049 FXUS66 KSEW 110337 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 837 PM PDT Sun May 10 2026 .SYNOPSIS... A weak system clipping the region has brought in an expansive cumulus field with partly sunny skies. A warming trend is expected through Tuesday. Thereafter, conditions become more unsettled with a chance for isolated thunderstorms on Wednesday. Cloudy and cooler conditions will persist through the end of the week. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... A mix of partly cloudy skies to mostly cloudy skies across Western Washington this evening. Light shower activity has dwindled across much of the area. Any remaining showers are expected to taper off tonight. High pressure bumps back in early this week, with warming temperatures through Tuesday. Tuesday looks to be on track for the warmest temperatures this week, with widespread upper 70s to mid 80s across the region. The warmest temperatures are forecast to be in areas from south King County in through Mason and Grays Harbor County. The Cascade valleys will also be well into the 80s. These locations are giving a 50 to 70% chance of reaching Moderate HeatRisk, which can impact the most sensitive demographics-especially with limited access to cooling. Given the pattern, minimum relative humidity values on Tuesday are forecast to be between 25 to 30% in the Cascades and 35 to 40% throughout much of Puget Sound. The winds, although light, seem to be slightly northeasterly which could drive these RH forecasts even lower. Overnight temperatures will be cool enough to offset some of it being in the low to mid 50s. Relief will be in short order as the pattern turns unsettled into the second half of the week. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... The pattern becomes more unsettled Wednesday through the second half of the week. A cutoff low offshore of the OR/CA border amplifies and nudges the ridge off to the east. While the exact track of that cutoff low is still carrying some uncertainty, it does provide potentially favorable conditions for a few thunderstorms Wednesday morning into early afternoon. Southerly flow and an increase in CAPE could favor some orographically enhanced storms in the southern WA Cascades and foothills. Right now, it seems as though some of the ingredients are misaligned with the generally necessary solar insolation of the day, but this will be monitored as Wednesday approaches. Broader troughing in the NE Pacific keeps onshore flow into Washington for the rest of the week, allowing some weaker systems to move in. Scattered showers could occur during this timeframe but are unlikely to produce significant rains. 21 && .AVIATION... West to southwest flow aloft will gradually become more west/ northwesterly on Monday as an upper level ridge moves back into the region. The majority of the terminals are VFR this evening, except for KHQM and KCLM which are MVFR in stratus. Some lingering mid level cloud cover remains over the region in the wake of some light shower activity this afternoon and the weak front that moved across the area earlier. Otherwise, with an increase of onshore flow tonight, expect stratus to push inland into portions of the Southwest Interior and south/central Sound late tonight into early Monday. This may yield some brief periods of MVFR conditions for terminals across the central Sound by early Monday. Expect conditions to improve mid-to late morning for a return to VFR by the afternoon. Low-level onshore winds expected to become lighter overnight before increasing to 8-12 kt out of the north on Monday afternoon. KSEA...VFR this evening. However, areas of stratus are set to redevelop this evening in moist onshore flow. The NBM has a 25- 30% chance of ceilings under 3,000 ft moving into the terminal by early Monday. Should this occur, VFR conditions are set to return by mid to late morning. Northerly surface winds will persist between 3-6 kt overnight and will increase to 8-12 kt between 18-21Z. 41/14 && .MARINE... Post-frontal onshore flow will continue in the wake of a weak front. A westerly push will continue to bring SCA-strength winds through the Strait of Juan de Fuca through tonight. Winds remain relatively light elsewhere and primarily out of the north. A thermal trough will build along the coast on Tuesday, yielding a brief period of offshore flow. A potential system approaching the area midweek may bring another push through the Strait. Additionally, while low stratus is expected off the coast the next couple of mornings, there is potential for some pockets of fog over the coastal waters (especially in areas where the wind is calmer). Combined seas will hover around 4-6 ft through the week (with a brief jump to 6-8 ft midweek). 41/14 && .HYDROLOGY... The daily hydrology discussion has ended until the start of the next rainy season; it will only be updated during this time as needed. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 3 AM PDT Monday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. && $$

960 FXUS66 KPQR 110427 AAA AFDPQR Area Forecast Discussion National Weather Service Portland OR 927 PM PDT Sun May 10 2026 Updated Aviation discussion .SYNOPSIS...A weak shortwave trough will continue to bring increased cloud cover and slightly cooler temperatures today. Temperatures rebound on Monday and Tuesday as high pressure re- builds, with the warmest temperatures on Tuesday. Precipitation chances return on Wednesday as a trough approaches the West Coast. Another trough from the Gulf of Alaska will maintain precipitation chances and a trend toward cooler temperatures by the end of next week. && .DISCUSSION...Today through Saturday...Satellite imagery as of early Saturday afternoon depicts scattered low stratus and a band of mid to high level clouds moving over northwest Oregon and southwest Washington as a shortwave trough brushes the Pacific Northwest. Don`t expect any precipitation with this shortwave since most of the moisture is directed toward British Columbia while we remain in a drier airmass. Given the increased cloud cover today, temperatures will be a few degrees cooler than yesterday but remain near or slightly above seasonal normals across interior valleys. Afternoon highs are forecast in the upper 60s to low 70s for interior valleys and upper 50s to low 60s along the coast. Monday to Tuesday, deterministic and ensemble guidance remain in agreement with upper-level ridging re-building over the Pacific Northwest. We`ll see a return of sunny skies while dry