934 FXUS66 KSEW 030351 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 851 PM PDT Wed Apr 2 2025 .SYNOPSIS...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. && .UPDATE...Forecast remains on track this evening as shower coverage is becoming less widespread and generally pushing into the mountains and a few near the coast. It`ll still be a quite cool night and temperatures may be cold enough for a few patches of frost south of Puget Sound through Lewis County. No other concerns this evening, with the previous short/long term sections following. && .SHORT TERM /TONIGHT THROUGH SATURDAY/...Onshore flow prevails across western WA today with a broad trough across the West. Temperatures will be chilly overnight and in the 30s for most areas, with temps near freezing around the south sound. We`re under dry, N flow, on Thursday as a ridge builds offshore. Expect more sunshine and slightly warmer temperatures with highs in the mid 50s. High pressure shifts inland through Saturday for dry and mild conditions. Morning lows will stay chilly and in the 30s. Afternoon highs will reach the 60s to lower 70s with plenty of sunshine. 33 .LONG TERM /SUNDAY THROUGH WEDNESDAY/...High pressure will shift eastward on Sunday as a trough moves in from the west. Clouds will increase through the day with rain, from the next incoming system, reaching the coast during the afternoon. Expect one last dry day in the interior with highs in the lower to mid 60s. Precipitation spreads farther inland Sunday night as the cold front moves in. We`re under moist, westerly flow, through early next week for more rain and locally windy weather. 33 && .AVIATION...Northerly flow aloft as a offshore ridge nudges closer to western Washington. Widespread VFR conditions this evening and, for most terminals, expected to persist throughout the TAF period. Locations more prone to lower cigs, such as OLM, HQM and PWT, may see cigs dip into MVFR overnight/early Thursday morning thanks to lingering low level moisture as the aforementioned ridge sets up. Showers continue to dissipate this evening, likely fizzling out completely tonight. Winds in process of shifting direction at the time of this writing...so while most terminals still showing west to southwesterly winds, seeing the northernmost terminals already switching to north to northwesterly with speeds generally 4-8 kts now. Speeds expected to slow further overnight, easing to 5 kts or less. KSEA...VFR conditions expected at the terminal for the TAF period. W winds 4 to 8 knots still have a little bit of time to switch more northwesterly before 06Z, when direction is expected to switch back to a more southerly component throughout the rest of the overnight and into Thursday morning. While VFR will likely continue through the TAF period, but there is a 35% chance of low MVFR clouds to develop early Thursday morning. Mazurkiewicz/18 && .MARINE...Surface high pressure will continue to build offshore, easing marine winds and seas through the rest of the week. Benign conditions will continue through the weekend, before a frontal system approaches the waters Sunday evening. Here, we will likely see elevated winds and seas return to the coastal waters. Combined seas 5 to 7 feet this afternoon will start to taper down to 3 to 5 feet through the rest of the week and into the weekend. Seas will start to gradually build upwards by Sunday ranging from 9 to 12 feet. Mazurkiewicz && .HYDROLOGY....No river flooding is expected over the next 7 days. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$

848 FXUS66 KPQR 022148 AFDPQR Area Forecast Discussion National Weather Service Portland OR 248 PM PDT Wed Apr 2 2025 .SYNOPSIS...Showers persist today dissipating overnight as high pressure builds. Clear days and mostly clear evenings will set the stage for fog/frost development tonight and Thur night/Fri morning. Increasing temperatures on Saturday will be above normal. Frontal system arrives Sunday through early next week. && .SHORT TERM...Now through Friday Night...Satellite shows patchy skies associated with post frontal showers. These showers have brought periods of heavy rain and small hail to the region. A dry slot will be moving inland later this evening which will cause skies to clear or become partically clear. The clear skies combined with colder air will promote fog development throughout the Willamette Valley, and coastal valleys especially. There are some limiting factors though, the first of which being cloud cover. If the clouds are too dense, radiational cooling will not be enough to reach the dewpoint. However, the amount of available moisture from the previous day`s showers will provide the moisture needed fo saturation. High pressure persists through Saturday with clearer skies each day. The next weather factor to consider occurs Thursday night into Friday morning. Overnight temperatures will dip into the 30s. This, combined with light winds and drier conditions, can produce frost through the area. This would be the first frost of the growing season so it is something we are watching closely. In order to get frost we need a few ingredients: calm winds, temperatures between 33-38 deg F, a drier atmosphere initially, then temperatures reaching the dewpoint temperature (the temperature an airmass has to cool to inorder to become saturated). Light easterly winds during the day will create the decreased moisture and cooler air filtering in; winds are expected to then go calm. Probabilitistcally there are a few concerns. First: temperatures are sitting on the upper threshold for frost formation closer to 37-40 deg F overnight. While the 10th percentile would be cold enough, any fluctuation to warmer would not. In addition, the spread between the dew point depression is around 3 degrees which may be just large enough to prevent frost. Ultimately, it`s not a bad idea if you`re below 1500 ft in the valleys (coastal, inland, Cowlitz, and Gorge) to prepare for patchy to widespread frost. Areas most at risk will be rural areas and the southern