817
FXUS63 KMPX 280245
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
945 PM CDT Sun Sep 27 2026

.KEY MESSAGES...

- Dense fog develops tonight across much of central Minnesota,
  the Twin Cities, & western Wisconsin. Fog lingers through
  mid- morning tomorrow.

- More rain chances over the next week with the best chance
  coming on Tuesday. Increasing chance for rain to continue on
  Wednesday, especially across southern Minnesota.

- Temperatures will be around or slightly above average through
  midweek.

&&

.UPDATE...
Issued at 942 PM CDT Sun Sep 27 2026

Skies continue to clear out across much of central Minnesota &
western Wisconsin, with visibilities quickly dropping below 1
mile under the clear skies. Visibility will plunger further
through the overnight hours with much of the area expected to
see dense fog with visibility less than 1/4 mile. Issued a Dense
Fog Advisory for much of central Minnesota, the Twin Cities
metro, & western Wisconsin until mid-morning, when the fog is
expected to dissipate by 9-10 AM.

&&

.DISCUSSION...
Issued at 102 PM CDT Sun Sep 27 2026

Peeks of sunshine have begun to filter through the gloomy
stratus that was in place for much of the morning. This has
allowed temperatures to rise into the 70s in areas that have had
several hours of scattered clouds. Our rainy weather will stay
on hold while surface high pressure spreads across the Upper MS
Valley tonight into Monday. The light winds associated with the
high pressure in combination with 60F Tds should support
another night of patchy fog development similar to this
morning.

We`ll continue to see air and dewpoint temps rise as return flow
increases on the backside of the high pressure Monday. This will
set the stage for yet another round of showers that spread from
west to east ahead of a weak mid-level wave. The main change to
the forecast is an increase in QPF from Tuesday all of the way
through Thursday now, with the latest NBM producing a solid 1-2"
for much of southeast Minnesota into Wisconsin. The anomalous
moisture of 1.5" PWATs (over 200% of normal for this time of
year) is a key contributor to the rainfall potential despite
relatively weaker forcing. All that said, confidence is lower
than before for rainfall amounts with the bulk of that increase
in QPF being driven by an outlier in the model suite. If you
have been following weather recently, you probably can guess
which model that is before I even write it down. If you guessed
the GFS, you would be correct. It`s ensemble and deterministic
solutions generally place the stalled front on Wednesday a few
hundred miles north of its European and Canadian counterparts.
We tend to see the ECMWF AIFS perform well with the placement of
heavy precip for our area at this timeframe (24+ hours out),
which would favor the greatest footprint being across Iowa and
SE Minnesota into Wisconsin. Even in this scenario, we do expect
to see the rain showers move from west to east on Tuesday, the
low confidence part of the forecast is just with how far south
that front stalls out and if we stay largely dry or see another
full day of rain Wednesday.

Northwest flow and ridging will eventually build in to end the
week, resulting in a cooler and drier Canadian air mass
spreading south. Any rain chances will be tied to more subtle
waves within the flow, meaning there is no clear consensus on
when, where, or even how much we will see next weekend. The
higher confidence part of the forecast is that it`ll become a
breezier period as winds shift out of the northwest and advect
in the cooler airmass.

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 702 PM CDT Sun Sep 27 2026

MVFR stratus has scattered out across much of central Minnesota
& is beginning to clear out across southern Minnesota & western
Wisconsin. However, this creates greater chances for LIFR
conditions overnight with ceilings below 500 ft and/or fog with
visibility below 1 mile. The greatest chance for fog is
expected to be across central Minnesota & western Wisconsin, but
mist with visibility down to 1-2 miles is still likely across
southern Minnesota. Low ceilings are likely area-wide with
ceilings of 500 ft or lower. The worst conditions develop after
midnight & persist into the morning, with conditions improving
by 9-10 AM. MVFR ceilings still stick around through much of the
day but some improvement to VFR looks possibly by later
afternoon.

KMSP...Expect IFR conditions overnight from both ceilings &
mist, but still uncertain just how poor conditions could become.
Dense fog is more likely in the river valleys, but could spread
onto the runways if skies remain clear for a few hours tonight.
Otherwise, the greatest impacts look to be from low ceilings
after midnight through 8-9 AM.

/OUTLOOK FOR KMSP/
TUE...MVFR/-SHRA likely, chc IFR. Wind SE 5-10G20 kts.
WED...VFR, chc -SHRA/MVFR. Wind S to SE 5-10 kts.
THU...VFR. Wind NW 10-20 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Dense Fog Advisory until 10 AM CDT Monday for Anoka-Benton-
     Brown-Carver-Chippewa-Chisago-Dakota-Douglas-Goodhue-
     Hennepin-Isanti-Kanabec-Kandiyohi-Lac Qui Parle-Le Sueur-
     McLeod-Meeker-Mille Lacs-Morrison-Nicollet-Pope-Ramsey-
     Redwood-Renville-Rice-Scott-Sherburne-Sibley-Stearns-
     Stevens-Swift-Todd-Washington-Wright-Yellow Medicine.
WI...Dense Fog Advisory until 10 AM CDT Monday for Barron-Chippewa-
     Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix.

&&

$$

UPDATE...ETA
DISCUSSION...BED
AVIATION...ETA