Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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470 FXUS66 KOTX 192205 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 305 PM PDT Wed Jun 19 2024 .SYNOPSIS... Showers and isolated thunderstorms will continue into the evening across across the northern mountains. A warming trend is expected through the week, with high temperatures rebounding into the mid 80s to mid 90s on Saturday. A dry cold front on Sunday will create elevated fire weather concerns with widespread breezy winds across the region. This will likely be followed by considerable cooling with a small chance of showers and thunderstorms into early next week. && .DISCUSSION... Today through Friday: Today features another day of cumulus buildups with a small risk (20%) of thunderstorms in the Cascades, northern mountains, and Blue Mountains. Thunderstorms will be capable of small hail, gusty winds, and infrequent lightning. Temperatures will peak in the 70s and 80s today. The influence of the 500 mb cold pool over us decreases tomorrow as a trough off the gulf of alaska starts to form/amplify a shortwave ridge in the pacific northwest. Tomorrow will feature more sunny conditions with highs in the 80s to low 90s. One exception is a small chance of a thunderstorm (20%) over the Paseyten Wilderness. Friday will be dry and even warmer yet with highs in the 80s to mid 90s. /Butler Saturday...Model confidence is high that the upper level ridge axis will shift into the ID Panhandle by afternoon which will allow the 850 mb temperatures to peak with a thermal ridge axis focused over the Inland NW. The result will be the warmest temperatures weve see this summer for many locations. Right now we have forecast highs in the mid 80s and 90s, with the hottest readings expected over the lower Columbia Basin and LC Valley where we cant rule out a stray 100. The chance of exceeding 100F is around 50% for downtown Lewiston, and a 10-25% from Wenatchee to Vantage. This should be the peak of the heat though as the ridge pushes farther east and we begin to see some cooler air work over the Cascade Crest by late afternoon/evening. This will be accompanied by increasing west winds over central WA, but nothing terribly strong. Saturday night/Sunday...Model agreement remains high the ridge axis will migrate into eastern MT with an offshore heading onto the west coast. This will begin a significant cooling trend with high temperatures dropping anywhere from 6 to 14F which is still a little warmer than normal, however the bigger news will be the introduction of winds into the mix. The 850 mb winds arent terribly strong (20-30 kts) which will equate to surface wind gusts of 25-35 mph. The winds will combine with relative humidity values of less than 20% over much of central and eastern WA and this will result in an enhanced fire concerns especially for areas with cured fuels which includes much of the Columbia Basin. Monday through Wednesday...Model agreement begins to falter during this period as some of the models move the upper level trough inland while others keep it offshore. The offshore members largely consist of the Canadian members and if this occurs wed be looking at only a slight cooling with dry weather. However nearly 2/3rds of the other models support the trough pattern with high temperatures cooling into mid 70s to mid 80s. There would also be a small chance of showers and thunderstorms mainly near the Canadian border. Stay tuned to see which scenario verifies. fx && .AVIATION... 18z TAFS: For this afternoon another round of showers and thunderstorms will develop over the northern mountains. There is a 20% chance of thunderstorms for the northern airports from Winthrop through Omak, eastward through Republic, Colville, Sandpoint, and Bonners Ferry. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in continued VFR conditions for 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 47 82 52 86 55 89 / 0 0 0 0 0 0 Coeur d`Alene 46 80 51 83 53 87 / 0 0 0 0 0 0 Pullman 47 81 51 82 53 86 / 0 0 0 0 0 0 Lewiston 53 90 59 92 59 96 / 0 0 0 0 0 0 Colville 41 80 44 85 49 86 / 10 0 0 0 0 0 Sandpoint 45 78 50 81 50 83 / 0 0 0 10 0 0 Kellogg 49 79 56 80 57 85 / 0 0 0 10 0 0 Moses Lake 52 87 53 92 58 95 / 0 0 0 0 0 0 Wenatchee 56 85 61 91 64 93 / 0 0 0 0 0 0 Omak 51 85 54 90 57 91 / 10 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$