Willamette Valley. Once the sun rises, any frost that did form will melt off and conditions will warm to a spring-like day. -Muessle .LONG TERM...Saturday through Wednesday...Saturday will be anyother springy day giving us a break before the next rain arrives on Sunday. High pressure will usher in warmer air from the south aloft, which will mix down causing highs to increase into the upper 60s to lower 70s. Along the coast, will remain seasonable, but sunnier than we have seen the last week. Inland areas will be warmer than normal. Models still have some discontinuity with the overall high temperature forecast. For example, the NBM ranges from 70 deg F to nearly 76 deg F (the 90th percentile). The deterministic forecast though sat right along the 25th percentile and in some areas even below this value. Decided to incorporate and nudge to the 50th percentile in the forecast in the Willamette Valley, Clark County, and the lowlands of Cowlitz county. If easterly winds are elevated, these tempeatures may be less if close to the Cascades or the Gorge. Enjoy the sun as a frontal system will move in Sunday night with a series of shortwaves through Wednesday. Overall troughing is not necessarily well realized by models at this point, and precipitation amounts will be low in comparison to what we typically see this time of year. The coast though will be the exception as the ECMWF is depicting anywhere from a quarter of an inch in 24 hours, to some of the ensembles of greater than 1.25 inches. The GFS is less wet with much lower amounts (closer to 0.25 inch). -Muessle && .AVIATION...Radar, satellite and surface observations continue to show mostly generally VFR conditions with scattered showers moving into the airspace from the northwest. These showers will persist throughout the day and will result in predominately VFR conditions with FL030 to FL050. Showers could result in brief periods of MVFR conditions (15%-30% probability) through 00Z-03Z Thursday. For inland locations there is also a 20% probability for thunderstorms through 03Z Thursday as well. Any thunderstorm that does develop could produce small hail as well as gusty and erratic winds. Afterwards, conditions will gradually dry up and result in widespread VFR. However, as we clear out, there will be a 20% probability of fog development within the Willamette Valley starting around 13Z Thursday. Expect westerly to northwesterly winds across all terminals around up to 10 kt. KAST anemometer is still inoperative. Therefore, TAFs limited to CIG and VIS. PDX AND APPROACHES...Predominately VFR conditions with scattered showers through 03Z Thursday. Any showers could result in brief periods of MVFR conditions (15%-30% probability) through 03Z Thursday. Afterwards, widespread VFR. Westerly winds become more northwesterly, generally less than 10 kt. -42 && .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. The next front arrives Saturday evening into Sunday and that will bring a return to breezy southerly winds across all waters. As the front approaches, there is a 15-30% probability for Gale-force southerly wind gusts up to 40 kt on Sunday. Seas generally 3 to 6 ft through Sunday. As the front approaches the waters, seas will build towards 10 to 12 ft as a fresh westerly swell pushes into the waters. Another strong ebb is expected Thursday morning; however, seas with this ebb are forecast around 4 to 5 ft. -42 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

456 FXUS66 KMFR 030354 AFDMFR Area Forecast Discussion National Weather Service Medford OR 854 PM PDT Wed Apr 2 2025 .DISCUSSION...Updated Aviation Discussion. && .AVIATION...03/03Z TAFs...Scattered light showers continue to move across northern California and southern Oregon, but flight levels have generally stayed at VFR across the area. A stray shower may cause locally lower flight levels, but extended poor conditions are not expected at area terminals in this TAF period. Showers will decrease through the night. Roseburg may see a period of MVFR ceilings tonight as well as a period of fog on Thursday morning, but confidence is slight to moderate in these possibilities. With dew points trending up at Klamath Falls, the chance of fog in the Klamath Basin is also worth mentioning. High-res guidance has a 10% chance of IFR and LIFR visibilities moving over the Klamath Falls terminal early Thursday morning. These conditions are only present for a couple of hours in model guidance and dissipate in the late morning hours. -TAD && .PREV DISCUSSION... /Issued 500 PM PDT Wed Apr 2 2025/ DISCUSSION...A long wave upper trough is settling into the Great Basin and moving slowly toward the Four Corners region. The PacNW is currently on the back side of this upper trough with northerly flow aloft. Some energy in the northerly flow aloft and instability due to daytime heating is resulting in isolated to scattered showers this afternoon, especially from the Cascades and Siskiyous north and west, but also over Winter Rim and the Warners. Some of these may contain brief gusty winds. An isolated shower or two still could pop up outside those locations as well through this evening. Coverage of showers should diminish around/after sunset and cloud cover should also gradually break up. While we`re getting out of the time of year for fog formation, there is a 20-30% chance some forms in the west side valleys toward morning. This is most likely in the Umpqua Basin, where low level moisture is highest. Low temperatures tonight will be a bit below normal. So, it`ll be chilly east of the Cascades with lows largely in the 20s. West side valleys will bottom out in the 30s, which could lead to patchy frost where it is clear long enough (perhaps Illinois Valley). High pressure offshore will build into the area on Thursday. There is still just enough instability for a slight chance/isolated rain/snow showers in far SE sections during Thursday afternoon, but most areas will be dry and turn milder, though high temperatures remain mostly below normal. Chilly mornings and milder