242 FXUS66 KSEW 020959 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 259 AM PDT Wed Apr 2 2025 .SYNOPSIS...Troughing will continue over the region today, maintaining unsettled conditions across western Washington. A high pressure ridge will build inland Thursday through Saturday, bringing dry and warmer conditions. Wet conditions are on track to return by the end of the weekend and into early next week as troughing returns. && .SHORT TERM /TODAY THROUGH SATURDAY/...Radar imagery early this morning shows continued convergence zone shower activity east of the Puget Sound, and high resolution forecast models show this activity holding strong through the late morning. Elsewhere, onshore flow will continue scattered shower activity throughout the day with snow levels near 2500-3000 ft. Accumulation amounts will be light, with up to a tenth of an inch of rain across the lowlands and up to an inch or two of additional snow over the mountains. Shower activity will taper off through the evening hours as drier air enters the region. Cooler conditions will persist today under southerly flow, with highs several degrees below normal in the low 50s across the lowlands. High pressure will build offshore on Thursday and amplify inland through Saturday, allowing conditions to warm up and dry out with plenty of sun. Temperatures will reach the 60s across the lowlands by Friday, increasing into Saturday with potential (10% to 20% probability) to reach 70 degrees east of the Puget Sound. .LONG TERM /SUNDAY THROUGH TUESDAY/...Rain will make a return to western Washington by the end of the weekend, though models show some disagreement over the timing. Ensemble consensus shows precipitation spreading inland throughout the day Sunday, with accumulations up to an inch. With warm temperatures in place, snow levels will remain elevated on Sunday near 6000 ft. Troughing is on track to continue into early next week, bringing in cooler temperatures and periods of locally breezy conditions alongside lowland rain and mountain snow. 15 && .AVIATION...An area of rain is impacting terminals primarily north of SEA, with periods of RA as of around 230 AM this morning. This should linger for the next few hours as it behaves somewhat like a convergence zone. Winds have shifted to northerly at PAE and AWO but remain southerly throughout the rest of Puget Sound. Northwesterlies along the coast are bringing in additional showers. Mostly MVFR to VFR cigs early this morning, with the expectation of continued MVFR and VFR cigs into the rest of today. A turn to more northwesterly winds is expected for more terminals this afternoon, generally after 03Z. KSEA...MVFR at the terminal this morning, with southerly winds of 10 to 15 kts. The lower extent of the area of rain is clipping the terminal, keeping cigs at 015 to 020 feet. Showers may linger in the vicinity through much of the morning hours before breaking out to VFR after 19Z. Winds will remain southwesterly at 5 to 7 kts before turning to a northwesterly after about 03Z between 5 to 7 kts. High res guidance seems to suggest that the duration of the northerly winds will be limited, and suggest a return to south/southeasterly flow around 07Z. 21 && .MARINE...Winds through the Strait of Juan de Fuca have eased below small craft advisory thresholds early this morning, with no additional headline level winds expected in the near term. High pressure will build into the area by the later half of the week. Combined seas are in the 6 to 7 feet range, but will be decreasing to 3 to 5 feet by Thursday as high pressure settles in. The next time frame that could see headlines in terms of seas and potentially stronger southerlies would be late in the weekend as the next front possibly materializes later on Sunday. 21 && .HYDROLOGY...No river flooding is expected over the next 7 days. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$

577 FXUS66 KPQR 021026 AFDPQR Area Forecast Discussion National Weather Service Portland OR 326 AM PDT Wed Apr 2 2025 .SYNOPSIS...One more showery day across the area today as a weak disturbance passes overhead. Drier weather expected for Thursday, with chilly overnight lows leading to frost potential Friday morning. High pressure brings warmer temperatures Friday into the weekend, with the pattern then trending back towards cooler and wetter by early next week. && .DISCUSSION...Early morning radar imagery shows isolated to scattered shower activity ongoing across northwest Oregon and southwest Washington in northwest flow aloft. Shower activity will be enhanced later this morning into this afternoon as an embedded shortwave trough crosses the region. Thunderstorm potential today will again be minimized by a relative lack of surface based instability, but can`t rule out a rumble or two of thunder in any over-performing cells this afternoon. Model QPF values remain rather meager, with most locations maxing out around a tenth of an inch through this evening, perhaps with a few spots in the higher terrain getting closer to a quarter inch. Minor snow accumulations will remain possible through the Cascade passes as snow levels continue to reside around 2500-3000 ft. Shower activity will taper off tonight in the wake of the shortwave as drier northerly flow begins to filter into the region. Partial clearing will help temperatures drop into the 30s in the interior valleys tonight. Current thinking is that fog will be more prevalent than frost tonight given recent rainfall and enhanced low level moisture. Thursday looks to be a dry and pleasant spring day with temperatures close to seasonal norms in the upper 50s across the lowlands. Expect another chilly night Thursday night into Friday morning, with frost becoming the more prevalent concern as northerly flow continues to dry out the low levels of the atmosphere. Will continue to monitor the eventual need for Frost Advisories for Friday morning, with the most likely locations being the south and central Willamette Valley as well as