Dexter, Minnesota Weather Forecast Discussion

016
FXUS63 KARX 251831
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
131 PM CDT Thu Sep 25 2025
.KEY MESSAGES...
- Unseasonably mild conditions through the middle part of next
  week (approx 10 degrees above the late Sep normals). Some
  locations likely to push north of 80 degrees starting Friday -
  especially along/south of I-90 and in the Mississippi River
  Valley.
- Staying dry into the start of next week, but could linger
  untilthe following weekend.
&&
.DISCUSSION...
Issued at 124 PM CDT Thu Sep 25 2025
Valley fog has finally dissipated across the region leaving
abundant sunshine in its wake. This increase in sunshine will
allow for afternoon highs to climb well into the 70s for the
entire Driftless region. Unfortunately, we are in the season of
(valley) fog so we will see yet another morning with potentially
dense fog across the region tomorrow. Low level moisture will
pool ahead of a weak cold front dropping south into the area
overnight. Fog is expected to develop mainly along and east of
the Mississippi River, primarily impacting western portions of
Wisconsin. This is expected to be both an areal and a valley fog
event with many Wisconsin river valleys seeing visibilities go
down hard overnight and into early tomorrow morning. The good
news is that similar to today, we are not expecting widespread
low stratus which will allow for the fog to steadily mix out
through the morning once the nocturnal inversion breaks. This
looks to be the last night with widespread fog chances as drier
air in the lower levels will gradually move into the region
behind the "cold" front.
A trough axis, currently extending from Michigan to the
Southern Plains, will pivot eastward into tomorrow, creating a
weak cutoff low in its wake. Upper level ridging is expected to
build through the weekend between the aforementioned cutoff low
and a second cutoff low across the Northern Baja California
region. As this builds in, temperatures will very gradually get
warmer this weekend, peaking on Monday. NBM probabilities show a
roughly 20-50% chance of high temperatures at or above 80
degrees for areas south of I-90, mainly across Southwestern
Wisconsin in the river valleys. This jumps to nearly 50-85% for
areas along and south of I-94 during the day on Monday. These
come down slightly into mid-next week with highs largely back
into the 70s. While these temperatures could hardly be
considered "hot", they`re still around 10 degrees above normal
for late September so we`ll see an overall mild end to the
month.
Rain chances look null and void for much of the forecast
period. The strong upper level ridging should keep any chances
at bay through most of next week. We finally start to see the
ridge break down a bit by late next week, which will allow for
some low chances for rain to creep back in. All members of the
European and GFS ensembles keep our area dry through at least
next Thursday. Winds are expected to veer to the south by Sunday
and stay in a general south/southeast direction next week
allowing for low level moisture to slowly return to the area.
The rain chances for next Thursday would likely come from a cold
front coming in from the west, extending from a Canadian low
well to our north. There is still much that could change so have
largely stuck with the NBM through the extended for
temperatures and PoPs.
&&
.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1221 PM CDT Thu Sep 25 2025
Overnight into early morning fog, mainly along and east of the
Mississippi River, continues to be the focus of the aviation
forecast. Think the chances are pretty good for additional
development tonight but some guidance is pointing toward a bit
stronger winds aloft compared to the previous few nights which
would inhibit formation of valley fog and potentially stratus to
boot. Due to this uncertainty, have retained BCFG and a SCT
group at LSE with a view toward refinement with the 00z and 06z
cycles. Outside of the fog, a few fair weather cumulus around 4
kft are possible this afternoon.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Barendse
AVIATION...Ferguson

NWS ARX Office Area Forecast Discussion