228 FXUS66 KOTX 151206 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 406 AM PST Sat Jan 15 2022 .SYNOPSIS... Low clouds, fog and light winds will persist. A dry weather pattern will be in place for the weekend. Precipitation chances return to some areas early next week, with the potential for light mountain snow, but no major winter storm systems are anticipated at this time. && .DISCUSSION... Today and Sunday: A weak ridge along the coast is keeping the region generally dry. It is expected to bring benign weather for the Inland Northwest. The main concern is the continuing overnight fog and below freezing temperatures creating icy conditions for untreated surfaces during the morning hours. Fog will decrease through the day. Ensembles indicate a very slight chance of isolated shower activity for North Idaho but confidence is low. Winds will continue to be light and variable under the stable airmass. Highs for the period will be in the 30s. Lows will be in the 20s. /JDC Monday through Tuesday...The strong upper level ridge axis this weekend is expected to flatten as a weak upper level trough crosses SW BC and merges with one sweeping southeast across the BC/AB border. The main result of this will be an increasing threat of light precipitation near the Canadian border, beginning Monday and spreading slowly southward through Tuesday. The mid-level flow will remain primarily out of the west suggesting most of the precipitation is going to fall near the Cascade Crest and pick up again over the Idaho Panhandle. Meanwhile most of central Washington will miss out on the precipitation due to downslope flow over the Cascades. During this 48 hour period precipitation amounts could range from 0.15-0.30” along the immediate Cascade Crest, and anywhere from 0.08-0.15” over the Idaho Panhandle. Based on 850 mb temperatures most of this will fall as snow north of Highway 2, however as it sinks southward we could see a transition from snow to rain, as well as a small chance of messy wintry precipitation in the lee of the Cascades. This is due to a persistent elevated melting layer over the southern half of eastern Washington. Again, we don’t have a lot of precipitation across central Washington, but if this notion changes, we’d will likely have to increasing messaging on this potential. Wednesday through Friday...All the ensemble model solutions are depicting a re-amplification of the upper level ridge over the region. The big question is how amplified will it become? Unlike yesterday’s model runs which showed the GEFS as an outlier with a very strong 570dm ridge over the region, today’s solutions are generally supportive of a flatter ridge. The offshoot is we are looking at a continued threat of light precipitation near the Cascades and over the ID Panhandle through at least Thursday. By this time, any precipitation which falls will generally consist of rain or snow as any elevated melting layer will likely shift well south of the forecast area. By Friday, the model remain in good agreement, that the ridge will amplify strongly along 132w, with northerly flow developing over the region. The deterministic runs of the GFS and EC place the jet well north of the area on Friday and keep any threat of precipitation well north and east of the forecast area, however the ensemble means hold onto a threat of light precipitation, especially over the southern half of the ID Panhandle due to upslope northwest flow. In any case, this looks like a fairly benign weather pattern for most of the region. Temperatures for this period will generally run near normal or warmer than normal which equates to highs in the 30s to lower 40s, however this is far from certain as much will depend on how effectively (if at all) we mix out any low-level inversions. fx && .AVIATION... 12Z TAFS: The region will influenced by low ceilings and fog through the period. They will lead to IFR conditions for most sites. KPUW-KLWS are expected to be MVFR to VFR. Brief periods in the afternoon could bring MVFR for portions of the rest of the region. Any improvements will will decline back to IFR conditions during the overnight hours. /JDC && .PRELIMINARY POINT TEMPS/POPS... Spokane 35 28 35 27 36 27 / 10 0 0 0 0 0 Coeur d'Alene 36 26 36 27 38 27 / 0 0 0 0 0 10 Pullman 37 27 37 28 38 29 / 0 0 0 0 0 10 Lewiston 41 30 39 30 42 32 / 0 0 0 0 0 0 Colville 35 26 34 26 34 26 / 10 0 0 0 0 0 Sandpoint 35 28 35 27 35 29 / 10 0 0 0 10 10 Kellogg 38 26 38 29 39 30 / 0 0 0 0 0 10 Moses Lake 33 26 33 25 34 24 / 0 0 0 0 0 0 Wenatchee 33 25 31 26 33 29 / 0 0 0 0 0 10 Omak 34 23 31 25 33 27 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...Dense Fog Advisory until noon PST today for Moses Lake Area- Spokane Area-Upper Columbia Basin-Washington Palouse- Waterville Plateau. && $$