192 FXUS66 KOTX 122346 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 446 PM PDT Wed Sep 12 2018 .SYNOPSIS... Unsettled...cool and showery conditions will prevail over the inland northwest through the weekend. The mountains will see a daily round of showers and a few thunderstorms through Friday with a better chance of showers all over the region Saturday and especially Sunday. A drying and weak warming trend will occur for the new work week. && .DISCUSSION... Tonight through Sunday...Satellite loop shows a huge upper level Gulf of Alaska trough beginning to envelop the northwestern US. Latest models are in quite good agreement in hooking the axis of this trough into the forecast area through the next 24 hours and then digging another reinforcing trough or closed low down the coast and ejecting inland into the northwest on Sunday. The cold pool interior of this trough will act with surface heating to produce instability each afternoon from now through Friday...but coherent focusing mechanisms and synoptic ascent axes are difficult of pin down in the chaotic vorticity field in the cusp of this trough as it passes. Thus...except for the outside chance of a random shower on the margins of the Columbia Basin...shower and wet garden variety thunderstorm activity will be mainly focused over the mountains ringing the basin for the next couple days. The basin itself will experience variably cloudy skies...with the best shot at any shower activity over the southeast which may come under the margin of the moisture shield from a weak trough base short wave late tonight or early tomorrow. Otherwise expect continued below normal temperatures and relatively light winds except for some locally breezy conditions near the Cascade Gaps. There is also a threat of random gusty winds emanating from nearby thunderstorms during the afternoon and early evening hours. On Saturday the region will begin to come under the influence of the follow-up trough digging just off the coast. The moisture feed looks richer with this next system and the trough is forecast to be deeper with a stronger and more coherent cold front to focus moisture into precipitation. There is still no evidence of a typical cold season warm front/cold occlusion complex which would bring the chance of widespread stratiform wetting rain...but the strength and moisture feed with this wave will bring a better chance of hit-and-miss showers not just to the mountains but to the basin as well. Sunday looks like the highest risk of showers over the entire forecast area. Monday through Wednesday...This trough will kick out of the region to the east Sunday night or so...with lingering showers in the Panhandle through the night. The region will enter a more progressive westerly or northwesterly flow regime which should allow a drying trend to envelop the forecast area through the middle of next week with a modest warm up to around normal with any further shower activity limited to the mountains near the Canadian border closest to the polar storm track. /Fugazzi && .AVIATION... 00Z TAFS: Scattered showers with a few thunderstorms mainly over the higher terrain of northern WA will decrease around 02z this evening with the loss of daytime heating. On Thursday another round of mainly afternoon convection is expected. These will again primarily stay over the mountains. TAF sites are expected to remain VFR through 06z Friday. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 48 65 45 68 48 66 / 0 10 10 10 30 30 Coeur d'Alene 47 64 43 68 47 66 / 0 30 10 10 40 40 Pullman 46 63 42 67 44 66 / 0 20 10 0 20 20 Lewiston 51 69 47 74 49 73 / 0 30 10 10 20 20 Colville 43 67 41 69 43 66 / 20 30 20 20 20 40 Sandpoint 44 62 40 66 42 64 / 20 40 20 10 40 50 Kellogg 44 61 39 66 41 64 / 10 30 20 10 30 30 Moses Lake 47 71 43 72 46 69 / 10 10 0 0 20 20 Wenatchee 51 69 48 69 50 66 / 0 10 10 20 30 40 Omak 46 68 44 68 47 66 / 30 20 10 20 30 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$