Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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535 FXUS66 KOTX 081144 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 444 AM PDT Wed May 8 2024 .SYNOPSIS... A warming and drying trend is forecast through the weekend. Temperatures on Friday through the weekend will warm to the highest values of the season so far, with high temperatures reaching the 80s into the lower 90s for much of the region. The weather pattern for early next week is uncertain, however odds favor a cooling trend with increasing clouds, and a small chance of precipitation for the Cascade Crest, extreme northeast Washington, and the northern half of the Idaho Panhandle. && .DISCUSSION... Wednesday: The Inland Northwest is current between under two distinct weather regimes early this morning as ridging shifts in from the west and a large closed low remains nearly stationary over the Plains. Drier air associated with the ridge will keep skies clear over central Washington with temperatures warming into the mid 70s. Building high pressure will also result in breezy winds down the Okanogan Valley into the western Columbia Basin this afternoon. Meanwhile, for far eastern Washington and north Idaho, a weak wave associated with the closed low moving in from the northeast will keep skies overcast today with light precipitation across north Idaho. Temperatures will also be notably cooler compared to central Washington with highs in the upper 50s to mid 60s. Thursday and Friday: Models are in good agreement for a quiet end to the work week as the upper level ridge shifts further inland. Expect plenty of sunshine with the warmest temperatures of the year so far. Winds will be slightly breezy from the northeast Thursday afternoon as a thermally induced surface trough builds along the Pacific Northwest coast and enhances the northeast pressure gradient. Temperatures will be in the low 70s to low 80s. The thermal trough shifts east of the Cascades later Friday into Saturday, with lighter winds and widespread temperatures in the upper 70s to upper 80s. /vmt Saturday and Sunday...Ensemble model agreement is very good that a strong ridge will build over the Inland NW. This will result in the warmest weekend so far this year across the Inland NW as 850 mb temperatures surges into mid to upper teens. This equates to high temperatures in the 80s for most locations with lower 90s possible over for some of the warmer locations. These values are about 10-18F warmer than normal for this time of year. Despite these lofty temperatures, we dont expect to break any records. For the Spokane area we are forecasting highs in the lower 80s on both Saturday and Sunday while the records are in the lower 90s for both dates. So what are the chances of hitting 90F or greater this weekend for other locations? On Saturday the chances for Moses Lake, Wenatchee, and Omak range from 75-90%, and drop to 40-50% on Sunday. For the LC Valley, chances are around 20%. Monday and Tuesday...this is where the model confidence begins to slip as some solutions keep the ridge fixed over the area, while others shift the ridge into central Montana or the Dakotas. About 40% of the ensembles support the persistent ridge and most of these are comprised of Canadian Ensembles, however nearly a third of the GFS and Euro solutions are give this scenario support. If this were to happen, wed still be looking at a dry and warm forecast, albeit not quite as warm as Sunday. If the majority solution verifies, wed be looking at about a 10F or greater cool down, thickening clouds, and a chance of showers, mainly near the Cascades, and extreme NE WA and the northern half of the ID Panhandle. The cool down would also be accompanied by breezy westerly winds. Suffice it to say confidence for the forecast early next week isnt high, however it will likely remain dry for most locations no matter which ensemble scenario pans out. fx && .AVIATION... 12Z TAFS: High pressure is building into the region from the west, while a low pressure over the Great Plains is advecting high level clouds into eastern Washington and north Idaho from the east. Outside of the central Idaho Panhandle mountains, widespread VFR conditions are expected through the TAF period. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: There is high confidence for VFR conditions across all TAF sites. ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https://www.weather.gov/otx/avndashboard && .PRELIMINARY POINT TEMPS/POPS... Spokane 65 41 75 47 79 49 / 0 0 0 0 0 0 Coeur d`Alene 62 42 73 47 78 49 / 0 0 0 0 0 0 Pullman 58 39 71 46 75 48 / 10 0 0 0 0 0 Lewiston 64 44 76 50 82 54 / 20 0 0 0 0 0 Colville 69 38 77 43 82 46 / 0 0 0 0 0 0 Sandpoint 62 42 74 45 77 49 / 0 0 0 0 0 0 Kellogg 57 43 71 48 76 51 / 40 0 0 0 0 0 Moses Lake 72 41 80 48 85 51 / 0 0 0 0 0 0 Wenatchee 71 48 78 55 83 57 / 0 0 0 0 0 0 Omak 74 46 82 50 86 54 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$