Galena, Illinois Weather Forecast Discussion

266
FXUS63 KDVN 242336
AFDDVN
Area Forecast Discussion
National Weather Service Quad Cities IA IL
636 PM CDT Wed Sep 24 2025
...00z Aviation Update...
.KEY MESSAGES...
- Prolonged period of dry conditions and above normal
  temperatures expected through early next week, with
  comfortable humidity.
&&
.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 129 PM CDT Wed Sep 24 2025
Cumulus filled skies continue to flow southwestward over the CWA,
with a trajectory that has included some moisture/saturation from
Lake Michigan. Models are generally under-doing this moisture, but
the general message of today being a beautiful day with comfortable
temperatures in the 70s with a pleasant northeast breeze has not
changed.
Tonight, the diurnal clouds are expected to dissipate through mid
evening, though we`ll have to watch to see if any stratus can begin
to move southwest from Wisconsin.  Models are suggesting that
stratus will thin and lift this afternoon, and not reform, but it`s
persistence through 1 PM has me at least somewhat concerned that it
would last into the overnight. An evening update may be required,
but that would only impact temperatures, which remain forecast to
reach the lower to mid 50s tonight, making for good windows open
conditions.
High pressure will drift east the surface through tonight into
Thursday, with light southwest winds returning the region. Thursday
will be another very pleasant day, with less numerous cumulus
expected compared to today, and highs in the mid to upper 70s.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 129 PM CDT Wed Sep 24 2025
Friday-Saturday Night...northwest flow aloft to start the period
transitioning to another blocking pattern this weekend. This will
bring a prolonged period of dry conditions, comfortable humidity,
and above normal temperatures. A cold front will move through
Saturday night, but 1000-500mb RH progs continue to show quite a bit
of dry air to overcome and I have continued a dry forecast.
Highs in the upper 70s and lower 80s are expected and while this is
still above normal for late September, the humidity levels will be
lower making for great conditions for any outdoor plans.
Early Next Week...all 12z deterministic and ensemble model solutions
continue to show a building upper ridge bringing warmer and
continued dry conditions. Ensemble 850mb temps to rise into the 15-
16C range Sunday through Tuesday, which is near or above the 90th
percentile per SPC climatology. Taking a look at the NBM members
distribution for highs at MLI for the 28th through the 30th, now
shows over 2/3rds of the members with a high over 80 degrees each
day. Not surprisingly, the NBM loaded highs were 2-3 degrees higher
for Sunday-Tuesday, with some upper 80s possible on Monday. There is
also high confidence in dry conditions for the rest of September,
with all but 3 of the 100 members of the NBM showing no
precipitation. This will be good to dry out the fields, but not so
much to alleviate any developing drought conditions.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 630 PM CDT Wed Sep 24 2025
Broad LLVL ridging acrs the upper Midwest will keep VFR
conditions going through the TAF cycle. North to northeast sfc
winds of 4-8 KTs tonight will back to the northwest by Midday
Thursday with some increase to 10 KTs. Will bank on the winds
maintaining tonight enough to keep fog development away from
the TAF sites, but a few models continue to break out at least
patchy MVFR fog at a few sites like DBQ and CID toward 12z Thu.
Thursday should be another day of ambient CU development to SCT
or BKN coverage by at VFR heights.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...Ervin
LONG TERM...Ervin/Gross
AVIATION...12

NWS DVN Office Area Forecast Discussion