textproduct: Twin Cities

KEY MESSAGES

- Severe thunderstorms possible tonight, most likely across north-central Minnesota. Damaging wind gusts are the primary threat.

- Hot & humid Friday into saturday with heat index values of 95-100 possible.

- Frequent chances for scattered showers & thunderstorms into next week.

DISCUSSION

Issued at 353 PM CDT Thu Sep 3 2026

Tonight: Scattered thunderstorms continue to fester across eastern Minnesota & western Wisconsin this afternoon, with brief instances of small hail occurring in the strongest storms. This continued activity through the day has basically mitigated our potential for explosive storm growth this afternoon, despite very steep mid-level lapse rates & surface based CAPE values in excess of 3000 J/kg.

Our eyes continue to be on the complex of thunderstorms exiting eastern North Dakota into northwestern Minnesota, & especially where it tracks through the evening. So far, the thunderstorm complex has been making an orderly progression off to the east, with no signs of a southeasterly turn towards our area of central Minnesota. recent radar trends suggest the line of storms may even be breaking up into discrete clusters or even discrete supercells. These would be even less likely to migrate southeastwards, so we will continue to wait & see if any thunderstorm complexes can develop back to the west across eastern ND, or something new can develop from the remnants of the ongoing storms. It's still too early to write of any severe potential for tonight given the environment in place & instability gradient extending southeastwards into north- central Minnesota, & northwest Wisconsin, although our confidenceis increasing that it should remain north of an Alexandria-St. Cloud-Rice Rake/Barron line. Damaging wind gusts would be the primary hazard with this thunderstorm complex, followed by large hail. Timing looks to mainly be tonight - 7-9 PM across western portions of central MN, 9-11 PM across eastern portions, & 11 PM-1 AM across northwest Wisconsin.

Friday: Friday will be dry, with a low chance of some isolated thunderstorms developing near the Iowa-Minnesota border tomorrow afternoon. Should these storms develop, the strongest storms could contain large hail. Otherwise, heat & humidity will be the main weather concern with temperatures expected to warm into the low 90s across much of the area. Less confident is the dew point forecast, with many of the latest 18Z high-resolutin models suggesting we have some drier air move into at least central Minnesota 7 western Wisconsin tomorrow afternoon. This could create a sharp gradient where heat index values stay in the low 90s across central MN & western WI, while approaching 100 degrees across far-southern Minnesota. We only look to approach Heat Advisory criteria in the twin Cities metro (where thresholds are at 95 degrees), but have decided to hold off on any issuance at this time given the trend towards lower dew points & heat index values tomorrow afternoon.

This Weekend: Low confidence on the heat forecast this weekend, owing to the possibility for cooler flow off of Lake Superior saturday & precipitation/cloud cover Sunday. We could see another day of heat & humidity Saturday with many of the legacy global models suggesting highs around 90 along with muggy dew points, however AI models & a few of the high-resolution models suggest we could be entrenched in cooler northeast flow off of Lake Superior throughout the day. This would result in a rather comfortable day with highs around 80 and less muggy dewpoints, while a gradient sets up somewhere over western Minnesota where we still see heat index values approach 100 degrees where the lake- cooled air does not reach.

A shortwave arrives late Saturday night, providing another chance for scattered showers & thunderstorms overnight Saturday night through Sunday morning. Low confidence eon any of the details, but the best chances for appreciable rainfall appear to be across western Minnesota.

Next Week: The upper air pattern remains active as a number of disturbances ride over the ridge centered over the region. Confidence is low on when & where the greatest precipitation chances will be, the main window for more widespread rainfall looks to be late Monday through Tuesday. Temperatures will depend on the timing of any precipitation systems, but will tend to be well-above normal earlier in the week with some cooling relief (but still likely above- normal) coming later in the week. For reference - average temperatures for early September are in the mid to upper 70s for highs & upper 50s for lows.

AVIATION /18Z TAFS THROUGH 00Z SATURDAY/

Issued at 1215 PM CDT Thu Sep 3 2026

A relatively tricky period is ahead of us with a warm frontal boundary draped west to east across the area resulting in isolated to scattered -SHRA/-TSRA, with activity expected to weaken somewhat over the first few hours of the TAF. A brief lull is then expected before a cluster/line of storms is possible, favoring central MN and therefore having the best chance of affecting AXN/STC after 02-03z. During periods of -TSRA, MVFR/IFR is expected, with mainly VFR until then and between rounds, with visibility the primary category impact as cloud heights are generally 4kft or higher. Winds favor 130-160 at 10kts or lower south of the warm front with gusts confined mainly to areas of TS.

KMSP...Elected to continue the TEMPO due to ongoing -TSRA nearby, after deciding between TEMPO and VCTS. This activity should only last for an hour or two before diminishing into the afternoon. A prob30 group for another round of -TSRA is far less certain, and even a prob30 may be too aggressive at this point with most of the guidance favoring an area from roughly Moorhead to Brainerd to northern WI for the second round of storms this evening/tonight. We may end up removing it with the 21z AMD or 00z TAF depending on how things trend, with most of the guidance so far today keeping things pretty far to the north of MSP.

/OUTLOOK FOR KMSP/ SAT...VFR, chc -TSRA/MVFR late. Wind SE 5kts. SUN...Chc -TSRA, generally MVFR. Wind SE 5-10kts. MON...Sct -TSRA, generally MVFR. Wind SE 5-10kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None.