weather prevails. There is high confidence that temperatures across interior valleys will re-bound into the upper 70s to low 80s on Monday. Tuesday is looking to be the hottest day of the week with afternoon highs forecast in the mid 80s to near 90. There is currently a 30-50% chance that high temperatures exceed 90 degrees on Tuesday across the Portland/Vancouver Metro Area. The rest of the Willamette Valley, southwest Washington lowlands, Columbia River Gorge, and Upper Hood River Valley have a 5-10% chance of exceeding 90 degrees. If KPDX (Portland Airport) ends up at or above 90 degrees, this would tie or break the daily record of 90 degrees which was set in 2023. Given the warmer forecast temperatures on Tuesday, there is now Moderate HeatRisk across the Portland/Vancouver Metro Area, Cowlitz Valley, and Columbia River Gorge. Those who are sensitive to heat will be affected, especially those without cooling and hydration. The next chances for precipitation return on Wednesday as the next trough approaches the West Coast. The majority (78%) of ensemble members show this trough tracking south of our area and becoming a closed low towards Northern California. As a result, chances for precipitation are 15-25% west of the Cascades and 25-45% across the Cascades. In addition, southerly/southeasterly flow from this pattern would bring increased mid-level moisture and instability, bringing a 15-25% chance for thunderstorms across the Linn and Lane County Cascades Wednesday afternoon. The other scenario depicted by the remaining 22% of ensemble members has the trough swinging directly through the Pacific Northwest; if this were to occur, we would see increased chances for precipitation over our area and cooler temperatures. There is greater uncertainty in the pattern Thursday-Saturday, however, most ensemble members are showing another trough dipping down from the Gulf of Alaska by the end of the week. This will maintain chances for precipitation across the area and bring lower 500 mb heights, resulting in temperatures cooling down to seasonal normals. However, the exact track of this system, timing, and precipitation amounts are still uncertain. About 30% of ensemble members have ridging re-building by the weekend. -10 && .AVIATION...Dry southwesterly flow aloft continues as upper level ridging again builds over the region through Monday. Expect predominately VFR conditions, with highest chances of marine stratus developing along the coast tonight between 06-16z Monday. Elsewhere, there is less than a 20% chance for MVFR stratus to redevelop inland. Northwest winds increase by Monday afternoon. KPDX AND APPROACHES...VFR expected through the period, while there remains around a 10-20% chance for MVFR stratus redeveloping between 10-16z Monday. Light northwest winds expected to increase to around 8-10 kt by 20z Monday. /DH && .MARINE...Southwesterly winds over the waters today around 5-10 kt with gusts around 15 kt. Some periods of gusts up to 20 kt within the inner waters as a weak disturbance passes through but will be isolated and not widespread. Seas will remain below 8 ft. Monday, weak high pressure returns across all waters which will maintain northerly winds resulting in gusts up to 25 kt for all inner and outer marine zones (though at slightly staggered times). Have included the northern waters in the advisory as it appears there will be around a 6 hour period where they could branch into those zones. Looking towards Tuesday through at least Thursday conditions return to a more benign pattern with north to west winds, with gusts below 20 kt and seas 5 to 7 ft. -27/42 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory from 5 PM to 11 PM PDT Monday for PZZ251- 271. Small Craft Advisory from noon Monday to 2 AM PDT Tuesday for PZZ252-253-272-273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

462 FXUS66 KMFR 102340 AFDMFR Area Forecast Discussion National Weather Service Medford OR 440 PM PDT Sun May 10 2026 .Updated AVIATION Discussion... && .AVIATION...11/00Z TAFs...VFR prevails across the region under high clouds and gusty north to northwest winds (peaking near 20 kt) at all TAF terminals expected to continue through this evening (around 04Z Monday) before easing around/after sunset. With offshore flow developing tonight, low-level moisture gets squeezed/scoured somewhat, but models are still showing some along the coast north of Cape Blanco, near Brookings and in portions of the Umpqua Basin. In this case, any ceilings that develop in those areas are likely to be IFR (<1000 ft) and last until the early morning hours Monday before clearing to VFR again by Monday afternoon. Terminals most likely to be affected by IFR tonight into Monday morning are North Bend (60-70% chance) and Roseburg (40-50% chance). Medford`s chance is <10%. -Spilde/BR-y && .PREV DISCUSSION... /Issued 232 PM PDT Sun May 10 2026/ DISCUSSION...A dry front passing to the north is flattening an upper ridge, allowing for a few degrees of cooling west of the Cascades. Higher pressure remains in northern California and east of the Cascades, keeping warmer temperatures in place this afternoon. With the dry front passing by this evening, the ridge rebuilds and brings warmer temperatures across the area on Monday and Tuesday. Daytime highs along the coast look to be in the high 60s to low 70s across both days. Valleys west of the Cascades are expected to be in the high 80s to low 90s. East of the Cascades, valleys and basins are forecast to see the mid 80s on Monday then warm to the high 80s on Tuesday. These temperatures may be 15 to 20 degrees above seasonal norms, so extra awareness of how you`re feeling during the warmest part of the afternoon is encouraged. On Wednesday, a compact low remains in the expected pattern but significant timing differences in its expected arrival remain. Models still show a significant temperature range for Wednesday`s highs. NBM probabilistic guidance still has a nearly 20 degree range of expected highs for Medford, with an interquartile range (equal 25 percent chances) of 87 and 69 degrees, That sort of uncertainty is usually reserved for 7 days out rather than 3 days out. There`s relatively more clarity in other conditions, but still a few details to watch over the next day. Gusty winds are still expected, with 50% chances for Advisory-level winds in the Shasta Valley on Tuesday afternoon. Thunderstorms are looking unlikely, with modeled CAPE values in the 100-200 J/Kg range. This leaves some scattered showers, mostly