601
FXUS63 KMPX 021950
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
250 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 /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1218 PM CDT Tue Sep 2 2025

Scattered showers will continue over western and southern MN and
west-central WI into early this afternoon. A few rumbles of
thunder may also be possible across MN so have added TEMPOs for
-TSRA at RWF and MKT. This precip will push southeast by mid-
 afternoon with a line of additional scattered showers and
 storms expected to develop ahead of a cold front by late
 afternoon/early evening. Coverage remains questionable enough
 to maintain PROB30s for -TSRA at all terminals: MN`s starting
 in the late afternoon while WI`s start in the evening. If -TSRA
 occurs, expect visibility reductions to MVFR and low-end VFR
 cigs. This precip will also exit to the southeast by tonight.
 For MN, some light showers are possible overnight but
 conditions should remain VFR. For WI overnight, cigs will fall
 to MVFR with EAU possibly reaching IFR into Wednesday morning.
 However, confidence is not currently high enough to warrant
 mention of IFR cigs at EAU in this TAF period. Southwesterly
 winds turn northwesterly once the cold front passes through
 this evening/tonight. Winds will increase during Wednesday
 morning with gusts reaching 20 knots.

KMSP...Maintained PROB30 for -TSRA from 00-04Z this evening
until confidence in storm coverage and placement increases.
Winds turn northwesterly around 06Z Wednesday once the cold
front passes. Northwesterly winds will gust to 20-25 knots
during Wednesday and have added another PROB30 for possible
-SHRA Wednesday afternoon.

/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...CTG