269 FXUS63 KMPX 101741 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1241 PM CDT Fri Sep 10 2021 .UPDATE... Issued at 1241 PM CDT Fri Sep 10 2021 Updated to include 18Z aviation discussion. && .SHORT TERM...(Today through Saturday) Issued at 346 AM CDT Fri Sep 10 2021 Temperatures during the short term will be more summer than fall like, with the next 2 days featuring a couple of good opportunities to see highs top 80 south of I-94. It will also be dry during the short term, with the lack of forcing beyond surface convergence and strong capping keeping the front coming through tonight through Saturday morning a dry one. Water vapor imagery this morning shows a potent shortwave moving across Alberta. This wave will work over to James Bay by the end of the short term, which will help drive a cold front across our area tonight into Saturday morning. We look to be in the core of the thermal ridge overnight tonight, so we'll miss seeing the thermal ridge during peak heating, though 925mb temps in the 22C to 24C range will support highs into the mid 80s over western MN today, then along the I-90 corridor for Saturday. No precipitation is expected this period. We'll have WAA through much of today, but it will lack much of a moisture feed from the south, with the best forcing remaining closer to the shortwave up in Canada. Saturday, we'll see a rather unstable environment develop down near the Iowa border with the arrival of a very warm EML, with MUCAPE values likely to be around 4000 j/kg. However, that EML will have h7 temps up around 15C, so nothing will make it through that cap during the day on Saturday. && .LONG TERM...(Saturday night through Thursday) Issued at 346 AM CDT Fri Sep 10 2021 Low precipitation chances continue to look possible overnight Saturday into Sunday, as a weak front stalls out over the mid- Mississippi Valley. Most guidance keeps this boundary to our south across Iowa, which along with fairly strong capping north of the boundary, should keep the bulk of precipitation with this feature south of the area. More favorable conditions may develop Sunday night as a weak low-level jet develops and provides some forcing aloft,but this would still likely only lead to a few scattered showers and thunderstorms across southern Minnesota. More likely chances for precipitation come Monday night into Tuesday, as a trough moves through the Upper Midwest. Forcing aloft is much stronger with this system and deterministic/ensemble guidance are in fair agreement with a widespread region of precipitation developing over the Dakotas and continuing eastwards through Minnesota and Wisconsin. Increased PoPs during the Monday night and overnight hours, but these will likely need to be increased further once we see a bit more consistency on timing among the guidance. A stationary front along the Gulf coast will limit moisture return into the region and as a result, PW values show little in the way of an anomalous signal. Rainfall amounts on the order of a quarter to half an inch look most likely. A return to ridging aloft over the central CONUS should keep conditions dry midweek, but low precipitation chances return by the weekend as models depict the potential for another shortwave but differ on its strength. Temperatures will remain fairly seasonal through the period as the flow remains predominately zonal aloft, with a few transient and low- amplitude troughs and ridges. Temperatures will likely range a few degrees below normal early in the week under the influence of the trough aloft, and a few degrees above normal midweek under brief ridging. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1241 PM CDT Fri Sep 10 2021 Southerly winds remain as a front will pass through late tonight. Some high clouds are anticipated to move in this evening before beginning to clear near the end of the period. Fog is possible Saturday morning for EAU, but leaving out for now. KMSP...Timing of the front looks to be between 15z and 18z Monday morning. /OUTLOOK FOR KMSP/ SAT...VFR. Winds W becoming N 5-10 kts. SUN...VFR. Winds NE 5-10 kts. MON...VFR. Chc -shra/-tsra late. Winds SE 10G20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ UPDATE... SHORT TERM...MPG LONG TERM...ETA AVIATION...PEM