outlying colder areas of the Portland/Vancouver metro such as Hillsboro and Battleground. Models and their ensembles continue to show excellent agreement in warmer temperatures for Friday and Saturday as an upper level ridge builds over the region. Expect temperatures to climb well into the 60s on Friday afternoon, with the NBM depicting a 50-60% chance to reach 70 degrees in the Portland/Vancouver metro and closer to a 20% chance in the rest of the Willamette Valley. Saturday will likely be the warmest day of the week as NBM probs to reach 70 increase above 80-90% in most inland locations. Forecast confidence decreases on Sunday as models continue to struggle with timing the breakdown of the ridge and subsequent arrival of the next upper level trough. The uncertainty is reflected across the GEFS and ECENS which both have some members depicting rainfall arriving as early as Sunday morning while others hold off until Sunday night. NBM maintains a rather large spread of temperature outcomes as result, with highs remaining in the mid to upper 70s in the case of the slower solution but also possibly topping out in the mid 60s if the faster solution comes to fruition. Forecast confidence actually increases for Monday as models are in good agreement that the ridge will have shifted east of the region by early next week, with precipitation chances increasing and temperatures returning closer to seasonal norms through Tuesday. /CB && .AVIATION...Radar, satellite and surface observations as of early Wednesday morning show mostly low-end VFR CIGs with scattered showers as an upper level shortwave trough moves through the area. Expect predominately low-end VFR CIGs (3-5 kft) throughout the day the trough progresses eastward. Terminals could see occasional CIG/VIS drops to MVFR, especially during periods of heavier showers. Guidance suggests a 30-50% chance of MVFR CIGs (2-3 kft) along the coast and Willamette Valley through Wednesday afternoon. Later this evening after 03-06z Thu, conditions will gradually dry up and trend VFR as an upper level ridge moves over the Pacific Northwest. Expect westerly to northwesterly winds across all terminals around 5-10 kt today. PDX AND APPROACHES...Predominately low-end VFR CIGs today with scattered showers. Guidance suggests a 20-40% chance of MVFR CIGs through 00-03z Thu, which would likely occur during periods of heavier showers. Westerly winds turn more northwesterly today, generally around 5 kt or less. -Alviz && .MARINE...High pressure over the northeast Pacific and lower pressure inland will maintain northerly to northwesterly winds under 15 kt through the end of the week. Seas 5-7 ft at 9 seconds today will gradually decrease to 3-4 ft by Thursday. The next front arrives Saturday evening into Sunday, returning breezy southerly winds. As the front approaches the waters, there is a 20-30% chance for Gale-force southerly wind gusts up to 35 kt on Sunday. At the same time, seas will likely (greater than 90% chance) build to 10-12 ft as a westerly swell pushes into the waters. Finally, we are in a period of stronger ebb currents. A Small Craft Advisory is in effect for the Columbia River Bar from 6-10 AM Wednesday for a very strong ebb bringing 8-9 ft seas. Another strong ebb is expected Thursday morning; however, seas with this ebb are forecast lower around 4-5 ft so decided not to issue another Small Craft Advisory for this ebb. -Alviz && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory from 6 AM to 10 AM PDT this morning for PZZ210. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

081 FXUS66 KMFR 021052 AFDMFR Area Forecast Discussion National Weather Service Medford OR 352 AM PDT Wed Apr 2 2025 .DISCUSSION...A weak disturbance in a moist northwest flow aloft will move into the area today. This will result in isolated showers mainly along and west of the Cascades in Oregon. Meanwhile, most hours and locations will be dry in northern Cal and east of the Cascades, although could not rule out a few stray showers in portions of Lake County. Seasonably cool temperatures and continued cloud cover will continue today. Isolated showers will end early this evening with most along and north of the Umpqua Divide and coastal mountains in southwest Oregon. It will be dry overnight Wednesday. Dry northerly flow will result in dry weather on Thursday. We`ll have another day of seasonably cool afternoon temperatures and decreasing cloud cover. It will breezy Thursday afternoon while we remain under northerly flow. It will be dry warmer Friday and Saturday as upper ridging builds into the area, with warmer afternoon temperatures. id-upper 70s are in the forecast for West Side Valleys with mid to upper 60s for East Side locations. Sunday, the operational models differ with the timing of the next front. The operational GFS and ensemble members show the front arriving Sunday. The operational ECMWF and individual ensemble members keeps the front offshore until late Sunday afternoon. The clusters are in pretty good agreement with the upper pattern which is similar to the ECMWF solutions. Therefore the forecast for Saturday night into Sunday will lean towards the slower arrival of the front. The front will move inland Sunday evening followed by post frontal showers Monday. Flat ridging will build into the area Tuesday with the storm track expected to shift far enough north to keep conditions dry, except for the northwest part of the forecast area. Even then, were only expecting a slight chance of rain. -Petrucelli && .AVIATION...02/06Z TAFs...Scattered showers continue across northern California and southern Oregon tonight, with most of the activity east of the Cascades. Thunderstorms are no longer a concern, and generally VFR levels are bring observed across the area. There`s chances of periodic MVFR ceilings through the night. A chance of fog at the Klamath Falls terminal is also in the forecast, although this is expected to be brief if fog does develop. Slight to moderate (30-50%) chances of scattered showers west of and along the Cascades continue through the TAF period. However, amounts are light and flight levels should not be generally impacted. -TAD && .MARINE...Updated 200 AM Wednesday, April 2, 2025...While very isolated areas could briefly experience steep seas today, we are generally expecting easing conditions over the waters today. However, northerly winds increase once again on Thursday which will result in steep seas. Then another period of improving conditions will exist Friday through Saturday. A building long period west swell on is anticipated on Sunday, and this will likely lead to steep seas once again && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. PACIFIC COASTAL WATERS...None. && $$

