637 FXUS66 KSEW 291055 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 355 AM PDT Mon Sep 29 2025 .SYNOPSIS...A frontal system will push through Western Washington today. A stronger frontal system is expected Tuesday through Wednesday. These systems will bring widespread rain, breezy to gusty winds, and a slight chance of thunder. Unsettled conditions are favored to continue late into the week as additional systems move into the region. && .SHORT TERM /TODAY THROUGH WEDNESDAY/...A frontal system continues to push across Western Washington early this morning. Latest satellite imagery as of 350 AM shows light to moderate rain making its way along the coast and a few light showers moving across the interior locations. This weather system will bring breezy to gusty winds to the coast, locations along the east Strait, and northern interior Monday morning. There is high confidence (80-90% chance) of seeing wind gusts exceed 25 mph for the east Strait and Whidbey Island, while there is medium to high confidence (50-80% chance) for the northern interior. There is medium confidence (40-65% chance) of seeing wind gusts exceed 35 mph for locations along the east Strait and Whidbey Island. There is a slight chance (10-25%) of thunder this afternoon, with the highest chances along the Olympic Peninsula and Cascades. Rainfall totals with this system will range between 0.10-0.50 inches in the interior, 1.00-2.00 inches for the Olympics and Cascades, and 0.50-1.00 inches along the coast. A stronger frontal system associated with an upper level low offshore will move through Western Washington Tuesday through Wednesday. This system will bring more rain than the last system. WPC has included the Olympic Peninsula under a marginal risk for their Excessive Rainfall Outlook, indicating at least a 5% risk for significant rainfall. Latest guidance suggests, the Olympic Peninsula may see between 2.00-4.00 inches of rain, with higher amounts in the mountain peaks. As for other locations, 0.25-1.00 inches in the interior and 1.00-3.00 inches in the Cascades. In addition, this system will bring breezy to gusty winds and the chance for thunder. There is high confidence of seeing wind gusts exceed 25 mph along the coast, east Strait, Whidbey Island, and northern interior. Stronger winds will be along the coast, east Strait, and Whidbey Island, where there is medium confidence (40-60% chance) of seeing gusts exceed 35 mph. Latest model runs have trended higher on the chance of thunder for Tuesday and Wednesday. On Tuesday thunder chances (20-30%) will be mostly confined to the coast, with a smaller chance (10-15%) in the interior. On Wednesday evening , thunder chances are slightly higher; guidance suggests a 20-40% chance for the Olympic Peninsula and a 15-20% chance for other locations. Wave heights along the coast will approach 15 feet or higher on Wednesday. This may generate hazardous surf conditions with waves running higher on beaches that can sweep people off jetties and breakwaters. Beach erosion is also possible. .LONG TERM /THURSDAY THROUGH SUNDAY/...Latest deterministic models and ensemble data are coming to a general agreement that the center of upper level low offshore will move through Western Washington on Thursday. This will keep unsettled conditions late into the week. However, uncertainty still remains over the weekend on the upper level pattern. Latest ensemble guidance shows zonal flow is likely behind the upper level low on Friday with with another upper level trough following on Saturday and Sunday. 29 && .AVIATION...Southwesterly flow aloft will persist through the TAF period with upper level troughing over the region. A slow moving frontal system will continue to push inland this morning, bringing rain and gusty southerly winds to the area terminals. Radar shows the heaviest rain continuing to push inland along the coast early this morning, with the bands of heavier precipitation likely to push inland into the interior terminals between 16-19Z. Expect ceilings to lower towards MVFR and for terminals to see reduced visibilities as the front pushes through. Gusty southerly winds to 25 kt will also be possible for area terminals in the vicinity of the front. A slight chance of thunderstorms is possible area- wide this afternoon and evening, but confidence in occurrence is too low to include in TAFs at this time. Gradually improving conditions are then expected by the afternoon with residual showers tapering this evening. KSEA...VFR conditions with light SE winds early this morning. Expect winds to increase through the morning hours, with gusts to 25 kt possible around the frontal passage. Ceilings and visibilities will lower towards MVFR conditions as the front moves inland and brings rain to the terminal. Conditions look to gradually improve this afternoon, with showers tapering tonight. 14 && .MARINE...A slow-moving frontal system will continue to cross the area waters this morning, bringing gusty winds to the coastal waters, the Eastern Strait of Juan de Fuca, Admiralty Inlet, and the Northern Inland Waters. Frequent gusts to gale force are likely across the eastern Strait through the late morning hours. Winds will then ease again by this afternoon for a brief lull in between systems. Latest observations show steep seas across the coastal waters currently persisting between 10-12 feet with an average period around 8 seconds. Seas will become less steep through the morning and will gradually subside back to 8 to 9 ft. A stronger frontal system will then move across the area waters Tuesday into Wednesday, likely bringing gales to the coastal waters, the Eastern Strait of Juan de Fuca, and portions of the Northern Inland Waters. Confidence remains high in the occurrence of gales, with latest probabilistic guidance showing a 75-90 percent probability of gale gusts across the coastal waters and a 45-55 percent probability across the East Strait/Northern Interior Waters. Thus, a Gale Watch remains in effect for these areas. Elsewhere, the majority of the remaining marine zones will likely see gusty winds of at least SCA criteria during this period. Waves over the coastal waters will build towards 15-18 ft and will primarily be southerly associated with the frontal passage, then will transition to more westerly by Wednesday. Winds will decrease through the day Thursday and into Friday as the low pressure system associated with the front weakens and starts to move inland. Seas will gradually fall back below 10 ft on Thursday. High pressure will then build back into the northeastern Pacific late in the week, shifting winds back to the northwest over the coastal waters. 14 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Gale Warning until 11 AM PDT this morning for East Entrance U.S. Waters Strait Of Juan De Fuca. Gale Watch from late tonight through Wednesday morning for 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. 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-Northern Inland Waters Including The San Juan Islands. && $$

