Cosmos, Minnesota Weather Forecast Discussion

693
FXUS63 KMPX 202357
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
657 PM CDT Sat Sep 20 2025
.KEY MESSAGES...
- Chance for storms today and again Sunday afternoon. The risk
for severe weather is very low.
- Next week, drying out with above normal temperatures of highs
the mid 70s.
&&
.DISCUSSION...
Issued at 112 PM CDT Sat Sep 20 2025
Today through Sunday...
Early afternoon satellite imagery and surface obs showed mostly
cloudy skies and light winds across the region. Water Vapor imagery
showed a circulation across southern Minnesota, with another one
upstream over the Dakotas.
These circulations will be the main driver in the weather over the
next 48 hours, brining scattered thunderstorms across the Upper
Midwest. Forecast soundings show less instability today compared to
Friday, which translates to less coverage in storms this
afternoon/evening, and a lower risk for heavy rain.
On Sunday, the southern circulation will move east and be replaced
by the one that is currently over the Dakotas. Forecast soundings
show more instability across southern Minnesota as compared to today,
so should see a bit more coverage in the storms tomorrow, and a
chance for some small hail or pockets of heavy rain.
Monday through Friday...
Looking ahead, the main upper level trough currently bringing
clouds and rain chances across the region will take on a more
positive tilt and get sheared out Monday through Tuesday as an
upper level wave crashes upstream. This will lead to decreasing
chances for rain each day to start the week, but can`t completely
rule out a stray shower or thunderstorm.
By Wednesday, confidence in dry weather increases as the upper level
subsidence should overcome any diurnal heating showers, leading to a
flat cumulus field and more sun than clouds. Expect dry weather to
continue the rest of the week, with light winds and mostly sunny
skies heading into the weekend. Temperatures will run above normal
for late September, with highs in the mid 70s.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 643 PM CDT Sat Sep 20 2025
The upper low and associated moisture and cloud cover will
remain with us through this period. The two main areas of
uncertainty are how long will showers west of I-35 survive into
the evening, then what happens with fog/stratus again tonight.
For the rain, the going thought is that the showers will begin
to diminish over the next couple of hours as we loose what
daytime heating we`ve had, so we did not expand shra mention
east of AXN/RWF/STC. Other than that, much of the period is
expected to be dry, with models trending later with possible
shra/tsra development late Sunday afternoon. Will wait to see if
the 00z HRRR is as robust with convection Sunday evening as the
18z run was before putting much chance into the late
afternoon/evening shra & tsra threat Sunday. Looking at cigs/vis,
we`ll have light winds tonight, with forecast soundings from
the RAP showing plenty of low level moisture. However, we`ll
keep this 5k-10k foot cloud deck going through the night, which
really limits confidence on how widespread fog and low stratus
will be tonight. Short term guidance is hitting STC/AXN hardest
with the stratus/fog tonight, so limited it`s mention to those
terminals, though all terminals are susceptible to seeing
IFR/MVFR conditions overnight.
KMSP...If showers to the west persist, the threat for MSP will
not arrive until the 4z to 8z window. There would be no thunder,
with the worst that could happen being an MVFR vis. However,
confidence in showers still being around by then is too low to
include in the TAF. For the late Sunday potential, we have seen
a shift toward that threat really holding off until 00z or
later. For tonight, can`t rule out some MVFR/IFR cigs between 9z
and 15z.
/OUTLOOK FOR KMSP/
MON...Chc MVFR cigs early. Wind E 5 kts or less.
TUE...VFR. Wind NE 5-10 kts.
WED...VFR. Wind NE 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...JRB
AVIATION...MPG

NWS MPX Office Area Forecast Discussion