT Wed Sep 2 2026 - Beneficial rain Thursday, mainly in the North Bay - Hazardous beach conditions this weekend && .SHORT TERM... Issued at 1010 PM PDT Wed Sep 2 2026 (Tonight through Friday) The marine layer is gone. A cold front is currently located about 200 miles west of San Francisco and is supported in the upper levels by a 500 mb trough and a meridional jet stream. We saw some pre- frontal rain in the North Bay on Wednesday. Santa Rosa received 0.08" and Mt. Tam recorded 0.64". That was just the warm-up. The main event will occur Thursday morning as the front moves through. Models have been trending wetter, and we`re now expected around 1/4" in Santa Rosa through the morning and up to 1" in the mountains. That`s not enough to cause any major issues, but it is real rain, especially for this time of year. The normal rainfall for the entire moth of September is 0.15" at Santa Rosa. Expect slick roadways in the North Bay Thursday morning. As the front continues to march south, the associated rain should cross the Golden Gate by midday, but it will be losing upper level support and start to rapidly weaken. While a good portion of the Bay Area should see some rain, it likely won`t be more than a few hundredths outside of the coastal mountains. The Central Coast will be even drier, and will have to wait until Thursday evening to see if any rain will fall. In addition to rain, this front will bring NW winds with gusts up to 25 mph for most. Stronger gusts of 30-40mph are expected through favored gaps/passes, and in the Salinas Valley. We`ll obviously have more cloud cover Thursday as well, keeping the temperatures cool and comfortable. After the front passes, skies will clear from North to South through Thursday evening. As the skies clear, radiational cooling overnight will help the marine layer will start to reform. While there is still some uncertainty with the timing, marine layer stratus will likely return to the North Bay by Friday morning, but may take until Saturday or even Sunday to reach the Central Coast. && .LONG TERM... Issued at 1010 PM PDT Wed Sep 2 2026 (Friday night through next Wednesday) Speaking of this weekend, a Beach Hazards Statement is in effect from Friday through Monday as southerly swell from multiple distant hurricanes reaches the coast. Days when it`s nice outside but the ocean is energetic are typically the most deadly. On top of that it`s a holiday weekend. Please refer to the Beaches section below for more details. Behind the front the temperature outside of the newly forming marine layer will start to warm up through the weekend. At 500 mb the trough over the coast will become a pseudo cut-off low. While it detaches from the 500 mb flow, a healthy jet finger will continue to provide some upper level divergence through the weekend. Nevertheless the low pressure will gradually fill. Meanwhile high pressure over the Southwest will start to influence the weather, allowing temperatures to rebound back to normal by Monday. As Hurricane Marie now looks like it will take a more westerly track out to sea, the residual moisture impacts are much less likely to reach any further north than Southern California this weekend. Models are also showing a slug of dry air Sunday over the Central Coast that blocks the less dense tropical air mass from moving north. The deterministic ECMWF shows 1.8" of PW at Los Angeles Sunday afternoon, while Monterey has 0.5". That would give Southern California a decent amount of rain, but nothing for the Bay Area. It`s a similar story with instability. Not a single member of the ECMWF ensemble has MUCAPE over 50 J/kg north of Pt. Conception. There is always the chance that the tropical moisture rides over this dry air mass, opening the door for dry thunderstorms. There`s no direct support for that in the model guidance at the moment, but pattern recognition suggests it`s worth keeping an eye on. While this weekend now looks like it will probably be dry, there is a hint in the guidance that the remnants of Marie will eventually get caught up in the persistent SW flow if the cut-off low can survive long enough. If that happens, we may see some associated moisture by the middle of next week. && .AVIATION... (12Z TAFS) Issued at 438 AM PDT Thu Sep 3 2026 A weak cold front is on track to move through the Bay Area this morning. This cold front will bring scattered showers in the North Bay (higher confidence) and potentially into the rest of the Bay Area (lower confidence). Stratus coverage is patchy this morning with the incoming cold front keeping the marine layer mixed out. After cold frontal passage, the marine layer looks to return tonight (around 2000 ft) and will see MVFR CIGs along the coast. Confidence is slightly lower as to the timing of stratus return for interior sites with guidance indicating a later return between 09-12Z likely. Winds initially start more southwesterly this morning before shifting northwesterly again after cold frontal passage. Breezy to gusty winds are possible as the front moves through with winds to diminish after frontal passage. Vicinity of SFO...Shower chances increase by late this morning and continue through the early evening. The cold front is expected to pass through SFO this afternoon/early this evening with the highest potential for showers during this time. Breezy southwesterly winds become more northwesterly by this evening after cold frontal passage. Guidance is mixed as to if stratus will return to SFO tonight as the marine layer redevelops. For the 12Z TAFs opted to keep VFR conditions at SFO tonight (similar to the HRRR) but this may need to be updated. