707 FXUS66 KOTX 061141 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 441 AM PDT Sun Oct 6 2019 .SYNOPSIS... Dry weather is expected for the rest of the weekend as high pressure dominates. This pattern begins to break down on Monday bringing a chance of preciptiation to the Cascades and northern mountains. A strong cold front passage Monday night into Tuesday will bring windy conditions, a chance of precipitation to all locations, and much cooler temperatures to the region. Cool, dry weather is expected after mid-week. && .DISCUSSION... Sunday: A look at the 500 mb analysis this morning reveals a ridge of high pressure nosing into the Pacific Northwest allowing for mostly clear skies across our region. Because of this, temperatures are running some 5 to 10 degrees colder than at this time yesterday. Currently, our GOES-17 fog product shows some fog along the I-90 corridor east of Coeur d'Alene in addition to some patches over the northern WA valleys. Given the time of year, we are expecting this fog to burn off a few hours after sunrise. Seasonably warm temperatures are forecast this afternoon with most lower elevations hitting 60 and above. Thanks to the aforementioned ridge, synoptic scale gradients will remain weak with light southwesterly flow across our area. While we are expecting clear skies to start the day, high clouds will begin streaming over our area by late morning in advance of our next system. Monday: Upper level ridging will transition into quasi-zonal flow by Monday bringing in moisture to the Pacific Northwest. This will bring showers Monday morning to our higher terrain (mainly to the Cascades) while preciptiation is forecast to hold off until after sunset for the lower elevations. Despite ample cloud cover, high temperatures will likely be several degrees warmer for most locations on Monday as decent warm air advection occurs ahead of an approaching cold front. In addition, this front will act to tighten surface pressure gradients causing winds to steadily increase throughout the day with the strongest winds expected Monday evening/night. Wilson Monday night through Wednesday: The cold frontal system will begin to move through the region Monday night with precipitation continuing into Tuesday and possibly Tuesday night. This system has sped up the last few model runs: the jet streak aloft is now expected to be over the region Monday night, with rapidly lowering snow levels Tuesday and Tuesday night. Wind will be a tricky forecast with this system, again as the best upper level support will be Monday night. Downward mixing may be limited given this timing. Gusts of 25-35 mph, locally up to 40 mph, will continue to be possible late Monday into early Tuesday. Breeziest locations will be across the Columbia Basin, the Palouse, and the West Plains. Gusty north to northeast winds may also develop late Tuesday into Wednesday after the cold front passes through. Snow levels will be rapidly lowering as the storm system traverses across the region. Across the Cascades, rain could change over to snow Monday night at pass level, with snow continuing through the day on Tuesday. A few inches of snow accumulation will be possible across Cascade passes. Portions of central WA will likely be rain-shadowed with strong westerly flow across the Cascades. Farther east, snow levels should drop below Lookout Pass Tuesday morning, and continue to fall through the day. Higher mountains can expect a few inches of snow, and at this stage it looks like the northern Idaho valleys could see light snow accumulations. Ensemble model guidance suggests we can't completely rule out flurries or light snow showers across eastern WA Tuesday evening as precipitation dissipates. Wednesday night through Sunday: High pressure will likely rebuild over the region late next week. Given the rapidly drying conditions and clearing skies, strong radiational cooling will bring cold overnight temperatures. Widespread freeze conditions will be possible with temperatures forecast to drop down into the 20s, and possibly even into the teens in sheltered locations and over higher terrain. We'll start to see some moderation in temperatures late in the week, but will remain below normal for this time of year. Dang && .AVIATION... 12Z TAFS: Light and diurnal winds will prevail for the next 24 hours as high pressure remains in control. High clouds will gradually thicken and lower today while VFR conditions prevail. No other aviation concerns. Wilson && .PRELIMINARY POINT TEMPS/POPS... Spokane 60 39 63 41 52 27 / 0 0 10 40 20 30 Coeur d'Alene 59 36 62 41 51 27 / 0 0 20 70 30 40 Pullman 61 37 67 42 52 27 / 0 0 0 70 50 30 Lewiston 68 40 74 51 59 35 / 0 0 0 60 50 50 Colville 62 33 64 34 55 23 / 0 0 20 60 30 30 Sandpoint 59 35 59 40 49 25 / 0 0 30 80 70 70 Kellogg 57 39 60 42 49 29 / 0 0 20 90 60 60 Moses Lake 67 41 71 41 59 30 / 0 0 0 10 10 20 Wenatchee 63 44 67 44 55 34 / 0 0 30 50 20 10 Omak 62 43 63 39 54 29 / 0 0 40 40 20 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$