061 FXUS66 KPQR 291143 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 443 AM PDT Mon Sep 29 2025 Updated Watches, Warnings and Advisories .SYNOPSIS...Active weather will result in wet and cool conditions for the work week. Multiple frontal systems will bring periods of widespread rain and breezy winds to the region. The first will be Monday, followed by the strongest system Tuesday through Wednesday, with unsettled conditions continuing through Friday. && .DISCUSSION...Today through Saturday...Satellite imagery this morning has a broad low pressure centered near 55N/142.45W. This low will send multiple frontal systems into the PacNW. The first front this morning will bring increased cloud cover, southerly winds and widespread rain to the region. Expect southerly winds along the coast with gusts up to 35 mph through Monday afternoon. Widespread rain is already being observed along the coast this morning and will be slowly moving inland into the valley by mid to late morning. Model guidance continues to indicate this front will weaken as it makes landfall, and rain is mostly expected to dissipate by late afternoon/early evening before becoming more showery in nature. Latest guidance indicates up to 0.25"-0.50" of rain expected along the coast and Coast Range with 0.10"-0.33" inland and 0.20"-0.50" for the Cascades through 5 AM Tuesday. The second front will not be far behind even with a very brief break late Monday night into Tuesday morning. This second front looks to be stronger and will bring much heavier precipitation to the region by late Tuesday morning/Tuesday afternoon. Southerly winds expected to be stronger with gusts up to 45 mph along the coast, though there could be a few isolated gusts up to 50 mph. Inland areas will mainly see gusts up to 25 mph. However, guidance is showing that there is a 25-50% probability of peak gusts up to 30 mph Tuesday. Rain will be more widespread with this system. Current HREF onset timing has precipitation starting around 5AM-8AM along the coast and 12PM-2PM for inland locations. Conditions become more showery by Tuesday afternoon and will result in increasing chances (10-20%) of thunderstorms for the coast through Tuesday afternoon through the evening. Not expecting severe thunderstorms, but any that form could produce heavy rain, gusty winds, and frequent lightning. Guidance indicates up to 0.40"-1.00" of rain expected along the coast and Coast Range with 0.20"-0.40" inland and 0.30"-0.70" for the Cascades through Wednesday morning. Wednesday into Thursday, the third frontal system will swing across the region. Some uncertainty remains on the timing and strength of the next frontal system. Winds are expected to remain generally elevated Wednesday through Thursday with gusts up to 35 mph along the coast and 25 mph inland, possibly increasing again briefly as the front passes. Thunderstorm chances return and will be more widespread across the CWA from Wednesday through Thursday evening. Again, not expecting severe thunderstorms, but any that form could produce heavy rain, gusty winds, and frequent lightning. Guidance indicates an additional rain totals up to 0.30"-1.00" of rain expected along the coast and Coast Range with 0.15"-0.40" inland and 0.15"-0.70" for the Cascades for Wednesday into Thursday. Depending on the timing and track of this last system, showers could continue into Friday and Saturday, though a number of ensemble members show dry conditions for the latter part of the week and into the weekend. Ensembles indicate a longwave trough will begin deepening somewhere over the Western US on Saturday, but the WPC 500 mb cluster analysis indicates a nearly 50/50 chance of it deepening over the Great Basin area vs over the Pac NW. If it deepens over the PacNW, rain chances will be higher. If it deepens over the Great Basin, dry weather will prevail. /42-HEC && .AVIATION...VFR conditions with high clouds persist across the Willamette Valley ahead of the next system. High-end MVFR/low-end VFR conditions along the coast as a frontal system moves in. Rain should begin along the coast over the next few hours and reach the Willamette Valley by 15Z-18Z Monday. Winds generally out of the south ahead of the front, with gusts up to 25 kt likely at coastal terminals through the TAF period. Inland, winds remain under 10 kt and generally out of the south. Once the front moves inland, flight conditions within the Valley will fall towards low-end VFR (less than FL040) with a 20-40% chance for MVFR conditions. Widespread rain transitions into post-frontal showers behind the front around 18Z Mon along the coast and 18Z-20Z Mon for inland locations. The front is expected to be out of the airspace around 00Z-03Z Tues with flight conditions expected to improve to VFR. KPDX AND APPROACHES...VFR with high clouds, dropping to low-end VFR around 18Z Mon as a front moves through and brings widespread rain. 10-25% chance for MVFR conditions from 18Z Mon-00Z Tue. Southeasterly winds around 6-10 kt. /42 && .MARINE...A cold front moving across the waters through early this morning will continue to produce southerly winds of 15-25 kt with gusts up to 30 kt. Seas of 8-11 ft will persist as well. Therefore will maintain the current Small Craft Advisory for all waters. After the front moves onshore Monday morning, winds will ease to 10-15 kt while seas subside to 7-9 ft by late Monday afternoon. Another, more potent frontal boundary will approach the waters tonight and push onshore through Tuesday night. Southerly winds will increase as the front approaches the coast and moves inland. This will result in southerly winds of 25 to 35 kt with gusts up to 45 kt. These strong winds will also result in seas building to 15-18 ft by Tuesday afternoon, with a 5-25% chance of 20 ft seas beyond 30 NM. These elevated winds and seas are expected to persist through at least Thursday night. Therefore, have upgraded the Gale Watch to a Gale Warning. As the front moves further inland by early Wednesday, winds and seas will remain elevated. These conditions will warrant a Small Craft Advisory or more likely a Hazardous Seas Warning to be issued. Southerly winds steadily weaken below 15 kt by Thursday evening while seas similarly ease to 7-9 ft, with conditions continuing to subside by the end of the week. With the persistent upper low responsible for the repeated frontal passages finally moving inland by the weekend and being replace by a building surface high pressure over the northeastern Pacific this will see winds return to a seasonable northerly pattern. /42-Picard && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory until 11 AM PDT this morning for PZZ210- 251>253-271>273. Small Craft Advisory from 2 AM to 11 AM PDT Tuesday for PZZ210- 251>253. Gale Warning from 11 AM Tuesday to 2 AM PDT Wednesday for PZZ210- 251>253. Small Craft Advisory from 11 PM this evening to 5 AM PDT Tuesday for PZZ271>273. Gale Warning from 5 AM to 11 PM PDT Tuesday for PZZ271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

479 FXUS66 KMFR 291010 AFDMFR Area Forecast Discussion National Weather Service Medford OR 310 AM PDT Mon Sep 29 2025 .DISCUSSION...Radar is showing precipitation over the marine waters with some light returns in portions of Douglas County. A front will reach the coast early this morning, then move onshore west of the Cascades during the morning. Precipitation will also move inland with most of the rainfall likely to be along the coast, coastal mountains and Cascades. Ahead of the front moderate to strong south winds are likely in the Shasta Valley and a wind advisory remain in affect. Winds in the Shasta Valley will shift to the west and diminish later this afternoon. Meanwhile, moderate to strong winds are expected for portions of the eastside and a wind advisory remains in effect. Please see NPWMFR for more details. East of the Cascades, it will be windy with precipitation increasing later in the afternoon, with most centered in Modoc and Lake County, even then rainfall amounts will be lighter compared to the Cascades west. A very brief break between systems tonight into Tuesday morning will be followed by the second front later Tuesday into Tuesday night. Compared to the first front, the model trend has been for a more dramatic