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Patchy MVFR-IFR CIGs have been developing over the Monterey Peninsula with ceilings coming in and out at both MRY and SNS. Moderate confidence that ceilings will continue to fluctuate at SNS through mid morning while confidence is low to moderate that a ceiling will, at least temporarily, return to MRY this morning. VFR conditions expected this afternoon with breezy SW to W winds expected. The cold front will largely have fallen apart by the time it reaches MRY/SNS but there is still a low potential for drizzle to impact both sites late this evening. && .MARINE... (Today through Tuesday) Issued at 438 AM PDT Thu Sep 3 2026 Rain chances increase over the northern waters this morning as a weak cold front moves through the region. Southwesterly winds gradually shift northwesterly by this afternoon after cold frontal passage. Winds generally stay gentle to moderate but diurnal fresh to strong gusts return within the Monterey Bay and along the Big Sur Coast Friday into the weekend. More widespread fresh to strong gusts return by early next week across the coastal waters. Long period southerly swell associated with tropical activity well to our south will reach the coastal waters Friday and continue into early next week. && .BEACHES... Issued at 1010 PM PDT Wed Sep 2 2026 A Beach Hazards Statement is in effect Friday-Monday as the swell from both Hurricane Marie and Hurricane Karina reaches the coast. As these hurricane whip up the ocean, the waves travel over 1,000 miles in all directions, gradually flattening out to low amplitude, but long period swell. These waves aren`t very intimidating if you`re on a boat in the open ocean, but the long period allows them to push much farther up the beach. Long period swell always increases the chance for sneaker waves, but that`s particularly true this weekend since there are 2 different sets of southerly swell, and their energy will periodically combine. In addition to sneaker waves, expect strong rip currents and breaking waves up to 10 ft. As this is a holiday weekend and the weather is otherwise pretty nice, the exposure to the risk is high. Avoid the water if you`re not an expert swimmer. If caught in a rip current, swim parallel to shore until you stop feeling the pull. Even on the beach, be prepared for sneaker waves this weekend and never turn your back on the ocean. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement from Friday morning through Monday evening for CAZ006-505-509-529-530. PZ...None. && $$ SHORT TERM...Flynn LONG TERM....Flynn AVIATION...Kennedy MARINE...Kennedy Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea

183 FXUS66 KOTX 031146 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 446 AM PDT Thu Sep 3 2026 .KEY MESSAGES... - Cool and showery weather expected through Labor Day Weekend with isolated thunderstorms. && .SYNOPSIS... Active weather sticks around the rest of the workweek with widely scattered showers and isolated thunderstorms, breezy winds and temperatures cooling back below normal. && .DISCUSSION... Today through Friday: The offshore low will spiral down the coast, ejecting shortwaves across the Inland NW before it too pivots inland tonight into Friday. One of those shortwave began its trek inland last night and will be moving tracking northeast this morning. Rain along and ahead of it will impact the northeast half of WA and the ID Panhandle early this morning, shifting to mainly the northern counties and Idaho Panhandle late this morning. Thereafter the precipitation start to turn more isolated to scattered in nature, becoming more convective focused around the mountains and up against the Cascades for this afternoon. Some embedded t-storms are possible this morning along the axis of that shortwave and then in more isolated fashion around the mountains this afternoon. Heading into this evening, tonight and Friday that low pivots in. The showers and t-storm threat near the Cascades wane through dark, but farther east shortwave moves up the northern Rockies. That will renew rain chances over southeast WA/lower ID this evening and across northeast WA to northern ID late this evening into the overnight, wrapping back toward the norther mountains through Friday morning. By Friday afternoon the linger