afternoons are expected Friday and Saturday with a period of drying east winds Friday, which will shift to southerly during Saturday. The warming trend continues with high temperatures of 5-10F above normal west of the Cascades Friday (near 70F west side valleys) and 10-15F above normal there on Saturday (mid 70s). East side areas warm more gradually, but still end up about 5-10F above normal on Saturday (generally 60-65F for highs). Sunday will be a transition day as the next trough approaches the coast. This will probably be the warmest day east of the Cascades, but increasing cloud cover should result in slightly cooler temperatures west of the Cascades. Expect an uptick in southerly winds in the usual spots (along the coast, in the Shasta Valley and over the East Side), but overall, just a breezy afternoon. Rain chances increase along the coast and rain is likely there, if if not late morning, then by afternoon. Most other areas escape the day dry, but there is a chance of rain along I-5 (30-50%) Sunday afternoon. A period of rain moves through most areas Sunday night with snow levels around 7500 feet dropping to the higher passes (5000 feet) by Monday morning. Post-frontal showers continue 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. -Spilde MARINE...Updated 200 PM Wednesday, April 2, 2025...Overall, expect seas of 6 to 9 feet at 10 seconds with north to northwest winds generally in the 10-20kt range into tonight. Northerly winds increase once again on Thursday which will result in steep short-period seas. We have issued a Small Craft Advisory out to 20 NM from shore off Cape Blanco, and extending to 60 NM from shore off Pt. St. George. Then, another period of improving conditions is expected Friday through Saturday. A building long period (18-20 seconds) west swell is anticipated on Sunday, and this will likely lead to steep seas once again. -Spilde && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory from 11 AM Thursday to 3 AM PDT Friday for PZZ356-376. && $$

156 FXUS66 KEKA 022203 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 303 PM PDT Wed Apr 2 2025 .SYNOPSIS...Few isolated showers continue to diminish 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...A cold upper low continues to pass south of the forecast area and into the Four Corners Region this afternoon. Wrap- around moisture is generating some light showers over mainly Humboldt and Del Norte counties, and that activity will fade tonight. As with last night, lingering moisture, dissipating cloudcover, and some patchy fog formation will hold up overnight temperatures for some, particularly where additional light showers occurred today. Overall, the area has dried out more than the last 24 hours, and areas of frost and subfreezing temperatures are expected in portions of areas where the agricultural growing season has begun. Frost Advisories and Freeze Warnings are out in Southern Mendocino and Lake counties. Interior Humboldt will be watched closely, as the agricultural season has begun, but confidence is low on the coverage of frost potential at this time given the previously described conditions. On Thursday, a ridge of high pressure will begin amplifying over the NE Pacific and into the Western CONUS. The pressure gradient will increase against the departing upper low and northerly winds will increase to breezy levels, with gusts of 18 to 25 mph in the exposed ridges and coastal headlands in response. For Friday, the ridge progresses over W CONUS when abundant warmth will ensue. There are indications an inverted trough may form with favorable positioning for enhanced offshore winds and perhaps higher temperatures than forecast. Currently, daytime highs of around 5 degrees above climatological norms are forecast, with low 60s at the coast and low 70s for the interior valleys. Saturday may be the apex of warmth, with daytime highs nearing 10 degrees above average, with some mid 70s for interior valleys. Cloud cover arriving ahead of the short wave trough may inhibit the full potential of warmth for some. The shortwave will be the first of two systems that will deliver light rainfall to the region late Saturday through Monday, and maybe into Tuesday. Snow levels look to be high, at 4500 to 5000 ft, and snowfall does should not be an issue. The proximity of the low to the low will determine the strength of the southerly winds, and NBM is still struggling to resolve meaningful probabilities of wind gusts over 25 mph through that period. There are some ensemble solutions that portray a stronger 925mb low level jet and heavier rainfall, and there is high uncertainty in 24 rainfall amounts from ensemble spread (1-2 inches difference). Probabilities for 24 rainfall over 0.5 inch are currently moderate to high (46 to 75%). /JJW && .AVIATION...Improving weather, under drying northerly flow, rendered the TAF sites mostly VFR today. However, widely scattered, diminishing showers continued to lurk off the Humboldt Coast and interior areas through early afternoon. Infrequent MVFR Cigs have been associated with showers. Winds across the region shifted more to the WNW-N this afternoon. Due to a micro "bubble" high over CEC, the wind gradient was slower to develop until around 1300 LST (20Z). In the meantime, winds were already gusty at UKI and ACV airports. At the coast, winds will diminished somewhat tonight, but should stay relevant enough to prevent any marine layer development under a northerly gradient flow. Winds will be light overnight at UKI. Therefore light fog is possible for a short period of time Thursday morning, but seems unlikely at this time (Wed Afternoon). /TA && .MARINE...Fresh to moderate northerlies will persist tonight through Thu evening. Strongest north winds are initially forecast to occur over the outer waters and in the lee of Cape Mendocino inside 10NM tonight. Generally, 15-25 kt is forecast with gusts up to 30 kt. The largest steep waves of 6-8 ft are also expected across the southern waters. Diurnal wind max is forecast to expand northward on