Area Forecast Discussion
Issued by NWS Twin Cities, MN

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111
FXUS63 KMPX 201126
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
626 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 /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 624 AM CDT Wed Aug 20 2025

Patchy morning fog could lead to brief VIS reductions to 4-5sm
through 14z, after which time most locations will see FEW250 to
SKC. A mid level cloud deck is possible resulting in a chance
for FEW to SCT050 through around 21z, after which we return to
SKC/FEW250. Winds will trend towards 060-090 at or below 6kts.
Fog is possible by the end of the period but was not included
for now due to low confidence.

KMSP...Guidance is suggesting a mid level cloud deck around
5kft, which was left at SCT for the TAF but could end up being
BKN intermittently.

/OUTLOOK FOR KMSP/
FRI...VFR, chc MVFR/-TSRA. Wind W 5-10kts.
SAT...VFR. Wind NW 10-15kts.
SUN...VFR. Wind NW 5-10kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...TDH