upper low and boundary near the SE CWA will continue to mean some risk for showers and t-storm. Chances will be best around the mountains and others will be possible in SE WA and the lower ID Panhandle near that boundary and some of the better lapse rates and instability. Wind will remain a bit breezy today, especially over central WA with winds from the south to southwest at 10 to 15 mph and gusts up to 20 mph. However comparatively lighter winds are forecast for Friday. Highs will be in the 60s to lower 70s. Lows will in the upper 30s and 40s Thursday night and mid-30s to 40s Friday night/Saturday AM. We will have to watch for some patchy frost then. Saturday to Wednesday: The Inland NW remains dominated by the trough of low pressure and boundary stalled near the eastern CWA for some of this period. That boundary will give some embedded disturbances something to focus along. That will bring some moderate precipitation chances through the weekend and Monday, with the highest chances over the eastern third of WA and ID. Models are not entirely in good agreement on the evolution of the precise waves and precipitation potential, so the forecast will continue to be fine-tuned. Models trends toward the low losing influence Tuesday and Wednesday, Some embedded t-storms will remain a risk, but the potential is inconsistent as the focus has been changing day to day. Expect moderating temperatures into the weekend. /Solveig && .AVIATION... 12Z TAFS: MVFR conditions at KGEG-KSFF-KCOE will trend towards VFR in the next couple hours as a band of rain moves out of the area. Otherwise, VFR conditions will prevail. There is a small chance of thunderstorms at KLWS from 22z-00z before steadier showers move into the region in the evening. Winds will be breezy out the south/southwest for the Columbia Basin and Spokane area this afternoon. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in MVFR conditions improving to VFR. Low confidence in thunderstorms impacting KLWS this afternoon. ----------------------- 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 66 47 66 43 68 43 / 40 10 30 20 30 10 Coeur d`Alene 66 46 66 43 68 43 / 80 30 40 10 40 20 Pullman 62 44 63 36 66 37 / 70 50 30 20 30 10 Lewiston 67 52 68 49 72 49 / 90 80 40 30 30 10 Colville 67 41 67 35 68 35 / 60 0 30 10 40 10 Sandpoint 64 44 64 38 65 38 / 80 20 30 30 50 20 Kellogg 61 44 61 43 65 43 / 90 60 50 30 40 10 Moses Lake 70 46 69 43 71 44 / 0 10 20 20 10 0 Wenatchee 68 51 68 53 71 54 / 30 20 40 20 30 10 Omak 70 46 69 45 70 45 / 60 10 30 30 30 10 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$

448 FXUS66 KPDT 031121 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 421 AM PDT Thu Sep 3 2026 .KEY MESSAGES... - Periodic shower chances (35-85%) across the mountain zones will continue through the weekend, with lower chances in the lower elevations - Isolated thunderstorm chances (15-25%) will develop across Cascades, Blues, and Wallowa county Today and Friday - Below normal temperatures through early next week, with potential for freezing temperatures in mountain valleys tonight and Friday night && .DISCUSSION...Water vapor satellite imagery tonight shows a shortwave trough lifting northeast across the intermountain PacNW, while an upper low offshore is swinging southeast towards the coast. The shortwave trough passage this morning has resulted in light to moderate rainfall continuing across the eastern half of the forecast area. This activity will diminish in the lower elevations over the next couple of hours as the shortwave lifts into ID, with light showers continuing across the mountains. Today through this weekend, the PacNW will be under the influence of the upper level low currently offshore, with another couple rounds of rain showers in the lower elevations, with more persistent chances across the mountains (confidence 70-90%). Temperatures across the region will be nearly 10-15 degrees below average each day, with afternoon high temperatures at their lowest in the mid 60s and low 70s today and Friday (confidence 80-90%). By this afternoon, the upper closed low will park itself over the PacNW, with the center of the low remaining west of the Cascade crest through Saturday before sliding east Sunday into Monday(confidence 75-85%). During this time, persistent rain shower chances (30-60%) will remain over the Cascades and eastern mountains each day, with shortwave impulses Friday/Saturday and the low passage Sunday/Monday producing light rain chances (15-40%) in the lower elevations. Isolated thunderstorms will be possible over the mountains today and Friday as weak instability develops in these areas with additional support from the cold core of the low aloft. As for precipitation amounts, the Cascades and Blues will see 0.1 to 0.25 inches of daily precip (confidence 70-90%), with locally higher amounts where thunderstorms develop. Sunday into Monday, ensemble and deterministic members show the upper closed low beginning