Thu with HREF probabilities of 30-60% for gale force gusts to 35 kt around and offshore of Pt St George Thursday afternoon and evening. Coverage of these gale gusts based on the HREF does not appear sufficient at this time to warrant a gale watch. Later runs of the CAMS could expand. Northern inner waters will be much more marginal for gusts to 21 to 24kt this afternoon and evening. Winds will likely lay down overnight and Thu morning before increasing again Thu afternoon in response to land mass heating. North winds should be stronger Thu afternoon and evening for the northern waters and a small craft advisory will be necessary as steep waves increase. Northerly conditions should begin to relax and ease up on Friday as a thermal trough shifts over the coastal waters. Steep wind waves around 5-7 feet will probably persist in the outer waters, however. Southerly winds are forecast to develop over the weekend in advance of a frontal system. NBM guidance continues with probabilities not more than 20% for gusts over 25 kt, so right now winds do not look to be very strong and impactful. A long period westerly swell group will build on Sunday and peak to 9 to 11 ft near 18 seconds by mid to late morning according to GFS-waves. GFS wind fields could be wrong and the swell overdone. Stay tuned as this swell may pose a risk for sneaker waves on Sunday. DB && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Freeze Warning from 2 AM to 9 AM PDT Thursday for CAZ110- 111-114. Frost Advisory from 2 AM to 9 AM PDT Thursday for CAZ112- 113-115. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 9 PM PDT this evening for PZZ450. Small Craft Advisory until 9 AM PDT Thursday for PZZ455. Small Craft Advisory until 3 AM PDT Friday for PZZ470-475. && $$ 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

419 FXUS66 KMTR 030008 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 508 PM PDT Wed Apr 2 2025 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 1243 PM PDT Wed Apr 2 2025 Warming and drying trend begins today with temperatures above seasonal averages by Friday. A weak cold front is possible later this upcoming weekend. && .SHORT TERM... (This evening through Thursday) Issued at 1243 PM PDT Wed Apr 2 2025 Fair weather cumulus clouds are popping off across the region as the upper level low and surface trough that gave us the last two days of convective showers continues to move towards the southeast. Today marks the start of a warming and drying trend that will begin rather modestly, with high temperatures today reaching the lower to middle 60s in the inland valleys, the middle 50s to near 60 in the coastal areas, and the 40s to the lower 50s in the higher elevations. Gusty post-trough winds will develop this afternoon and evening, with gusts reaching 25 to 30 mph along the coast, through the gaps and passes, along the ridgelines, and within the northern Salinas Valley. Tonight, clear skies and calmer winds will enhance radiational cooling, with low temperatures expected to be chilly across the region. A Frost Advisory has been issued for the North Bay valleys and the interior Central Coast, including the southern Salinas Valley, from 2 AM to 9 AM Thursday morning. Lows in these areas will reach the middle to upper 30s, with the coldest spots across the interior Central Coast reaching the lower 30s. These are borderline as far as the Frost Advisory criteria, especially in the North Bay, but the start of the budding season means that agricultural interests are currently extremely sensitive to low temperatures, which tipped the scales toward issuing the Frost Advisory. Elsewhere, lows will range from the upper 30s inland to the middle to upper 40s along the coast. Three long-term climate sites continue to see forecasts threatening daily minimum temperature records: San Rafael, where a forecast of 42 compares to a record of 39 degrees from 2010; downtown San Francisco, where a forecast of 44 degrees compares to a record of 41 degrees from 2001; and the Oakland Museum, where a forecast of 44 degrees compares to a record of 43 degrees from 2003. High temperatures will feel slightly warmer on Thursday with most regions seeing highs around 3 degrees warmer than today`s highs, give or take a couple of degrees. && .LONG TERM... (Thursday night through next Tuesday) Issued at 1243 PM PDT Wed Apr 2 2025 The warming and drying trend continues through the week as an upper level ridge builds across the West Coast. This upcoming weekend, highs should reach the middle 70s to near 80 across the inland valleys. For context, this is around 5 to 10 degrees above the seasonal average, and Minor HeatRisk could return to the inland valleys, meaning that there is a low risk for heat related illnesses among people extremely sensitive to heat, especially those without effective cooling and.or adequate hydration. On Sunday and Monday, a cold front will skirt the Bay Area, bringing an interruption to the warming trend and a chance for light rain. Confidence is increasing in the chances for rain in the Bay Area, especially across the North Bay. However, the rainfall totals are yet to come into better focus. As before, potential rainfall totals continue to be modulated by the exact location of the cold front and how it interacts with a upper level ridge over the western United States. That said, even the most optimistic forecasts top out around a half to three quarters of an inch across the Sonoma County mountains, and every forecast agrees with progressively lower rainfall totals the farther south you go. Stay tuned to the forecast as the details evolve. The warming trend resumes after the cold front moves out, with high temperatures continuing to climb into the lower to middle 80s by mid- week. && .AVIATION... (00Z TAFS) Issued at 508 PM PDT Wed Apr 2 2025 VFR with some potential MVFR CIGs along the Monterey Peninsula overnight. Patchy low level clouds continue to drift across the Bay Area with gusty winds to continue through 03-06Z. Winds ease overnight before moderate onshore flow returns again during the day tomorrow. Low chance for fog overnight at STS and APC with slightly higher confidence in lower visibilities at STS than at APC. Vicinity of SFO...VFR with gusty winds through 03Z-06Z. Ensemble guidance shows some potential for winds to gust 35 knots through 06Z with winds to drop off through the overnight hours. Moderate northwest winds return to SFO late tomorrow morning/early afternoon with winds around 15 knots expected. