827 FXUS63 KMPX 132352 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 552 PM CST Fri Jan 13 2023 .UPDATE... Issued at 552 PM CST Fri Jan 13 2023 Updated to include 00z aviation discussion below. && .SHORT TERM...(This evening through Saturday night) Issued at 224 PM CST Fri Jan 13 2023 KEY MESSAGES: - Clouds and fog linger in parts of the area through Saturday morning. The surface analysis this afternoon indicated a weak ridge over south central, east central MN, and into west central WI. Southerly flow developed on the west side of this ridge today along with skies becoming clear. Tonight's fog/low clouds is based on winds shifting to the south/southeast overnight and increase in speed. Until this develops, areas of fog and low clouds will continue for mainly the eastern 1/4 of MPX CWA. Very warm air will commence on Saturday leading to well above normal temperatures. Some residual low clouds/fog are possible over far eastern MN, and west central WI until midday. Wind speeds will also increase as a storm system moves along the Canada border with a strong pressure gradient developing over the Upper Midwest. .LONG TERM...(Sunday through Friday) Issued at 224 PM CST Fri Jan 13 2023 KEY MESSAGES: - A couple systems to watch through next week. The first Sunday night into Tuesday will bring widespread precip, mostly rain but some snow and freezing rain are possible. The second is trending south away from the area Thursday. A large scale ridge will shift east this weekend and stall over the Appalachians in response to a cut off upper low over the western Atlantic. A disturbance over the Desert Southwest will track northeast in the resultant southwest upper flow and impact the region early week. Isentropic upglide will begin Sunday night and precipitation will break out after midnight across much of the Upper Midwest. Temperatures aloft should be warm enough to support liquid initially (except perhaps across western MN), but surface temps could still be subfreezing. Therefore, some icing threat is plausible as precipitation begins. Boundary temperatures warm above freezing Monday and any icing threat should be minimized as plain rain becomes the dominant p-type. Enough cold air throughout the column may still exist across western MN to be an exception and it is here where snow may still be the main p-type. As colder air wraps around the system Monday night, the rain/snow line will shift east. The majority of the precip should be done before this transition occurs across eastern MN and WI, but it will need to be watched for the potential of light accumulation if precip lingers longer or turns to snow quicker. Temps will cool a bit midweek with high pressure building into the Upper Midwest. As the last shift noted, the 00Z ECMWF was a northwest outlier within its ensemble envelope and the 12Z has shifted southeast a bit more in line with the bulk of the members. Most guidance is now dry for our area and PoPs took a hit with this afternoon's update. The upper low looks rather potent, but with a split flow and a largely zonal southern stream, there isn't much support to bring it this far north unless the northern and southern streams phase. That scenario looks remote at this time. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 552 PM CST Fri Jan 13 2023 FEW-SCT high clouds in western MN with low stratus, even into IFR, in eastern MN and western WI. Little change in this scenario is expected this evening, at least in an optimistic sense, as low stratus and fog will develop later this evening in western MN and remain in place through sunrise, even with breezier S winds but that is due to warm air advection atop the snowpack creating the overnight thru midday degraded flight conditions. Improvement to VFR at all sites not expected until mid-to-late day Saturday. Winds throughout this cycle will come generally from the south at close to 10 kts. KMSP...Low stratus will be difficult to erode in eastern MN, thus will look for the low stratus to remain in place past sunrise Saturday morning. IFR ceilings at the start will gradually increase to MVFR levels but remain below 1700ft through this evening and nearly the entire overnight period. Improvement will come mid-to-late Saturday morning, with clouds scattering out by around noon. Some breezy/gusty winds from the south look likely for Saturday night. /OUTLOOK FOR KMSP/ Sun...VFR. MVFR/Chc -RA overnight. Wind S 10 kts. Mon...MVFR with -RA. Wind NE 5-10 kts. Tue...MVFR ceilings. Chc -SN. Wind NW 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ UPDATE...JPC SHORT TERM...JLT LONG TERM...Borghoff AVIATION...JPC