over higher terrain and with amounts near 0.2 inches at best. Cooling is certain behind the low, with a cooling trend in the forest from Thursday through Saturday. Some showers may linger into early Thursday morning depending on the timing of the low`s exit to the east, but this seems unlikely (10-20% chances). -TAD MARINE...Updated 200 PM PDT Sunday, May 10, 2026...A thermal trough will bring gusty north winds and wind driven steep seas south of Cape Blanco through Monday. Gusty north winds and steep seas are expected to expand north of Cape Blanco Monday afternoon before subsiding again late Monday night through Tuesday. Low pressure will move south of the waters Tuesday night into Wednesday with showers that will at least brush the southern half, except could be farther north if the low takes a more northern track. Winds won`t be too strong and remain mostly from the north. A thermal trough pattern could redevelop Friday into next weekend with stronger north winds and steeper seas again, especially south of Cape Blanco. -Spilde && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Monday for PZZ350-356-370-376. && $$

346 FXUS66 KEKA 102221 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 321 PM PDT Sun May 10 2026 .SYNOPSIS...Temperatures will slowly continue to warm and are expected to peak on Monday. Stratus will continue to scatter out again Monday afternoon with returning coastal overcast skies in the evening. There is the possibility of some rain, drizzle, and inland thunderstorms on Wednesday or Thursday. && .KEY MESSAGES... -High interior temperatures will peak today through Monday with moderate HeatRisk in Mendocino and Lake Counties. -Scattering out will continue again Monday. -Cooler temperatures and slight thunderstorm and coastal drizzle potential around Wednesday or Thursday. .DISCUSSION...With a week shortwave moving trough today, accompanied with northerly winds, the coastal stratus has thinned out as mixing has broken the spell of overcast skies. This shifts the wind to more offshore by Monday morning. There are better chances of more clearing by Monday afternoon. This offshore flow should also help bring warmer temperatures to the near coastal areas 10 to 20 miles inland with many of these areas reaching into the upper 80s to low 90s. Farther inland mid 90s are expected. There is the potential that the low clouds will linger at the immediate coast and keep temperatures around 60. This will likely be the warmest day of the next week for much of the area with a Heat risk expected in the moderate range for areas of Lake and Trinity. Tuesday an upper level low starts to approach the area and this is where model solutions start to diverge. Some of the ensemble clusters bring this low quickly north and into Washington and Oregon while the slowest solution keeps the low well off the California coast. The evolution of this low into Wednesday and Thursday will have big impacts on the forecast. This could bring the chance for Thunderstorms if the low moves onshore in northern CA. However some of the other solutions could keep hot temperatures over the area. Late in the week the models are showing zonal flow developing over the west coast. There are still some big differences whether there will be some weak ridging and dry weather or the remnants of the upper level low continuing to move through the area. Overall confidence is below normal in the extended period. && .AVIATION...Steady clearing is being observed along the North Coast today. MVFR ceilings expected to give way to VFR from 21Z through 03Z (+/-1hr). Gusty north winds along the coast will increase mixing and the chance for light Low Level Turbulence. Forecast confidence is moderate for prolonged clearing at KCEC (~50%) through the night. KACV however is expected to have MVFR ceilings (>80%) with periods of IFR (~70%) early in the morning. Inland terminals will continue with VFR conditions and daily terrain focused winds. Gusts forecasted mostly for ridgetops as minimal mixing reaches the valley floor, especially at KUKI. DS && .MARINE...A surface high pressure center in the eastern Pacific Ocean will flow northward today strengthening the surface pressure gradient as it interacts with a low pressure center in Baja. The response to this strengthening will be a steady increase of northerly winds this afternoon. Most of the coastal waters can expect strong breezes this afternoon up to 30kts. Areas downwind of Cape Blanco and Cape Mendocino are forecasted to have gale force gusts, yet the forecasted coverage of these winds is minimal enough to not warrant an official Gale Warning for the outer waters. Winds are expected to remain at least moderately breezy through Monday afternoon before sustained gentle breezes develop Tuesday. Short period seas have been increasing in height through the morning, especially in the southern waters. These waves have warranted small craft advisories to be hoisted for zones 470, 475, and 455 in turn. Northerly short period waves will mix with a mid period westerly swell through the early week. Tuesday evening through Thursday, this westerly swell will dominate the coastal waters. DS && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 AM PDT Monday for PZZ455. Small Craft Advisory until 9 PM PDT Monday for PZZ470-475. && $$ 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

561 FXUS66 KMTR 110451 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 951 PM PDT Sun May 10 2026 ...New AVIATION... .KEY MESSAGES... Updated at 1252 PM PDT Sun May 10 2026 - Warming and drying trend will continue through Monday - Moderate risk for heat-related illnesses for sensitive populations across the interior on Monday - Gradual cooling trend and unsettled weather midweek through late week && .UPDATE... Issued at 845 PM PDT Sun May 10 2026 We`re keeping an eye on the marine layer tonight as it continues blossom along the coast. It should deepen to about 1000ft tonight, which will bring low clouds into portions of the interior valleys. Guidance shows the clouds mixing out by mid to late morning, which may impact high temperatures tomorrow. && .SHORT TERM... Issued at 1252 PM PDT Sun May 10 2026 (This evening through Monday) Temperatures this afternoon are struggling to reach their forecasted highs. This is as a deeper marine layer around 1500 ft in the North Bay and 2000 ft in the Bay Area and Central Coast developed overnight. Again, where cloud cover lingers or is slow to dissipate across inland areas is where we are most