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Primarily VFR with some potential for MVFR CIGs to develop. Patchy low level clouds may result in temporary MVFR CIGs through this evening before chances increase slightly for MVFR CIGs overnight. Confidence remains low to moderate at this time with ensemble guidance leaning towards CIGs around 5000 feet. Gusty onshore flow will ease overnight before moderate onshore flow returns tomorrow during the day. && .MARINE... (Tonight through next Tuesday) Issued at 508 PM PDT Wed Apr 2 2025 High pressure will continue to build in offshore with gusty north/northwest flow continuing over the coastal waters. Wave heights will continue to gradually decrease tonight into Thursday, however wind driven rough seas resulting in hazardous boating conditions will persist into early Friday. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Frost Advisory from 2 AM to 9 AM PDT Thursday for CAZ506-516>518. PZ...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 Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 3 AM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm. && $$ SHORT TERM...DialH LONG TERM....DialH AVIATION...Kennedy MARINE...JM 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

397 FXUS66 KOTX 022121 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 209 PM 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... Tonight through Thursday: As the low continues to shift east, the back edge of the trough will allow for some showers over Eastern WA and ID Panhandle. We have already begun to receive reports of light rain and small hail with these showers. Showers will diminish after sunset. Thunder has also been added for the much of the region today as there will be some CAPE available. Highs will be in the upper 40s and 50s with lows in the 30s. Thursday will be 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. Winds will also increase as the ridge moves in, mainly down the Okanogan Valley. Friday through Tuesday: The ridge continues to strengthen over the PacNW and we will begin to see a warming and drying trend. Daytime temperatures will rise into the 50s on Friday and into the 60s by Sunday, with some low 70s possible in the Columbia Basin and LC Valley areas. Dry air and clear skies will result in chilly overnight temperatures due to radiational cooling. Ensembles are coming into better agreement that the ridge will continue through the weekend. By Monday and Tuesday, the ridge begins to move east although there is uncertainty in the timing of this occurring. A trough will slide in behind, that will bring some precipitation to the Cascades and shower activity to the lower elevations. Temperatures will cool slightly to start the week but there are hints of another ridge forming late next week. /KK && .AVIATION... 00Z TAFS: Widespread showers will continue this afternoon, with rain, graupel and small hail in the strongest cells. Showers will decrease around sunset, and will redevelop again after 09Z and could impact KCOE and KPUW. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Low confidence in ceiling heights changing this afternoon due to shower activity. High confidence in VFR conditions at KEAT and KMWH. ----------------------- 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 33 53 31 57 32 63 / 40 20 10 0 0 0 Coeur d`Alene 32 51 28 56 29 61 / 50 50 10 0 0 0 Pullman 31 49 30 54 31 60 / 20 30 10 0 0 0 Lewiston 36 56 34 60 34 66 / 20 20 10 0 0 0 Colville 30 54 27 58 30 62 / 70 20 10 0 0 0 Sandpoint 32 48 27 54 29 60 / 70 60 10 0 0 0 Kellogg 34 45 27 51 30 58 / 40 80 20 0 0 0 Moses Lake 34 59 32 62 34 66 / 10 0 0 0 0 0 Wenatchee 34 57 35 60 37 64 / 10 0 0 0 0 0 Omak 33 57 31 62 34 66 / 40 10 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$

278 FXUS66 KPDT 022355 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 455 PM PDT Wed Apr 2 2025 .Updated Aviation Discussion. .AVIATION...00Z TAFS...VFR conditions currently at all sites, which will stay the course through the period. Breezy west winds with gusts between 15-25 kts will occur for KDLS/KPDT/KRDM through the evening before dissipating later tonight. Ceilings will hover around 10kft and stay BKN overnight and into Thursday morning for most sites. KDLS/KYKM will be the exception, with ceilings at 25kft and BKN through the period. 75 && .PREV DISCUSSION... /issued 216 PM PDT Wed Apr 2 2025/ SHORT TERM...Tonight through Friday...Satellite imagery this afternoon shows the PacNW on the backside of a broad upper trough over the western CONUS with partly cloudy conditions in the lower elevations and mostly cloudy across the mountain zones. While the lower elevations have remained dry, scattered rain/snow showers across the mountains have resulted in very light precipitation being reported. Light rain/snow showers will continue across the Cascades, eastern mountains, and Wallowa county today as a shortwave slides down the backside of the trough and across the PacNW. The shortwave trough passage combined with cold air aloft (resulting in higher mid/low level lapse rates) and daytime heating will result in a slight chance of thunder over eastern Wallowa county this afternoon, as well as convective rain/snow showers over the rest of the mountain areas. In the lower elevations, the shortwave passage will result in breezy conditions through the evening, with strongest winds (25-35mph gusts) through the eastern Gorge, Kittitas valley, and other Cascade gap regions. Shower activity will gradually decline overnight with the lack of daytime heating. Shower activity will pick up once again early tomorrow afternoon across the Blues and Wallowa county as the shortwave trough and parent trough continue to push east.Breezy winds will once again develop through the Cascade gaps tomorrow afternoon, with winds becoming locally breezy as they reach the Columbia Basin and adjacent lower elevations. The upper trough will continue to push east of the region tomorrow, allowing an upper level ridge to build into the PacNW late Thursday through Friday. A drier and more mild airmass will filter into the PacNW with the arrival of the upper ridge, bringing an end to shower activity area-wide Thursday night. Dry conditions will persist through Friday and into the weekend, while a warming trend will result in temperatures warming into the lower to mid 60s across the lower elevations Friday afternoon. Lawhorn/82 LONG TERM...Saturday through Wednesday... 