805 FXUS66 KOTX 082147 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 247 PM PDT Tue Oct 8 2019 .SYNOPSIS... Blustery north winds will bring much colder air into the Inland Northwest tonight. Portions of the Idaho Panhandle and southeast Washington will wake up to a bit of new snow on Wednesday. The majority of the region will experience a hard freeze the next few nights with low temperatures as cold as the teens and twenties on Thursday morning. Temperatures will moderate heading into the weekend. && .DISCUSSION... Tonight and Wednesday: Who likes the beautiful weather we expect in Inland Northwest during the fall? It seems as though fall has betrayed us this year, and tonight will feature another rude blast of winter-like weather. Blustery north winds will spill down the Okanogan Valley this evening into central Washington causing temperatures to plummet by Wed morning. The cold air intrusion will also bring a change from rain to snow over portions of the Idaho Panhandle and eastern Washington. *Low Elevation Snow: Forecasting the location of deformation bands is tough. Forecasting snow amounts for events with rain changing to snow is even tougher which leads to a low confidence forecast for tonight. The morning model runs are targeting Spokane, Whitman, Latah, Benewah, southern Shoshone, and southern Kootenai counties tonight as a compact surface low develops south of I-90 in central WA this evening and slides into the southern ID Panhandle overnight. The NAM and GFS forecast as much as a quarter to half inch of liquid precipitation. Much of it should fall as rain this evening, but as cold air spills southward overnight...look for rain to change to snow. Grassy surfaces around Spokane, Couer d'Alene, Pullman, Moscow, and Kellogg will have a shot of accumulations. The most likely scenarios is for these communities to get less than and inch. However, high intensity precipitation in localized bands could produce amounts of a couple inches as low as 2000 feet. *High Elevation Snow: Winter Weather Advisories are in effect for the mountains of the Central Idaho Panhandle and the Camas Prairie above 3500 feet as well as the Blue Mountains of southeast Washington. Again, the location of snow bands will make or break snow amounts. At this time, it looks like Lookout Pass will have the potential for up to 4 inches by early Wed morning. The high terrain of southern Shoshone county around Clarkia and Calder could get up to 6 inches. Motorists on Hwy 95 will likely encounter a couple inches of wet accumulation around Winchester and Craigmont early Wed as well. *Wind: North winds of 15 to 20 mph with gusts to 30 mph or more will be common tonight in the Okanogan Valley and down the Hwy 95 corridor between Bonners Ferry and Rathdrum. With temperatures falling into the mid 20s and low 30s, wind chill values on Wednesday morning will be in the teens. Kids waiting for the bus should be bundled up with their winter coats Wed morning. /GKoch Wednesday night through Tuesday: Thursday morning will be cold with many lower elevation locations seeing freezing temperatures. These temperatures also figure to break a number of records for the date. This will include locations that have not experienced freezing temperatures yet such as Wenatchee and the Lewiston- Clarkston Valley. There is a good chance that much of the rest of the region will experience its first hard freeze of the fall season with lows bottoming out in the teens to low 20s. Temperatures will crash once again Thursday night. There's a good chance that a freeze warning will be needed for locations that haven't experienced freezing temperatures yet, which includes the Wenatchee Area and Lewiston- Clarkston Valley. Temperatures will gradually moderate out heading into next week. Models are showing a low pressure trough moving into the Northwest. The prognosis is for this trough to stretch out and weaken as it moves inland off of the eastern Pacific. The low dew points, although should be increasing, will likely result in much of the moisture with this wave to evaporate before actually reaching the surface as precipitation. A better chance for precipitation may come early next week, but confidence in details is low. /SVH && .AVIATION... 18Z TAFS: As daytime mixing increases this late morning, gusty surface winds should resume and continue into the evening for the TAF sites. The surface flow is still expected to veer more from the northwest this afternoon into the evening, but a secondary surge of precipitation will move first into central WA and push east and southeast into southeast WA and the northern/central Panhandle late this afternoon through the evening. A mixed bag of rain, rain/snow mixed, and light snow will first move into GEG-SFF-COE. A few hours later this precipitation will move into PUW and LWS. Visibilities should remain mostly VFR in those TAF sites affected by light SN through the Purcell trench and vicinity GEG, but there is a chance light snow occurring PUW- LWS late this evening into the early morning hours may drop briefly to IFR conditions. Low confidence with this scenario will necessitate a closer monitoring for any changes in the current forecast. Ceilings, however, will range from MVFR to IFR in those sites affected by a mixture of the rain/snow or light snow later in the evening. Showers developing in the colder more unstable air over the Cascade crest this afternoon should not directly affect EAT and MWH with those sites remaining VFR. But those sites will also be monitored closely as well. By early morning a north- northeast surface flow will increase over the TAFS sites bringing much colder/drier continental air into the region. /aky && .PRELIMINARY POINT TEMPS/POPS... Spokane 27 45 22 47 25 53 / 60 0 0 0 0 0 Coeur d'Alene 27 43 21 47 23 54 / 60 0 0 0 0 0 Pullman 27 43 21 46 25 53 / 80 10 0 0 0 0 Lewiston 37 50 28 51 28 60 / 80 30 0 0 0 0 Colville 23 50 17 53 24 57 / 20 0 0 0 0 0 Sandpoint 26 43 22 47 23 52 / 70 0 0 0 0 0 Kellogg 27 40 21 46 26 52 / 80 0 0 0 0 0 Moses Lake 31 53 21 54 24 58 / 30 0 0 0 0 0 Wenatchee 34 53 29 53 31 54 / 50 0 0 0 0 0 Omak 30 53 23 52 27 55 / 20 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory from 11 PM this evening to 11 AM PDT Wednesday above 3500 feet for Central Panhandle Mountains. Winter Weather Advisory from 11 PM this evening to 11 AM PDT Wednesday for Lewis and Southern Nez Perce Counties. WA...Winter Weather Advisory from 8 PM this evening to 11 AM PDT Wednesday above 4000 feet for Northeast Blue Mountains. && $$