likely to see cooler temperatures than previously forecasted. That said, inland clearing will still allow for temperatures to warm this afternoon as high pressure to the south of the region continues to strengthen. Overnight, temperatures will cool into the upper 40s to mid 50s across most valley locations. Meanwhile, the higher ridges and peaks will likely bottom out in the upper 50s to 60s. If persistence holds, low clouds will fill back inland overnight, yet not expecting as much of an inland penetration as the marine layer is still on track to compress. Monday is still on track to be the warmest day of the week, yet we are seeing less widespread Moderate HeatRisk across the interior. Mondays afternoon maximum temperatures are expected to be in the mid 80s to lower 90s across the interior with cooler conditions near the coast as a shallow marine layer and onshore flow will persist. However, these temperatures could be off by a few to several degrees where cloud cover develops and lingers. Tricky forecast as high pressure aloft supports warming afternoon temperatures, yet the marine influences have been winning out. && .LONG TERM... Issued at 1252 PM PDT Sun May 10 2026 (Monday night through next Saturday) The pattern begins to shift Monday night into Tuesday as a trough of low pressure approaches the Pacific Northwest and northern California. Thus, temperatures will cool by several degrees on Tuesday, yet are likely to remain above seasonal averages. A cut-off low pressure system is forecast to develop and move inland Tuesday night and into Wednesday bringing even cooler and unsettled weather to the region. We are still expecting drizzle and/or light rain Tuesday night through Thursday morning as a result of the mid/upper level cut-off low moving inland across northern California or the Bay Area. Rainfall amounts generally will remain less than a few hundredths of an inch or so. More of a zonal flow returns by late week and will persist through the upcoming weekend. This will result in a warming and drying trend through this timeframe. && .AVIATION... (06Z TAFS) Issued at 950 PM PDT Sun May 10 2026 No major changes to the forecast with this TAF package. Tonight`s observations include Mainly VFR conditions with the exception being along the San Francisco Peninsula and Monterey coastlines where sites are reporting MVFR to IFR cigs. These will likely hold and even build for the overnight hours bringing MVFR to IFR ceilings. The marine layer is expected to be around 1000ft tonight which means the onset of stratus in the valleys will be delayed or non-existent. Most sites have hints of cigs, with them lifting by mid to late morning. VFR conditions are expected for the majority of the region by Monday afternoon. The marine layer looks to return again tomorrow evening, opted to hint or fully bring it in for terminals near the coast. Medium to high confidence in the forecast. Vicinity of SFO...Westerly winds are winding down and will fall to around 10kt or less after 6Z. The challenge outside of winds is the stratus. Satellite imagery and webcams show stratus building around the San Francisco Peninsula and slowly filtering into the western portion of KSFO`s range ring. With the marine layer expected to be around 1000ft again, we should see the return of stratus tonight. Kept the pessimism in the TAFs with IFR cigs based on the last few nights, but time will tell if go that low or stay in the MVFR category. Stratus looks to dissipate mid to late morning, with breezy westerlies of 10-15kt returning Monday afternoon. The marine layer looks to return Monday night into Tuesday morning, which was brought into the latest TAF. Medium confidence in the forecast. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...A small band of stratus remains around the Monterey Peninsula, which has been brought IFR cigs to KMRY. Expect this to build back in this evening bringing MVFR to IFR cigs to the terminals. Stratus should begin to erode by mid to late morning, though a few clouds could linger around KMRY for the afternoon. Stratus and low cigs look to return Monday evening. && .MARINE... (Tonight through next Saturday) Issued at 845 PM PDT Sun May 10 2026 Moderate seas and a fresh to strong northwest breeze with isolated near gale force gusts continuing through tonight. Winds ease late tonight across the inner waters then across the outer waters tomorrow becoming a moderate to fresh northwest breeze. Seas subside in response, but remain moderate with 4 to 5 foot seas by mid week.Locally gusty conditions are likely across the San Pablo and San Francisco Bays where terrain promotes wind funneling. Winds increase and seas build again late Wednesday into Thursday. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 3 PM PDT Monday for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory until 9 AM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...RGass LONG TERM....RGass AVIATION...KR MARINE...KR 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

998 FXUS66 KOTX 110505 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 1005 PM PDT Sun May 10 2026 .KEY MESSAGES... - Breezy to locally gusty winds Sunday evening. - Very warm temperatures Tuesday. This level of heat primarily affects those who are sensitive to heat. - Cold water temperatures pose a high risk for cold water shock and hypothermia for anyone who unexpectedly falls in. Wear a life jacket if recreating on or near the water. - Periodic shower and thunderstorm chances middle to late week. && .SYNOPSIS... Breezy to windy conditions this evening. Warming and drying Monday and Tuesday. High temperatures on Tuesday will be very warm with mid 80s to low 90s. The warmth will linger into Wednesday then begin to cool late week. This will come with an increasing risk for showers and thunderstorms. && .DISCUSSION... This evening and tonight: A dry cold front has moved on the WA Coast and will traverse through the Inland NW this evening. The shortwave that will give the cold front a shove inland is closing in on Portland, OR and will track to the northeast through the N Cascades and into southern BC. Breezy to locally gusty winds will be in place this evening with the strongest speeds along the East Slopes and Western Basin. Cloud cover this afternoon is keeping temperatures cooler than this time yesterday for much of Eastern and Central WA but majority of the Blue Mountains and lower Idaho Panhandle are running 7-12 degrees warmer. As winds increase there will be a low threat for patchy