463 FXUS63 KMPX 020510 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1110 PM CST Tue Mar 1 2022 .UPDATE... Issued at 1110 PM CST Tue Mar 1 2022 Updated to include 06Z aviation discussion. && .DISCUSSION...(This evening through Tuesday) Issued at 318 PM CST Tue Mar 1 2022 Key Messages: - Freezing precipitation development overnight, and early Wednesday. - A potentially significant storm system Friday night through Saturday night could bring all types of wintry precipitation. Snow and ice accumulations are likely, but confidence in specific details and amounts is low. A large area of low stratus and fog was present this afternoon across North Dakota. The surface front has moved southward into central Iowa with a general weak north/northeast flow at the surface across central/southern Mn and adjacent west central Wi. Winds become more west/northwest at the surface and in the boundary layer across the Dakotas overnight. First, the area of low stratus/fog should progress east/southeast across Mn tonight. Weak lift associated with 850-700MB Fgen boundary and increasing mid-level moisture could be ample enough to generate light precipitation across mostly the northeastern 1/3 of MPX CWA late tonight. The timing of both deeper mid-level moisture and the effective lift will occur between midnight and 9 AM. Either way, the chances of freezing precipitation will likely be south of I-94 where deeper moisture is limited. QPF amounts only support a few hundredths of an inch of liquid equivalent. So, if any freezing precipitation develops it should have minimal impacts. By late morning, any mid- level moisture will quickly exit the region, so low clouds and moisture will remain in the boundary layer until later Wednesday as much cooler and drier air advects southward across the Upper Midwest. Tonight's and Wednesday's temperatures will have limited variation due to cloud cover. The front associated with Wednesday system will stall south of our CWA. Along this front, a much stronger thermal profile will lead to stronger forcing and precipitation along it late Wednesday night. How far northeast this precipitation band moves remains questionable. However, it should be close enough to warrant high percentages along the Iowa border. Snow will be the predominate weather type due to much cooler temperatures expected in the moisture column. Thursday and Friday - High pressure will drift eastward allowing for a quiet period to end the work week. Temperatures will be chilly, in the mid to upper 20s on Thursday, but return flow develops and sets up WAA on Friday. Friday's high will be near average in the mid-30s and will remain dry as a low pressure begins to develop lee of the Rockies. Friday night through Monday - Models remain fairly consistent with the weekend storm system. 12Z guidance continues to favor a stronger, warmer scenario and continues to trend drier with respect to QPF amounts. Still expecting snow and a wintry mix initially late Friday night before the low center approaches and brings in milder air. A brief period of freezing rain is likely before a changeover to all rain occurs on Saturday. It is unknown how long the freezing rain will last until we get closer to the event, but sub-freezing surfaces may freeze liquid precipitation despite temperatures in the 33 to 35 degree range Saturday AM. However, persistent warm air advection will eventually warm temperatures in to the upper 30s Saturday afternoon across southern MN. This will be warm enough to stop the influence of sub-freezing surface temperatures and allow rain to fall and remain liquid. Another caveat is that the track will continue to wobble over the next few days and this forecast likely won't be the final result come Sunday morning. However, for a large synoptic system, models have been remarkably consistent despite the changing of weather types due to minor differences in thermal profiles. This remains a highly complex set up that will require fine tuning over the next day or two but a significant storm will impact the region starting Friday night through Sunday morning with all precipitation types possible across much of the MPX CWA. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1110 PM CST Tue Mar 1 2022 Recent model trends have been keeping more dry air in the lower levels of the atmosphere so chances for precipitation tonight have gone down. There remains a chance for snow at AXN, STC, MSP, RNH, and EAU overnight. CIGS will still fall into MVFR tonight as the cloud deck moves in. Winds will either be calm or light and variable overnight before rising to light winds from the north during the day Wednesday. Tomorrow CIGS will remain MVFR to start the day before scattering out to VFR in the afternoon/evening. KMSP... Chances for snow have gone down with more dry air present at lower levels of the atmosphere. Some snow could still fall early Wednesday morning, but totals would be very light (under 0.5"). CIGS will fall to MVFR as the cloud deck moves in overnight and scatter out tomorrow late afternoon/evening. Wind will be light overnight rising up to around 10 knots from the north on Wednesday. /OUTLOOK FOR KMSP/ Thu...VFR. Wind E/NE 5-10 kts. Fri...MVFR/IFR and a wintry mix likely late. Wind E 10-20 kts. Sat...MVFR/IFR. Wintry mix bcmg rain during daylight hours. Wind E 10-20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ UPDATE...NDC DISCUSSION...BPH/JLT AVIATION...NDC