365 FXUS63 KMPX 232355 AAA AFDMPX Area Forecast Discussion...UPDATED National Weather Service Twin Cities/Chanhassen MN 655 PM CDT Fri Apr 23 2021 .SHORT TERM...(This evening through Saturday night) Issued at 322 PM CDT Fri Apr 23 2021 Surface analysis this afternoon depicts a weak low pressure center over southwest MN along a cold front extending NE into the Arrowhead and then WSW over northern Nebraska, southern Wyoming and southern Idaho. High pressure is nudging southward from western Canada into Montana and the Dakotas. Aloft, the north-central CONUS remains under the influence of a broad longwave trough associated with an upper level low in northern Canada. One notable axis is to the west of the aforementioned Upper Midwest surface low. Scattered rain showers are north of I-94 and east of I-35 this afternoon and will continue shifting off to the north and east through the rest of this afternoon and evening as the upper trough axis nudges the cold front east. Some modest lift with the sharpening of the trough axis may allow additional rain/snow shower development over the northern half of the WFO MPX coverage area overnight, resulting in some snowflakes falling close to sunrise Saturday morning. If any snow accumulation occurs, it'd be a tenth or two on grassy areas. Otherwise, any and all precipitation will shift off to the east and diminish overnight through the first half of Saturday. Surface high pressure and drier northwest flow aloft will then take hold across the Upper Midwest Saturday afternoon and be the prevailing influence through Saturday evening, allowing for clearing skies and tranquil conditions. However, a stronger area of low pressure, currently over the Intermountain West and along the aforementioned western front, will shift across the Rockies Saturday night into Sunday morning. The coldest air of this system will remain in place over the Dakotas and Minnesota while isentropic lift increases in advance of this system. This will allow precipitation to return to the area early Sunday morning over western MN, mainly in the form of light snow. It is with this stronger system that some snow accumulations are possible but there is still plenty of uncertainty on where the focus area of the accumulation will be. The proverbial bullseye could be anywhere from west-central MN to far southwest MN to along the MN River, so while there is fairly good confidence that snow will occur, trying to pinpoint the highest amounts is still a bit problematic. Through early Sunday morning, highest amounts would be up to about an inch. Temperatures will remain below climatological normals through Saturday night. After highs generally in the 50s area-wide today, highs behind the cold front for Sunday will generally run in the 40s, with some 50s possible near the Iowa border. Lows tonight will range from the upper 20s to upper 30s, but with cold air advection more solid Saturday night, lows will drop to the 20s to lower 30s. .LONG TERM...(Sunday through Friday) Issued at 322 PM CDT Fri Apr 23 2021 The typical roller coaster of Spring-time weather continues this coming week. Winter will make a brief return Sunday, as snowfall appears likely. However, temperatures quickly warm heading into Monday, with summer-like temperatures possibly across southern MN Monday afternoon. More normal weather returns Tuesday onward along with multiple chances for rain. On Sunday morning, most models show a warm front draped across SD, extreme southwest MN, and into northern IA. A band of strong, 850 mb WAA will be present over eastern SD and into southwest MN along the nose of a southerly LLJ. This WAA band should shift northeast across MN during Sunday as the LLJ pushes east. Surface temperatures will be in the upper 20s to lower 30s at 7am Sunday morning and warming into the mid 30s as the morning progresses. However, low to mid- level temperatures north of the warm front will be cold enough to support snow crystal growth. Thus, as precipitation pushes east with the band of WAA, snow will be the most likely precip type during the morning hours until a changeover to rain occurs when temperatures rise to well above freezing. In fact, with guidance hinting at the possibility of over a half inch of QPF in western MN, there is potential for larger snowfall accumulations. The GFS gives further support showing very strong lift occurring within the dendritic growth zone over Redwood Falls for a 2-3 hour period. Future model trends will need to be monitored regarding the snowfall potential. Farther east, snowfall accumulations should be minimal. Rain will last into Sunday evening before exiting to the east. Forecast highs Sunday will be near 40 across western MN increasing to mid 40s east and south. A break in the rain is likely Sunday night before another round of light, widespread rain develops Monday morning across the Northern Plains. This precip will be generated by strong, southerly WAA as a strong 850 mb thermal ridge shifts eastward into the Upper Midwest. Precipitation should stay focused across the northern halves of MN and WI, meaning only 0.1-0.2" of QPF is possible for our northern counties. Monday's high temperatures for the central and northern CWA will be very dependent on the southern extent of a WAA stratus deck. If skies fail to clear, highs will be cooler in the low to mid 60s. However, any clearing could quickly boost temperatures. Farther south, breaks in the clouds are more likely and highs should easily reach the mid 70s. Have also boosted winds Monday across southern MN to account for strong southerly winds and greater mixing. Temperatures will return to near normal Tuesday onward as the thermal ridge axis shifts east. Another chance of rain is progged Tuesday into Tuesday night as an eastward moving cold front follows the thermal ridge. One or two thunderstorms may also be possible. The long-range deterministic and ensemble guidance continues to trend drier mid to late next week. The southern stream upper-level wave that was supposed to travel northward from the Southern Plains has remained farther south in latest model runs keeping our region mostly dry Thursday, aside from possibly our extreme southeast. After Thursday, large model differences build. The GFS shows the Northern Plains remaining warmer next weekend while the ECMWF and GEM hint the possibility of another cool down. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 655 PM CDT Fri Apr 23 2021 Scattered light showers and areas of drizzle continue early this evening, especially across WI. Stratus will remain in place tonight, then clear from west to east Saturday with few-scattered CU remaining into the afternoon. Cigs should drop to IFR levels across eastern MN and WI later tonight, with generally MVFR elsewhere. KMSP...Cigs are VFR for now, but as low pressure pulls away, lower cigs from the northwest will move in and then likely become IFR overnight. A small band of rain or snow could rotate through late tonight as well, but it's expected to be brief. /OUTLOOK FOR KMSP/ Sun...-RASN likely early, -RA likely late. MVFR ceilings likely. Wind SE 10-15 kts. Mon...Chc -RA early. MVFR ceilings likely. Wind SE 10-20 kts. Tue...Chc -RA. MVFR ceilings likely. Wind NW 10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ SHORT TERM...JPC LONG TERM...CTG AVIATION...Borghoff