blowing dust on the Waterville Plateau and between Vantage and Moses Lake. The main threat for a few showers with the trough passage will be along the Cascade crest and Canadian border as the trough with little to no rainfall. Monday-Tuesday: A warming and drying trend commences Monday and Tuesday as an upper-level ridge of high pressure builds inland. This will promote mostly sunny skies with light winds. Temperatures will be unusually warm by Tuesday with high confidence for widespread mid to upper 80s and few low 90s. Wednesday-Saturday: Precise details in the forecast become a bit more uncertain heading into midweek. There is moderate to high confidence for the ridge axis to shift inland into Central MT as compact upper low wobbles toward the Oregon Coast. This leads to increasing southerly flow with an influx of moisture. The exact track of the low and if any smaller impulses eject from the feature leads to moderate uncertainty in our precipitation forecast. The combination of moisture and daytime heating does not look like a likely scenario for convection alone due to CIN values on the order of -40 to -90 J/kg. The NBM does carry a 10-20% chance for showers/storms in the mountains. This likely due to some ensemble members showing the low take a more northward inland track and providing some lift. Majority of the ensemble members keep the low closer to the OR/CA Coast then track it through Oregon. By Thursday-Saturday, a secondary low coming from the Gulf of AK comes into the picture and sends additional impulses through. This period looks more favorable for showers and storms given increased odds for forcing. Uncertainty is whether these impulses offer a glancing blow to North Cascades and international border or come in deeper and swing through the Basin. This will play a large role where convection can fire and how much shadowing occurs in the lee of the Cascades. So many details to still iron out before identifying where and when showers or storms occur and have any confidence in the forecast PoPs which at this time, blend many different scenarios together. What we know is that the warmth will break down by Friday-Saturday. Wednesday-Friday will be somewhat transition days and likely breezy. Temperatures Wednesday will be as warm as the 80s or cool as the 70s, then upper 60s to low 80s Thursday, and finally into the 60-70s Friday. To given some context, there is a 12F spread between the 25-75th percentiles for high temperatures at Spokane Wednesday; 17F for Thursday; and 7F Friday. Sunday-Monday: The uncertainty in the forecast is compounded further into early next week with ensemble clusters have low probabilities for a trough, low probabilities for a ridge, and slight majority showing zonal flow. There looks to be a battle setting up between high pressure over the East-Central Pacific and low pressure over Western AK. This results in a strengthening zonal jet across the North Pacific. This jet noses toward the Pac NW Coast with time and would favor the zonal flow but exactly when that time comes is uncertain. At this point, best odds lean toward drying and warming coming out of Saturday. /sb && .AVIATION... 06Z TAFS: Winds across central Washington will remain elevated through 06-09z in the lee of a dry cold front passage with speeds decreasing by sunrise. Skies will be mostly clear aside from passing high level clouds. VFR conditions will prevail at all sites. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions for all TAF sites. ----------------------- 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 46 74 45 84 52 82 / 0 0 0 0 0 0 Coeur d`Alene 45 72 45 84 53 80 / 0 0 0 0 0 10 Pullman 45 69 43 83 52 78 / 0 0 0 0 0 10 Lewiston 49 75 47 87 56 85 / 10 0 0 0 0 10 Colville 41 78 42 86 50 86 / 0 0 0 0 0 0 Sandpoint 45 74 45 83 51 80 / 0 0 0 0 0 10 Kellogg 46 72 44 88 52 84 / 0 0 0 0 0 10 Moses Lake 45 78 46 89 55 87 / 0 0 0 0 0 10 Wenatchee 50 78 52 86 59 87 / 0 0 0 0 0 10 Omak 45 79 48 87 56 89 / 0 0 0 0 0 10 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$

373 FXUS66 KPDT 110430 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 930 PM PDT Sun May 10 2026 .KEY MESSAGES... - Conditions will remain dry and warm into the midweek - Breezy conditions today, with strongest winds in the Cascade Gaps - Mountain rain shower and isolated thunderstorm chances return midweek && .EVENING UPDATE...issued 422 PM PDT Sun May 10 2026... Winds have touched advisory criteria through the Kittitas Valley this afternoon, and am anticipating (80 percent confidence) them to remain in the 25-35 mph range with gusts up to 45 mph through evening as a shortwave trough passes over the region and cross- Cascade pressure gradients remain tight (5-7 mb difference between SEA and ELN). Thus, have opted to issue a short-duration Wind Advisory, valid until 8 PM this evening. && .DISCUSSION...issued 251 PM PDT Sun May 10 2026... Tonight through Monday: Satellite imagery this afternoon shows a shortwave flattening a ridge over the PacNW, with mostly cloudy conditions across the forecast area. Breezy winds are developing through the Cascade gaps and along the Cascade east slopes, with winds beginning to push further east into the Basin and adjacent valleys. The upper ridge will continue to influence the region into Tuesday, keeping conditions dry and warm across the forecast area. The shortwave passage today will continue to produce breezy winds late into this evening, with winds generally 15-25 mph and gusts up to 40 mph. Tomorrow, winds will become light again with clear skies. Tuesday through Saturday: Ensemble cluster guidance remains in good agreement in the breakdown of upper level ridging over the region Tuesday, with a deeper south to southwest flow developing as well as a signal for thermal troughing to develop into eastern and central OR. This will promote a modest increase in high temperatures over the region, with upper 80s to mid 90s in the lower elevations, and mid 70s to mid 80s in mountain valleys. In addition to warming temperatures, instability across central OR and the eastern mountains will result in an increased cumulus field across the OR Cascades and eastern mountains, with a very low chance (<10%) of an isolated shower/thunderstorm. Tuesday night through Thursday, uncertainty remains around the evolution of an upper low/trough that will shift inland and across the PacNW. While there is good agreement that low will kick inland sometime Wednesday, ensemble members are split on the track of the trough and