to push east, with the low over the forecast area during the day Sunday. While light to moderate rain showers are forecast across the area, the upper low being overhead and weak instability developing will also result in slight chances (15-25%) of isolated thunderstorms focused across central OR and the eastern mountains Sunday afternoon and evening. By Monday evening, what is left of the upper level low will have pushed east of the region, with showers diminishing area wide. Tuesday and Wednesday, ensemble members are in good agreement of weak split flow developing over the PacNW as weak zonal flow develops to the north and troughing to the south. This will result in mostly dry conditions, light winds, and near normal temperatures across the region (confidence 40-50%). Lawhorn/82 && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...VFR conditions to prevail through the period. Upper level low pressure system impacting the region will produce a chance (25-35%) of light rain showers at most sites between 22Z-06Z, except at sites YKM/PSC where chances are much lower through the period. CIGs may lower down to around 5kft with precipitation, with vsby remaining above 6 miles in precipitation. Winds will be light, 12kts or less, through the period. Lawhorn/82 && .Preliminary Point Temps/PoPs... PDT 68 42 68 43 / 10 40 30 10 ALW 69 46 68 47 / 20 40 30 20 PSC 73 43 73 43 / 0 10 20 10 YKM 70 45 71 47 / 10 10 20 10 HRI 71 43 71 43 / 0 20 10 20 ELN 66 40 66 41 / 30 20 40 20 RDM 64 31 63 32 / 20 40 50 60 LGD 66 41 66 39 / 80 80 60 40 GCD 63 39 65 39 / 80 70 40 30 DLS 70 47 72 48 / 30 30 20 30 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...None. OR...None. && $$ DISCUSSION...82 AVIATION...82

216 FXUS65 KREV 030804 AFDREV Area Forecast Discussion National Weather Service Reno NV 104 AM PDT Thu Sep 3 2026 .KEY MESSAGES... * Cooler and breezy conditions again today, with widespread gusts up to 30-40 mph and wind pones gusting 50-60 mph. * Rain chances today for NE CA and the Tahoe Basin, with the highest probabilities Thursday afternoon and evening. * Uncertainty remains high regarding the trajectory of TS Marie, but an increase in tropical moisture could bring shower and thunderstorm chances to the region Sunday into early next week. && .DISCUSSION... Current radar imagery shows light showers moving into Plumas county. Rain showers will creep into the rest of NE CA and the Sierra as day breaks. The greatest precip chances, however, will be this afternoon and evening, with 60-90% chances across the Tahoe Basin and NE CA. The Sierra Front will be mostly rain shadowed out, with chances between 10-25%. Precip totals will range from 0.01-0.25" through much of the area, with locally higher totals (greater than 0.5") in far western Lassen county and along the highest peaks of the Sierra in the Tahoe Basin. Another windy day is in store today, though the strongest wind will be confined to the areas not receiving precipitation today. Gusts along the wind prone areas of US-395 may reach over 50 mph. Before showers move into northern Washoe county, blowing dust will be likely on desert playas and sinks, including the Black Rock Desert. Rain amounts for the playa will be less than 0.05" but may produce locally muddy areas. Showers will linger in NE CA and the Tahoe Basin Friday morning. Otherwise, dry conditions will continue through Saturday areawide with winds decreasing to our typical zephyr gusts of 20-25 mph. Sunday, light shower and thunderstorm chances are possible in NE CA and northern Washoe county as a low pressure system currently cycling over the PacNW drops further south. Latest long range guidance shows drier conditions for the Labor Day holiday as Hurricane Marie is expected to propagate further out to sea. Depending how south that aforementioned low pressure sags early next week, we could see tropical moisture being drawn up, regardless. However, impacts from said tropical moisture wouldn`t be until Tuesday at the earliest; still plenty of time for things to change between now and then. Temperatures through the remainder of the week will be in the mid to upper 70s for valleys and mid to upper 60s for Sierra communities. Overnight lows for colder Sierra communities will continue to flirt with near freezing. A slight warming trend looks to renew early next week, with highs back up in the low 80s for valleys by Wednesday. -Giralte && .AVIATION... Rain showers will bring MVFR/IFR conditions for KTRK/KTVL today (by 19Z) with lower CIGS/VIS. Light showers may impact KRNO/KCXP/KMEV but confidence is low. Expect mountain obscurations for all Sierra and Sierra Front sites today, with the exception of KMMH. FL100 winds will range up to 50-60 kts again today, creating LLWS for all Sierra and Sierra Front sites. Otherwise, expect southwest winds gusting up to 35-40 kts. -Giralte && .REV Watches/Warnings/Advisories... NV...Lake Wind Advisory until 11 PM PDT Thursday NVZ002>004. CA...Lake Wind Advisory until 11 PM PDT Thursday CAZ071>073. && $$