weakening of this front as it moves inland. Still enough for gusty southerly winds along the coast, and Shasta Valley. Showers are expected on Wednesday as the trough shifts inland, with activity mainly from the coast to the Cascades. When all is said and done, 1 to 3 inches of rain are expected during the first half of the week for the coast, a quarter of an inch to an inch elsewhere on the west side, and up to a quarter of an inch on the east side. Clouds and cool temperatures persist on Thursday as the upper trough remains over the region, but additional showers will be light and few. Dry weather and a modest warming trend is likely to follow with weak ridging on Friday, a weak shortwave trough on Saturday, then the beginning of a rex block pattern early next week. && .AVIATION...29/12Z TAFs...Along the coast and just offshore, ceilings will lower to MVFR with occasional IFR. Ceilings are expected to improve later in the day, but they are expected to remain MVFR. Also, moderate to strong winds will continue through 14z, then diminish as the front moves onshore. Inland, west of the Cascades, ceilings will lower as the front moves inland this morning with MVFR ceilings north of the Umpqua Divide, including Roseburg. The Medford terminal should remain VFR, however the higher terrain will be partly obscured between 15-21z. East of the Cascades, VFR conditions are expected through the TAF period, but the higher terrain could be partly obscured in showers n the afternoon. Moderate to strong winds are likely at Klamath Falls this afternoon with peak gusts close to 35 kts. -Petrucelli && .MARINE...Updated 200 AM PDT Monday, September 29, 2025...Very steep and hazardous seas with gale gusts will continue into early this morning, then both winds and seas will diminish towards mid morning as the front moves onshore. After a brief break, south winds will increase again as the next front approaches the waters overnight tonight. A Gale Watch remains in effect Tuesday morning into Tuesday evening, and will likely be upgraded to a warning later this morning or this afternoon. Winds and seas will diminish Tuesday night, with moderate southwest winds to continue through Wednesday. -Petrucelli && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Wind Advisory until 5 PM PDT this afternoon for ORZ024-030-031. CA...Wind Advisory until 5 PM PDT this afternoon for CAZ081. PACIFIC COASTAL WATERS...Small Craft Advisory until 8 AM PDT this morning for PZZ350-356. Gale Watch from Tuesday morning through Tuesday evening for PZZ350-356-370-376. Gale Warning until 8 AM PDT this morning for PZZ370-376. && $$

900 FXUS66 KEKA 290735 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1235 AM PDT Mon Sep 29 2025 .SYNOPSIS...Rain is expected to arrive this morning in the north, quickly spreading south across the area through the day. Additional rain and wind are expected Tuesday afternoon and overnight. Lingering showers are expected Wednesday and will off on Thursday. Dry weather is expected to return for Friday and the weekend. && .DISCUSSION...A cold front is approaching the area bringing southerly winds to the area. These are strongest are along the coast and over the higher terrain with gusts of 20 to 30 mph in some areas. The winds are not expected to get much stronger, the lower levels are fairly stable and the wind at 850 mb only peaks around 30 to 35 kt. The models are still showing some differences in the timing of the onset of the rain, although they do seem to be converging on a slightly earlier solution. Crescent City is expected to see rain start around 7 or 8am am and then it is expected to be 1 to 2 hours later in the Humboldt Bay area. This is expected to continue to move south and east through the day reaching Mendocino and Trinity counties by early to mid afternoon and Lake county mid to late afternoon. Rainfall totals are currently expected to be around 0.75 to 1.50 inches in Humboldt and Del Norte counties, around a half inch in Trinity and northern Mendocino counties and around a quarter inch in southern Mendocino and northern Lake counties. Southern and southeastern Lake county may see only a tenth of a inch through Monday evening. There is also the threat for thunderstorms Monday afternoon in the interior areas. The soundings at the coast only show a shallow layer of instability. Areas farther inland could see a few embedded thunderstorms in the afternoon. The GFS is showing some areas with 100 j/kg of CAPE. Lapse rates aloft are only around 6c/km so few, if any, thunderstorms are expected. Monday night is generally expected to be dry with lighter winds between cold fronts. Any areas that do clear out will likely see valley fog develop. Tuesday the next cold front is expected to move onshore bringing more wind and rain. The rain is generally expected to hold off until the afternoon. Overall this second system is expected to have less rain and more wind as it moves onshore. The strongest winds are expected to move onshore in the evening. The NAM is showing 850 MB winds of 30 to 40 kt over Humboldt and Del Norte counties. This will likely bring some 40 mph gusts to higher terrain of these areas. The low levels remain fairly dry and unstable along the coast so these areas could see a few gusts to 40 mph or even 45 mph in Crescent City. So have decided to issue a wind advisory, for now have confined it to Del Norte county, but it may need to be expanded. Rainfall amounts are expected to be fairly light with this second front. This will be especially true in areas in the lee of the mountains, notably the Humboldt Bay area. Most areas are expected to see less than a half inch with the exception of a few mountainous areas of Humboldt and Del Norte counties. Wednesday may see some lingering showers around the area, but in general not much rain is expected. Winds are also expected to diminish. There is still the potential for a thunderstorm or two, but confidence is low on this with poor lapse rates aloft. Wednesday night if there is some clearing aloft many of the valleys are expected to see widespread low clouds and fog. Thursday there may be a few lingering showers in the morning, but generally dry weather is expected. Friday and into the weekend high pressure is expected to start building into the area. This will bring a return of high temperatures in the 80s in the warmer inland valleys. Some of the colder valleys of Trinity could see their first frost of the season. This will depend on which nights manage to stay clear and dry. Hayfork dropped to 40 degrees Saturday morning so with a slightly cooler and drier airmass it could easily drop into the low 30s. Sunny weather is possible along the coast with offshore flow returning as well. MKK && .AVIATION...Forecast confidence is increasing with the impacts of an incoming upper level trough will create degraded conditions through the TAF period. Strong southerly winds with gusts up to 20-25kts on exposed coastal areas and ridgelines tonight through tomorrow. Wind shear of 30-35kts at 1500 ft AGL can create turbulent conditions and localized mountain wave conditions. Low clouds will give way to precipitation, further degrading flight conditions early through tomorrow. There is a slight potential for fog, yet model data shows cloud ceilings will be between 1-3 kft AGL along the coast. Inland, winds will be forced by this incoming synoptic event and be generally MVFR overnight before giving way to VFR conditions by 00Z this afternoon. DS && .MARINE...Southerly winds expand across the area waters as a cold front approaches the area this morning. Wind waves to increase as the front crosses the waters, mixing