030 FXUS63 KMPX 242249 AFDMPXArea Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 549 PM CDT Wed Sep 24 2025
.KEY MESSAGES...
- Patchy fog likely late tonight through Thursday morning. Isolated pockets of dense fog are possible.
- Mild temperatures and dry conditions to persist through at least the first half of next week.
&&
.DISCUSSION... Issued at 233 PM CDT Wed Sep 24 2025
Visible satellite reveals mostly sunny skies across much of the region. The greatest impact to sky cover can be found across far SE MN/portions of W WI, where lingering strato-cu (following morning dense fog) has been slow to clear. In addition, scattered Cu has developed across western MN, where morning fog was also present. Afternoon highs are on track to reach the mid to upper 70s across much of south central MN. Temperatures are running slightly cooler across western WI due to the persistence of cloud cover this morning. Skies will clear heading into this evening with light and variable winds overnight. The influence of lake fog should be less pronounced tonight, though will likely see patchy fog develop across eastern MN/western WI and it`s possible that visibility may dip below 1 mile in spots. Fog is forecast to mix out by 14/15z and we`ll be left with a gorgeous Thursday characterized by sunny skies and highs in the low 80s. Little change in the airmass by Friday, so expect similar conditions with high temperatures running ~10+ degrees above normal. Of note, we did give the high temperatures a little bit of a boost by blending in NBM90th percentile highs given the persistence of a pattern that has produced overachievement above the operational NBM over the past few days.
A shortwave is forecast to slide across southern Canada Friday into Saturday, sending a cold front through our portion of the Upper Midwest. Model consensus keeps the best forcing for rain chances to the north of the International Border. Chances for precipitation with this wave were already very slim and now are essentially zero, as no members of the Grand Ensemble (GEFS/EPS/GEPS) produce precipitation across our forecast area. With that in mind, the main story heading into the weekend will continue to be the anomalous late September warmth. The shortwave is progged to lift north towards Hudson Bay Saturday into Sunday. Large scale ridging will build northward in response, which opens the door for an 8-10C 850mb temperature anomaly to build Sunday into Monday. Latest forecast features highs in the low to mid 80s both days, though as I mentioned yesterday this type of setup supports potential overachievement by a few degrees. Should that be the case, we could be looking at widespread highs in the mid 80s, which is more than 15 degrees above normal for late September.
For next week, the upper-air pattern is forecast to take on a meridional look that features longwave troughing in the west and ridging over the eastern CONUS. This places our portion of the country in a zone of persistent southwesterly flow which aims to keep the mild air flowing northward to open October. Conceptually, there should be some low-level jet activity setting up across the central CONUS for the middle to end of next week which may yield the return of precipitation chances. That being said, this scenario is typically not handled well by the global guidance so the continuation of a zero PoP forecast through at least the middle of next week is appropriate. By late next week/the weekend of 10/4-10/5, long term guidance shows the return of a more active upper- level pattern that may bring better rain chances to the region. For now, the theme is more dry and mild Fall weather.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 541 PM CDT Wed Sep 24 2025
Clear skies and light winds are expected again overnight. Fog should be less widespread than the past two nights and have only added MVFR/IFR conditions for our western Wisconsin sites. KSTC and KMKT could see some patchy fog develop, but confidence is lower than the past couple nights and have kept MVFR visibilities. Winds become southwesterly/westerly by late tomorrow morning, but should remain under 10kts.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/ FRI...VFR. Wind S 5-10 kts. SAT...VFR. Wind NW 5-10 kts. SUN...VFR. Wind S 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None.
&&
$$
DISCUSSION...Strus AVIATION...Dye
NWS MPX Office Area Forecast Discussion