Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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288 FXUS66 KOTX 161725 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 1025 AM PDT Mon Sep 16 2024 .SYNOPSIS... Today will be the warmest day of the week. Tuesday and Wednesday will be cooler with periods of rain over north Idaho and the eastern third of Washington. Gusty north winds down the Okanogan valley today will become breezy from the west on Tuesday and be more widespread across parts of central and eastern Washington. Drier weather will be found heading into the end of the work week, with precipitaiton chances returning for the weekend. && .DISCUSSION... Today through Tuesday: Today the low will begin to move inland over central California, another chance of shower activity over the Camas Prairie and LC Valley. Any rain will be light. Winds will increase early this morning in the Okanogan Valley and Waterville Plateau with gusts up to 35 mph, continuing through the early afternoon. As the low shifts east, the winds will gradually decrease this afternoon. Temperatures will warm back to normal today. Showers increase along the WA/ID border early Tuesday as the wrap around moisture sets up behind the low. Another low is tracking down along the coast, but most of the moisture will remain on the west side of the Cascades. The heaviest moisture will remain to our south unlike the system last week, with rain totals less than a quarter inch in the heaviest showers. Most areas will receive a tenth or less. Temperatures will cool again on Tuesday in most areas, with the exception of the Okanogan Valley seeing temperatures similar to today. /KM Wednesday to Sunday: Low pressure centered south of the area gradually shifts southeast of the region, while weak high pressure builds in before another system approaches toward next weekend. However models continues to disagree over the precise nature of the system, which some keeping the brunt of it north and others bringing it more directly in. First Wednesday shower chances continue near the Cascade crest and around the ID Panhandle, before chance wane heading into Wednesday night. Thursday and Friday are forecast to be drier, save for lingering shower chances near the Cascade crest in the onshore flow and as some moisture slips over the top of the weak ridge. Saturday and Sunday the chance of precipitation expands across the region again with the potential system slipping near or into the region. Confidence will increase as we get closer and models come into better agreement. Some guidance has higher overall potential for precipitation around the mountain zones, with the chances of wetting rains ranging from 20-70%, depending on the model. However about 60% of the models lean toward the 20-30% chance of those wetting rains, meaning right now confidence leans toward a lower risk for wetting rains. Some low-grade breezy conditions are expected Wednesday and again toward the weekend with gusts near 10-20 mph. Temperatures will near the slightly above normal through Friday, then trend slightly below normal toward the weekend. Overnight lows will be in the 40s and low 50s, with some 30s in the sheltered valleys. We could see some patchy frost in some of those sheltered valleys over northeast WA and the ID Panhandle, but it is expected to very localized. Patchy fog is also possible in some of the sheltered valleys and near bodies of water during the late night/early morning hours from Thursday to Saturday. /Solveig && .AVIATION... 18Z TAFS: VFR conditions will prevail. Mid and high clouds will persist over SE WA and Central Idaho. There is a 20% chance of showers early this afternoon for Lewiston. Otherwise dry conditions are expected until near or just after the end of the TAF period. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in VFR conditions. Low confidence in shower activity near KLWS. && .PRELIMINARY POINT TEMPS/POPS... Spokane 79 50 72 48 74 49 / 10 20 20 10 0 0 Coeur d`Alene 77 50 69 49 69 48 / 10 20 30 20 10 10 Pullman 70 48 64 44 67 44 / 20 40 50 20 10 0 Lewiston 77 58 71 54 74 54 / 20 40 50 20 10 10 Colville 79 38 76 38 76 38 / 0 10 10 10 0 0 Sandpoint 75 47 69 46 67 44 / 10 10 40 30 20 10 Kellogg 74 52 65 50 65 49 / 20 30 70 40 40 10 Moses Lake 82 48 78 48 78 47 / 0 0 10 0 0 0 Wenatchee 81 53 76 55 78 54 / 0 0 0 0 0 0 Omak 82 50 81 52 80 50 / 0 0 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$