timing of its passage overhead. Solutions range from a track over the PacNW, which would result in shower chances and isolated thunderstorm chances across our mountain zones and along foothill locations, while a southern track would limit showers and thunderstorms to central and eastern OR. Timing of the trough passage will also impact timing of showers/thunderstorms across the area, with members split on having the trough out of the region by Thursday evening, or the trough still impacting the area through Thursday night. Forecast confidence in shower/thunderstorm extent is moderate (45-55%) while timing is low-moderate (30-40%). Friday into Saturday, ensemble members are in generally good agreement of upper level troughing developing offshore Friday, then kicking inland through Saturday, though there is uncertainty in exact timing this far out. As the next trough kicks inland, expect another round of mountain rain showers to develop into the weekend. Lawhorn/82 && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... VFR conditions are forecast for all sites over the next 24 hours, with cloud cover ranging from SKC to BKN250. Breezy winds late this evening will slacken overnight, becoming diurnally and terrain-driven Monday, predominantly 10 kts or less with periodic afternoon gusts. && .FIRE WEATHER...issued 251 PM PDT Sun May 10 2026... High pressure remains over the region with dry and warming conditions into late Tuesday. Breezy west to northwest winds will continue to impact the region today, with strongest winds in the Cascade gaps. There will be increasing unstable conditions across central OR and the eastern mountains Tuesday. Min RHs Tuesday will generally be in the teens to mid 20s, with single digits in Central OR. Isolated to scattered mountain showers and thunderstorms develop Wednesday into the weekend. && .Preliminary Point Temps/PoPs... PDT 45 75 47 85 / 0 0 0 0 ALW 49 76 51 88 / 0 0 0 0 PSC 49 80 50 91 / 0 0 0 0 YKM 46 79 49 87 / 0 0 0 0 HRI 47 78 48 88 / 0 0 0 0 ELN 43 74 45 83 / 0 0 0 0 RDM 37 81 44 91 / 0 0 0 0 LGD 42 77 45 91 / 10 0 0 0 GCD 42 83 46 95 / 0 0 0 0 DLS 48 81 52 89 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...None. OR...None. && $$ UPDATE...86 DISCUSSION...82 AVIATION...86 FIRE WEATHER...82

206 FXUS65 KREV 101932 AFDREV Area Forecast Discussion National Weather Service Reno NV 1232 PM PDT Sun May 10 2026 .KEY MESSAGES... * Very warm days prevail through Tuesday with temperatures near record highs. * Dry conditions are expected through early this week with typical afternoon west breezes. A few stronger gusts may occur Tuesday afternoon in west central NV. * Some cooling returns by mid-late week with isolated shower chances and periods of breezy winds. && .DISCUSSION... Mother`s Day will be on the warm side as building high pressure over the southwest US brings temperatures to their peak levels so far this year, with several valley areas in western NV surpassing 90 degrees. Sierra communities can expect highs near 80 degrees. Record highs are within reach at our primary climate sites (Reno NV and South Lake Tahoe CA)--see the Climate section below for each date`s current record highs. Similar temperatures are expected each afternoon through Tuesday, with a few warmer valleys in west central NV approaching 95 degrees. Typical zephyr-type west-southwest breezes (gusts up to around 25 mph) are expected each afternoon through Tuesday. The latest NWS HeatRisk forecast continues to show warmer valleys of western NV in the Moderate category, with the remainder of the region in the Minor category today through Tuesday. Remember to stay hydrated and limit exposure to the sun during the warmest parts of the day, especially if you have outdoor plans and are sensitive to heat. Also, use extra caution near rivers which remain cold and could be flowing fast, presenting a risk of hypothermia or loss of body control from the shock of sudden cold water exposure. Dry weather is likely to prevail through the early part of this week. Increased heating will lead to cumulus formation each afternoon through Monday mainly from eastern Mono County to west central NV, but strong subsidence under the ridge should limit vertical growth. Tuesday afternoon could present a more complex scenario as some higher resolution guidance sources are producing isolated showers over portions of far western-west central NV. Meanwhile, a deep layer of dry air remains in place below the high-based cloud layer, which would lead to potentially strong wind gusts (50+ mph) from seemingly weak-looking showers. Currently the guidance is having some difficulty in resolving specific surface and mid-level weather elements across western and west central NV, so while the risk of these enhanced gusts is present, the confidence in all the ingredients coming together remains on the low side. For Wednesday-Thursday, confidence is high for temperatures cooling from their near-record levels as the upper ridge gives way to an area of low pressure arriving from the eastern Pacific. However, in terms of precipitation chances and wind, confidence is lower as timing differences continue with the track of this low, with a near-equal split among the ensemble guidance members between a faster passage on Wednesday vs. a slower passage on Thursday. First runs of higher-resolution guidance covering Wednesday afternoon seem to favor the faster scenario. In summary, a period of showers with isolated thunder remains in play as soon as Wednesday afternoon-night with higher chances (25-40%) favoring the Tahoe basin northward into northeast CA/northwest NV, while increased winds (gusts 30-40 mph) spread across much of western NV. We`ll maintain the shower chances for Thursday as well to account for the potentially slower storm track, although this scenario would reduce the chances of enhanced wind gusts for either day. From Friday through next weekend, confidence is higher for dry conditions returning as more of a zonal flow sets up across northern CA-NV. Temperatures won`t be as warm compared to this weekend but should remain a few degrees above average (mid-upper 70s for lower elevations/upper 60s-near 70 for Sierra communities), with typical zepyhr-type breezes each afternoon. MJD && .AVIATION... VFR conditions are expected at the main terminals through at least Tuesday, with potential density altitude concerns for western NV terminals due to very warm temperatures each afternoon. Southwest to west wind gusts of 20-25 kt are expected each afternoon through Tuesday mainly between 20Z-03Z. MJD && .CLIMATE... Current record high temperatures for Reno, NV that have potential to be broken or tied (Today-Tuesday): May 10: 88 F, set in 1934. May 11: 90 F, set in 2001 and 2013. May 12: 89 F, set in 1959 and 2013. Current record high temperatures for South Lake Tahoe, CA that have potential to be broken or tied (Today-Tuesday): May 10: 75 F, set in 2025. May 11: 78 F, set in 2013. May 12: 79 F, set in 1988 and 1996. && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

