030 FXUS66 KOTX 312337 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 337 PM PST Mon Dec 31 2018 .SYNOPSIS... Mainly dry and seasonably cold weather will persist through Wednesday, with the exception of light snow or flurries on Tuesday. The next weather system will arrive late Wednesday into Friday, with the possibility of a wintry mix of precipitation in the lowlands and moderate mountain snow. && .DISCUSSION... Tonight: The Inland Northwest will ring in the New Year with cold temperatures tonight. Look for widespread overnight lows in the teens and low 20s with a smattering of single digits around Republic, the Methow Valley, and in other sheltered valleys of north Idaho and northeast Washington. A chilly and dry air mass has settled over the region following our stormy weekend. With light winds tonight and surface dewpoints in the teens and low 20s, we are expecting one of the coldest nights in the last 2 to 3 weeks. Bands of mid and high clouds will likely increase during the early morning hours, but midnight revelers from Wenatchee to Spokane to Lewiston should experience mostly clear and chilly conditions at the stroke of midnight. Tuesday: A weak clipper type system will overtop our high pressure ridge on Tue. The majority of the lift associated with this system will occur over BC and Alberta, but there will be enough mid level warm/moist advection to produce a thick cloud deck. Light snow or flurries will be possible across north central and northeast Washington and into the Idaho Panhandle during the day. Spokane, CDA, and Pullman may even experience a bit of light snow or flurry activity. Afternoon highs are only expected to reach the upper 20s and low 30s which is a few degrees below average for Jan 1st. Wednesday: Our high pressure ridge will flatten on Wed. Look for thickening clouds and increasing chances for snow over the high terrain of the Cascades Wed afternoon. Warm frontal precipitation will likely spread into northeast Washington and north Idaho by sunrise. Thursday: We will be watching Thu closely as a frontal system moves inland bringing the potential for a mix of wintry precipitation to our region. *Freezing Rain: There are some model differences in the track and depth of this system so there may be changes to this forecast, but the NAM and GFS suggest the potential for light freezing rain Thu morning around Wenatchee, Moses Lake, Wilbur, and Grand Coulee. At this time, we are not expecting heavy icing, but up to a tenth of an inch of freezing rain may occur in localized portions of the Columbia Basin and along the East Slopes of the Cascades south of Lake Chelan. *Snow: Light accumulations (up to 3 inches) will be possible around Sandpoint, Bonners Ferry, and Northport on Thu. Precipitation may begin as snow at Spokane/CDA and Pullman but will likely transition to rain or light freezing rain as temperatures warm into the mid to upper 30s Thu afternoon. Mountain accumulations of a foot or more will be possible in the North Washington Cascades above 3000 feet. At this time, it looks like up to 10 inches for the mountains around Sandpoint and lesser amounts for the central and southern Panhandle mountains given the northern track of this frontal system. Friday through Tuesday: Models are in good agreement for the the period. For early Friday, the weak trough from the previous night will exit the area and lingering showers will remain into Saturday. This will be mainly mountain snow and rain/snow mix for the basin and valleys. Accumulations are expected to be a few tenths for Idaho Panhandle and up to to couple of inches for the Cascades. Winds will be breezy on Friday as the pressure gradient tightens in the region. The Basin could see gusts near 35 MPH and the Leeside Cascades could expect gusts near 60MPH. By late Sunday, a more robust system bringing more moisture and cooler temps is expected to bring another round of widespread snow to the region. As for amounts, the models are not in good agreement on the moisture content with this system. Temperatures in the region will be in the mid 30s for highs and mid 20s for lows. /JDC && .AVIATION... 00Z TAFS: High pressure builds in tonight, but a weak system slips by Tuesday. Some stratocumulus will dissipate over GEG/SFF/COE this evening, then the next wave of clouds moves in overnight into Tuesday with that system. There will be a limited snow chances with it, with the main risk for any accumulations north of TAF sites. However a few flurries are possible over GEG/SFF/COE/PUW. Expect mostly VFR conditions, but there is a limited risk for some lower stratus around MWH/GEG/SFF/COE toward morning, but ht threat is limited and confidence is low. /Cote' && .PRELIMINARY POINT TEMPS/POPS... Spokane 18 29 20 32 27 36 / 0 10 10 0 30 80 Coeur d'Alene 17 28 19 33 27 37 / 0 10 10 0 30 80 Pullman 17 28 21 33 28 37 / 0 10 10 0 20 60 Lewiston 21 34 25 40 31 44 / 0 10 10 0 10 40 Colville 14 31 15 34 23 39 / 0 10 10 10 30 80 Sandpoint 15 27 17 32 25 36 / 0 10 10 10 50 80 Kellogg 12 26 17 32 25 37 / 0 10 10 0 30 80 Moses Lake 22 32 21 32 26 38 / 0 0 0 0 10 60 Wenatchee 21 31 22 32 26 36 / 0 10 0 0 10 40 Omak 19 30 20 31 25 36 / 0 10 10 0 20 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$