with the ongoing NW Swell. There may be some localized gale force gusts as the front passes, however the airmass is looking somewhat stable as the front passes by and the may keep too many gusts from mixing down to sea level. Later in the day, the winds are expected to diminish quickly behind the front. This lull will be brief, only about 18-24 hours or so. Another cold front will impact the coastal waters early Tuesday morning with more southerlies. These are expected to peak around 30- 35kts, especially in the northern waters near Cape Mendocino. A Gale Warning has been issued for the northern outer waters (PZZ470) from midday Tuesday until around dawn on Wednesday. More hazards are possible as increased high resolution data becomes available this afternoon. Southerly winds are expected to continue on Wednesday and Thursday with models still confirming a large NW swell entering the coastal the waters. The NBM and GlobalWaveWatch both show this building to 12 to 14 feet around 14 seconds. If this materializes, this would be the first large swell of the fall. The beaches generally still have their shallower summer slopes allowing larger than expected breakers with it. Breakers may exceed 16 feet Wednesday night. DS && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Wind Advisory from 11 AM Tuesday to 1 AM PDT Wednesday for CAZ101-102. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 8 PM PDT Monday for PZZ450-470. Gale Watch from Tuesday afternoon through late Tuesday night for PZZ450-470. Small Craft Advisory from 8 AM to 8 PM PDT Monday for PZZ455-475. && $$ 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

804 FXUS66 KMTR 291159 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 459 AM PDT Mon Sep 29 2025 ...New AVIATION, MARINE... .KEY MESSAGES... Updated at 119 AM PDT Mon Sep 29 2025 - A cold front will bring rain and a slight chance for thunderstorms today - A second cold front will bring renewed rain chances Wednesday && .SHORT TERM... Issued at 119 AM PDT Mon Sep 29 2025 (Today and tonight) Fall is here and we have our first wet cold front of the season. According to the OPC/WPC 06Z surface analysis, the front is located about 300 miles west of Bodega Bay and will be heading our way today. We are already seeing widespread southerly wind and extensive cloud cover ahead of the front. As the cool, dense air behind the front lifts the warm moist air mass, many of these clouds will grow dark and bring some rain later today, particularly for the North Bay. After a recent drying trend in the forecast, the lastest update has stabilized with around 1/4" expected in the North Bay and 1/10" along the Peninsula this afternoon and evening. The rest of the area (East Bay, South Bay, Central Coast) should only see a few hundredths if anything from this first cold front. It now looks like the associated surface low will make landfall around 12Z Tuesday. These landfalling lows tend to serve as a good trigger for stronger convection if the environment is unstable. The 06Z HRRR model soundings show surface CAPE peaking around 200 J/kg this afternoon at Santa Rosa, with 0-6 km shear reaching as high as 50-60 kts ahead of FROPA around 18Z. The ingredients are all there, but they don`t line up perfectly in time (first high shear, then CAPE, then trigger) and while the chance for thunderstorms has increased, it remains slight at around 15% in the North Bay from the late afternoon through the evening. && .LONG TERM... Issued at 119 AM PDT Mon Sep 29 2025 (Tuesday through Sunday) Brief ridging will build in after the first front on Tuesday. This will bring drier, more stable weather, and perhaps allow the sun to peak back out. Temperatures will remain suppressed as the 850 mb temperature drops below 10C for just the 2nd time since June 22 (9.8C 00Z 9/10). This calmer weather won`t last long as a second cold front arrives Wednesday. This system looks a little more robust than the Monday system, with the West WRF ensemble mean IVT peaking around 400 kg/ms and remaining above 250 for around 30 hours from 30/18Z to 02/00Z. This moisture has the potential to bring around 1/2" of rain to the North Bay and between a few hundredths to 1/4" to the rest of the Bay Area. Again, the Central Coast will be lucky to get more than a few novelty drops. While the moisture looks pretty robust and the deep layer shear persists, the instability looks a little more anemic on Wednesday with 700-500 mb lapse rates around -5 C/km compared to around -7 C/km on Monday. This should keep the chance for thunderstorms lower than 10%, but still higher than zero. When all is said and done, we should be off to a good start for the first day of the 2026 water year. By Thursday, most of the interesting weather will be behind us, but the details of the more subtle pattern become uncertain. The ensemble cluster analysis reveals significant uncertainty by Saturday with either weak ridging or weak troughing possible. While there isn`t any real threat of more rain, the exact temperatures are hard to pin down with this uncertainty. Our official forecast shows a warming trend, while the current WPC progs actually bring a dry cold front through on Saturday. && .AVIATION... (12Z TAFS) Issued at 458 AM PDT Mon Sep 29 2025 Light rain showers have reached the Bay Area with temporary reductions in visibility and ceiling heights possible if showers move directly over an airport. Scattered showers continue through early Tuesday morning and are most likely to impact coastal airports and STS/APC. Ceiling heights have been fluctuating between high end MVFR (2500-2900 ft) and VFR this morning. Leaned slightly more pessimistic in the TAFs and kept MVFR CIGs through at least 18Z. It is likely that we will continue to see temporary improvements to VFR conditions but these will be temporary with MVFR the prevailing conditions. Southerly winds continue this morning and gradually become more SW through the TAF period. Cold frontal passage is expected to take place between 00Z-12Z with winds easing after frontal passage. Guidance indicates MVFR CIGs will return towards the end of the TAF period but confidence is low to moderate in the exact timing. Vicinity of SFO...Scattered showers may result in temporary decreases in visibility and ceiling heights. The first round of showers continues this morning with showers likely to impact the airport again tonight. CIGs generally stay VFR but temporary decreases in ceiling heights may result in MVFR conditions at SFO. Breezy southerly winds gusting to around 18-20 knots are expected this afternoon and evening. Cold frontal passage will take place at SFO late tonight with winds easing and becoming more westerly after frontal passage. Scattered showers return late Tuesday as another system approaches the region. SFO Bridge Approach...Similar to SFO. Scattered showers may result in temporary reductions in visibility and CIG heights, resulting in a loss of VAPS, on the SFO Bridge Approach through tonight. Monterey Bay Terminals...Showers and MVFR conditions continue through late this morning. Guidance indicates conditions are likely to improve and become VFR by late morning but confidence is low in the exact timing. For now, kept CIGs improving by mid to late morning with winds between 12-15 knots at both MRY and SNS this afternoon. Showers become more likely late this evening/overnight with MVFR CIGs likely to return. If a shower moves directly over the airport temporary drops in visibility and ceiling heights are possible. && .MARINE... (Today through Saturday) Issued at 458 AM PDT Mon Sep 29 2025 Rain showers continue across the coastal waters through early Tuesday as an upper level trough and surface cold front approach. Embedded thunderstorms are possible across the northern outer waters from late this morning through early this evening. A second system will bring additional rain showers to the waters late Tuesday into Wednesday. Gentle to moderate southerly winds generally prevail across the coastal waters through late this week. Isolated to scattered fresh wind gusts are possible across the northern waters as each system passes. Seas become moderate to rough and build to 10 to 12 feet mid to late week and winds are expected to strengthen again late week into next weekend. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. 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

