596
FXUS63 KARX 071923
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
223 PM CDT Mon Apr 7 2025

.KEY MESSAGES...

- After a chilly Monday night, steadily warming temperatures
  through the upcoming weekend with highs returning to the 60s
  by Saturday.

- A longer period of scattered light rain showers is possible
  Wednesday into Thursday. A bit of snow cannot be ruled out.
  Either way, impacts look to be low with rainfall amounts
  generally under 0.25", with highest amounts south of
  Interstate 90 where amounts could be locally higher.

&&

.DISCUSSION...
Issued at 220 PM CDT Mon Apr 7 2025

Warming trend ahead:

Tonight, dry antecedent conditions - dewpoint depressions this
afternoon are around 30F - combined with light winds and clear skies
courtesy of a surface high building in the wake of a shortwave
located to our east as of 18z will cause temperatures to tumble into
the teens with a 10-20% chance for areas northeast of I-94 to reach
the single digits.

Looking ahead to the rest of the week, heights aloft will trend
upward, particularly Friday into Saturday. The end result will be an
increase in temperature values with confidence fairly strong for 5
days out (55-95% with interquartile ranges of about 5 degrees) for
highs to reach the 60s Saturday. In fact, depending on how quickly
an upper trough advances over the Upper Midwest Sunday, could see
some 70 degree readings, especially west of the Mississippi (60-70%
chance). Wednesday and Thursday continue to remain uncertain with
interquartile ranges of 7-10 degrees, high for 2-3 days out, due to
potential for northeasterly winds, widespread cloudiness, and
precipitation - more on that below - as a surface low develops to
our south.

Precipitation potential Wednesday and Thursday:

Upper trough looks to advance over the Upper Midwest Wednesday into
Thursday. Multiple disturbances rounding the edge of this feature
should lead to rounds of precipitation. Of particular interest is an
initial wave Wednesday. As low level moisture advection increases in
response to a surface low developing under the left exit region of
an upper jet advancing over NE/IA, this should be enough forcing for
precipitation to occur to the north of the low near the developing
front. While confidence in this overall setup is good, placement
remains uncertain with operational GFS/NAM remaining farther north
than many ensembles. Given the ensemble support for the favored area
of precip ending up to our south, have retained the somewhat modest
(25-50%) NBM PoPs with this update. As for precipitation type,
progged soundings suggest mainly rain will occur with the potential
for at least an inch of snow remaining very low (10%). In the more
probable rain scenario, amounts tend to be modest with only a 5-25%
to reach above a quarter inch but there are a very limited number of
outlier solutions reaching above an inch, the result of
multiple rounds tracking over the same localized area. Will need
to continue to monitor this period, but overall concerns for
impacts are low.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1227 PM CDT Mon Apr 7 2025

VFR conditions should prevail over the next 24 hours. Broken
stratocumulus are present east of the Mississippi River and will
be for much of the afternoon, with ceilings remaining mainly in
the 35-45 kft range. A stray flurry or two could occur there as
well, with the chance for this increasing as one goes east, in
any case chance is too low (10%) for a mention at LSE.
Otherwise, winds out of the north with gusts to 20-25 knots are
expected this afternoon before light and variable winds occur
overnight and light southwesterly winds set up during the day
Tuesday.

&&

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

&&

$$

DISCUSSION...Ferguson
AVIATION...Ferguson