NWS-La Crosse Forecast Discussion

						FXUS63 KARX 301025
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
525 AM CDT Wed Apr 30 2025

.KEY MESSAGES...

- Periodic showers and a few thunderstorms this afternoon
  through Thursday evening. Rain amounts are roughly 0.1" to
  0.25" for areas along and north of I-94 and 0.25" to 0.4" for
  areas south of I- 94.

- Warming trend this weekend. High temperatures warming into
  the mid to upper 70s by Sunday and possibly near 80 in a few
  locations by early next week.

&&

.DISCUSSION...
Issued at 309 AM CDT Wed Apr 30 2025

Today-Friday: Near Normal Temperatures, Periodic Rain and
Thunderstorm Chances:

Ahead of an approaching upper level low from the southern Plains and
a shortwave trough dipping down into the Upper Midwest, southwest
flow aloft is over the area through the day. This will help mix us
out a little and as a result, high temperatures warm into mid to
upper 60s. Rain chances increase during the afternoon across
northeast Iowa, southeast Iowa, and southwestern Wisconsin as the
upper level low shoots off some shortwave impulses into the area.
Initially the lower levels will be drier and may take a couple hours
to saturate enough for the rain to reach the surface. Some light
rain showers will be possible until enough saturation takes place. A
few thunderstorms will also be possible this evening through
Thursday evening primarily along and south of I-90 as 100-300
J/kg of MUCAPE moves into the area. There is still some
uncertainty in the CAMs as far as coverage of these showers and
thunderstorms and where the higher rain totals will be located
at.

After Thursday evening, the upper level low moves off to the
northeast and we transition to northwest flow aloft as the shortwave
trough shifts into our region. This will give the area 20 to 40%
chance at some showers for Friday. All precipitation chances are
expected to diminish by evening. Overall rain amounts have changed
slightly for the forecast area with locations to the north of I-94
receiving 0.1" to 0.25" and locations to the south of I-94
potentially receiving anywhere from 0.25" to 0.4". High temperatures
for Thursday and Friday cool slightly compared to today, ranging
from the upper 50s to mid 60s.

Saturday-Early Next Week: Warmer Temperatures and Drier?

Once the trough moves off to the east, ridging builds into the area.
While the region remains in northwest flow, temperatures only warm
slightly compared to Friday, into the mid to upper 60s, however by
Sunday and early next week, southwest flow returns and helps to warm
our temperatures into the mid to upper 70s and even near 80 degrees
for some locations. Dry conditions are expected for the weekend.
There are some differences in the deterministic models on how
early next week pans out. The EC and CMC have an omega block
pattern over the central US from Saturday through Wednesday
while the GFS brings a shortwave on Monday and shortwave
impulses for Tuesday and Wednesday that could increase
precipitation chances. Current ensemble guidance does have a low
chance for rain to return early next week, however it is
roughly 20-30% of all ensemble members. The majority of ensemble
members keep us dry through at least the middle of next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 525 AM CDT Wed Apr 30 2025

VFR conditions throughout the daytime hours will give way to MVFR
and eventually IFR cigs overnight. Winds will remain around 8-12 kts
during the afternoon before diminishing and switching to the east
with sct to bkn high clouds. As a weather system approaches the
area, cigs will decrease to MVFR (70-90% chance in the 30.00z HREF)
and eventually IFR (50-80% chance in the 30.00z HREF) by 12z.
Additionally, scattered to numerous showers will move into the area
with visibility reductions to MVFR and perhaps IFR at times.

&&

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

&&

$$

DISCUSSION...Cecava
AVIATION...Naylor