193 FXUS66 KEKA 012241 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 341 PM PDT Tue Apr 1 2025 .SYNOPSIS...The threat for showers and thunderstorms with small hail ends as a cold upper low progresses south. Clearing and drying will allow for some colder overnight lows. A sharp warmup with building high pressure can be expected for the end of the week, followed by some rain chances. && .DISCUSSION...Afternoon radar shows some lingering light showers moving through as a cold, upper low proceeds south. Instability will continue weakening, along with the chances for stronger showers and thunderstorms that have been producing prolific small hail on occasion. Though the usual post frontal deterrents for cold overnight lows will exist tonight, that is lingering cloud cover and moisture, and chance for developing fog, there is a potential for frost and freezing temperatures in some of our inland locations where the growing season has officially begun. A Frost Advisory and Freeze Warning have been hoisted for interior Mendocino and Lake County. There are also frosty temperatures of 36 degrees or less forecast for interior Humboldt, but confidence is lower there for the reasons outlined above. Growing season has begun for interior Humboldt today, so it will be closely watched, and a Frost Advisory may be warranted is drying and clearing occurs trends sooner. Confidence is higher for cooler temps and frost/freeze Wednesday night and Thursday morning. A stout area of high pressure will then amplify in Friday and through the weekend, and temperatures will nicely warm in response. The apex of the warming will be Saturday, when low to mid 60s are forecast for the coast, and low to mid 70s for the interior valleys. Rain chances increase late Saturday and Sunday from a clipping weather system. If cloudcover arrives earlier on Saturday, temperatures may be held down a bit. Currently, rainfall looks light with this system, with probability of 24 hour rainfall over 0.50 inch 40-60% for the Humboldt through Del Norte Sunday and Monday.There may be some increased southerly winds, especially if the low takes a more southerly track. There are currently low probabilities currently low for wind gusts over 25 mph. /JJW && .AVIATION...Once again conditions have been predominantly VFR with difficult to time periodic reductions in visibilities and ceilings in moderate to heavy rain in the stronger convection. Convective allowing models continue to indicate shower activity spreading over the area tonight. Impacts in terminals will continue. but should decrease on Wednesday as northerly breezes increase and warmer air results in greater stability. Gusty northwesterly winds this evening should also develop at the terminals with low level wind shear after surface wind decouple later this evening. Confidence KUKI will fog up is not high with cloud cover and mixing in the boundary layer through the night. DB && .MARINE...Hazardous seas warning for steep westerly swell and steeper NW wind waves continues for the southern waters tonight. Gale force gust are still not impossible based on the convective allowing models and HREF means. Probabilities are highest in the lee of Cape, however the duration of the gale gust appears short lived and confined just downwind of Cape Mendocino. Otherwise, northerly winds will fill in across all waters tonight as a cold upper trough shifts into the Great Basin and high pressure offshore builds closer to the coast. Steep northerly winds will likely continue on Wed, highest south of Cape Mendocino. Moderate ti fresh northerly breezes around 20kt and steep wind waves will continue Wed into Thu, and should start to subside on Friday. A lull is expected before winds shift to southerly over the weekend. How strong winds get is not certain, but current NBM guidance has low probabilities (<20% chance for gusts to 25 kt. Now there is a slight risk for sneaker waves as a long period westerly swell group builds. DB && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Winter Weather Advisory until 5 PM PDT this afternoon for CAZ105. Winter Storm Warning until 5 PM PDT this afternoon for CAZ107-108. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 4 AM PDT Wednesday for PZZ450. Small Craft Advisory until 5 AM PDT Thursday for PZZ455. Hazardous Seas Warning until 9 PM PDT this evening for PZZ470. Hazardous Seas Warning until 3 AM PDT Wednesday for PZZ475. && $$ 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

