408
FXUS63 KMPX 032317
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
617 PM CDT Thu Sep 3 2026

.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
confidence is 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 on 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 /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 559 PM CDT Thu Sep 3 2026

A thunderstorm will remain near EAU for the next hour before
moving east. Afterwards, it is looking increasingly more likely
that all TAF sites will remain dry through the entire period.
The clusters of thunderstorms currently in northern MN should
remain well to our north as it travels east-southeast into
Friday morning. CAMs do show additional -SHRA/TSRA development
over WI after 09z Friday but this activity should be east of
EAU. Fog and low clouds appear more probable within the few
hours of sunrise Friday morning, particularly over central MN
and west- central WI. LIFR/IFR conditions are expected until
about 14z. Afterwards, skies clear with VFR conditions the rest
of Friday. Southeasterly winds lessen to 5 knots overnight
before turning northeasterly and increasing to 5-10 knots from
west to east during Friday.

KMSP...Removed PROB30 for -TSRA tonight as convection looks to
stay well north and east of MSP. Some patchy fog may occur near
the terminal, especially in the river valley but opted not to
include a mention of it in the TAF at this time. Northeasterly
winds of 5-10 knots are expected late Friday morning through the
evening.

/OUTLOOK FOR KMSP/
SAT...VFR, chc -TSRA/MVFR late. Wind E 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.

&&

$$

DISCUSSION...ETA
AVIATION...CTG