Blomkest, Minnesota Weather Forecast Discussion

813
FXUS63 KMPX 120824
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
324 AM CDT Fri Sep 12 2025
.KEY MESSAGES...
- Very warm and humid for the next several days. Highs in the
  upper 80s to lower 90s this weekend.
- Chance of thunderstorms this afternoon and evening with
  additional chances next week.
&&
.DISCUSSION...
Issued at 324 AM CDT Fri Sep 12 2025
It`s a quiet and mild morning with scattered high clouds
streaming east across the region. Some patchy fog and low clouds
have developed in Wisconsin, but the most widespread fog remains
to the east. Any fog will burn off quickly after dawn. An Omega
pattern remains in place across the country with the ridge axis
stretching from Texas to Minnesota. A weak disturbance will lift
north across the Plains, then turn east and crest the ridge this
afternoon and evening across the southern half of Minnesota and
Wisconsin. Steep lapse rates greater than 7.5 C/km, pwats in
the range of 1.5 to 1.75 inches, MUCAPE of 500-1000 J/kg, a
persistent weak LLJ, and a stalled frontal boundary draping
northern IA or southern MN will all aid in the potential for
thunderstorm development this afternoon and evening. The
boundary layer will remain dry, however, and some CIN is
expected to remain. Many CAMs show some scattered thunderstorms
by early afternoon across western Minnesota, progressing east
through the rest of the day and into the early evening.
Introduced 30-50% PoPs across the whole area.
The surface front is expected to lift north into southern
Minnesota Saturday. A hot airmass to the south characterized by
925 mb temps exceeding +27C will send highs into the low to mid
90s. Cooler air to the north and southeast flow will keep highs
elsewhere in the mid 80s. Winds shift more southerly area wide
Sunday, and while the intensity of warm air aloft will ease a
bit, a larger portion of the region will reach the upper 80s to
lower 90s. Combined with dew points around 70, heat indices will
likely top off in the mid 90s.
The ridge shifts slightly east Sunday, and by afternoon an upper
trough will advance toward the Upper Midwest. It will become a
bit negatively tilted Sunday evening and spread a 40-50 kt mid
level jet into western Minnesota. Lapse rates will remain weak,
but an uncapped atmosphere and stronger forcing arriving should
allow storms to develop in the afternoon and evening. SPC
highlights western Minnesota in a day 3 marginal risk. PoPs
will likely need to be increased in later forecasts.
Sunday`s upper trough will lift north Monday and ridging will
build back in its wake. However, additional short wave troughs
embedded in the gyre of a parent trough over the northern
Rockies will keep the forecast unsettled for much of next week.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1231 AM CDT Fri Sep 12 2025
Mostly clear overnight with just a few high clouds. Patchy fog
could develop in parts of western WI through early this morning.
Southeast winds will increase this morning and mid level clouds
will increase. A few thunderstorms may develop by early
afternoon across western MN and advance east through the early
evening. Introduced PROB30s at all TAF sites for that
possibility.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/
SAT...VFR. Wind SE 5-10 kts.
SUN...VFR. Slgt Chc -TSRA/MVFR late. Wind S 5-15 kts.
MON...VFR. Slgt Chc -TSRA/MVFR early. Wind S 10-15G20 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Borghoff
AVIATION...Borghoff

NWS MPX Office Area Forecast Discussion