858 FXUS66 KMTR 020905 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 205 AM PDT Wed Apr 2 2025 ...New SYNOPSIS, SHORT TERM, LONG TERM... .SYNOPSIS... Issued at 203 AM PDT Wed Apr 2 2025 Warming and drying trend kicks off today with the return of above seasonal normal temperatures and minor HeatRisk by Friday. && .SHORT TERM... (Today and tonight) Issued at 203 AM PDT Wed Apr 2 2025 KMUX continues to show isolated rain and snow showers, primarily across the Central Coast. This activity will continue to diminish over the next few hours as the responsible surface low pressure system continues to drift southeastward. While today will begin the warming and drying trend, it may not necessarily feel like it with the 00Z OAK sounding showing a -0.75 degrees Celsius temperature at 850 millibars, this is below the 10th percentile for April 2nd. San Francisco Downtown (SFOC1) is actually forecast to come within two degrees of their daily record low for today (this morning), the official forecast is 45 degrees and the current record is 43 degrees in 1955. Records or not, cold conditions can be expected in the higher terrain as skies clear and winds diminish, promoting maximal radiational cooling. Dry conditions and temperatures several degrees below normal are on tap for today. && .LONG TERM... (Thursday through Tuesday) Issued at 203 AM PDT Wed Apr 2 2025 Warming trend continues Thursday, but widespread below normal temperatures and cold conditions in the higher terrain continue to be expected. Three climate sites daily low temperatures will be in jeopardy Thursday morning: San Rafael (SARC1) forecast is 41 degrees with a previous record of 39 degrees in 2010, San Francisco Downtown (SFOC1) forecast is 44 degrees with a previous record of 41 degrees in 2001, and Oakland Museum (OAMC1) forecast is 44 degrees with a previous record of 43 degrees in 2003. Friday is when the sensible weather will feel noticeably warmer with the return of above seasonal normal temperatures and even minor HeatRisk. Global ensemble clusters are in excellent agreement through Saturday with an upper-level longwave ridge building into the West from the Eastern Pacific Ocean. A cold front will try and dampen the warming and drying party, but it`s impacts are largely only expected to be a brief pause in the warming trend and rainfall totals of only a few hundredths in the North Bay. Warming and drying trend resumes Tuesday with the Climate Prediction Center indicating a 60-70% probability that temperatures will be above normal April 7th-11th. && .AVIATION... (06Z TAFS) Issued at 1019 PM PDT Tue Apr 1 2025 Some residual isolated showers may continue after 06Z, but should subside shortly after. Overall, VFR is expected to prevail through the TAF period. Northwesterly/westerly winds will remain breezy for the coastal terminals through most of the TAF period, but inland terminals should see moderate winds overnight. Winds rebuild to breezy for most terminals by Wednesday afternoon. Vicinity of SFO...VFR through the TAF period. Westerly gusty winds will continue to diminish tonight but breezy sustained winds (11-15 knots) will continue until late Wednesday night where winds diminish to moderate. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR through the TAF period, with a chance for MVFR as there is a chance for residual isolated showers after 06Z. && .MARINE... (Tonight through next Monday) Issued at 1019 PM PDT Tue Apr 1 2025 Some lingering isolated showers may continue over the waters overnight. A strong NW breeze will continue into Thursday and gradually diminish into fresh to moderate breeze by the weekend. Seas will remain elevated tonight with heights up to 14 feet and will subside by Wednesday night. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 3 AM PDT early this morning for SF Bay N of Bay Bridge. Small Craft Advisory until 3 PM PDT this afternoon for Mry Bay. Small Craft Advisory until 3 AM PDT Thursday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 9 AM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...Sarment LONG TERM....Sarment AVIATION...SO MARINE...SO 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

719 FXUS66 KOTX 020924 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 224 AM PDT Wed Apr 2 2025 .SYNOPSIS... A cool and unsettled weather pattern will persist through Thursday with a warming and drying trend by the weekend. && .DISCUSSION... Today through Thursday: The low has moved south, but we remain on the backside of the trough with additional weather disturbances moving through. Showers are again redeveloping this morning and will continue through the evening hours across northern Washington, extreme eastern WA and the ID Panhandle. As of 2am, there is an area of convergence between the two disturbances that is creating some light rain or sprinkles across the Spokane/CdA area south onto the Palouse and moving towards Shoshone county. While most of it will be rain, temps are cold enough on the Palouse for some light brief snow this morning. There is enough instability for isolated afternoon thunderstorms (15-20% chance), mainly for northern WA and the northern and central ID Panhandle. However, cannot rule out the potential for the Spokane area as well. Thursday is looking fairly similar as the last push from the north will bring a shower and isolated thunder threat, mainly to extreme eastern WA and the ID Panhandle. With this stronger northerly push as the trough begins to exit and the ridge nudges closer to the coast, we will see an increase in winds down the Okanogan Valley. There is a 60-70% chance of sustained winds of 15 mph and a 20-30% chance of sustained speeds over 20 mph. There is a 30-40% chance of seeing gusts to 30 mph.The winds will push down the Okanogan Valley and onto the Waterville Plateau and parts of the northern Columbia Basin. Temperatures will be at or a couple degrees below average for the beginning of April. Highs will be in the upper 40s and 50s, with lows in the upper 20s to mid 30s. Friday through Sunday: Ensembles models are in really good agreement that the ridge builds in for Friday through the weekend brining warming temperatures and a very pleasant weekend. Daytime temps will be in the 50s Friday and by Sunday widespread 60s with around 70 for parts of the LC Valley and areas south of Moses Lake. Dry air in place and clear to mostly clear skies will allow overnight temps to remain chilly through the weekend. The EC ensemble is still showing drier precipitable water values than the GFS ensemble, which could impact low temps, as well as relative humidity values for any prescribed burns planned. Monday and Tuesday: The ensembles are in agreement of the ridge being transient and moving east Monday, but they differ in how much influence a trough trying to approach the west coast will have. Currently about 65% of the guidance suggest precipitation moving east of the Cascades. The NBM has increased the chance of precipitation to 30-40%. Have daytime temps cooling a few degrees given the increase in cloud cover and potential for light rain. Overnight temps will be above average given the cloud cover. Snow levels start out high at 5-6k ft, and lower by about 1k ft by Tuesday morning. Wednesday: Guidance shows a broad ridge developing over the western US. About 30% of the ensembles suggest it to be a messier ridge with continued threat of mainly mountain showers. /Nisbet && .AVIATION... 