1. Dry weather to begin the period 2. Upper level trough to bring precipitation to region 3. Temperatures to flux between above and near seasonable The long term will be characterized by a ridging pattern to begin bringing dry and warmer conditions. The next system will approach the region late Sunday afternoon bringing with it a surface front, mountain rain and high mountain snow followed by lower elevation rain Monday. Another upper level ridge will follow soon after bringing warmer and dry temperatures back to the region Tuesday and Wednesday. Models are in relatively firm agreement with an upper level ridge situated over the region Saturday through Sunday afternoon. The upper level ridge will bring dry conditions across the region. By Sunday afternoon, models show an upper level trough to begin pushing onshore. Most notable variation in the clusters for the trough is the timing. GFS wants to bring the mountain precipitation in around 11 AM where as the ECMWF as well as the Canadian bring it in 6-12 hours later. Models show the trough to meander across the region and exiting Monday night. An upper level ridge will then begin to build in over the region bringing drier conditions to the lower elevations with some high mountain showers. Much of the precipitation that will come with the upper level trough will be along the crests of the Cascades and along the eastern mountains and the Blues. 24 hour raw ensembles show the precipitation accumulation along the Cascades to be primarily rain except above 6500 ft. 60-80% of the raw ensembles show the 24 hr probability of precipitation of 0.20 inches to be 60-80% along the Cascade crests and the higher elevations of the eastern slopes. 50-60% show the same amount of precipitation totals for the eastern mountains and the Blues. Moving into central OR and the foothills of the Blues, 30-50% of the raw ensembles show probabilities for 0.10 inches for central OR and 40- 60% for the foothills of the Blues. Lastly, 30-40% probabilities of 0.05 inches for the Basin and the adjacent valleys. Lingering showers will continue over the Cascades, eastern mountains, and the Blues with less than 15% probabilities of embedded isolated thunderstorms. Temperatures will fluctuate through the longer term between above and near normal temperatures. The ridge to start will bring warmer temperatures across the region with the EFI showing the higher than normal temperatures being along the eastern slopes of the Cascades. The difference from climatological normal temperatures ranges between 5-10 degrees. Above normal temperatures will become more widespread Sunday as the ridge settles over the region with 5-10 degrees above normal across the majority of the region. A surface cold front associated with the upper level trough will bring with it cooler temperatures Monday and the difference from climatological is roughly at or just slightly below normal. The next ridge will then bring temperatures back above normal again Tuesday and Wednesday. With that said, NBM shows temperatures to be in the upper 60s to low 70s across central OR, the Gorge, Basin, foothills and mountain valleys Saturday and Sunday. Monday NBM shows temperatures to drop into the upper 50s to low 60s with isolated upper 60s in the Basin. Tuesday and Wednesday will return to temperatures much like Saturday and Sunday. Confidence in temperatures is moderate/high (60-80%) with raw ensembles in agreement. Bennese/90 && .PRELIMINARY POINT TEMPS/POPS... PDT 35 55 33 61 / 0 10 0 0 ALW 36 56 36 61 / 0 10 0 0 PSC 36 61 34 65 / 0 0 0 0 YKM 34 60 34 63 / 0 0 0 0 HRI 36 60 34 65 / 0 10 0 0 ELN 35 57 33 61 / 0 0 0 0 RDM 28 52 27 60 / 10 10 0 0 LGD 29 50 28 56 / 0 10 0 0 GCD 27 48 26 57 / 10 10 0 0 DLS 38 60 37 66 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...82 LONG TERM....90 AVIATION...75

302 FXUS65 KREV 021914 AFDREV Area Forecast Discussion National Weather Service Reno NV 1214 PM PDT Wed Apr 2 2025 .KEY MESSAGES... * Light snow showers possible through Thursday, mainly in the mountains. * Cold temperatures with hard freezes widespread through Friday morning. * Warming trend starting this weekend, with well above normal temperatures much of next week. A few showers possible Monday mainly north of I-80. && .DISCUSSION... * Isolated rain/snow showers will continue today with cold trough overhead coupled with embedded shortwaves. Most of the activity will be in the mountains per latest HREF. Light amounts with NBM probability of 0.1" snowfall at or under 40%. Trough axis slides east Thursday but enough cool air aloft could yield a couple mountain showers but probabilities are even lower, at or under 20%. * Hard freezes remain widespread Thursday morning even in urban areas, with odds for sub-25 degrees ranging from 40% at RNO to 60%+ in Minden, Fallon, Yerington areas. Friday AM is chilly but lower risk of hard freezes, 10% at RNO and 20-40% in W Nevada valleys. * With recent moisture and clearing skies Thursday morning, freezing fog is likely (60%+) for normally prone valleys such as Truckee, Sierra Valley, and possibly (20-30%) for Tahoe basin and around Reno, N Valleys, Minden. * Ridge builds in Friday-Sunday with