110 FXUS63 KMPX 060727 AFDMPXArea Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 227 AM CDT Sat Sep 6 2025
.KEY MESSAGES...
- Cooler than normal again today, with a chance for patchy frost tonight in central MN.
- Warming trend through the middle of the week with a return to normal temperatures, in the 70s after the weekend.
- Chance for isolated to scattered showers today, with a better chance of scattered showers and thunderstorms Monday PM into Tuesday AM.
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.DISCUSSION... Issued at 227 AM CDT Sat Sep 6 2025
The Hudson Bay low that has been driving our recent weather finally starts to move out today. This will put an end to the consistent strong cold air advection that we have seen. This circulation does have one final move though, as a shortwave will move into the Upper Midwest today. This will provide enough forcing to allow for isolated to scattered shower to occur. Can`t completely rule out thunder, but with limited instability it would be a few brief rumbles of thunder at most. Overall with the location of this forcing the best chances for seeing some rain will be in eastern Minnesota to western Wisconsin. Behind the Hudson Bay low will be surface high pressure, which will be dominant for the rest of the weekend. This will allow for clear skies and light winds tonight. An ideal setup for radiational cooling and frost formation. However as it is still early September, ground temperatures will remain warm enough to prevent widespread temperatures falling cool enough for frost with just radiational cooling. However there could be enough cooling in some parts of central Minnesota and maybe parts of Rusk County, WI for some more isolated patchy frost. For this reason held off on any frost advisory on this shift.
So far September is the typical start to early fall. By that I mean a season of transition. Periods of summer like warmth followed by cool air back and forth. Today will be the start of a warming trend that will last into the middle of next week. With less cold air advection today, there will be much more widespread highs in the 60s. Sunday will see even less cold air advecting in and highs will rise into the mid 60s. By Monday we move into warm air advection again and highs jump back into the 70s. With this warmer air will come instability and a return of thunderstorms to the forecast. This forecast is driven by increasing instability combined with high pressure moving out and a shortwave moving in. Looking towards global ensemble guidance, there is widespread agreement in precipitation Monday PM into Tuesday AM. What is less certain is QPF, where a wide range from a few hundredths to around a inch present in membership. With the potential for convection and time range this is not surprising. As we get closer this range should start to cluster more.
Behind the early week shortwave a ridge will build into the central CONUS. This will keep us in mild, near normal, temperatures with little chance for rain. This pattern looks to start to break down and change by the end of the week, but ensemble spread remains to high to have much confidence yet.
In summary below normal temperatures continue this weekend with a warming trend back to normal temperatures for next week. Chance for isolated to scattered rain showers today (mainly E MN to W WI). A better and more widespread chance for rain and storms Monday PM to Tuesday AM.
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.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1220 AM CDT Sat Sep 6 2025
VFR through the period. Winds will continue from a northwest direction with some shifting over the period from closer to westerly at the start to more northerly by the end. Some gusts during the day up to 20 knots, before diminishing to light tomorrow night.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/ SUN...VFR. Wind NW 5-10 kts becoming SW. MON...VFR. Chc -SHRA/TSRA/MVFR late. Wind S 10-15G20 kts. TUE...VFR. Chc -SHRA/TSRA/MVFR early. Wind SW 5-10 kts.
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.MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None.
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DISCUSSION...NDC AVIATION...NDC
NWS MPX Office Area Forecast Discussion