755 FXUS63 KFSD 071725 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 1125 AM CST Mon Jan 7 2019 .SHORT TERM...(Today through Tuesday afternoon) Issued at 224 AM CST Mon Jan 7 2019 Cool front near the James River Valley at 07Z will continue to push eastward today, followed by a period of post-frontal stratus/fog as cooler air pushes into relatively moist air mass. Subtle cooling behind the front not expected to last long, as good mixing in west- northwest flow will help temperatures once again climb well above normal today. With snow cover dwindling in many areas and favorable mixing profile, will again favor warmer side of guidance spectrum, with highs from the mid-upper 30s in our northern counties around the Coteau des Prairies and Buffalo Ridge, to mid 40s near/south of I-90. Fairly compact wave currently passing through the Pacific Northwest will be our next feature of interest, as it quickly crosses the northern Rockies today, and continues across the Dakotas/Minnesota tonight. Models indicate potential for spotty precip on the warm advection wing of the wave this evening, with a greater chance of measurable rain changing to snow as colder air dives in behind the wave later tonight. Due to the quick movement of the system, expect precip amounts to remain on the light side, with around an inch of snow possible east of Highway 81/north of Highway 14, in our far northeast counties. Winds behind the wave/surface front expected to be quite burly, with most models showing 925mb winds @ 35-40kt and 850mb winds @ 45-55kt spreading across the forecast area tonight and persisting through the day Tuesday. Would not be surprised to see a wind advisory for at least eastern parts of the forecast area on Tuesday, but for now will just highlight the strong winds in the HWO and on social media platforms. With the anticipated light snowfall tonight, will include mention of patchy blowing snow with these stronger winds, mainly in our far northeast where the amounts near 1 inch are expected, as the existing snowpack has become less prone to blowing with the recent warmth. Reinforcing shot of cold advection into southwest Minnesota Tuesday could drop cloud-layer temperatures down into the favored snow-growth range, and have also added a chance of flurries to this area, with more sunshine expected to prevail over the remainder of the CWA. .LONG TERM...(Tuesday evening through Sunday) Issued at 224 AM CST Mon Jan 7 2019 Gusty winds will persist into Tuesday night, especially in eastern areas, but should continue to diminish through the day Wednesday as surface and upper ridge work eastward into the area. Despite the ridging aloft, low level cold air persists thanks to limited mixing ahead of approaching surface ridge, so Wednesday likely to be the coldest day of the week with highs near to even below normal in the teens and 20s. Warmth begins to build back into the region for the latter part of the week, though not to the extent that we have seen of late, with highs generally in the upper 20s and 30s for Thursday and Friday. Greater uncertainty in how temperatures will pan out next weekend, as models show considerable differences in handling of an upper trough which drops through the region Thursday night and Friday. Canadian moves the trough out of the area more quickly, allowing temperatures to warm further by Saturday. Meanwhile GFS/ECMWF are slower to kick the trough eastward, and thus temperatures remain more modest Saturday, with warming delayed until Sunday when upper ridge builds eastward. For now have favored this somewhat slower solution, but confidence in weekend temperatures is rather low at this point. As far as precip chances in the later periods, it looks rather sparse for our forecast area. Aforementioned wave dropping through Thursday night/Friday could scrape our far northern/eastern areas with some very light precipitation, though better chance currently looks to remain farther northeast into Minnesota. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 1122 AM CST Mon Jan 7 2019 IFR conditions will quickly mix out and shift east by about 20z. Rain, mixed precipitation and snow will be possible later tonight with the better chances in southwest MN from about 5z to 10z. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ SHORT TERM...JH LONG TERM...JH AVIATION...08