winds shifting from cool E/NE Friday (breezy Sierra ridges) to warmer W/SW by Sunday. One caveat to a totally dry outlook and warming - models are showing a trough swinging through late Sunday into Monday. Depending on amplitude of this wave, scenarios range from mostly dry with a slight cooling Monday to rain/snow showers as far south as I-80 and a more notable cooling Monday. TBD on which one wins out. NBM showing 20-30% probability of 0.1" rainfall from Tahoe northward in the mountains, 5% at RNO. * Looking into next week - pretty good confidence in an appreciable warmup with ridging over much of CA/NV along with mainly W/SW flow at ridgetop. Starting Wednesday NBM has 50-80% odds of highs 80+ in W Nevada cities, with decent odds of 70s Sunday & Tuesday. This will likely result in lower elevation snowpack melting with minor increases in streamflows. -Chris && .AVIATION... * Isolated rain/snow showers will continue through sundown/3z today. Mainly MVFR showers, but a few IFR heavier snow showers possible in the mountains (MMH, TVL, TRK), 30% odds. A few showers possible again tomorrow afternoon but less coverage, 10% or less. * Otherwise VFR-MVFR clouds across W Nevada including RNO with light winds. Clouds look to break up after sunset. * With recent moisture and clearing skies, fog could be an issue Thursday morning after 9z. Especially for TRK (60%+ odds) but can`t rule it out around TVL (30%) and in vicinity of RNO/RTS/MEV (20%). -Chris && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

264 FXUS66 KSTO 021925 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1225 PM PDT Wed Apr 2 2025 .Discussion... .Synopsis... Temperatures will warm each day through the end of the weekend with mid 70s by Sunday. Dry conditions are also expected. A weak weather system will then move across the area Sunday night through Monday and bring light precipiation to the northern Sacramento Valley areas...mainly in the foothills and mountains. Dry and mild weather will then continue into mid week next week. .Key Messages... * Drier and warmer weather returns through the weekend. * Chances for Valley Highs > 75 Degrees Saturday/Sunday: 40-80% * A weak system will bring clouds and light precipitation mainly to areas in northern Sacramento Valley Sunday night and Monday. * Mild and dry conditions after Monday into middle of the week. .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 across portions of the Sacramento Valley through 00z Thursday. A few light showers over the Sierra through 00z Thursday, and again after 18z Thursday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

308 FXUS65 KMSO 021850 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1250 PM MDT Wed Apr 2 2025 .DISCUSSION... KEY MESSAGES: - A Canadian cold front will bring snow to northwest Montana, including the Flathead valley late tonight into Thursday - Warmer and drier conditions expected Friday into the weekend An unstable airmass today into this evening will favor showers through the evening hours. Brief periods of accumulating snow will be possible on mountain passes, while valleys will see mainly rain or a rain snow mix. The backdoor Canadian cold front is still on schedule to cross the Continental Divide late tonight into Thursday. An area of enhanced snowfall will occur with the front, primarily affecting the Thursday morning commute. The cold front will bring a period of moderate snow for locations generally along and north of Highway 2 tomorrow 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. Winter weather advisories have been issued to account for a period of winter-like travel tomorrow morning. High pressure begins to build over the region Friday and will linger into the weekend. Friday morning could be quite chilly due to drier air moving into the region and clearing skies. Warmer and drier conditions will be on tap through the weekend, though forecast models are not warming temperatures to the degree previous runs were showing. Confidence has increased for a cold front to move through the region on Monday. Increasing clouds, breezy winds and possibly some evening thunderstorms will accompany the front. The majority of forecast models (around 80 percent) do rebuild the high pressure ridge by Wednesday. && .AVIATION...Snow showers will persist this afternoon and evening over southwest Montana including KBTM. Showers will be capable of dropping visibility down to about 2SM around 03/0000Z. A cold front will cross the Continental Divide by early Thursday morning, resulting in a shift to gusty northerly or northeasterly winds. KGPI will experience decreasing visibility and ceilings due to snow by about 03/1300Z. Impacts will spread southward to KMSO by about 03/1500Z. && .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. ID...None. && $$

173 FXUS65 KBOI 030301 AFDBOI Area Forecast Discussion National Weather Service Boise ID 901 PM MDT Wed Apr 2 2025 .DISCUSSION...Showers were winding down this evening with just a few lingering showers, but will redevelop over the high terrain Thursday afternoon due to a large upper trough over the interior west. There is also a slight chance (< 20 percent) of afternoon thunderstorms in central Idaho. Temperatures may be a degree or two warmer, but still several degrees below normal. No updates. && .AVIATION...Mainly VFR. Scattered showers after 03/18Z will create periods of MVFR/IFR, mainly over the West Central ID Mtns and near the NV border. Showers will be capable of graupel, isolated lightning, and outflow winds up to 30 kt. Snow levels 3500-4500 feet MSL. Patchy valley stratus/fog through Thursday morning will create periods of IFR/LIFR, mainly around KMYL, KTWF, and KJER. Mountains obscured at times. Surface winds: W-NW 5-15 kt with gusts around 25 kt. Winds aloft at 10kft: N-NW 10-20 kt. KBOI...Generally VFR. Scattered showers developing Thursday afternoon over Boise foothills. Mountains obscured in precipitation. Surface winds: NW 8-14 kt with gusts around 20 kt by this afternoon. && .PREV DISCUSSION... SHORT TERM...Tonight