668 FXUS66 KSTO 101937 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1237 PM PDT Sun May 10 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Hot and dry conditions throughout the week. - Hottest Days Monday and Tuesday with triple digit temperatures, possible daily record highs, and widespread Moderate HeatRisk. - Slightly cooler temperatures from Wednesday onward, though temperatures will still be well above normal. && .DISCUSSION... ...Today through Tuesday... Hot temperatures continue today and through early this week as ridging builds eastward. Widespread Minor HeatRisk with areas of Moderate Heat Risk is expected today in the Valley. Maximum Valley temperatures today will be primarily be in the low 90s, though closer to the Delta temperatures will remain a little cooler thanks to the influence of the Delta Breeze. On Monday and Tuesday, daytime temperatures will climb again, with widespread Moderate HeatRisk in the Valley both days. Valley highs have potential to both meet or exceed local records, as well as reach triple digits in some locations. The NBM has a 30 to 50% chance of 100 degrees or more in the northern San Joaquin Valley, as well as in the central Sacramento Valley (particularly around eastern Glenn and Colusa Counties, and Butte County). A Heat Advisory remains in place for these areas from 11am on Monday through 8pm on Tuesday. Areas closer to the Delta will see much better overnight relief on Monday and Tuesday, though daytime temperatures will still be quite hot. Be sure to practice heat safety! Drink plenty of fluids, stay in an air-conditioned room or in the shade during the heat of the day, and consider checking in on those more susceptible to heat. ...Wednesday through Saturday... Ensembles depict the ridge breaking down towards the middle of the week, which will result a decent amount of cooling on Wednesday; however temperatures will still be 5 to 15 degrees above normal through the end of the week. As lower pressure moves through the area on Wednesday, the change in pattern brings with it a slight chance (10-20%) for isolated thunderstorms in the northern Sacramento Valley, as well as the foothills and mountains north of HWY 50. Best chances are in northeastern Shasta County, though any thunderstorm chances are somewhat uncertain in the ensembles and will depend on the path of the troughing. && .AVIATION... General VFR conditions are expected over the next 24 hours. Surface winds generally 12 kts or less except near the Delta, where winds to 15 kts and gusts to 20-25 kts are possible through 12z on Monday. && .STO WATCHES/WARNINGS/ADVISORIES... Heat Advisory from 11 AM Monday to 8 PM PDT Tuesday for Butte County Below 1000 ft-C. Stanislaus County including Modesto- Eastern Colusa County-Eastern Glenn County-W. Stanislaus County Above 1000 ft & I-5. && $$

924 FXUS65 KMSO 101847 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1247 PM MDT Sun May 10 2026 .DISCUSSION... KEY MESSAGES: - Hot and dry weather through Wednesday, with temperatures reaching into the mid 80s to low 90s by Tuesday and Wednesday. - Spring thunderstorms Wednesday and Thursday; main hazards will be lightning and erratic/gusty outflow winds. - Weekend Cool Down, but near seasonable levels. An area of high pressure will bring an early taste of summer to the Northern Rockies this week. A weak weather system passing near the Canadian border tonight will introduce mid to high-level clouds and breezy conditions through Monday, providing minor relief from the heat for most locations. However, southern areas of our region, such as Salmon, will remain unseasonably warm with highs in the mid-80s. Temperatures will peak Tuesday into Wednesday as the high pressure strengthens, bringing near-record heat. There is a 50 to 60 percent chance that some lower valleys in western Montana will reach 90 degrees on Wednesday, with some locations within a degree or two of the daily record high temperatures. This rapid warm-up will accelerate high-elevation snowmelt, leading to steady rises on area rivers. Outdoor recreationists should exercise extreme caution, as local waterways will be running very fast and dangerously cold. As the week progresses, changing weather conditions will introduce new hazards. Breezy and dry conditions developing across southwest Montana on Wednesday afternoon will lead to elevated fire weather concerns. Concurrently, the overall weather pattern will begin to shift, bringing a threat of spring thunderstorms capable of producing lightning and gusty winds from Wednesday afternoon through Thursday. Looking toward the end of the week, forecast models indicate a potential for a significant pattern change. Considerable uncertainty remains regarding the exact timing and evolution of this change, with current guidance split between extending the warm weather or introducing a much cooler and wetter system to the region. && .AVIATION...VFR conditions will prevail across the Northern Rockies airspace through the forecast period under the influence of a building upper-level ridge. A weak shortwave passing near the Canadian border tonight into Monday will bring passing mid to high-level clouds and localized showers, primarily impacting northern terminals like KGPI, though ceilings will remain firmly VFR. This feature will also yield breezy surface winds across the region through Monday with gusts of 20 to 25 knots, which may introduce localized mechanical turbulence. Aside from the winds, the primary operational impact will be steadily increasing density altitudes as early-season heat develops, remaining a persistent concern into mid week. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