545 FXUS66 KOTX 291149 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 449 AM PDT Mon Sep 29 2025 .KEY MESSAGES... - Showers and thunderstorms with gusty outflow winds this afternoon and evening - Areas of haze and smoke impacting air quality across the region. - Unsettled weather pattern this week with multiple chances for showers and a few thunderstorms. && .SYNOPSIS... A pattern change commences Monday and continues through the week. Temperatures will be cooling closer to normal with an increasing risk for showers and isolated thunderstorms. Winds will be gusty at times, especially Monday and Tuesday. && .DISCUSSION... Monday through Thursday: A pattern change is underway. Was Sunday the last taste of the 80s for folks across the Inland NW? It sure looks that way. Satellite reveals a broad upper- level trough tracking into the Western US tonight. The eastward progression is very slow and the band of steady rain along the WA Coast will only make it to the Cascade Crest by this afternoon. Ahead of this front, southerly flow is pumping mid and high level moisture into the area. The moisture will have a few hundred joules of elevated instability to work with along the spine of the ID/WA border which will bring a 20-30% chance for high based showers and perhaps a few rumbles of thunder Monday morning. Shower chances will increase further region-wide later this afternoon and into Monday evening as a shortwave swings around the base of the trough and ejects inland. As these showers come inland, they will bring the potential for gusty outflow winds. Numerous hi-res models are indicating wind gusts 25-35 mph with showers due subcloud layers being so dry. We should start seeing winds increasing across the region after 1PM with locally gusty conditions stretching from the Saddle Mountains northward into the Okanogan Valley (southerly winds). A push of stronger winds will be possible with the aforementioned shortwave and showers arriving in the evening roughly 5PM-9PM. HRRR, UW WRF, and NAM3km indicate brief burst of 30-35 mph with these showers with highly localized speeds around 45 mph in the foothills of the Blue Mountains, Palouse and L-C Valley. This comes with decaying thunderstorms from Northeastern Oregon and this area will need to be monitored closely this evening. These quick surges of winds are known to produce patchy blowing dust, throw around light weight objects like ez-ups and umbrellas, and result in minor tree damage. Any folks planning to be on lakes within the Inland NW this afternoon should be prepared for rapidly changing conditions if showers or thunderstorms are moving in! Tuesday is looking to start off dry with weak subsidence behind Monday night`s shortwave passage but another frontal band will be swinging inland from a deepening low off the coast. Instability parameters increase further for SE WA and lower ID Panhandle with cam models indicated discrete thunderstorm cells ahead of the incoming frontal band. Impacts from these will be lightning, brief downpours of rain and small hail, and gusty winds. Bands of light rain will cross into Central WA in the afternoon and track eastward through the evening and overnight hours. Embedded thunderstorms through the evening will remain a possibility. Snow levels will waver from 6000-7000 feet over the Cascades. Wednesday and Thursday will be cooler with periods of showers and afternoon thunderstorms as the offshore low weakens and drifts inland. It will feel a bit more like October with highs in the 60s, mix of sun and clouds, and showers. The main threat for thunderstorms on Wednesday will migrate into the northern mountains with a 20-30% chance in NE WA and N ID and 10-20% for much of the Upper Basin and Cascades. Snow levels will remain between 6000-7000 feet with potential for higher peaks to receive light snow. Friday into the weekend: While confidence is not high, there is an increasing trend in the models for the remnants of Thursday low to drift south of the area, high pressure to amplify off the coast, and another shortwave to quickly drop in from the northwest. Loose agreement is for this wave to arrive Friday afternoon into Saturday and dig into the Great Basin Sunday. Some ensemble members indicate the potential for this wave to deliver gusty winds and shifting winds from the west to north then northeast as the wave progresses through over the period. Not seeing a lot of significant cooling at the surface reflected in the NBM temperature forecast but there is certainty a good deal of chilly air drawn into Canada north and east of our borders indicative of a drier, continental air mass. This is also reflected in the PWAT anomalies that start near 100% Friday and lower to 40% by Monday. So this is a system we will need to monitor for localized gusty winds, especially for any ongoing fires. Wouldn`t rule out more widepsread freezing temperatures for the morning as we get into early next week which is quite common with drier air masses. Stay tuned! /sb && .AVIATION... 12Z TAFS: MVFR/VFR conditions continue through the period with areas of haze and smoke. Main concern for restrictions to vis will be Wenatchee, Chelan, Omak, and into the East Slopes including Winthrop, Plain, and Lake Wenatchee. There is a small chance of showers and isolated thunderstorms through 18z Monday for KGEG-KSFF-KCOE-KPUW-KLWS-KEAT (15-20% chance). Looks to be more showers than thunderstorms and high based activity. Shower chances increase to around 30-40% around 21z starting in the Cascades (KEAT) and spreading into eastern WA after 00z Tue. Gusty outflow winds will be a concern with any showers and storms with several hi res models indicating gusts 30+ mph briefly. Pilots should be prepared for erratic winds with any precipitation approaching between 21-04z. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Low confidence for MVFR or worse conditions from wildfire smoke at any terminals outside the East Slopes of the Cascades. Moderate confidence for gusty outflow winds, especially over far SE WA and NC Idaho where hi-res models are showing gusts 30+ kts as showers/decaying storms come through around 02-03z. Moderate uncertainty with exact timing. /sb ----------------------- 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:/weather.gov/otx/avndashboard && .Preliminary Point Temps/PoPs... Spokane 75 51 69 50 65 46 / 10 60 30 50 60 40 Coeur d`Alene 76 52 69 50 65 47 / 20 70 50 60 70 60 Pullman 74 47 67 47 64 43 / 20 70 50 50 60 60 Lewiston 81 57 74 55 71 52 / 10 60 50 50 50 60 Colville 74 41 67 40 62 34 / 10 80 60 60 90 60 Sandpoint 73 47 66 45 62 42 / 20 80 70 70 90 70 Kellogg 77 52 66 52 63 49 / 20 80 70 70 80 80 Moses Lake 75 48 71 50 68 43 / 10 50 20 40 50 20 Wenatchee 74 51 68 51 67 47 / 40 70 20 60 50 20 Omak 76 50 70 49 67 44 / 20 80 30 50 50 30 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until noon PDT today for Central Chelan County-Okanogan Valley-Waterville Plateau-Wenatchee Area- Western Chelan County. ID...None. && $$