06Z TAFS: With similar temperatures and humidity values tonight as last night, ceilings may drop again at GEG, SFF, COE, and PUW with a few hours of IFR conditions possible around sunrise. Showers will redevelop over the Idaho Panhandle in the early morning hours so included a PROB30 group for showers in the COE TAF. LWS is looking drier tonight so did not put fog in the TAF. EAT and MWH will remain VFR. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Low confidence on showers impacting COE. Low to moderate confidence in IFR conditions developing for GEG, SFF, and COE. ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance && .PRELIMINARY POINT TEMPS/POPS... Spokane 53 33 53 31 56 32 / 50 30 20 0 0 0 Coeur d`Alene 50 32 51 28 55 29 / 60 50 50 0 0 0 Pullman 49 31 48 30 54 31 / 30 20 30 10 0 0 Lewiston 55 36 56 34 59 34 / 20 0 20 10 0 0 Colville 52 30 53 27 57 30 / 60 50 10 0 0 0 Sandpoint 47 32 48 27 55 29 / 60 50 60 10 0 0 Kellogg 45 34 45 27 50 30 / 70 40 70 10 0 0 Moses Lake 59 34 59 32 62 34 / 0 0 0 0 0 0 Wenatchee 56 34 58 35 59 37 / 0 0 0 0 0 0 Omak 57 33 59 31 61 34 / 20 30 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$

772 FXUS66 KPDT 020507 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1007 PM PDT Tue Apr 1 2025 .Updated for Aviation... AVIATION... 06Z TAFS...Shower activity continues to decrease. VFR conditions are expected for the most part, though MVFR CIGS can not be ruled out at BDN or RDM. For now, have both sites going down close to MVFR but maintaining VFR conditions. Most of the guidance keeps VFR, though some guidance suggests MVFR. Confidence is 33% or less, but its possible especially toward daybreak. Otherwise, gusty winds to around 25 kts are expected at PDT and DLS from late morning through the afternoon hours. The rest of the TAF sites should have winds 10 kts or less. && .PREV DISCUSSION... /issued 516 PM PDT Tue Apr 1 2025/ Updated for Aviation... AVIATION... 00Z TAFS...Latest radar showed isolated showers across the area. These showers are expected to decrease in coverage this evening. While almost any site could get a passing shower, included in the locations that seemed most likely during the early evening. Otherwise, winds could get gusty around any heavy showers, otherwise will generally be 10 kts or less except at PDT, DLS and ALW where there will be some gusty winds in the 20 to 25 kt range at DLS and PDT this evening and around 15 to 20 kts at ALW. Winds will gust again Wednesday afternoon at these locations. PREV DISCUSSION... /issued 257 PM PDT Tue Apr 1 2025/ SHORT TERM...Tonight through Thursday... Radar currently shows scattered to isolated showers developing through the Columbia Basin. No lightning currently associated with these pockets of precipitation, but current instability values shows a few pockets of 500 J/kg of CAPE in the CWA. This along with some break in the clouds could fuel some isolated thunderstorms to develop later in the afternoon (10-30% chance). Rain across the Basin will taper off as we head into the late Tue PM hours and into the overnight. A few areas of light mountain snow in the Cascades and Blue Mountains that will continue through tonight as the trough continues southeastward. Had to adjust Bend/Redmond highs and lows slightly lower for the next 24 hours to account for the brief snowfall that occurred earlier this morning. As rain dries out of the Basin, light mountain snow will remain throughout all mountain regions as the upper ridge continues to move into the region. Guidance for additional snow accumulations is suggesting up to 3" of additional mountain snow (including the passes) with a 70-80% confidence. Mountain snow will clear up by Thursday morning, but model guidance is a bit divisive if it wants to give the Northern Blue Mountains a brief second round of snow or rain in the afternoon hours of Thursday. About 57% of clusters are projecting a brief period of rain before the ridge takes over the pattern and dries out any precipitation for the remainder of the short term. Winds aloft will have a more northward nature by Thursday evening, dropping any remaining precip chances area wide, making way for a warmer trend to commence shortly after. Winds across the region will be breezy with most areas of Basin gusting up to 15 to 25 knots with mostly west/west- northwest predominately surface winds with a decrease in strength at night time hours. LONG TERM...Thursday night through Tuesday... Key Messages... - Drying and warming trend peaking Sunday with highs 10-15 degrees above average. - Unsettled conditions with light precip chances late Sunday into Tuesday, mainly in the mountains. The large scale pattern early Thursday will be characterized by an amplified, deep synoptic heights with an upper-level ridge offshore the West Coast into Yukon and deep upper-level troughs upstream and downstream, the latter extending across the Canadian Prairies into the Four Corners region. The pattern will be fairly progressive day 3 to day 7 with upper ridging promoting drying and warming through the weekend until near seasonable temperatures and low chances return Monday-Tuesday, mainly in the mountains. Overall, guidance in fair agreement with increasing uncertainty revolving around a shortwave trough and its amplitude Sunday-Monday. Guidance support anomalous upper ridging building Friday still