Bloomington, Wisconsin Weather Forecast Discussion

418
FXUS63 KARX 051653
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
1150 AM CDT Fri Sep 5 2025
.KEY MESSAGES...
- Isolated showers (20%) possible today and into Saturday.
  Otherwise mainly dry weather through the weekend.
- Unseasonably cool temperatures through this weekend. Some
  locations may reach record cold high temperatures today with
  highs of 52-62 degrees.
- Temperatures begin to warm next week, with highs in the 70s
  returning by the middle of the week.
&&
.DISCUSSION...
Issued at 258 AM CDT Fri Sep 5 2025
Today through Sunday night
Latest water vapor satellite imagery shows upper level trough
digging over southern Ontario Canada/Great Lakes region. First
impulse and associated shower activity has pushed of the forecast
area per latest mosaic radar. Upper level trough will continue to
dig over southern Ontario Canada/Upper Great Lakes Region through
the weekend. A couple of shortwave troughs will rotate around the
upper level trough and into the forecast area today into Saturday.
With daytime heating and lift associated with the first shortwave
trough today. However with moisture limited...expect isolated
showers to develop this afternoon/evening. Have introduce isolated
showers this afternoon/evening with higher probability of showers
northern portions of the forecast area where the deeper moisture is
located.
Another shortwave embedded in the northerly flow aloft tracks over
the forecast area Saturday. Isolated showers will once again be
possible across the forecast area mainly Saturday afternoon/evening.
At this time will let later shifts to introduce small chances of
showers.
With the northerly flow aloft...colder airmass will advect into the
forecast area over the weekend. The 05.00z deterministic models
suggest 850mb temperatures to be plus 1 to plus 3 degrees celsius
through 00z Monday. Latest NAEFS indicate standard anomalies of
minus 2 to minus 4. Temperatures through the weekend will be well
below normal. High temperatures are expected to be mainly in the 50s
to lower 60s today and Saturday and slightly warmer in the upper 50s
to middle 60s Sunday.
Monday through Thursday
Main forecast concerns are shower chances Monday night into Tuesday
night...then temperatures warming. Another shortwave trough embedded
in the northwesterly flow aloft moves across the Upper Great Lakes
Region Monday night into Tuesday night. Vertical motion and moisture
convergence along the surface front will allow for development of
showers and possibly storm or two across the forecast area. With the
surface slowly moving east/southeast over the southern forecast area
Tuesday evening/night will chance of showers or a couple of
storms into the Tuesday night. Then...upper level trough over
the northeast United States breaks down and upper level ridge
builds into the central United States Wednesday into Thursday.
The latest ensembles and deterministic models have differences
on how amplified the upper level ridge will be.
However...temperatures are expected to warm back to near or
slightly below normal by middle of next week.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1150 AM CDT Fri Sep 5 2025
CIGS: mostly bkn VFR deck expected through the afternoon with short
term guidance favoring a scattering this evening. Can`t rule out
short periods of BKN here and there. Moving into Sat afternoon,
diurnal cu enhanced by an upper level shortwave suggest another
round of BKN cigs - but favoring VFR at this time.
VSBY/WX: a smattering of sprinkles possible this afternoon, but
chances generally 

NWS ARX Office Area Forecast Discussion