990 FXUS66 KOTX 040001 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 401 PM PST Sun Feb 3 2019 .SYNOPSIS... Rain and snow this afternoon will transition to all snow as an arctic boundary slips in from the north this evening and overnight. Very cold temperatures are expected to arrive early next week as a cold Canadian air mass invades the region. This will likely deliver the coldest temperatures of the winter with highs in the teens and 20s and lows in the single digits. This cold will persist through most of next week, while light snow chance will increase later in the week. && .DISCUSSION... Wednesday through Thursday...High pressure will build into the region Wednesday as the storm system ejects off to the southeast. This puts the region in a dry and very chilly northerly flow. Winds will not be as strong as earlier in the week, but temperatures will remain below normal. Morning lows will be in the single digits to lower teens and afternoon highs will only make it into the low 20s. By Thursday afternoon another Upper level low will begin to drop down the B.C. coast. This will bring the potential for light snow along the Cascade crest and possibly to the Okanogan Highlands. Friday through Sunday...The upper level low will get hung up over northwest Washington Thursday night and Friday, then continue to drop south off the Washington coast on Saturday before ejecting inland into northern Californian Saturday night and Sunday. Moisture will wrap around the main low pressure system on Friday and Friday night and with southwest flow over the Inland Northwest it should tap into some decent moisture. This will be out best chance for widespread measurable precipitation. Temperatures will remain cool and snow levels will be at the valley floors. As such, precipitation will be as snow and there will be the possibility of several inches even in our normally warm sites. As the upper low slides south the area will lose the moisture tap. Light snow will still be possible, but not likely, and any accumulations will be light. Temperatures will warm up a bit, but will remain well below average. Tobin && .AVIATION... 00Z TAFS: Complex weather pattern consisting of disturbances pinwheeling outward and ahead of an area of low pressure moving south along the coast clutter overhead of the aviation area over Eastern Washington and North Idaho at times with modified polar continental air coming down from the north. Have relied on the mesoscale models such as the latest HRRR and the 18Z NAMNST to attempt to time the precipitation brought about by these disturbances as the pass across portions of the aviation area. As a result some MVFR/IFR ceilings and visibilities remain at various times due to the precipitation and possibly due to some of the leftover low stratus that may remain in the lowlands and valleys In addition tomorrow afternoon some of the modified polar continental air will seep further south thru the north to south oriented passes and bring about a more robust low level north/northeast wind. The drier air associated with this northerly flow should help dry out the low level boundary layer and erode stratus and make it way less likely to reappear. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 15 23 12 22 8 22 / 80 20 20 10 0 0 Coeur d'Alene 14 21 12 22 7 22 / 80 20 20 10 0 0 Pullman 23 31 18 23 10 22 / 60 60 60 30 0 0 Lewiston 31 38 25 28 15 27 / 70 60 50 40 0 0 Colville 16 29 8 27 4 26 / 80 20 10 0 0 0 Sandpoint 12 19 11 22 7 22 / 80 20 10 10 0 0 Kellogg 14 21 12 22 9 22 / 80 60 50 30 10 10 Moses Lake 25 31 18 28 13 27 / 20 20 20 0 0 0 Wenatchee 23 27 17 26 11 26 / 60 40 10 0 0 0 Omak 18 24 9 23 8 24 / 40 20 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory until 9 AM PST Monday for Coeur d'Alene Area-Idaho Palouse. Winter Storm Warning until 9 AM PST Monday for Central Panhandle Mountains. Winter Storm Warning until 1 AM PST Tuesday for Lewis and Southern Nez Perce Counties. Winter Weather Advisory from 7 PM this evening to 7 AM PST Monday for Lewiston Area. Winter Weather Advisory until 9 AM PST Monday for Northern Panhandle. WA...Winter Weather Advisory from 7 PM this evening to 7 AM PST Monday for Lower Garfield and Asotin Counties. Winter Weather Advisory until 9 AM PST Monday for Northeast Mountains. Winter Weather Advisory until 9 AM PST Monday for Spokane Area- Washington Palouse. Winter Weather Advisory until 1 AM PST Tuesday for Northeast Blue Mountains. && $$