offshore before moving into the PacNW and British Columbia Saturday. Of which, forecasts show the highest heights above average for this time of year across BC into the Northwest Territories with EPS mean 500 hPA heights forecast to exceed model climate for this time of year. Meantime, start to see 850 hPa temperature anomalies +7C across the Interior NW as warmer air mass takes hold under southerly flow this weekend peaking on Sunday. That said, not atypical with highs forecast 10-15 degrees with the greatest departure from average on Sunday. This is supported with only a minor signal in the Extreme Forecast Index only showing limited areas of 0.5-0.6 indicative of high but not unusual temperatures forecast by the EPS, that increases confidence in the forecast and magnitude of the highs with them not being atypical. Looking ahead, clustering scenarios show an upper trough building in the eastern North Pacific with a shortwave trough ejecting into the Pacific NW and likely crossing Monday though differences in strength and timing are apparent. Current thinking is the front will be somewhat weak with its attendant moisture plume largely out of the SSW with a trajectory favoring the OR/WA Cascades, and not so much the eastern mountains. Further, the plume shows limited IVT to work with limited probs in excess of 150 Kg/ms seen via the inland transect of the foothills of the Cascades (~60-70%) and less in the inland transect (40-60%). As such, the combination of weak forcing and a less favorable pathway seems conducive for limited mountain accumulating precip, mainly in the form of high mountain rain with snow levels above 5 kft forecast through Sunday night before falling some Monday. Latest QPF clusters show increasing chances with the most likely scenario (~60%) for precip to be confined to the upper slopes of the eastern Cascades through Sunday night. With the best chances for lowlands and eastern mountains to see any rain falling more so in the window of Monday-Monday night. Meantime, with the weak frontal passage, expect highs to fall closer to near average Monday and Tuesday. Otherwise, winds look largely light in the long term except for breezy conditions Monday-Tuesday. Current thinking is peak daily gusts in excess of 25 mph is likely (60%) across much of the lower elevations on Monday. AVIATION...18Z TAFs...Latest aviation concerns revolve around a) ongoing snow showers in central OR, b) afternoon rain shower chances with a low chance of thunder this afternoon, and c) possibly sub-VFR late tonight. Latest radar and satellite depicts some isolated light rain showers across south central WA and area of light snow across KBDN. Both should lessen in coverage and diminish between now and 20 UTC before renewed isolated-widely scattered showers develop this afternoon. Latest HREF guidance and marginal instability support a risk for thunder (10-30%) outside our TAF terminals across the eastern mountains. Otherwise, these shower chances will diminish in the evening with loss of daytime heating. The other concern is potential for stratus to build into central OR overnight-early morning tomorrow with sub-VFR ceilings looking more likely than not. && .PRELIMINARY POINT TEMPS/POPS... PDT 36 55 34 57 / 30 10 0 10 ALW 38 54 36 55 / 30 20 10 20 PSC 35 60 35 61 / 20 0 0 0 YKM 33 58 32 60 / 10 0 0 0 HRI 36 58 35 60 / 30 0 0 10 ELN 35 54 35 57 / 0 0 0 10 RDM 26 50 26 52 / 20 0 0 0 LGD 32 48 28 49 / 30 20 10 20 GCD 31 46 27 48 / 60 20 10 10 DLS 39 57 37 61 / 20 10 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...95 LONG TERM....80 AVIATION...77

847 FXUS65 KREV 020927 AFDREV Area Forecast Discussion National Weather Service Reno NV 227 AM PDT Wed Apr 2 2025 .KEY MESSAGES... * Cold temperatures with isolated showers are forecast today and Thursday. Hard freezes are expected for Western Nevada valleys and urban areas. * A warming trend begins this weekend going into next week with above normal temperatures favored. Increases in stream flows are possible with snowmelt anticipated. * Chances for light showers may return on Sunday and Monday though the region looks to stay mostly dry otherwise. && .DISCUSSION... * A cold trough remains over the Western CONUS today and Thursday causing more limited forcing and allowing for rain/snow showers on both days. The latest NBM probabilities show around a 40-60% chance for measurable snow mostly for areas south of US-50 as well as Sierra mountain communities. The latest Winter Storm Severity Index (WSSI) shows not even much in the ways of minor impacts over the next two days as a result, so it will to be a better time to travel within the region compared to the snowy conditions we have seen over the last few days. * Well below normal temperatures are projected through Friday morning. The main impact will be a high risk of hard freezes for Western NV valley and urban areas. The latest NBM Probabilities for sub-25 degrees range from around 30% at Reno Airport to around 60-80% at Yerington and Lovelock. Please consider protecting any early season vegetation and irrigation systems that you may have. * A warming trend is in the forecast this weekend as winds turn more westerly/southwesterly. Parts of Western NV like Fallon look to see 50-70% probabilities for highs above 70 degrees starting on Sunday with similar numbers for highs above 80 degrees starting next Wednesday. Portions of the Reno-Sparks area see a 20-30% chance of highs greater than 70 degrees begin on Sunday with similar probabilities of highs greater than 80 degrees on Wednesday. With the warmer temperatures expected, some increased snowmelt could be result causing some minor rises in area rivers and streams. Long term forecast ensembles currently do not show a change in the upper air pattern until the weekend after this upcoming one, so these above normal temperatures could be here for a few days at least. * Forecast ensembles still show a ridge building over the CA/NV region starting this weekend and going into next week. This