829 FXUS66 KPDT 291130 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 429 AM PDT Mon Sep 29 2025 .DISCUSSION... Key Messages: 1. Showers and isolated storms possible through mid-week. 2. Breezy afternoon winds through the week. 3. Cooling and wetter trend begins today. Current radar and infrared satellite imagery shows light returns over Wallowa county and over the east slopes of the Cascades under partly to mostly cloudy skies. This is in response to the upper level trough and attendant cold front beginning to slowly push onshore. The cold front is poised to cross into the Columbia Basin late this afternoon before stalling over eastern Oregon and southeast Washington tonight into Tuesday morning. As a result, showers are expected to be mainly confined along the east slopes of the Cascades, Central Oregon, southern Blue Mountains, and the John Day Highlands before becoming more widespread after 5 PM today. Rain will then taper off overnight into Tuesday morning before a reinforcing cold front moves onshore to return widespread showers chances (30-60%) to the region Tuesday afternoon through Wednesday evening. Better rain chances will reside at elevation over the east slopes of the Cascades and Blue Mountains. Even with the moderate (45-65%) overnight humidity recoveries this morning and afternoon humidities still dipping into the 35-45% range, today looks to provide the most efficient moisture transport and highest rain chances as indicated by Precipitable Water (PW) amounts around 1" and Integrated Water Vapor of 24-28 mm from the subtropics. Rain amounts of 0.10-0.20" are expected at elevations above 4000 feet, with amounts of 0.05-0.10" along the Blue Mountain foothills, and 0.05" or less for elevations of 1500 feet or less. Confidence in these rain amounts is moderate to good (50-70%) as the NBM suggests a 60-70% chance of 0.10" over the east slopes and Blue Mountains, a 50-60% of 0.05" or greater over the Blue Mountain foothills and Central Oregon, and 40-60% chance of 0.02" across lower elevations of the Columbia Basin (Tri-Cities, Hermiston, Sunnyside, Arlington). The incoming system will be eroding the backside of the exiting ridge, which will provide enough instability to allow for some isolated, discrete thunderstorms to develop through the afternoon. There also looks to be some cloud breaks by late morning, which would allow additional energy and lifting properties to be present. This is indicated by 100-200 J/kg of surface CAPE via the NAM and HRDPS. HREF ensembles also indicated isolated thunderstorm potential initiating after 1 PM across Central Oregon, moving into the Columbia Basin and Grande Ronde Valley after 3 PM, then into Wallowa county after 5 PM and dissipating after 8 PM. The main concerns with any developing thunderstorms will be frequent lightning, brief downpours, small hail, and gusty/erratic winds. Severe thunderstorms are not expected (<15% chance). The cold front passes later today, allowing breezy winds to develop across Central Oregon with gusts of around 25 mph possible. Elevated southwest winds may also extend into the Columbia Basin, but confidence is lacking as the HREF suggests a 30-50% chance of occurrence (Tri-Cities, Hermiston, The Dalles, Pendleton) versus a 60-90% chance over Central Oregon (Bend, Redmond, La Pine) this afternoon. Breezy afternoon winds persist Tuesday and Wednesday as a parade of shortwaves pass through the area off the parent upper level low pressure system located off the British Columbia coast. Rain and thunderstorm chances return on Tuesday, but storm potential will be confined to areas of Wallowa county. Minimal rain amounts are expected, with mountainous areas picking up 0.05-0.10" and elsewhere staying below 0.05". Wednesday`s rain amounts may approach similar amounts today for lower elevations due to the primary upper level system that has been parked offshore through the early part of the week finally moving through the Pacific Northwest. Rain amounts over the Cascades and Blue Mountains will be between 0.10-0.30", with lower elevations receiving 0.10" or less. Thunderstorm chances materialize across the east slopes of the Oregon Cascades and the Blue Mountains/Foothills through the afternoon, shifting into Union and Wallowa counties during the evening. Drier conditions are expected Thursday with light showers still possible over mountainous terrain, but ensemble members struggle with the path and strength of the primary upper level system. The current consensus, 61% of members, suggest a weakening trough that passes to our north and along the Washington/Canadian border. The other scenario, 39 % of members, would drop the system to our south and bring drier conditions earlier Wednesday night into Thursday morning due to the overall west flow and moisture supply being cut off. This is unlikely, but worth noting as this outcome does allow for a stronger transient ridge Friday and dropping trough that could bring unsettled weather over the weekend. The earlier outcome does show these synoptic features, but much more muted. Due to the more active pattern taking hold this week, temperatures will be on a downward trend and approach near normal Tuesday before becoming below normal Wednesday onward. Temperatures are expected to bottom-out on Thursday as lows drop into the low to mid-40s and highs peak in the mid-to upper 60s - which is about 5 degrees below normal. 75 && .AVIATION...12Z TAFS...VFR conditions currently across all sites, which will stay the course through the period for most sites. MVFR conditions are expected to occur for KDLS/KRDM/KBDN due to reduced visibilities of 5SM as a result of light rain occuring. Light rain is expected across all sites this afternoon and evening as a weather system slowly passes through the region. decreased ceilings of 5kft will also coincide with afternoon/evening rain. Ceilings will improve toward the end of the period. Breezy winds are also anticipated for KPDT/KRDM/KBDN late morning through the afternoon as the cold front passes, with gusts of 20-25kts likely. 75 && .PRELIMINARY POINT TEMPS/POPS... PDT 78 49 73 51 / 20 60 20 40 ALW 80 54 74 55 / 10 60 30 40 PSC 78 50 73 51 / 10 50 10 40 YKM 75 46 71 48 / 40 60 20 60 HRI 78 49 74 51 / 20 50 10 40 ELN 72 42 67 44 / 50 70 30 70 RDM 71 37 68 41 / 60 60 20 60 LGD 79 49 71 48 / 20 80 30 40 GCD 75 46 71 47 / 40 70 10 50 DLS 74 50 72 52 / 60 70 40 80 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...75 LONG TERM....75 AVIATION...75

