Area Forecast Discussion
Issued by NWS Spokane, WA
Issued by NWS Spokane, WA
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253 FXUS66 KOTX 160945 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 245 AM PDT Tue Jul 16 2024 .SYNOPSIS... Hot and dry weather will continue this week with widespread upper 90s and triple digit temperatures. On Wednesday there is chance of thunderstorms across the region containing little to no rainfall. && .DISCUSSION... Today through Wednesday night: Upper level ridge will have its axis placed over Northwest Montana through most of this time interval. This will allow for a warm/hot southwest flow on the west side of the ridge axis to continue to allow for a warming trend through Wednesday and beyond. In addition it appears a negatively tilted upper level shortwave will run up the west side of this ridge and have enough upper level moisture and instability to allow for a mention of low precipitation producing (dry) thunderstorms Wednesday and Wednesday night. Lightning will raise concerns for new fire starts across the landscape. In addition, gusty outflow winds could result in fire spread with any new starts. A Fire Weather Watch has been issued for several areas of North Central Washington Wednesday. Pioneer Fire near lake Chelan will continue to produce smoke and impact air quality around Lake Chelan, and portions of the Methow Valley. The Department of Ecology has an Air Quality Alert until for Chelan and Okanogan counties in effect until further notice. /Pelatti Thursday to Monday: A ridge rebounds over the region this period, building over the northern Rockies and helping to promote a warming trend. Models are in good agreement in temperatures pushing well above normal, with many areas pushing into the 100s by the weekend, i.e. more dangerous heat potential. There are a couple shortwaves that ride up the west side of the ridge around Friday and again around Sunday. However they appear to just skim the western CWA or remain just west and do not encounter the instability that we see Wednesday. So the forecast remains dry. A broader trough starts to approach toward early next week, leading to some increased wind later Monday (into next Tuesday) especially closer to the Cascades. Looking a little beyond the next seven days, as we head into next week we will keep an eye on that offshore trough which may shift inland to dampen the ridge over the region and cool things off perhaps closer to seasonal norms. Models still don`t show much of a risk for precipitation with any dampening of the ridge, but it would come with increase winds. Just how strong those may be has low confidence but this will be monitored especially for fire weather concerns. /Solveig && .AVIATION... 06Z TAFS: Skies will be mainly cloud-free through the night and into Tuesday. High clouds over Oregon aren`t expected to make much northward progress as moisture above 20 thousand feet encounters strong upper level high pressure. Drainage winds along the East Slopes of the Cascades will push smoke from the Pioneer Fire down Lake Chelan into the Chelan and Methow Valley airports. Some minor visibility reductions will also be possible at Ephrata and Moses Lake Tuesday morning before light south winds develop around noon. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: With the exception of smoke near the Pioneer Fire, there is high confidence in VFR conditions. /GKoch ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https:/www.weather.gov/otx/avndashboard && .PRELIMINARY POINT TEMPS/POPS... Spokane 98 64 99 64 99 65 / 0 0 20 20 0 0 Coeur d`Alene 95 61 97 63 96 63 / 0 0 10 20 0 0 Pullman 93 60 95 60 94 60 / 0 0 20 10 0 0 Lewiston 103 69 104 71 105 70 / 0 0 20 10 0 0 Colville 95 55 97 54 97 55 / 0 0 20 20 0 0 Sandpoint 93 58 96 56 94 58 / 0 0 10 20 0 0 Kellogg 91 67 95 68 94 67 / 0 0 10 20 0 0 Moses Lake 100 63 102 63 102 63 / 0 0 20 10 0 0 Wenatchee 100 75 100 71 102 69 / 0 0 20 20 0 0 Omak 103 67 103 66 104 66 / 0 0 20 20 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Heat Advisory from noon today to 10 PM PDT Thursday for Coeur d`Alene Area-Idaho Palouse-Lewiston Area. WA...Heat Advisory from noon today to 10 PM PDT Thursday for Central Chelan County-Lower Garfield and Asotin Counties-Moses Lake Area-Okanogan Valley-Spokane Area-Upper Columbia Basin- Washington Palouse-Waterville Plateau-Wenatchee Area- Western Okanogan County. Fire Weather Watch from Wednesday afternoon through Wednesday evening for Colville Reservation (Zone 702)-East Portion of North Cascades National Park/Lake Chelan National Recreation Area (Zone 697)-East Washington Central Cascades (Zone 696)-East Washington North Cascades (Zone 698)- Foothills of Central Washington Cascades (Zone 705)-Methow Valley (Zone 704)-Okanogan Highlands and Kettle Mountains (Zone 699)-Okanogan Valley (Zone 703)-Waterville Plateau (Zone 706). && $$