should keep heavier precipitation systems to our north, but the latest NBM probabilities are currently showing a 30-40% chance of light showers on Sunday and Monday due to the influence of low pressure residing in the Gulf of Alaska. With the warmer daytime temperatures, the precipitation type looks to be mostly light rain though the Sierra portions of the region could see some light snow mixed in as snow levels and temperatures drop a bit overnight. QPF and snowfall totals look to be minimal at this time, so not anticipating many impacts on account of this precipitation. -078 && .AVIATION... Winds across the region look to be relatively light today compared to the area winds seen over the last few day associated with the departing winter storm system. Wintry shower chances are tapering off early this morning allowing for conditions to improve by the mid- morning. But after 02/20Z, convective models show isolated shower chances increasing today which may cause brief sub-VFR conditions at some area terminals should a shower pass nearby. While most of the region looks to stay dry tomorrow, isolated Sierra shower chances of 10-20% are in the forecast again during Thursday afternoon. -078 && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

520 FXUS66 KSTO 020953 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 253 AM PDT Wed Apr 2 2025 .Discussion... .Synopsis... Light showers over the Northern Sierra today and tomorrow but otherwise dry and mild weather outside of breezy northerly winds at times. .Key Messages... * Today-Thursday: A very weak system enters the region, with just some light showers over the higher elevations of the northern Sierra. Little to no impacts are expected. * Drier and warmer weather returns late week into the weekend with periods of breezy north to east winds with afternoon gusts near 15 to 25 MPH. * Chances for Valley Highs > 75 Degrees Saturday/Sunday: 40-80% .Changes from previous forecast... *No changes from previous forecast. && .AVIATION... Mainly VFR conditions across interior NorCal next 24 hours. Periods of northerly wind gusts up to 20 knots from 18z today through 00z Thursday. A few scattered rain showers in the Valley/foothills and light lingering snow showers in the mountains through 00z Thursday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

217 FXUS65 KMSO 021028 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 428 AM MDT Wed Apr 2 2025 .DISCUSSION... KEY MESSAGES: - Winter driving conditions across portions of southwest Montana this morning. - Snow will develop in the Glacier Region and other parts of northwest Montana later tonight through Thursday. - Warm and dry weekend on tap. The residual wrap-around light snow will continue to impact southwest Montana through daybreak. There is a winter weather advisory to capture this impact. Satellite trends depict this feature slowly drifting southwards with time and will be out of our area by late morning. Instability showers will develop this afternoon and evening across the region. Not much change has occurred with the shortwave trough on Thursday and backdoor cold front. We have issued winter weather advisories to cover the snow impacts tonight through Thursday across northwest Montana. The low-hanging fruit for snowfall appears to be in the Glacier Region where 2 to 8 inches could fall. The other areas will depend on how much snow shower coverage there will be tonight. The start time for the Lincoln County/Kootenai/Cabinet Region advisory was a bit tricky, but felt that probabilities were high enough to warrant starting at midnight to capture snow on US-93 between Eureka and Whitefish. Eastern parts of the Flathead Valley could be snowing after midnight, then Kalispell by daybreak onwards. The cold front will bring a period of moderate snow in these areas in the morning, and then across Flathead Lake by early afternoon. By then, the ground temps will be warm enough that any snow accumulation would melt on the roads. Once the cold front moves through from the northeast, drier air will cause showers to end in the afternoon up north, but continue across west-central Montana. With high pressure developing by Friday, there could be some valley fog to start, but temperatures will warm into the upper 40s to lower 50s. And this will begin the very pleasant warm and dry weekend. The timing of the cold front on Monday has trended a little faster, so the chance for highs getting to the 70s has been squashed. There`s only a 20 percent for highs to get into the mid to upper 60s across the west-central Montana valleys on Monday. && .AVIATION...Satellite trends early this morning depict a narrow area of wrap-around rain and snow across southwest Montana. This feature will slowly shift southwards and weaken by 02/1700Z or late this morning. KBTM will likely continue to see periods of lowered ceiling and visibility with light snow. Low stratus has formed across northwest Montana and portions of Idaho. Expect improvement by this afternoon. Afternoon and evening showers will bring brief visibility reductions. An upper level wave will bring more organized snow showers after 03/0300z or 9 pm MDT this evening across northwest Montana. A cold front from Canada will bring a period of moderate snow to the Glacier Region and portions of northwest Montana Thursday morning. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Winter Weather Advisory from midnight tonight to 3 PM MDT Thursday for Kootenai/Cabinet Region...West Glacier Region. Winter Weather Advisory from 3 AM to 3 PM MDT Thursday for Flathead/Mission Valleys. Winter Weather Advisory until 9 AM MDT this morning for Butte/Blackfoot Region. ID...None. && $$

