198 FXUS66 KOTX 131151 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 351 AM PST Wed Feb 13 2019 .SYNOPSIS... Snowfall will come to an end later today across southeast WA and the ID Panhandle. The unsettled and cool pattern will persist through the next week with another organized storm system expected to impact the region Thursday night and Friday. && .DISCUSSION... Today: A cold front continues to ever so slowly move southeast this morning. Snow continues to fall across Adams and Spokane counties as well as Kootenai and Shoshone counties and points to the south. The front will slowly exit the region later this morning and afternoon, but not before moderate to heavy snow falls across portions of the Palouse, Kootenai and Shoshone counties. Will keep all current advisories and warnings as they look to be on track. The Spokane area may be able to be cancelled slightly earlier as the front should move south of the metro fairly early. An area to watch will be the Camas Prairie. They will see about 3 inches of snow today, which is the low end for an Advisory. Am hesitant to issue anything as cameras are not showing anything going on, even though the weather models suggest it should be snowing there now. Their winds look to remain from a southerly direction through the morning and don't switch to an upslope northwest flow until afternoon. Expect to see a decrease in snow for most locations through the day. Current temperatures are much warmer than this time yesterday. Models are suggesting highs below what many locations currently are. Have trended towards a warmer model, though temps should remain near steady or slightly cool through the day. Winds are currently funneling down the Okanogan Valley and will continue through the morning and then decrease through the afternoon. Gusts up to 20 mph is possible. Tonight: A shortwave ridge builds into the region tonight for our only area wide dry period. (the exception may be the Camas prairie that sees snowfall through the evening) Some drier air moves in and we will see partly cloudy to mostly clear skies. This will drop our temps into the single digits and teens. (20s Pullman and areas to the south) Thursday: The ridge gets pushed east as the next weather system nears the Pac NW. Chance of precip moves into portions of central WA during the morning and then spreads north and east through the afternoon. A northerly pressure gradient will increase through the day across portions of eastern WA and north ID. Have added some blowing snow to the forecast, though temperatures should warm enough that the snow should be heavier that what we have seen all week. Confidence is low. There is also the potential as warmer air moves in that some of the cold air at the surface will remain. This poses the risk of freezing rain. Think that threat will extend mostly across portions of Whitman, Adams, Grant, Lincoln and Spokane counties. The NAM has been showing this in the afternoon, while the GFS has been waiting until the evening or overnight hours. Confidence is quite low. Any freezing rain should be brief as surface temps will warm across many of these locations to just above freezing. During the afternoon the best threat for widespread snow will be across central WA. /Nisbet Friday through Sunday...Model guidance tonight is actually in decent agreement with the next upper level low poised to move into the region Thursday night and linger over the region through Sunday. The low will once again drop south just off the Washington coast Thursday night and Friday. This will put the region in a warm and moist southerly upper level flow. The warm front will move east of the Cascades Thursday night. Isentropic up glide along with south-southeast low level winds will result in moderate to heavy precipitation Thursday night for the Cascades. By early Friday morning a surface low will set up across the upper basin and provide a focusing point for heavier precipitation from just south of Highway 2 north to the Canadian Border. This convergence zone will slowly move north through the day Friday resulting in a little drier conditions across the southern zones. The closed low will open into a wave on Saturday with several short waves wrapping around the periphery of the Inland Northwest. This will keep a good chance for snow showers in the mountains through Sunday with a lower chance of showers for the higher terrain surrounding the Columbia Basin. Temperatures will gradually cool off to below normal again through the period. *Precipitation amounts and Type: Precipitation amounts will range from around a tenth of an inch in the deep basin to just under a half inch in the mountains. Storm total snow from Thursday night through Saturday afternoon will range from 4-10 inches in the mountain with some areas receiving over a foot. The Wenatchee area and the Waterville Plateau could see 4-6 inches, The Upper Basin east to the Coeur d'Alene area 3-5 inches. The lower Basin and Palouse 1-3 inches, The L-C Valley 0-2 inches and the Camas Prairie 3-5 inches. A bigger challenge is that it looks like there could be a few hours of spotty freezing rain through about midnight on Thursday for portions of the Columbia Basin north up to the Columbia River. Ice accumulation should remain light, less than 0.05. Light to moderate Snow and ice accumulations will more than likely cause travel impacts for the Friday morning commute and we will be looking to put out additional winter advisories or warnings. Monday through Wednesday...High pressure is expected to build in from the west Sunday night as the upper low exits the region. This will put the region in a mostly dry northwest-northerly flow. Another weak short wave looks possible around Wednesday afternoon/night but confidence in the timing is pretty low at this time. The forecast through this period will be on the cool side of normal with localized mountain snow at times Monday and Tuesday, then a better chance for snow by Wednesday. Tobin && .AVIATION... 06Z TAFs: A cold front will slowly sag across southeast WA and the southern to central ID Panhandle tonight into Wednesday. The Spokane/Coeur d'Alene corridor will be on the northern fringe of the snow that falls along the front. Heaviest snowfall will occur at KPUW with moderate snowfall and low IFR conditions expected overnight into Wednesday morning. Lewiston will see a rain/snow mix to start out with by early Wednesday morning with switch over to snow expected by late morning or early afternoon. Drier air funneling down out of the Okanogan Valley is expected to result in VFR conditions for KEAT and KMWH by Wednesday afternoon. Lower confidence if stratus cover will break up at KGEG, KSFF and KCOE. There is moderate to high confidence that KPUW will remain IFR through at least Wednesday afternoon. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 33 15 34 27 32 21 / 70 10 70 80 40 20 Coeur d'Alene 35 18 35 28 34 24 / 80 10 60 80 60 30 Pullman 34 22 38 27 34 23 / 100 10 80 80 50 30 Lewiston 40 29 44 34 40 27 / 80 20 60 70 40 30 Colville 36 11 36 25 37 21 / 10 0 40 80 60 30 Sandpoint 34 20 35 30 35 27 / 20 10 40 80 80 40 Kellogg 35 20 36 29 35 26 / 100 20 70 80 80 40 Moses Lake 32 15 35 24 32 20 / 10 10 80 70 20 10 Wenatchee 32 15 31 23 32 21 / 10 10 90 70 30 20 Omak 31 13 31 26 33 22 / 10 0 60 80 40 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Storm Warning until 4 PM PST this afternoon for Central Panhandle Mountains. Winter Storm Warning until 1 PM PST this afternoon for Idaho Palouse. Winter Storm Warning until 7 AM PST this morning for Coeur d'Alene Area-Northern Panhandle. WA...Winter Storm Warning until 1 PM PST this afternoon for Washington Palouse. Winter Weather Advisory until 4 PM PST this afternoon for Northeast Blue Mountains. Winter Weather Advisory until 7 AM PST this morning for Spokane Area. && $$