292
FXUS63 KARX 251126
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
626 AM CDT Tue Mar 25 2025

.KEY MESSAGES...

- Friday looks to be the warmest day of the week with highs into the
60s and 70s.

- Widespread rains for the weekend. Can`t rule out snow chances, but
higher probabilities farther north.

&&

.DISCUSSION...
Issued at 140 AM CDT Tue Mar 26 2025

- THRU MID WEEK: smattering of light precipitation chances.

A few weak perturbations in the upper level flow look to drop
southeast down the backside of a departing upper level trough,
bringing small in extent, light in QPF chances the next few days.
Locally, most of these chances hold to northeast IA and generally
rain (based on timing). Impacts will be minimal. It will stay dry
for most.

Seasonable temps today will see a few degree climb Wed and Thu as the
trough exits east, upper level heights increase, and flow turns more
southerly.


- WEEKEND: wet, can`t say "no" to snow chances (yet). Warm Friday,
more uncertainty for Sat/Sun temps.

OVERVIEW: Long range guidance still remains in good agreement with
amplifying an upper ridge across the west coast for the start of the
new work week, gradually working the ridge axis across the plains
thu night and then the upper mississippi river valley for the start
of the weekend. The ridge undergoes some flattening as it builds in
as various shortwaves work across the top of it, but will still
provide a pool for milder/warmer and more moist air - although how
warm it gets, and where, will be highly dependent on where various
shortwaves move and their related surface fronts lay up. The
warmer/more moist airmass will provide the fuel for widespread rain
chances and most locations are expected to get wet this weekend.

PRECIPITATION: a parade of ripples in the upper level flow will
precede a shortwave trough (kicking out of the desert southwest) for
the weekend. Coupled with a variety of surface fronts, there will be
ample forcing, with a milder/more moist airmass to work on. NAEFS
and EC pw anomalies continue to push 2+ while mean QPF sits at 1+".
QPF EFIs aren`t "much" at this time, but hints of a SoT - suggesting
there are some high end outliers in the model output. Essentially
everyone of the GEFS and EPS drops pcpn across the area over the
weekend. Amounts are highly variable, ranging from a few tenths to
as much as 2 to 3" (10 and 90%) in both ensemble suites. Confident
in getting preciptiation for the weekend, timing and how much is
far, far less certain,

And then there is the threat for snow. Depending on the track of the
shortwave and the main area of low pressure, there could be enough
cold air for a band of snow. Where and how much are highly
subjective. Stay tuned...

TEMPS: warmer air is a well progged outcome as we move into the
weekend, but how warm is up for debate. Latest runs of the GEFS and
EPS show some stark contrasts - all highly dependent on where the
individual members track shortwaves, place their warm fronts. A lot
of variability and fairly amount of volatility. For instance, the
GEFS means generally place highs in the low to mid 50s...but the
upper 10% warm into the low 70s while the lower 10% can`t climb out
of the 30s. The EPS is still the warmer of the two and still has 75%
of its members warming into the 70s Friday. That drops into the
weekend, and it too shows a lot of variety in its 10-90% outcomes,
but not nearly as broad as the GEFS. So, a lot of uncertainty for
temps as we push into the weekend, aside from Friday still looking
like the warmest day.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 621 AM CDT Tue Mar 25 2025

No flight restrictions expected over the 25.12Z TAF period.
Clearing skies primarily east of the Mississippi River Valley
expected to linger into this evening. Cloud cover increases
west of the Mississippi River Valley later this afternoon with
light rain chances through the evening. Given low overall
chances, have kept PROB30 at KRST TAF site. Low to moderate
confidence for MVFR ceilings remains southwest of the forecast
area into central Iowa later this morning.


&&

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

&&

$$

DISCUSSION...Rieck
AVIATION...JAR

NWS ARX Office Area Forecast Discussion