NWS-La Crosse Forecast Discussion

						FXUS63 KARX 062235
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
430 PM CST Thu Mar 6 2025

.KEY MESSAGES...

- Warmer than normal temperatures through next week. Daytime
  highs in the 50s and 60s Monday through Thursday (Day 7).

- Precipitation chances tonight through Friday along our
  southern periphery from northeast Iowa through southwest
  Wisconsin. Minimal impacts expected.

&&

.DISCUSSION...
Issued at 120 PM CST Thu Mar 6 2025

Gradual Warming This Weekend:

Besides the warmer temperatures today which are 30s area wide
on local surface observations early this afternoon, two quick
hitting areas of precipitation potential to monitor in the
immediate term.

The warming trend continues through the weekend into next week
as a closed low progresses through the Southern Plains
providing WAA through the Central Plains to Upper Midwest.
Expect strongest WAA to push through the Mid Mississippi River
Valley where the EPS long term global ensemble shows 100% for
the 50 degree isotherm; bordering our southern peripheral
counties in northeast Iowa a southwest Wisconsin this weekend.
The EPS shows a slightly warmer solution with 100% confidence
for the 50 degree isotherm farther north due to a less phased
mid level low better leveraging the subtropical airmass. The 50
degree isotherm will also graze our western periphery this
weekend as warmer low level air, evident on POES derived
temperatures, undercuts an amplified upper level ridge,
progressing into the Canadian West Coast on GOES water vapor
imagery, sags southeast through the Nortern Plains.

Staying Warm Through Next Week:

This upper level ridge continues an easterly progression
through next week, warming local surface temperatures into the
50s and 60s. Aforementioned trends between long term global
ensembles continue with the EPS enveloping 100% confidence for the
50 degree isotherm across the Upper Mississippi River Valley
while the GEFS only bifurcates the local forecast area.
Interesting note, the EPS is accounting for yesterday's heavy
snow from southeast Minnesota into west-central Wisconsin with
0% probabilities for greater than 50 degree temperatures. With
the continual warm temps, expect the confidence in these areas to
increase as snow melts.

Similarly, larger spread seen in the GEFS with 25th to 75th
percentile difference of 15 to 20 degrees Tuesday through
Wednesday while the EPS remains less than 10 degrees. All the
long term ensembles (EPS/GEFS/GEPs) have 10+ degree different in
Interquartile Range after midweek.

Difference in exact location and strength of the mid level ridge
causing discrepancies between models. Will be main synoptic
concern over coming forecasts.

Low Flurry Chances Today In Central Wisconsin:

Initially a meager frontal boundary, evident in a weak wind
shift over north-central Minnesota this morning, progresses
southeast through central WIsconsin today. Limiting factor for
precipitation will be dry air in place. The weakening nature of
the wave also decreases confidence for forcing to overcome said
dry air. Have increased flurry mention in locally northern
counties in central Wisconsin in collaboration with neighboring
offices.

Precipitation Chances Tonight Through Friday:

Subsequent precipitation chances graze our southern half in
northeast Iowa and southwest Wisconsin tonight through Friday as
a low progresses east through the Southern Plains today. A
slightly northern shift in the low track has moved /higher/
precipitation amounts and potential more into the local forecast
area. Sufficient forcing of low level frontogenesis has shifted
north in high resolution models. Given the increased consensus
and increased forcing, have increased precipitation potential,
moisture amounts, and resultant accumulations. Eventually
diurnal heating will overcome freezing temperatures and expect a
switch over to rain. Low confidence in exact location and
timing as temperatures expected to hover near freezing.

Biggest forecast buster will again be the intrusion of dry air to
the north. Expect a strong northern gradient in any rain/snow
amounts. Even so, any impacts are expected to be low as the low
center tracks east through the Mid Mississippi River Valley.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 430 PM CST Thu Mar 6 2025

CIGS: increasing high clouds tonight, associated with an upper level
shortwave trough tracking east across the mid mississippi river
valley. CIGS will stay VFR, with a likely scattering out later Fri
afternoon.

WX/vsby: west-east running bands of pcpn will lie across northern
IA/southern WI from late tonight/Friday. Short term guidance keeps
any threat for ra/sn south of KRST/KLSE.

WINDS: generally light through the period with westerly becoming
more northeast tonight, back to the north/northwest later Fri
afternoon. All associated with the passage of a sfc low south of the
area.

&&

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

&&

$$

DISCUSSION...JAR
AVIATION.....Rieck