931 FXUS66 KSTO 021954 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1254 PM PDT Wed Sep 2 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Well below normal temperatures persist through this week - Wet weather continues this week, thunderstorms and scattered showers, scattered showers for mainly Shasta County today, becoming widespread north of I-80 Thursday - Showers continue on Friday over the Sierra and southern Cascades and adjacent foothills - Mainly dry Saturday, with some mountain showers Sunday, mainly north of I-80 - There is the potential for some remnant tropical system moisture next week, but confidence in details remains low at this point && .DISCUSSION... Today... Showers last night brought moderate to locally heavy rain in Shasta County as a shortwave trough moved through, with rainfall amounts ranging from around a quarter of an inch to locally nearly an inch over the mountains in the northern portion of the county. Another wave is spreading some showers into Shasta County this afternoon, and these will become more widespread overnight, north of I-80. Elsewhere today there has been dry weather with low and mid level clouds and cool temperatures. Forecast high temperatures for today 10 to 30 degrees below normal, ranging from the low 70s in the northern Sacramento Valley to the low 80s in the northern San Joaquin Valley. Some breezy onshore winds continue today into tonight, south to southwest winds, with gusts to around 20 mph in the Valley and Delta, up to 30 to 40 mph in the mountains. Thursday to Early Next Week... The remainder of the week and into the weekend, troughing will remain the dominant pattern, maintaining cooler than normal temperatures and bringing more widespread precipitation. Most of the precipitation has trended to be on Thursday, with confidence and forecast rainfall amounts increasing for areas north of I-80, including into the Sacramento Valley. The latest storm totals have trended higher in those areas, ranging up to an additional 2 inches over the mountains of northern Shasta County, with the northern Sacramento Valley seeing a quarter to a half of an inch. Forecast amounts elsewhere in the Valley and Delta have trended lower, generally a tenth of an inch or less. Main impacts will be slick roads, especially with oil building up over the summer. There continues to be a 15-20% probability of thunderstorms Thursday in the mountains north of I-80, highest over the mountains of Shasta County and western Plumas County. An upper low spinning centered over Oregon may have bring some weak disturbances in the mountains over the weekend, but Saturday has trended dry. On Sunday the center of the upper low passes along the California and Oregon border, with slight chance of mainly Shasta County showers, generally dry elsewhere. There is still some potential for a tropical system to bring some moisture into California next week, but confidence in precipitation potential from this extending into interior Northern California remains fairly low and now looks more likely mid next week. Currently the best potential for rain is over the mountains south of I-80 on Wednesday, especially in the mountains. Temperatures trend warmer, to near normal by Wednesday. && .AVIATION... VFR conditions prevail over the next 24 hours across interior NorCal. Valley south to west 10 to 15 kts in the afternoon with gusts up to 20 to 30 kts and Sierra gusts up to 35 to 40 kts until 03z Wednesday with lingering gusts over the northeast foothills and Sierra through 12z Thursday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

182 FXUS65 KMSO 030915 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 315 AM MDT Thu Sep 3 2026 .DISCUSSION... KEY MESSAGES: - Widespread showers and seasonably cool temperatures persist through the rest of the week and into early next week. - Critical fire weather continues for Southwest Montana today due to gusty winds and low humidity. - Widespread heavy rain in North-Central Idaho late tonight through Friday morning. A broad upper-level low over the Pacific Northwest will maintain cool and unsettled conditions across the region today. The threat for strong thunderstorms is minimal compared to Wednesday, though scattered light rain showers and a couple thunderstorms will persist through the afternoon. A stronger shortwave disturbance and elongated cold front rotating around the parent low will advance eastward late tonight into early Friday morning, significantly increasing shower coverage and rain rates. North- Central Idaho will receive the heaviest precipitation, with a near 100 percent probability of rainfall amounts in the 0.25 to 0.50 inch range, and a 60 percent probability of exceeding 0.75 inches along and east of US Highway 95 through Friday morning. Precipitation amounts will taper spatially heading north into Northwest Montana and east toward the Continental Divide. Southwest Montana