through Friday night...The weather will remain cool and unsettled through Thursday under an elongating trough. Shower development will initiate off higher terrain Thursday afternoon, fed by daytime instability. Similar to recent days, lower elevations will see shallow cumulus buildups with any low threat of precipitation (<10%) coming from activity exiting the mtns on northerly flow. An upper ridge builds in from the coast on Friday bringing dry conditions to the region. Temperatures warm from around 5 degrees below normal Thursday, to around normal on Friday. Winds will remain gusty on Thursday, mostly along the I-84 corridor, relaxing some on Friday as the flow aloft weakens. LONG TERM...Saturday through Wednesday...A deep upper level ridge will build over the Western US, bringing warm, above normal temperatures, and dry conditions through Monday morning. Highs will be around 3-5 degrees above normal, with overnight lows still in the 30s in the valleys through the weekend. A shortwave trough will move in on Monday afternoon, bringing widespread showers and cooler temperatures on Tuesday. Snow levels will drop to around 5000-6000 feet on Tuesday, with minimal accumulations anticipated. A ridge will then quickly build back in on Wednesday, bringing another push of warm and dry weather with highs in the Treasure Valley approaching near 70 by Wednesday. This might be the end of the overnight frosts in the valley for the time being, with long range models favoring above normal temperatures through the month. && AVIATION...Mainly VFR. Scattered showers after 02/17Z will create periods of MVFR/IFR, mainly over the West Central ID Mtns and near KBKE-KBNO and the NV border. Showers will be capable of graupel, isolated lightning, and outflow winds up to 30 kt. Snow levels 3500- 4500 feet MSL. Patchy morning valley fog tomorrow will create periods of LIFR/IFR, mainly around KMYL. Mountains obscured at times. Surface winds: W-NW 5-15 kt with gusts around 25 kt. Winds aloft at 10kft: N-NW 10-20 kt. KBOI...Generally VFR. Scattered showers developing this afternoon over Boise foothills. A 10% chance of MVFR rain/graupel showers hitting KBOI terminal this evening. Mountains obscured in precipitation. Surface winds: NW 8-14 kt with gusts around 20 kt by this afternoon. && .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 DISCUSSION...BW AVIATION.....CH SHORT TERM...DG LONG TERM....SA

526 FXUS65 KLKN 021956 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1256 PM PDT Wed Apr 2 2025 .SYNOPSIS...Upper level troughing over much of the Intermountain West will continue unsettled weather with scattered snow showers into this evening, slowly diminishing in coverage tonight. Much of the same into Thursday as the trough remains over the region. High pressure looks to build across the West into this weekend and early next week with much warmer temperatures set to arrive. && .SHORT TERM...Tonight through Thursday night Upper-level troughing continues to amplify across the West as a shortwave digs southward across California and feeds the long wave trough. Expect fairly similar conditions to yesterday with below normal highs in the upper 30s and lower 40s and scattered snow and/or graupel showers as weak instability increases once again through the rest of the afternoon thanks to steep mid-level lapse rates in association with the anomalously low 500 mb heights with the long wave trough directly overhead. Hi-res guidance keeps these showers slightly less organized than yesterday, but continue to monitor conditions, especially on roadways this afternoon as conditions can deteriorate rapidly with stronger snow showers or squalls. Light snow can quickly accumulate on area roadways with abrupt drops in visibility. Greatest confidence in accumulations on roadways will be over passes and summits, particularly along US 93, 50 and 6, along with NV 225 and I-80 with a 40-50% chance for at least an inch of snow through Thursday morning. Snow showers should gradually taper off through the overnight as the atmosphere stabilizes, but any melting snow will likely freeze unless roadways are fully treated. Hi-res guidance keeps the snow showers going longest across northern Elko County with localized minor impacts. The main long wave trough axis shifts slightly to the east into Thursday, which leads to less instability and slightly warmer high temperatures in the mid to upper 40s, though still well below normal for this time of year. Another round of scattered snow and graupel showers, though more isolated in nature than today with lower instability. .LONG TERM...Friday through next Wednesday Light snow showers in parts of northeast and eastern Nevada will dissipate early Friday morning. Dry weather and warming temperatures expected for the rest of the day and this weekend as high pressure moves into our area. Highs will reach the 60s by Sunday. On Monday, a shortwave trough will move through northern Nevada, bringing slightly cooler temperatures and a chance for light precipitation in that part of the state. The trough will exit our area by early Tuesday morning, and dry weather will return for the rest of the week as a stronger ridge moves in and expands over the southwest United States. Temperatures will warm even more, reaching the 70s by Wednesday. Winds will be light throughout the forecast period. && .AVIATION...Similar conditions to yesterday afternoon at area terminals this afternoon with scattered snow showers and graupel showers through 03Z. Low confidence on coverage and timing of showers, though brief VSBY and CIG restrictions will likely accompany the stronger showers this afternoon, likely necessitating a few TEMPO groups as showers attempt to organize and drift from north to south. North-northwest winds from 5 to 10 kt, shifting more to the northeast after 03Z, then trending back to the north-northwest after 13Z Thursday morning. Added AMD NOT SKED to KTPH TAF due to unreliable wind readings from the ASOS. && .LKN Watches/Warnings/Advisories... None. && $$ 84/89/84