479
FXUS63 KMPX 022322
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
622 PM CDT Tue Sep 2 2025

.KEY MESSAGES...

- A Marginal Risk (1 of 5) for a few severe thunderstorms
  possible this afternoon/evening with the arrival of a cold
  front.

- Much colder temperatures settle in Wednesday through the
  weekend, before rebounding next week.

- Another round of rain & thunderstorms Thursday afternoon and
  evening.

&&

.DISCUSSION...
Issued at 249 PM CDT Tue Sep 2 2025

Latest GOES satellite imagery highlights two areas of interest early
this afternoon. The first is an area of Cu along and ahead of a
surface cold front across E SD into north central MN. This area will
should be the focus for additional convection this afternoon &
evening. The second area is the remnant clouds associated with this
morning`s thunderstorms/showers over S/SE MN and W WI. These should
exit and leave behind a brief period of sun prior to sunset. Surface
analysis reflect an uptick in dew points ahead of the front with
values in the low to mid 60s as low level moisture pools ahead of
the cold front. This will support 1000 to 2000 j/kg of MLCAPE ahead
of the incoming front. The primary limitation of severe weather can
be viewed in forecast soundings across lower Minnesota - wind shear
or the lack of wind shear. Guidance highlights 20 to 30 kts of
effective wind shear that should be enough to support multi cell
clusters with an isolated severe wind & hail threat. The better
shear & upper level support lags behind the surface front. Multiple
clusters are possible through the evening hours across western,
central & southern Minnesota as our boundary moves through. SPC
maintained a Marginal risk (1 of 5) for isolated wind & large hail
across much of lower Minnesota while western Wisconsin remains in
general thunder. This remains a reasonable take given recent
observations & forecast evolution this afternoon.

Much colder air will usher in across the region tonight and into
Wednesday behind the departing surface low. An early preview of Fall
will be in store through the weekend with high temperatures in the
mid 50s to lower 60s and low temperatures in the 40s and lower 50s.
Looking aloft, a prolonged stretch of northwesterly cyclonic flow &
cold air advection. Latest guidance would support CAA showers
primarily in the afternoon and early evening hours. Any rainfall
will be brief with amounts of a few hundredths to a tenth of an
inch. Low temperatures drop into the 40s Wednesday night with
potential for upper 30s in our western Wisconsin counties. A
compact, but potent shortwave will move through Thursday afternoon &
evening and bring another chance of showers & thunderstorms. Current
guidance has the warm sector across southern Minnesota Thursday
afternoon with enough moisture that a few hundred j/kg of
instability may be able to build ahead of the surface front. This
may be enough to produce a few isolated thunderstorms. Another
reinforcement of cold air arrives behind this system for the
weekend. Friday could see northwest winds with gusts up to 30 mph
behind the departing low. A broad Canadian surface high pressure
will settle in for the weekend that will allow for things to dry
out. Temperatures remain well below normal, with highs in the 60s.
This surface high will move east into the Great Lakes by Monday,
allowing for southerly return flow to set up early next week. This
will open the door for temperatures to return to normal with highs
in the 70s and lows in the 50s.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 622 PM CDT Tue Sep 2 2025

Today`s aviation weather will be driven by a frontal passage.
Ahead of the front will see thunderstorm chances and behind it
will be gusty northwest winds. Still some VCTS around RWF at TAF
issuance time, but the main impact is from storms currently
north of all terminals in central Minnesota. This will track to
the southeast through the evening and into the early overnight.
Have put TEMPO closer to this area where confidence is higher
and kept with PROB30 farther out where there is less confidence
in the storms holding together. Behind the front precipitation
chances will be lower, air temperatures cooler, and winds
higher.

KMSP...Keeping an eye on a line of storms starting to develop in
central Minnesota. If these storms can come together they could
impact the terminal area late this evening. Kept with a PROB30
to start, but will amend to higher confidence if the storms form
and look to maintain themselves all the way to the terminal.
Behind the front winds will pick up with gusts up around 20
knots from the northwest.

/OUTLOOK FOR KMSP/
THU...VFR. Chc MVFR/SHRA PM. Wind W 10-15 kts.
FRI...VFR. Wind NW 10-15G25 kts.
SAT...VFR. Wind NW 10-15 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...BPH
AVIATION...NDC