932
FXUS63 KMPX 031148
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
648 AM CDT Wed Sep 3 2025

.KEY MESSAGES...

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

- Strong clipper to bring another round of rain & thunderstorms
  Thursday afternoon and evening.

&&

.DISCUSSION...
Issued at 252 AM CDT Wed Sep 3 2025

At 230am, the cold front was just about to clear the southeast
border of the MPX CWA. We have seen a little bit of light rain try
to develop behind the front with the main upper wave moving in, but
at this point, we`re firmly on the cold side of the front and are
now unlikely to see 70 again until early next week. For this
afternoon, a trough of cold air at h5 moves down from northern MN.
This cold air aloft with a still healthy early September sun will
result steep lapse rates and the development of convection. A strong
inversion just above h7 will limit how deep convection can make it
today, but with freezing levels down around 5k feet, we may be able
to get some small hail out of any stronger cells, with forecast
soundings showing a couple hundred j/kg of CAPE developing this
afternoon. We`re expecting scattered showers this afternoon
northeast of the MN River Valley. Another thing to keep an eye on is
the potential for some surface based smoke in southwest MN. We`re
seeing MVFR cigs in NoDak this morning that is associated with
surface based smoke. There`s uncertainty with how far east this
smoke will make it, but the HRRR is showing potential for some smoke
issues in southwest MN (southwest of where our showers end up) this
afternoon.

Other than being a little chilly, there are few weather concerns for
tonight as we await what we`ve termed the `Angry Clipper` for
Thursday afternoon and evening. This is a pretty strong and dynamic
wave, with strong WAA, fgen, and PV anomaly. It doesn`t matter if
the model is a CAM, deterministic, AI/ML, or an ensemble member,
they all show rain with this system Thursday afternoon and evening.
Main change to the NBM was to boost its PoPs for Thursday afternoon,
but its PoPs looked reasonable by the evening. This would be a
sneaky severe setup. However, the antecedent airmass looks too cold
and dry, with there not being enough time for the atmo to build
sufficient heat/moisture ahead of the clipper to build enough
instability before it comes blasting through the area. In its wake,
we could see some wind gusts over 40 mph along and south of the MN
River valley, with the ECMWF showing a slug of h85 winds of 40-50
kts coming in behind the cold front (like we said, this is an Angry
Clipper!).

Friday will be the coldest day of this stretch of cooler weather,
with highs likely struggling to just reach the 60 degree mark. We`ll
have strong subsidence in the wake of the previous days clipper, so
dry weather is expected Friday. The same can`t be said for Saturday
when it comes to staying dry. Models overnight have started to hone
in on another clipper swinging around the main Hudson low on
Saturday, with another batch of light rain looking possible during
the day on Saturday as well, though this clipper does not look to be
as strong as what we`ll see Thursday. We`ll finish the weekend on a
cool note, though by the afternoon, we`ll start to see our winds
switch from a westerly over to a southerly direction, but WAA will
not be strong enough to send highs out of the 60s for Sunday as well.

Next week, the models show the general idea of a western
trough/eastern ridge developing. We`ll see surface winds out of some
form of a southerly direction, which will send highs at least back
into the 70s, though we could go warmer depending on how surface
features lay out through the course of the week. There`s still a lot
of uncertainty with whether or not the arrival of the warm air early
next week will result in precip. The GFS has rain developing in the
southerly flow early next week, but the ECMWF doesn`t have the
mid/upper level moisture joining the increase in low level moisture
and keeps us dry. Given what we`re seeing in the models, the low
PoPs showing up Monday afternoon into Tuesday next week from the NBM
makes sense, though time will tell if we get a little rain or not.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 632 AM CDT Wed Sep 3 2025

Main aviation concern this period will be increasing winds out
of the northwest. Gusts on the order of 20 to 25 kts look likely
for several hours following daybreak here. Some isolated gusts
to 30 kts are possible, especially across western Minnesota.
Isolated storms will also be possible during the afternoon,
primarily over eastern Minnesota and western Wisconsin. Winds
should quickly diminish around and after sunset, gradually
turning more westerly by Thursday morning.

KMSP...Introduced a prob30 for -SHRA during the afternoon. It is
possible we see some thunder with any isolated storms, but
confidence is too low to include at this time.

/OUTLOOK FOR KMSP/
THU PM...Chc MVFR/SHRA. 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...MPG
AVIATION...BED