145 FXUS65 KBOI 020900 AFDBOI Area Forecast Discussion National Weather Service Boise ID 300 AM MDT Wed Apr 2 2025 .SHORT TERM...Today through Friday night...Gradual warming and drying through Friday as the main upper trough over the interior northwest US slowly weakens. Scattered snow showers over the mountains today, and again Thursday in the central Idaho mountains but fewer than today. Still enough instability for isolated thunderstorms over the mountains late today and again late Thursday. High temps will increase about two degrees per day while lows hold generally steady. Winds will be northwest through Friday 5 to 15 mph in the nights and mornings, 10 to 20 mph in the afternoons, except 20 mph with afternoon gusts to 35 mph in the Snake Basin east of Boise. .LONG TERM...Saturday through Wednesday...An upper level ridge is expected to build across the northwest region through Saturday, continuing a warm and dry trend over the weekend with daytime temperatures in the 60s and 70s across the valleys, and snow levels in the 5000-6000 ft range over the entire area. A shortwave trough is expected to move into the region on Monday, slightly cooling temperatures and bringing showers and chance of thunderstorms Monday afternoon/evening. Snow levels will be expected to rise to 6000-7000 ft range, and snowfall is generally not expected over the area early next week. Following this brief trough passage, a longwave ridge is expected to move into the area through Tuesday and Wednesday, returning above normal temperatures and drier conditions until the end of the extended forecast period. && .AVIATION...Mainly VFR. Scattered showers after 02/17Z will create periods of MVFR/IFR, favoring higher terrain. Showers will be capable of graupel, isolated lightning, and outflow winds up to 20-30 kt. Snow levels 3k-4k feet MSL. Mountains obscured at times. Surface winds: light and variable, becoming W-NW 5-15 kt with gusts around 25 kt by late morning. Winds aloft at 10kft: N-NW 10-20 kt. KBOI...Generally VFR. Showers developing this afternoon over Boise foothills creating mtn obscuration. A 10% chance of MVFR rain/graupel showers hitting KBOI terminal. Surface winds: light NW, increasing to NW 8-14 kt with gusts around 20 kt by this afternoon. && .HYDROLOGY...A Flood warning continues on the Silvies River near Burns/OR due to snowmelt and a breached levee, although the river itself is forecast to recede below 12.0 flood stage this morning. Cool weather will limit snowmelt through Friday, but warmer weather this weekend should increase snowmelt again. After brief cooling Monday and Tuesday another warm period and more snowmelt is expected next week. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...LC LONG TERM....JY AVIATION.....SH HYDROLOGY....LC

543 FXUS65 KLKN 020733 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1233 AM PDT Wed Apr 2 2025 .SYNOPSIS... Scattered snow showers are expected throughout Northern and Central Nevada today into tonight. There may be a few rumbles of thunder and graupel as well this afternoon. Snow showers will be widely separated across Northern and Central Nevada Thursday into Thursday night. A warming trend is anticipated Friday through at least next Wednesday. && .SHORT TERM...Today through Thursday night A trough of low pressure will move eastward across Southern Nevada today into tonight, resulting in scattered snow showers in Northern and Central Nevada. A few strong thunderstorms are possible in Central and Eastern Nevada this afternoon. The possibility should be highest in White Pine, Northern Nye, and Southern Lander Counties. The strongest thunderstorms will produce wind gusts near 45 mph, dangerous cloud to ground lightning strikes, and graupel. One to two inches of snow is expected over passes and summits along Highway 50 today into tonight. One inch or less of snow is anticipated along passes and summits along Interstate 80 today into tonight. Here are probabilities of one inch of snow or more for select locations in Northern and Central Nevada from 5 AM PDT Wednesday, April 2nd, 2025 until 5 AM PDT Thursday, April 3rd, 2025: Austin - 61% Ely - 54% Great Basin National Park - 52% Jarbidge - 51% Ruby Lake - 41% Lages Junction - 38% Ruby Valley - 32% Lund - 27% Owyhee - 19% Eureka - 11% The aforementioned trough of low pressure will stall near the Utah/Nevada border Thursday and Thursday night, resulting in widely separated snow showers throughout Northern and Central Nevada. These snow showers will be less intense compared to today into tonight. Less than one inch of snow is expected along passes and summits across Northern and Central Nevada Thursday into Thursday night. .LONG TERM...Friday through next Wednesday Dry and warmer weather conditions becoming the dominant factor throughout the long term as a strong upper level ridging takes hold of the western U.S. increasing temperatures into the 50s to 60s through weekend, into the 60s to 70s by next week. Overnight lows still expected to be cool but also be on a warming trend, starting in the 20s on the weekend, increasing into the 30s next week. The upper level ridge is strongest over the weekend, however models are showing a low pressure trough heading into the northwestern U.S. that will weekend the ridge into a more zonal flow. The trough will be strong enough to extend some moisture towards the northern part of Nevada along the state border, however accumulations at this time are expected to be very light with little to no chance of snow due to warmer temperatures. Shortly after the trough, upper ridging quickly moves back over the state. Winds Friday and Saturday expected to be elevated from the north at 10-20 mph, followed by calm winds Sunday, then elevated winds from the west at 10-15 mph Monday and Tuesday afternoon. && .AVIATION... SHSN and/or VCSH conditions present at all terminals today as rain/snow showers expected to continue today from the low pressure system over the state. Expected lower CIGs at all terminals as showers move across the state and reaching the terminals which may reduce visibility to MVFR and possibly IFR conditions. Weather conditions expected to last into the evening hours. Winds expected to be light below 10 kts at all terminals from the north. && .LKN Watches/Warnings/Advisories... None. && $$ 87/90/97