will remain the most important exception to widespread wetting rains today into Friday. Strong southwesterly gradient winds and low relative humidity will sustain critical fire weather conditions through Thursday evening, particularly across Fire Zone 111. Elevated fire weather conditions will linger into Friday before the primary cold front crosses the Divide. Showers and cool conditions will spread into western Montana Friday morning as the upper low approaches. Persistent southwesterly flow aloft will keep temperatures near to slightly below early-fall averages through the weekend. Ensemble guidance continues to support the slow-mocing Pacific Northwest closed low ejecting across the Northern Rockies Sunday into Monday, bringing another surge of widespread precipitation (50 to 70 percent chance of exceeding 0.25 inches) and reinforcing cool, seasonable conditions. && .AVIATION...For the most part, widespread VFR flight categories will prevail across regional terminals today, with the exception of KGPI where morning dense fog and low stratus will cause localized IFR conditions likely to begin mixing out after 03/1500Z or with any moderate intensity rain showers. Scattered rain showers will increase across the region through the day, with brief visibility reductions to MVFR possible at all area terminals. Southwest gradient winds will remain gusty to 15-20 knots at KBTM and KSMN through sunset. Late tonight into early Friday morning, widespread rain and lowering ceilings are anticipated across central Idaho and western Montana, dropping flight categories to MVFR/IFR in rain showers and mist, along with mountain obscurations. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Red Flag Warning until 8 PM MDT this evening for East Beaverhead. ID...None. && $$

343 FXUS65 KBOI 031200 AFDBOI Area Forecast Discussion National Weather Service Boise ID 600 AM MDT Thu Sep 3 2026 .UPDATE...Updated aviation discussion. && .KEY MESSAGES... - Intermittent showers and embedded thunderstorms across much of southeast Oregon and west-central Idaho through Friday with significant rainfall totals possible. - Much cooler this week, with highs 10-20 degrees below normal by Thursday with periods of gusty winds. - Cooler than normal weather anticipated late this weekend into early next week. && .SHORT TERM /Through Saturday Night/... Issued 312 AM MDT THU SEP 3 2026 A large upper level low remains positioned off the Pacific Northwest coast, maintaining a moist southwest flow aloft across southeast Oregon and southwest Idaho. A plume of Pacific moisture interacting with synoptic forcing and upper level energy will keep a broad band of stratiform rain with periods of embedded convection ongoing across the region through Friday night. Satellite and radar show a broad area of precipitation early this morning associated with an embedded shortwave moving northeast across Washington State. As the shortwave exits the region this afternoon, widespread precipitation will transition to scattered showers, allowing for occasional breaks in cloud cover. A cold front approaching from the west later this afternoon will cross the forecast area overnight into Friday morning. This front will bring another wave of widespread rain and embedded thunderstorms, along with increased westerly winds, though wind speeds will remain below headline thresholds. The front exits early Friday, helping clear out cloud cover during the morning. The resulting surface heating will introduce weak daytime instability, triggering another round of isolated to scattered afternoon thunderstorms. The primary focus through Friday remains the potential for heavy rainfall with embedded thunderstorms. Instability will be sufficient for robust storm development, particularly during the afternoon and evening hours. Heavy downpours could produce locally high precipitation rates, elevating flash flood potential over recent burn scars across southeast Oregon and the central Idaho mountains, where Flash Flood Watches remain in effect (including the Wapiti burn scar). Total rainfall accumulations through Friday evening are forecast to range from 1.0 to 1.5 inches in mountain areas, with localized higher totals in core storm centers. High temperatures through Friday will stay 10 to 20 degrees below normal, with record low maximum temperatures possible in portions of southeast Oregon and west- central Idaho. By Saturday, the upper low center remains stacked near the Pacific Northwest coast. While lingering atmospheric moisture will support ongoing shower chances, spatial coverage will decrease as dynamic forcing temporarily weakens. Temperatures on Saturday will begin a slight recovery, warming back closer to seasonal averages under persistent southwest flow aloft. && .LONG TERM /Sunday through Thursday/... Issued 312 AM MDT THU SEP 3 2026 The large upper level low shifts slowly eastward directly over the Pacific Northwest on Sunday. As the system pivots inland, it