185 FXUS63 KMPX 052123 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 323 PM CST Wed Jan 5 2022 .DISCUSSION...(This evening through Tuesday) Issued at 322 PM CST Wed Jan 5 2022 - Arctic air has returned this afternoon, with dangerous wind chill values expected through Friday morning. - After a brief reprieve Saturday, more arctic air and hazardous wind chill values are expected Sunday through Tuesday morning. Tonight - Thursday night: Surface low this afternoon is heading for Lake Huron, but we remain within its moist cyclonic flow. We've had wind gusts up around 40 mph hang on well into the afternoon out in western MN, with visibilities slow to improve out there with blowing snow. As a result, extended the Winter Weather Advisory in the counties that were in the Blizzard Warning last night through 6pm tonight to account for the continued blowing and drifting snow issues. With the cyclonic flow, we will see light snow linger for a while longer, with it finally ending in eastern MN around or a little after midnight, while it may take until after sunrise Thursday morning to finally get the snow out of places like Ladysmith and Eau Claire. This snow will be very light with any additional accumulations coming in at under 1 inch. The bigger story this period is the cold. NBM lows and highs for tonight through Thursday night were above the 75th percentile in the spread, so did undercut the NBM temperatures some this whole period. Thursday afternoon will see highs not make it above zero in MN, with the coldest overnight lows expected Thursday night when the surface high moves overhead. Once again, lows down into the -30s F will be possible out toward Staples in central MN. Of course with these cold temperatures comes wind chill issues. Our threshold for a Wind Chill Warning is -35F or colder and we do occasionally hit that out toward Alexandria and Morris tonight/Thursday morning, but with FGF staying with an Advisory (their warning criteria is - 40F) and a warning for us being marginal, left an advy in place, though did expand it east to the I-35 corridor and the Twin Cities, with wind chill values in western Hennepin county forecast to get as low as -30F Thursday morning. More wind chill headlines will likely be needed Thursday night, but this gets a little tricky as winds will be nearly calm, so apparent temps won't be far from the actual air temps given the light winds. In fact, the most hazardous wind chills Thursday night into Friday morning will likely come mid to late Friday morning in western MN as southerly winds quickly ramp up. Friday and Saturday: This is a brief period of WAA ahead of another arctic front coming through Saturday night. NBM temperatures switch from running warmer than the 75th percentile in the arctic air, to running a bit below the 50th percentile in the warm air, so we could certainly be a bit warm on Saturday than currently forecast. Also underdone are the winds Friday night through Saturday night, though as the spread in timing of the front comes down, expect stronger winds to end up in the forecast, especially Saturday night, where forecast soundings from the GFS show the CAA could have wind gusts similar to what we just experienced last night into this morning. Precip chances continue to look best north of our area, but we could get some light snow in the strong WAA Friday night into Saturday morning east of US-71 and north of I-94. More concerning is that GFS soundings continue to show a stratus layer coming up ahead of the cold front, which could produce drizzle/freezing drizzle, so that is a threat future shifts will have to keep an eye on. Sunday through Monday night: This will be our next plunge into the Arctic icebox, though this time around, temperatures aren't looking quite as cold as what this and the previous arctic outbreak brought. Once again, the NBM is running above the 75th percentile in its spread in the arctic air, so the forecast will probably come in a bit lower as we get closer to this arctic airmass. Tuesday and beyond: The western ridge will start moving into central North America, which means our airmass source region will shift from the arctic to the Pacific, with a significant warmup expected for the middle to the end of next week. By Wednesday and Thursday, there's pretty strong indications that we'll see highs above 40 in southern MN, with much of the area having a good chance at getting temps above freezing. Lacking once again for the next week are precipitation chances with no significant precipitation makers showing up in the models in the upper MS Valley at any point in the next 10 days. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1153 AM CST Wed Jan 5 2022 We'll be in cyclonic flow with CAA through this evening, which means several more hours of light snow. Expect vsbys to generally be between 2sm and 6sm so any additional accumulations will be under 1 inch. Next issue is how long will clouds linger. Forecast soundings from the RAP/NAM/GFS all keep clouds pretty much locked in place until Friday morning. However, as the atmo continues to cool, we'll become too cold/dry to support much in the way of clouds during the day on Thursday, so followed the idea of the short term model blend for when to show improvements to VFR (and scattering out at MSP eventually). KMSP...Expect MVFR vis for the rest of the day with -SN and BLSN, but added a TEMPO group for IFR vis from 1z to 4z. For the last 24 hours, models have been pretty consistent with bringing one last organized area of snow through the metro shortly after 00z, so that's the reasoning behind the tempo group. Lower confidence on cig trends for Thursday as it gets difficult to figure out just how much cloud cover we'll be able to support when it gets as cold and dry as it's forecast to get tomorrow. /OUTLOOK FOR KMSP/ Fri...VFR. Wind SE 5-10kts. Sat...MVFR cigs likely. Chc IFR cigs. Wind S 10-15kts bcmg NW 15G25 kts late. Sun...VFR. Wind NW 10-20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...Wind Chill Advisory from 9 PM this evening to 3 PM CST Thursday for Anoka-Benton-Blue Earth-Carver-Dakota-Faribault-Freeborn- Goodhue-Hennepin-Isanti-Kanabec-Le Sueur-McLeod-Meeker-Mille Lacs-Morrison-Nicollet-Ramsey-Rice-Scott-Sherburne-Sibley- Stearns-Steele-Todd-Waseca-Wright. Wind Chill Advisory until 3 PM CST Thursday for Chippewa-Douglas- Lac Qui Parle-Pope-Stevens-Swift-Yellow Medicine. Winter Weather Advisory until 6 PM CST this evening for Chippewa- Goodhue-Kandiyohi-Lac Qui Parle-Pope-Renville-Stevens-Swift- Yellow Medicine. Wind Chill Advisory until 3 PM CST Thursday for Brown-Kandiyohi- Martin-Redwood-Renville-Watonwan. WI...Winter Weather Advisory until 6 PM CST this evening for Barron- Chippewa-Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix. && $$ DISCUSSION...MPG AVIATION...MPG