555 FXUS66 KOTX 241141 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 441 AM PDT Mon Jun 24 2019 .SYNOPSIS... A few showers and thunderstorms will linger near the Canadian border today. Another storm system will impact the region late Tuesday through the end of the week bringing a good chance for showers, thunderstorms, and a general cooling trend. A few thunderstorms on Wednesday could be strong producing strong winds and hail. && .DISCUSSION... Today through Tuesday: A mid level wave tracking into the North Idaho Panhandle this morning will bring a chance of showers. This wave will exit the area by afternoon but residual moisture and afternoon heating will lead to another round of afternoon convection over the northern mountains mainly near the Canadian border. Dry weather is expected overnight into Tuesday morning. Then all eyes turn to a closed low off the WA/OR coast. Models show southwest flow aloft with increasing moisture and instability over the Cascades, Blue Mountains, and Camas Prairie by Tuesday evening. Models have backed off a bit on the CAPE Tuesday afternoon over NE Oregon with high res models showing isolated convection developing with storms capable of producing gusty winds and small hail. The threat of strong storms looks better Wednesday as mentioned below. JW Tuesday night through Sunday...Through most of this period the latest GFS and EC model runs are in decent agreement with the overall pattern and plausibly reflect the ensemble model precipitation fields and instability potential over the region. It is during this period that the latest offshore closed low will eject inland through the forecast area and weaken into an amorphous trough by the beginning of the weekend. First...the easy part of the forecast for this period will be the persistence of cooler than normal temperatures around the region...perhaps nearing seasonal normal on Wednesday as southerly flow ahead of the incoming low dominates...but backing off into the lower 70s or even upper 60s as the cooler maritime air mass in the cusp of the low transits through Thursday and Friday before beginning a slow climb back toward normal for the weekend. The more difficult element of the forecast is a potentially consequential active convective regime especially on Wednesday afternoon and evening under the aforementioned deep and moist diffluent southerly flow as the low center approaches. Beginning Tuesday evening this flow will likely trigger some thunderstorms across the southeastern zones...but by Wednesday afternoon/evening this threat will maximize in areal extent and potential severity with models suggesting CAPE values on the order of 700 to 1200 Joules/kg over much of eastern WA and north ID...0-6km shear values adequate for organized convection and a strong jet aloft nosing into the region to enhance dynamic lift and create the potential for strong wind gusts if entrained into any storm downdrafts. Wednesday evening will be a period to keep an eye on for strong thunderstorms but being three days out...there is still time to refine the forecast and allow models to stabilize into tighter agreement before declaring high confidence for major impacts. Thursday and Friday as the upper low passes directly over the region confidence is reasonably high for a spring-like pattern featuring scattered showers and garden variety pulse type thunderstorms especially over the mountains ringing the basin...although depending on the location of any inter-trough vorticity lobes...a low confidence issue at this time...there could be a concentration of showers and a few thunderstorms just about anywhere in the forecast area on either of these days. After Friday model agreement deteriorates but where commonality and consistency exists they seem to agree on maintaining a baggy and ill defined trof over or near the northwest...much weakened but pattern recognition still suggests residual chances of mountain showers and a few thunderstorms with a better chance of the basin being largely dry and a bit warmer next weekend. /Fugazzi && .AVIATION... 12Z TAFS: Dry weather and VFR conditions are expected at all TAF sites through 12z Tuesday. Another round of showers along with a few possible embedded thunderstorms is expected today over the mountains near the Canadian border. Winds will be lower today compared to Sunday with sustained speeds generally 5-10 kts with a few higher gusts. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 71 49 75 51 74 51 / 0 0 0 10 20 40 Coeur d'Alene 69 47 75 50 76 51 / 10 0 0 10 20 60 Pullman 69 45 73 49 71 47 / 0 0 10 30 20 50 Lewiston 77 51 80 57 78 56 / 0 0 10 30 30 50 Colville 77 38 81 41 80 42 / 10 10 0 10 30 40 Sandpoint 68 44 74 49 74 51 / 20 10 0 10 30 60 Kellogg 66 49 73 53 74 54 / 0 0 0 20 20 60 Moses Lake 79 50 80 52 78 51 / 0 0 0 10 30 20 Wenatchee 76 52 78 56 76 54 / 0 0 10 10 50 30 Omak 76 50 77 52 76 52 / 0 0 10 10 40 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$