will pull additional Pacific moisture into the region, leading to an uptick in precipitation coverage and shower chances late Sunday into Monday. Guidance continues to track moisture from Hurricane Marie northward through the Great Basin into the Northern Rockies. The majority of this tropical moisture is expected to track east of the forecast area as the trough axis sits directly overhead. However, it will remain close enough for south- central Idaho to experience heightened chances for heavier rainfall, with snow levels dropping low enough over the highest peaks for a rain and snow mix. Below-normal temperatures will persist through early next week due to upper troughing and widespread cloud cover. Heading into Tuesday and Wednesday, ensemble guidance suggests the low will exit to the east, allowing an upper level ridge over the eastern Pacific to build inland. This pattern shift will bring drier conditions and a gradual warming trend back toward near-normal seasonal temperatures by the middle to end of next week. && .AVIATION /12Z Thursday through Friday/... Issued 553 AM MDT THU SEP 3 2026 Numerous rain showers today, becoming widespread Thu evening. MVFR/IFR conditions and mountain obscuration in heavier precip. A 15% chance of embedded thunderstorms in E Oregon and w- central ID through late this evening. Snow levels lowering to 7500 ft MSL in E Oregon tonight. Surface winds: variable 5-15 kt, then SE- SW 5-15 kt with gusts around 20-25 kt by late morning. Winds aloft at 10kft MSL: S-SW 15-30 kt. KBOI...Generally VFR. Light rain showers will continue through the afternoon. Then, continuous rain this evening with a 20% chance of MVFR. Surface winds: E-SE 5-15 kt shifting back to the W-NW with gusts to 20 kts by 01z/Fri. WEEKEND OUTLOOK...Showers to continue through the weekend as the upper level trough moves across the area. Saturday looks to be the driest with showers mainly in the higher terrain. However, areas of fog is likely (60% chance) to develop in many of the valley both Saturday and Sunday mornings. Showers return to much of the area on Sunday especially across the central mountains of Idaho. W-SW surface winds 5-15 kts with gusts 25 kts. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Flash Flood Watch from 3 PM MDT this afternoon through Friday evening for IDZ011. Flash Flood Watch through Friday evening for IDZ013. OR...Flash Flood Watch from 3 PM MDT /2 PM PDT/ this afternoon through Friday evening for ORZ061>063. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise AVIATION.....JDS SHORT TERM...JDS LONG TERM....JDS

227 FXUS65 KLKN 030940 AFDLKN Area Forecast Discussion National Weather Service Elko NV Issued by National Weather Service Reno NV 240 AM PDT Thu Sep 3 2026 .KEY MESSAGES... * Breezy conditions throughout Northern and Central Nevada this afternoon into this evening * Below average temperatures will continue through the next several days * Periods of rain late this weekend into early next week && .DISCUSSION... (Today through next Thursday) An upper level low off the Pac NW coast today will continue it`s gradual SE trajectory. Light rain showers across northern portion of Humboldt County this afternoon will expand slightly south and east late this evening and overnight, with light rain shower activity reaching most of Humboldt County and NW portions of Elko County. Winds this afternoon will be breezy once again, with slightly higher winds expected across central NV. Winds across east-central NV approach low end advisory levels Friday afternoon, with sustained SW winds of 15 to 25 mph and gust to 45 mph in valley locations across White Pine County, with higher terrain likely reaching advisory level gusts. Dry across the CWA on Saturday. Sunday scattered showers and isolated thunderstorms are expected across mainly the eastern half of the CWA, and possibly the NW corner of Humboldt County. Periods of unsettled weather continue into early next week. FORECAST CONFIDENCE & DEVIATIONS: High confidence in below normal temperatures and moderate confidence in precipitation chances for the next several days. Increasing confidence regarding storms this weekend, currently sitting around the moderate level. No changes to NBM output. && .AVIATION... Dry with VFR conditions expected at all TAF terminals today and tonight. Southwest winds of 10 to 20 knots gusting 20 to 30 knots are expected at all terminals this afternoon, except KENV where winds will remain below 15 knots. && .FIRE WEATHER... Increasing RHs and some light rain to portions of Northern NV this afternoon. Winds this afternoon will generally be SW 10 to 20 mph gusting 20 to 30 mph across all zones, with gusts to 35 mph possible in some locations. Elevated fire weather conditions are expected across portions of central NV this afternoon where gusty winds will combine with RHs in the 10 to 20 percent range. && .LKN Watches/Warnings/Advisories...None. && $$ DISCUSSION...96 AVIATION...96 FIRE WEATHER...96