751
FXUS63 KARX 252009
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
309 PM CDT Wed Sep 25 2024

.KEY MESSAGES...

- Trending drier through the weekend. Highs in the 70s to low
  80s are forecast for the end of September, with signal for a
  potential cool down sometime early next week.

&&

.DISCUSSION...
Issued at 309 PM CDT Wed Sep 25 2024

No significant changes as a fairly quiet forecast remains on track.
Clear skies, light low level flow, and longer nights will keep
valley/river valley fog the main forecast concern in the short term.
Have continued to mention valley fog for tonight/Wed morning and
will continue to watch the subtle details for further potential and
day to day impacts through the rest of the week. Otherwise, ensemble
solutions look to be in better agreement on the overall pattern as a
closed upper level low settles generally over the Mid-South region
and Helene moves inland and eventually gets absorbed by the low. As
has been noted with the past couple of forecasts, there has been a
trend towards a drier forecast heading into the weekend, with
highest probabilities in both the GEFS and ECMWF remaining just
southeast of the forecast area. Have noted a handful of ECMWF and
GEFS ensemble members hinting towards low probabilities (<30%)
reaching towards far southwestern WI late in the weekend, so will
continue to monitor trends over the next couple of days. Overall
though, have maintained the drier forecast. Otherwise, forecast high
temperatures remain in the 70s to around/low 80s.

Heading into early next week model guidance shows an upper level
trough and associated cold front moving through the region. Still a
bit of spread between ensemble solutions in regards to precipitation
potential and temperatures. However, there does appear to be signal
for a cooling trend back down to more normal/below normal
temperatures.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 107 PM CDT Wed Sep 25 2024

VFR conditions will prevail at both RST and LSE through the
afternoon under high pressure. A field of FEW-SCT cumulus has
developed across much of the region, generally around 4000ft.
This deck may vary BKN at times, especially south of I-90, but
is expected to dissipate this evening.

Valley fog is expected to impact LSE again late tonight into
Thursday morning as high pressure, clear skies, and weak winds
continue to influence the area. Currently thinking that fog
will begin to restrict visibilities to LIFR conditions around
26.10z although there may be drops in visibility in the hour or
two before. Have gone with a 1/2SM visibility for now, but
visibility of 1/4SM does appear possible again tonight. Fog
should dissipate by late Thursday morning with VFR conditions
again Thursday afternoon.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.

&&

$$

DISCUSSION...EMS
AVIATION...Falkinham