680 FXUS65 KBOI 102352 AFDBOI Area Forecast Discussion National Weather Service Boise ID 552 PM MDT Sun May 10 2026 .UPDATE...Updated aviation discussion. && .KEY MESSAGES... - Breezy and slightly cooler Monday. - Very hot Tuesday. Record high temperatures in the mid to upper 90s in the lower valleys. - Cooler beginning Wednesday with a chance of showers and thunderstorms. && .SHORT TERM /Through Tuesday Night/... Issued 225 PM MDT SUN MAY 10 2026 Warm, dry weather today under broad upper ridge. A dry cold front to our northwest will pass through eastern OR this evening and western ID overnight, marked by increasing mid and high clouds and a wind shift to west/northwest. Pre-frontal south or east winds will keep tonight warmer than last night, but Monday should be slightly cooler than today and Monday night cooler than tonight. Post-frontal west/northwest winds will increase to 15 to 25 mph on the Idaho side Monday, with afternoon gusts to 30 mph. The supporting upper level short wave trough will flatten the main ridge Monday, but after it exits to our east the ridge will rebuild to even greater amplitude as it passes over our area on Tuesday. That means record high temperatures Tuesday, but not quite as hot as forecast yesterday. && .LONG TERM /Wednesday through Sunday/... Issued 225 PM MDT SUN MAY 10 2026 An upper trough will approach the region on Wednesday with southerly flow over the area. Subtropical moisture will move northward from Baja on Wednesday, with precipitable water values reaching the 90th percentile. This combined with the trough moving inland will trigger scattered showers and thunderstorms on Wednesday afternoon and evening. Shear values are sufficient too for a severe weather threat with organized strong storms possible. The trough moves inland over southeast OR and southwest ID on Thursday with a continued chance of showers and thunderstorms. Model guidance shows zonal flow or weak troughing over the area Friday through the weekend with generally dry conditions. Temperatures expected to be well above normal again on Wednesday with lower valleys reaching into the 90s. Temperatures will trend down around 10 degrees Thursday, then cool to around season normals by the weekend. && .AVIATION /00Z Monday through Tuesday/... Issued 529 PM MDT SUN MAY 10 2026 VFR with areas of high ceilings overnight. Surface winds: S-SE shifting to NW with gusts 25-40 kt between 00-03Z across SE Oregon and after 03Z in SW Idaho with gusts 20-30 kt. Winds aloft 10kft MSL: W-SW 15-25 kt. KBOI...VFR. SE winds shifting to the NW late this evening. && .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 AVIATION.....DG SHORT TERM...LC LONG TERM....TL

856 FXUS65 KLKN 101916 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1216 PM PDT Sun May 10 2026 .KEY MESSAGES... * High pressure produces warm and dry weather through Wednesday. * Record high temperatures are likely, beginning Sunday and persisting through Wednesday * Gusty winds across the forecast area and a low chance for rain showers and thunderstorms north of I-80 Wednesday evening && .DISCUSSION... (This afternoon through next Sunday) Upper level ridge of high pressure will continue to dominate over much of the western US through Wednesday, as the result of a blocking pattern. As a result dry conditions with temperatures warming 15 to 20 degrees above normal will be likely through midweek. Daytime temperatures will likely be near to, or exceed record highs Sunday through Wednesday afternoon as highs reach the lower 90s, with a 75% to 100% chance of highs above 85 degrees Monday and Tuesday. Winds for this period will be generally Westerly at 10 mph to 20 mph with occasional gusts up to 35 mph possible. Wednesday afternoon models have been hinting at the passage of a upper trough that would kick the ridge east, and may bring a 10%-20% chance of showers across northern Nevada Wednesday evening. As well as, push a cool front through the area Thursday. EC and GFS solutions have continued to diverge as the EC favors a weaker trough that is farther north, and much faster, showing the trough over the northern plains by Thursday. The GFS solutions have continued to favor a much stronger system that is farther south with its track, with a closed low over central Nevada Thursday evening with showers and thunderstorms possible over much of the area. As a result confidence in the upper pattern has degraded after Wednesday evening. For now, have decided not to make any major changes in the longer term, but ave went ahead and enhanced the cooling trend forecast Thursday through next weekend by a few degrees, as well as raised pops across northern Nevada to about 15% to 25%. Which may need to be raised and drawn further south if trends consolidate in a wetter solution. As for now temperatures look to cool back into the low to upper 70s, with a few 80s across N Nye county Thursday through Sunday. Winds will be a bit lighter too out of the west to NW at 5 to 15 MPH with gust up to 25 MPH possible FORECAST CONFIDENCE & DEVIATIONS: There is high confidence for warming temperatures and dry conditions through Wednesday of next week. There is high confidence for a period of near record to record heat starting Saturday, and lasting through Wednesday afternoon. There is moderate confidence in cooler temperature Thursday through Sunday as ridge shifts eastward. There is low to moderate confidence in the possibility of isolated showers and thunderstorm north of the I-80 corridor Wednesday evening. There is very low confidence in the possibility of shower and thunderstorm south of the I-80 corridor Wednesday evening through Thursday. && .AVIATION... VFR conditions remain in place through Monday afternoon under mostly sunny and clear skies with a few high level clouds overhead at times. Winds will again be generally light to breezy Sunday and Monday afternoons. && .FIRE WEATHER... High pressure remains in control across the much of the west through Wednesday afternoon will lead to elevated fire weather concerns. Warming temperature are forecast to run 15 to 20 degrees above normal, reaching near to, or exceeding record highs, Sunday through Wednesday afternoon. Breezy afternoon westerly winds of 10 to 20 mph with gusts up to 30 mph, will combine with the temperatures to drop Humidity levels to the teens and single digits through at least Wednesday of next week. Winds will be even stronger Wednesday afternoon and evening as a upper trough passes to the north. West to SW winds will increase to 15 to 25 mph with gusts up to 40 mph will be possible, as well as a few isolated showers or thunderstorms across northern Nevada. Temperatures begin a cooling trend Thursday through Sunday as winds shift to the NW at 5 to 15 MPH. && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...98 AVIATION...92 FIRE WEATHER...98