693 FXUS63 KMPX 180942 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 342 AM CST Wed Dec 18 2019 .SHORT TERM...(Today through Thursday) Issued at 342 AM CST Wed Dec 18 2019 High pressure overhead has lead to clear skies and light winds across most of the CWA, allowing for temperatures to drop well below zero overnight. Expect the coldest temperatures across central Minnesota where lows will approach -20, and generally drop to around -5 to -15 across the rest of the area. Increasing cloud cover has already led to warming temperatures across western Minnesota, and this could keep temperatures a few degrees warmer this morning as clouds spread into central and eastern Minnesota before sunrise. High pressure slides off to the east during the afternoon with southerly flow developing, although temperatures are expected to stay cold this afternoon under mostly cloudy skies. The most pronounced warm up will be across southwest Minnesota where temperatures could reach the mid to upper 20s along the Buffalo Ridge, but otherwise expect highs this afternoon in the teens and upper single digits. The warming trend continues into Thursday as pronounced upper-level ridging builds into the upper Midwest and 850 mb temperatures approach 5 C across the CWA. It looks unlikely we will be able to tap into these warm temperatures aloft at the surface with a sizable snowpack still in place, and easterly winds likely resulting in widespread stratus being trapped under the inversion aloft. Still, a warmer day is expected with temperatures in the low to mid 20s across central Minnesota/west- central Wisconsin and approaching 30 towards the I-90 corridor. .LONG TERM...(Thursday night through Tuesday) Issued at 342 AM CST Wed Dec 18 2019 A quiet and mild long term portion of the forecast is still expected, with no hints of any precipitation chances until the middle of next week. Changes this forecast cycle were pretty minimal and we did not stray from what NBM populated with given a lack of any targets of opportunities to significantly improve upon the NBM. Beginning this weekend and lasting trough the final week of 2019, the upper pattern will be dominated by troughing across western NOAM and upper ridging into the Great Lakes. This will result in a much milder southwest flow for us. Typically, this can also be an active/wet flow, with large systems coming out of the southwest, but this will be a decidedly split version of southwest flow, with models not sending any shortwaves from the western trough our direction until mid to late next week. It does look like we'll start the long term Thursday night with plenty of status, but during the day on Friday, we'll see a shortwave pass through the area, with westerly flow coming in it's wake. This will usher in very mild h85 temps for the weekend and drier air as well, opening up the potential for seeing skies clear out. That's certainly the scene the NBM paints, but as h85 temps push out to 10C-15C by Sunday, it will result in a strengthening inversion. This will setup the opportunity for seeing moisture trapped beneath an inversion, which is a recipe for seeing a shallow stratus layer develop, especially with some snow melt likely to be occurring. It's this threat for seeing stratus, combined with the existing snowpack why we continue to stay with the NBM for temperatures, which is a tinge higher than the median of the model spread. Certainly, when looking at 90th percentile highs, you get a sense of what our potential is for highs this weekend, which would be upper 30s to the lower and even mid 40s, or about 3 to 5 degrees warmer than currently forecast. A week cold front coming through on Monday will knock our temperatures back slightly for the leadup to Christmas, but temperatures will remain well above normal. For the end of the forecast, the GFS/ECMWF agree on the idea that we'll start seeing energy head our way from the western trough, but there's still some significant timing differences. We left the 20s PoPs in for Christmas, but confidence is pretty low in seeing anything at this point. In addition, we have the type as all snow for now, but given how warm we'll be next week, any system we see will have the potential to bring with a rain/snow mix or just plain rain. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1005 PM CST Tue Dec 17 2019 A broken (VFR) mid-level deck over the eastern Dakotas will advance eastward across the area early Wednesday. Otherwise, light and variable winds overnight become south-southeasterly on Wednesday around 10 knots, with gusts to 20 knots at western sites (KAXN/KRWF/KMKT). KMSP...No concerns. /OUTLOOK FOR KMSP/ Thu...Mainly VFR. MVFR CIGS possible. Wind SE 5 kts. Fri...MVFR. Winds SSW 5 kts. Sat...Mainly VFR. MVFR CIGS possible. Winds SSW 5 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...ETA LONG TERM...MPG AVIATION...LS