827 FXUS66 KOTX 061218 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 418 AM PST Sun Jan 6 2019 .SYNOPSIS...An active weather pattern is expected through Wednesday before a drier pattern arrives by the end of next week. Rain and mountain snow with windy conditions are likely for this morning. Another round of mainly now is expected tonight into Monday. A stronger storm system will bring the potential for snow and freezing rain Tuesday into Wednesday. && .DISCUSSION... ...RAIN, SNOW AND GUSTY WINDS TODAY... Today...A deep closed low is spinning off Haida Gwaii this morning and dragging a cold front through the region. The cold front will swing through the Inland NW from south to north between 09-12z and bring rapid drying from the south as it is moves through the region. Precipitation will be as low elevation rain and mountain snow. Precipitation amounts have been pretty light with only trace amounts across the basin and up towards the Columbia River. But as the front gets into the northern mountains up-sloping should help to wring out enough precipitation for 1-3 inches of snow and as much as 3-5 for the Cascades. A bigger challenge will be strong gusty winds early this morning lasting through about mid-day. The newest model guidance has backed off a little on the low level jet that is expected to accompany the cold front this morning. But there will still be enough mixing potential for 20-35 mph winds with gusts 35-45 mph from about 4:00 AM through about 10:00 AM this morning. The position of the jet has shifted somewhat north and west of previously thinking but we covered that in earlier forecasts. A Wind Advisory for Lower Garfield and Asotin counties, the northern Basin, the Washington Palouse and the Spokane area is still valid. Precipitation chances will remain focused over the mountains through the afternoon. Southerly, gusty winds will keep temperatures on the warm side of normal. For tonight...A secondary wave will move through the upper level trough and result in another round of mainly snow showers. The trough will exit the region early Monday morning bringing a drying trend to the region. But not before depositing around a half inch of snow for the Spokane-Davenport area and 1-2 inches for Coeur d'Alene up to Bonners Ferry and 3-5 inches up in the Northeast and Panhandle mountains. This will make for an interesting commute Monday morning. By mid-day the showers will again be confined to the Cascades and eastern mountains where another few inches of snow will add to the snow pack. Winds will subside through the night but remain southerly. Monday and Monday night...High pressure will build into region on Monday and strengthen through the day. Snow showers will linger through Monday afternoon for the Cascades and the Panhandle mountains but additional accumulations will be pretty light. By Monday night conditions will be dry across the region. Temperatures will cool off a bit, but remain on the warm side of normal. Tobin ...WINTRY MIX OF SNOW AND FREEZING RAIN POSSIBLE TUESDAY THROUGH WEDNESDAY... Tuesday through Thursday: Models are in good agreement that a deep low pressure system will slowly wobble toward the coast on Tuesday...stall for a period...then fill and eject inland Tuesday night into Wednesday. The air mass will start off quite a bit cooler than our previous storm systems. In addition, persistent east to northeast pressure gradients drawn toward the offshore low will allow the cooler air to remain firmly in place until Wednesday. So with the initial onset of light precipitation Tuesday accompanying the warm front, most locations will start off as snow. Intensities through late afternoon will be light and snow amounts through the day will generally be less than an inch, perhaps slightly higher in the Cascades. Our concern for travel impacts will really ramp up Tuesday evening and into Wednesday morning as a deeper slug of moisture arrives and midlevel forcing increase. This will also bring a stronger punch of midlevel warming and threat for a transition to freezing rain across the outer rim of the Columbia Basin and into the valleys of NE WA and N ID. This includes locations like Ephrata, Grand Coulee, Davenport, Spokane, Rathdrum, and Coeur D Alene. There remains a lot of uncertainty regarding the duration of freezing rain and potential ice accumulations but this definitely bears monitoring. Cold air looks to remain deep enough in the lee of the Cascades and across the northern mountain valleys through at least Wednesday morning to maintain snow as the main precipitation type and this will lead to the potential for light to moderate snow accumulations before a potential transition to freezing rain or rain. The Palouse, Camas Prairie, L-C Valley, and Blue Mountains should see the least impacts from this system. A shortwave kicks through Wednesday morning and helps stir up the atmosphere. This will allow our winds at the surface and aloft to swing around to more of a south/southwest direction and shift the focus for preciptiation into NE WA and N ID and some drying across the lower Basin. We should see a transition to rain or rain/snow mix in most valleys around midday Wednesday while snow continues above 3000-5000 feet yet precipitation will have a tendency to become more showery. A second shortwave passes through Thursday ushering another band of precipitation but with little change in the temperature profile, expect similar snow levels. Travel impacts will be minimal in the lowlands but could remain an issue over the mountain passes. Friday and Saturday: Another deep low will move toward the coast allowing heights to build inland. This will bring a period of dry weather to our region accompanied by mild temperatures. Saturday night and Sunday: The next system will make a run inland but looks to undergo quite a bit of splitting and weakening while running into the ridge. As such, another light precipitation event is expected and looks to be mild with mainly valley rain and light high mountain snow. /sb && .AVIATION... 12Z TAFs: A co;d front is moving through the north and eastern portion of the forecast area this morning. This will result in rain showers at KCOE and KSZT and snow showers at Bonners Ferry and in the mountains through 13-14z this morning. Expect mountain obscurations. Gusty southwest winds can be expected through 18-20z at KPUW/KCOE/KSFF/KGEG with gusts of 25-40 kts. At KMWH southwest winds gusting 20-25 kts through 18z. Otherwise conditions will be VFR. The next weather system will follow closely late this afternoon and overnight. KEAT will see some light -shra/-shsn with light accumulations and KMWH will likely get missed entirely with cigs/vsby remaining VFR. KPUW/KLWS will see light -shsn after 07z with a good dusting at KPUW. KGEG/KSFF/KCOE will see light to possibly moderate snow after 06z with up to a half inch at KGEG and an inch plus at KCOE. Cigs/vsby will drop to IFR with the onset of the snow. Tobin && .PRELIMINARY POINT TEMPS/POPS... Spokane 42 29 36 24 34 32 / 30 40 20 10 40 80 Coeur d'Alene 40 29 35 23 34 32 / 60 70 40 10 30 80 Pullman 41 29 35 25 37 35 / 10 40 10 10 30 70 Lewiston 48 35 44 30 41 38 / 10 40 10 10 30 50 Colville 43 24 39 18 33 31 / 60 30 10 10 40 80 Sandpoint 38 28 34 23 32 30 / 80 70 50 10 30 80 Kellogg 38 29 32 22 35 31 / 70 80 70 10 20 60 Moses Lake 46 28 42 27 36 33 / 10 20 0 10 60 80 Wenatchee 43 28 38 26 32 29 / 10 30 10 10 70 80 Omak 41 24 37 21 31 29 / 30 20 10 10 50 80 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...Wind Advisory until 1 PM PST this afternoon for Lower Garfield and Asotin Counties-Spokane Area-Upper Columbia Basin- Washington Palouse. && $$