Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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775 FXUS66 KOTX 180453 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 953 PM PDT Tue Sep 17 2024 .SYNOPSIS... Some light rain will persist at times over north Idaho and the eastern third of Washington through early Wednesday. Conditions will trend drier toward the end of the work week, then precipitation chances return for the weekend. && .DISCUSSION... Evening update: Made some updates based on radar trends for a few lingering bands of light showers associated with mid level instability on the back side of a departing low pressure system. These isolated showers were occurring from near Priest Lake south through Liberty Lake and the WA Palouse. Steady stratiform rain has brought heavier rain amounts south of Lookout Pass with one station in SE Shoshone County picking up 1.28" of rain since 2 PM this afternoon. Rain in this area will be decreasing overnight as the low continues to pull away from the region. JW && .AVIATION... 06Z TAFS: Light showers will continue through 07-09z from near KSFF/KCOE south to near KPUW. Not much impact from these for the TAF sites, although will be monitoring the potential for IFR stratus Wednesday morning due to a moist boundary layer and upslope boundary layer winds into KGEG/KSFF/KCOE. Current probabilities are under 50% at these TAF sites so prevailing conditions were kept VFR. Any stratus that develops will lift and erode by 17-18z, with flat stratocumulus in the afternoon. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: HREF model shows a 60-70% chance of IFR stratus between 12-16z south of Spokane (Cheney, Spangle areas), decreasing to a 40% chance over GEG, with a 20% chance at KSFF/KCOE. With favorable low level winds and some light showers further moistening the boundary layer these probabilities seem reasonable. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 49 75 49 76 46 72 / 10 0 0 0 0 0 Coeur d`Alene 48 71 48 74 46 70 / 10 10 0 0 0 0 Pullman 45 69 44 73 44 65 / 10 10 0 0 0 0 Lewiston 54 78 53 80 53 75 / 10 10 0 0 0 0 Colville 38 77 39 76 37 71 / 0 0 0 0 0 0 Sandpoint 46 69 44 72 44 68 / 10 10 0 0 10 10 Kellogg 49 67 50 72 48 65 / 20 10 0 0 0 10 Moses Lake 48 79 46 78 46 73 / 0 0 0 0 0 0 Wenatchee 55 79 53 78 54 72 / 0 0 0 0 0 0 Omak 51 82 51 81 47 75 / 10 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$