778 FXUS65 KREV 290916 AFDREV Area Forecast Discussion National Weather Service Reno NV 216 AM PDT Mon Sep 29 2025 .KEY MESSAGES... * Scattered thunderstorms are expected this afternoon with a few becoming strong to severe. * Increasing winds may result in impacts to recreation and travel each afternoon through midweek. * Cooler, unsettled weather prevails through much of the week, and possibly over the weekend. && .DISCUSSION... Elongated low pressure in the eastern Pacific continues to approach the western states per latest moisture-channel imagery, eventually pivoting through the region later today. A favorable overlap of large scale ascent, moisture, and weak instability will support shower and thunderstorm development along and ahead of a leading frontal boundary in the afternoon and early evening. A few thunderstorms may even become strong to severe amid a strongly sheared environment. The W NV Basin and Range (generally along and east of Alt-95) remains the most favorable area for thunderstorms (40-70% odds) as greater instability and stronger updrafts are more likely to withstand deep-layer wind shear -- and is thus the most favorable area for severe thunderstorms. There is still some uncertainty in thunderstorm potential farther west (e.g., NE CA, Tahoe, Greater Reno-Carson-Minden area), but there does appear to be brief window in the early afternoon (between 11 AM and 3 PM) when t-storms are possible before the aforementioned front scours out moisture. In any case, the primary hazard will be strong to severe outflow gusts, but storms will also be capable of small hail and frequent lightning. Fortunately, strong steering flow will promote faster storm motions and limit the flash flooding potential today. Spotty showers and perhaps a few lightning strikes likely develop tonight in the Sierra, continuing into early Tuesday. Aside from thunderstorms, S/SW winds will become gusty this afternoon in response to the approaching low. Gusts of 30-40 mph will be common across valleys while Tahoe Basin ridges gust to 60-80 mph in the late afternoon into the overnight hours. As a result, expect choppy waters on area lakes, bumpy flights, and difficult driving conditions for high-profile vehicles. Otherwise, temperatures will be noticeably cooler today with daytime highs only reaching the 60s and 70s. A secondary cold front reaches northern California on Tuesday and slowly sinks southward Wednesday into Thursday. Additional showers will accompany the arrival of the front, but the slow- moving nature of the front will keep a fetch of Pacific moisture directed into the region. As a result, daily chances of showers continue Wednesday and Thursday before we dry out Friday. Afternoon winds will also remain gusty through midweek. Unsettled weather may linger over the weekend, but confidence is low. -Salas && .AVIATION... Showers and thunderstorms, and increasing winds will be the main weather concerns today as strong low pressure moves through the region. While the best odds will stay east of region TAF sites (40- 70% odds at KNFL and KLOL), there is at least a 20-30% chance of shower and t-storm impacts at KTRK-KTVL and KRNO-KCXP-KMEV in the early afternoon. Thunderstorms will be capable of brief downpours and MVFR conditions, strong outflow winds, small hail, and frequent lightning. S/SW surface gusts increase to 20-30 kts amid amplifying SW FL100 winds to 35-45 kts this afternoon and evening. This will likely pose some LLWS and mountain wave turbulence for Tahoe and western Nevada terminals, especially after 03Z when surface winds weaken. -Salas && .REV Watches/Warnings/Advisories... NV...Lake Wind Advisory from noon today to 8 PM PDT this evening NVZ002-004. CA...Lake Wind Advisory from noon today to 8 PM PDT this evening CAZ072. && $$

059 FXUS66 KSTO 282038 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 138 PM PDT Sun Sep 28 2025 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .SYNOPSIS... Cooler temperatures with widespread wetting rain early through the middle of this week across interior NorCal, with the highest chances within the Coastal Range, southern Cascades, and northern Sierra. Drier and warmer conditions heading into next weekend. && .KEY MESSAGES... * TODAY THROUGH WEDNESDAY: - Moisture and instability ahead of the low pressure system will bring thunderstorm chances south of I-80 this afternoon (generally 15-30%, highest south of HWY 50). - Low pressure moves into the area starting Monday, bringing chances for widespread wetting rain through Wednesday. Highest totals will be over the mountains. - Monday also sees a 10-40% chance for thunderstorms across interior NorCal, with highest chances in the foothills and along the Sierra Crest. Non-zero chance for convection to continue into the overnight hours. - The overall trend in precipitation totals has trended down again slightly, with most of the Valley looking at less than half an inch of rain over the 72 hr period. - 20-50% chance of a half inch of rain or more in the central and southern Sacramento Valley, and northern San Joaquin Valley - 60-80% chance in the northern Sacramento Valley - 50-80% chance of 1 inch or more of rain in the mountains * THURSDAY THROUGH SATURDAY: - Lingering showers are possible Thursday morning, though there is still some uncertainty in the timing of the end of this system and any totals for Thursday. - Friday sees a return to dry weather and a slight warming trend into the weekend, with daytime highs reaching closer to normal. .AVIATION... MVFR conditions in the northern and southern Sacramento Valley from overcast to broken clouds with 1000 to 2000 ft ceilings through 21z before decreasing througout the eveninig. VFR conditions otherwise with onshore flow and gusts 15-20 kts over the Valley and mountains until 06z Monday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

933 FXUS65 KMSO 290801 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 201 AM MDT Mon Sep 29 2025 .DISCUSSION... KEY MESSAGES: - Strong, gusty outflow from showers and thunderstorms are the main threat today. - Widespread rain Tuesday evolves into an unsettled and progressively cooler pattern for the rest of the week. The pattern change commences today as a Pacific trough to the west drives southerly flow over western Montana and north central Idaho. Increasing moisture will phase with a wave of energy to produce showers and thunderstorms, with activity peaking between 2pm and 9pm MDT this evening. Despite increasing moisture in the mid and upper levels of the atmosphere, relatively dry air at the surface will create an environment favorable for high-based thunderstorms.The primary threats, mainly along and south of I-90, will be strong outflow gusts up to 45 mph, small hail, and brief heavy rain. Shower and thunderstorm coverage will expand Monday night into Tuesday morning as an upper-level shortwave and cold front arrive. Widespread, beneficial precipitation is expected to continue through Tuesday before the focus for precipitation shifts toward northwest Montana on Wednesday. Probabilities for receiving at least 0.25" of rain through Wednesday evening are highest across north-central Idaho (70-80%) and decrease eastward across western Montana, from ~80% near the Idaho border to ~50% farther east. Looking ahead, ensemble guidance is in strong agreement on a persistently cool and unsettled pattern for the late week and weekend. Forecast uncertainty now centers on the trough`s evolution- whether a series of progressive shortwaves will bring daily shower chances, or if a deeper, cutoff low brings more significant precipitation and accumulating snow to elevations near 6000 ft. While the progressive shortwave solution is favored, about 20% of ensemble members suggest the higher-impact cutoff low scenario, which bears watching. Regardless of the exact evolution, valley temperatures will cool into the 60s by mid-week and the 50s for the weekend. Backcountry users should prepare for cold, wet, windy, and potentially snowy conditions this weekend. && .AVIATION...A significant pattern change will commence today as a Pacific trough drives southerly flow and increasing moisture into western Montana and north-central Idaho. While conditions will be quiet this morning, this instability is expected to generate showers and thunderstorms, with peak activity anticipated between 29/2000z and 30/0300z. Relatively dry air at the surface will create an environment favorable for high-based thunderstorms, making strong outflow gusts up to 40 kts the primary threat, particularly for areas along and south of I-90. In addition to the wind, these storms may also produce small hail and brief heavy rain. Airfields KSMN and KHRF have the highest potential for thunderstorms. This activity marks the beginning of the shift to a wetter pattern, as shower and thunderstorm coverage is expected to expand and become more widespread overnight into Tuesday. Anticipate obscurations of the higher terrain to increase due to lowering clouds cover and rain Monday afternoon into Tuesday morning. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

