746
FXUS63 KMPX 200807
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
307 AM CDT Wed Aug 20 2025

.KEY MESSAGES...

- Patchy fog this morning, otherwise mostly sunny and pleasant today.

- Shower chances arrive Friday along a cold front, with
  continued cool and pleasant weather afterwards.

&&

.DISCUSSION...
Issued at 305 AM CDT Wed Aug 20 2025

Fog is much patchier compared to 24 hours ago but visibility is
still dropping below a mile in several spots, with Nighttime
Microphysics RGB satellite imagery showing the most prevalent fog
banks in far southern MN and portions of western WI. Patchy dense
fog will persist through around 8-9am with daylight burning off any
lingering fog as temperatures rise. Unlike yesterday, lower dew
points should result in much lower cloud cover as well as no chance
for a few rogue showers as high pressure strengthens over Lake
Superior. By the afternoon, pressure will rise to 1020mb or higher
with large scale subsidence across the region and little in the way
of active weather. This will persist into tomorrow with another
night of patchy dense fog due to weak winds and dew points still in
the mid 60s as the high pressure moves eastwards.

A surface low will develop underneath a longwave trough that will
occlude as it moves eastwards across central Canada, with the
surface low tracking a cold front across the area beginning late
Thursday and continuing into Friday. 00z Friday NAMNest soundings in
western Minnesota ahead of the cold front show in excess of 1000
J/KG SBCAPE with decent mid level lapse rates, but also a fairly
large cap in the lower levels. The forcing along the front will
likely be enough to force showers and storms, however given the
thermal profile they will more than likely end up elevated with a
relatively low chance of being severe. Still, this gives us what
looks to be our only chance for rain over the period with an upper
level ridge building alongside surface high pressure over the
weekend and into early next week. Temperatures and dew points behind
the front cool significantly, with dew points dropping into the 50s
and highs generally in the 60s starting Saturday and continuing
through midweek. This will more than likely bring our first high
temperature in the 60s in August for the State Fair since 2018, with
a beautiful opening weekend in store. The good weather continues
next week with comfortable temperatures and a continued lack of
a significant system or moisture for airmass type storms.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1217 AM CDT Wed Aug 20 2025

Areas of fog are the primary concern this morning with the most
susceptible region being near RNH/EAU as clear skies couple with
temperatures falling to dew points. Fog increases in coverage
around 08-10z, lingering until 13-14z becoming FEW250/SKC for
the remainder of the day. End of period will see additional fog
concerns similar to the start of this TAF.

KMSP...Due to being slightly warmer from urban heat island, MSP
may not see any visibility reductions from fog, much like
yesterday during the 06z period.

/OUTLOOK FOR KMSP/
THU...VFR, chc MVFR/BR early. Wind S 5kts.
FRI...VFR, chc -SHRA/MVFR. Wind SW to NW 5-10kts.
SAT...VFR. Wind NW 10-15kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...TDH