Area Forecast Discussion
Issued by NWS Spokane, WA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
479 FXUS66 KOTX 192347 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 447 PM PDT Fri Apr 19 2019 .SYNOPSIS... Showery and breezy westerly winds are expected as a cold front sweeps through the Inland Northwest this evening. There is a chance of thunderstorms this afternoon and evening across southeast Washington into the southern Idaho Panhandle. This weekend through early next week will be mainly dry with seasonal temperatures. && .DISCUSSION... Tonight: Cold front/trof passage allows for an unsettled interval of weather tonight into tomorrow. Mesoscale models continue to suggest linear shower and thunderstorm development allowing potential for training of convective cells over the area, primarily south and east of I-90 and current radar mosaic is supporting this in some degree with surface based convection occurring up in northeast Oregon right now. Flood watch remains in effect from late this afternoon through early Saturday morning for Lewis, Nez Perce, and Asotin counties to address the potential impacts of the rainfall. The lines of organized cells are expected to be oriented southwest to northeast and the lines themselves will move from northwest to southeast. The cells in the lines will move with a storm motion to the northeast at 30 mph. Otherwise additional mention of spotty shallow very infrequent and short lived surface based pulse thunderstorm development expected is possible near the North Idaho and Southern British Columbia border into the very early evening with those expected to move with a storm motion to the northeast at 40 mph. Tomorrow: The baroclinic band along the far east edge of the shortwave trof over Washington allows for potential for rain to stream over the far eastern portion of the forecast area. Elsewhere the airmass is not too conditionally unstable in the trof and robust northwest and north winds should not only dry and cool things off but will downslope off the higher terrain, all of which support a dry forecast with an overall decrease in cloud cover. Cooler daytime highs in comparison to day expected. /Pelatti Saturday Night through Thursday: A zonal flow pattern is expected to set up over the Pacific Northwest and bring a trough ridge pattern for this period. Models are agreeing fairly well. The waves of moisture are mainly going to impact the Cascades and the Idaho Panhandle. The rain shadow effect of the Cascades will keep the Columbia Basin fairly dry excluding some stray showers. The amounts are not expected to be significant with only a few tenths of inch with each wave. Winds will increase during the afternoon with gusts into the mid teens. Temperatures will continue to be mild. The highs will be in the 60s to low 70s. Lows will be in the upper 30s to low 40s. /JDC && .AVIATION... 00Z TAFS: A frontal boundary will slowly push across the forecast area through the period. Ahead of the boundary, expect light showers with a mid level deck especially from KEAT, to KMWH and the KGEG-KCOE corridor. Expect a gradual decrease in clouds and showers from the west by early Saturday morning. Locally gusty westerly winds will taper off early this evening, and give way to north to northwest winds by midday Saturday. Gusty northerly winds are likely from KMWH-KEAT. Across southeast Washington into the southern Panhandle, it remains more unstable with scattered showers and thunderstorms with small hail, heavy downpours and gusty winds. The thunder threat should diminish by mid evening, while steady showers persist through the night into Saturday morning with local MVFR conditions. /rfox. && .PRELIMINARY POINT TEMPS/POPS... Spokane 45 62 38 65 40 66 / 20 10 0 0 0 0 Coeur d`Alene 44 61 38 64 39 65 / 20 10 10 0 0 0 Pullman 46 57 38 60 39 63 / 50 20 10 0 0 0 Lewiston 53 62 44 65 45 69 / 80 40 20 0 0 0 Colville 39 69 32 65 35 68 / 20 10 0 0 0 0 Sandpoint 42 61 38 64 39 65 / 40 20 10 0 0 0 Kellogg 45 57 39 62 40 63 / 40 20 20 0 0 0 Moses Lake 47 68 41 70 42 73 / 30 0 0 0 0 0 Wenatchee 45 65 42 68 43 71 / 20 0 0 0 0 0 Omak 43 66 38 70 41 70 / 10 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Flood Watch through Saturday morning for Lewis and Southern Nez Perce Counties-Lewiston Area. WA...Flood Watch through Saturday morning for Lower Garfield and Asotin Counties-Northeast Blue Mountains. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.