898 FXUS65 KBOI 290904 AFDBOI Area Forecast Discussion National Weather Service Boise ID 304 AM MDT Mon Sep 29 2025 .SHORT TERM...Today through Wednesday night...The leading edge of a broad upper trough will push a cold front through the region this afternoon/evening. Showers and thunderstorms will develop ahead of the front by early afternoon, with the threat continuing through late evening as the front tracks across SW Idaho. Wind gusts to 40 mph are possible from showers and storms with locally heavy rain amounts from stronger storms. The larger rain totals through tonight continue to line up over SW Idaho, generally east of a line from the ID/OR/NV triple point, through Idaho City and Warm Lake. Areas east of this line are looking at 0.25-0.50" totals in the Snake Plain with 0.50-1.0" amounts in the mountains. Otherwise 0.10-0.25" with local 0.50" amounts are expected across SE Oregon and the lower Snake Plain through tonight. The trough axis remains offshore, keeping the region under southwest flow aloft through Wednesday. Mountains will hold onto a 30-60% chance of precipitation during this time while southeast Oregon and lower elevations of SW Idaho trend drier with probabilities in the 10-25% range. The atmosphere will hold enough instability to support thunderstorm potential on Tuesday, with cloudy and more stable conditions diminishing the threat on Wednesday. Precipitation amounts during this period will be lighter with less than 0.10" across lower elevations and up to 0.25" in the mtns. Temperatures step down 3-6 degrees each day with highs around normal on Wednesday (valleys low 70s, mtns upper 50s). Snow levels remain above 8kft MSL through Wednesday night. .LONG TERM...Thursday through Monday...The unsettled pattern continues through Friday as the core of a Pacific low finally swings through the area. It moves quickly once making landfall, so only the short timeframe Thursday through Friday morning is affected. Thursday afternoon, higher elevations and s-central Idaho will see precipitation chances around 20 to 40%, correlated strongly with elevation. Right before the core of the low moves overhead, strong moisture flow Thursday evening and night is centered over the Magic Valley and s-central Idaho. While this will bring 0.1-0.2" of rainfall, the band of rain is narrow, and could easily shift in coming model runs. As the core of the low moves overhead Friday afternoon, precip chances drop drastically. Skies remain cloudy behind the strong trough, and while another wave begins to develop for Sunday, unfavorable moisture flow among ensemble means hints at a low chance for further precip outside of virga and very light rainfall amounts in the mountains. This secondary wave will however stall and amplify directly over the region Monday, increasing chances of precipitation in the eastern portions of our area, but also continuing the cooling trend. Temps about 5 degrees below normal Thursday through Saturday drop slightly to 5-10 degrees below normal Sunday and Monday. Given model agreement on the amplification of the Sun/Mon low, it seems likely that temps could continue the downward trend after Monday. && .AVIATION...VFR with isolated showers in SE OR. Rain band develops in SE-E OR Mon/15Z, that slowly moves eastward to KONO by Mon/20Z. Later, widespread showers and scattered thunderstorms develop across the area Mon/20Z thru Tue/08Z. Thunderstorms embedded in showers could produce locally heavy rainfall and gusty outflow winds to 35 kt. The main afternoon thunderstorm band moves eastward from KBNO at Mon/23Z to KBOI at Tue/03Z to KTWF at Tue/07Z before it moves out of our forecast area. Surface winds: E-SE 5-15 kts in the Snake Plain, elsewhere variable 10 kts or less. Winds aloft at 10kft MSL: S-SW 15- 25 kts. KBOI...VFR with scattered high clouds overnight. Rain showers Monday afternoon through midnight, with a period of heavy rain, gusty winds, and thunder possible Mon/22Z thru Tue/06Z. Surface winds: SE 5-15 kts. && .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...DG LONG TERM....JM AVIATION.....JM

422 FXUS65 KLKN 290742 AAA AFDLKN Area Forecast Discussion...Updated National Weather Service Elko NV 1242 AM PDT Mon Sep 29 2025 .KEY MESSAGES... Updated at 1102 AM PDT Sun Sep 28 2025 * Expect an increase in clouds and increasing chances for light rain showers and isolated thunderstorms for this afternoon and evening. * Stronger and wetter weather system will move into northern and central Nevada Monday, lasting through Tuesday. * Unsettled weather may continue after mid-week but confidence remains low in the forecast at this time. && .UPDATE... Issued at 1242 AM PDT Mon Sep 29 2025 No updates are needed for the current forecast as it remains on track. && .DISCUSSION... (This afternoon through next Sunday) WEATHER PATTERN OVERVIEW: Increasing cloud coverage with increasing chances for showers and isolated thunderstorms this afternoon as remnants of a tropical storm pushes moisture back into the silver state. The weather is expected to dissipate by the evening, leaving calmer conditions overnight with lows in the 40s to 50s. Monday, a stronger and wetter weather system will move into northern and central Nevada, expecting to last through Tuesday. Chances for isolated rain showers range from 50-90% with the highest chances across northern Nevada and along the I-80 corridor. The storm front will also bring in cooler temperatures with highs in the 70s Monday, dropping into the 60s to low 70s by Tuesday. Overnight lows remain in the 40s to 50s. By mid-week, drier conditions return, giving a break to the ongoing weather with a southwesterly flow and slightly warmer temperatures but stay in the upper 60s to 70s. A low pressure system off the northwest coast may bring additional light showers across northern Nevada each afternoon. By the end of the week, more unsettling weather may continue, however there is low confidence on the strength and position of the system at this time. FORECAST CONFIDENCE & DEVIATIONS: Moderate to high confidence of isolated showers and thunderstorms this afternoon, lasting through Tuesday. No changes have been made to the grids at this time. && .AVIATION... VFR conditions expected at all terminals, however isolated thunderstorms this afternoon may bring MVFR or lower conditions at the airports. VCTS and VCSH expected at all terminals this afternoon with possible -SHRA/TSRA, with the exception of KENV. Increasing cloud cover at all terminals ranging at FL080 and FL110. Light winds generally from the south below 10 kts expected, however gusty erratic winds may be present from passing storms. && .FIRE WEATHER... No fire weather concerns noted at this time. Isolated showers and thunderstorms this afternoon with 30-35% chance for wetting rains across zones 427, 438, 469, 470, 425, and southern half of 424. Zones 426 may see some wetting rains with a less than 20% chance while much of zone 437 have less than 10% chance. Look for a stronger and wetter system moving across all zones Monday, lasting through Tuesday. Winds expected to be breezy from the oncoming cold front, however min RH values expected to be well above critical thresholds. && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...97 AVIATION...97 FIRE WEATHER...97