340
FXUS63 KARX 011031
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
531 AM CDT Tue Jul 1 2025

.KEY MESSAGES...

- Terrific Tuesday

- Rounds of showers and thunderstorms possible Wednesday through
  Monday. While widespread issues are not expected, a couple of
  these days could feature a few strong to severe
  thunderstorms, with Wednesday and Saturday appearing to be the
  more probable candidates.

&&

.DISCUSSION...
Issued at 324 AM CDT Tue Jul 1 2025

Nice, dry weather today

Today, expect mostly sunny skies as large scale subsidence occurs in
the wake of yesterday`s upper trough. Additionally, 700/850mb ridge
centered well to our southwest should build with resulting warm
temperature aloft keeping a lid on potential convection even as an
upper disturbance moves over areas northeast of I-94 during the
afternoon. Precip free, highs in the 80s, and dewpoints in the low
60s should lead to a nice day across the area.

Unsettled weather returns and persists

Return of northwesterly flow aloft over the CWA Wednesday and
Thursday will bring potential for multiple rounds of convection as
shortwaves eject downstream. Lack of robust moist advection
suggests destabilization may be a limiting factor both of these
days, so have stuck with the 20-40 PoPs in NBM. Potential continues
as flow aloft quickly becomes southwesterly Friday afternoon
following a short lull as an upper trough quickly slides eastward.
With low level moist advection resuming, expect more widespread
precip Friday night into Saturday and have gone with 50-70s PoPs
accordingly. Sunday and Monday, while key details begin to differ
across guidance, zonal or quasi-zonal flow aloft appears to be the
more probable outcome with low end (20-30%) mentions of precip
warranted as a result.

On the subject of potential hazards, both severe thunderstorms and
heavy rain will be possible but am not expecting higher end risks of
either flavor. For severe thunderstorms, 30.12z LREF probabilities
suggest it will be difficult for both sufficient instability and
shear to be present for more than spotty severe storms - tomorrow
and Thursday have struggles with instability, Friday and Saturday
have relatively weak flow aloft and thus suboptimal shear, while
Sunday and Monday have low probabilities for either ingredient.
30.12z LREF joint probabilities are around a 50% chance for at least
500 J/kg of SBCAPE and 30 knots of deep layer shear for Wednesday
while longer range ML guidance based on both the GEFS and ECENS
suggest Saturday is a day to watch, presumably largely on the basis
of instability (playing mix and match with guidance, but 30.12z LREF
has a 60% chance to surpass 2000 J/kg of SBCAPE). In any case, at
this time widespread severe storms appear unlikely both of those
days given the presence of the aforementioned limiting factors. As
for heavy rain, while PWATs Friday night into Saturday return to the
99th percentile in both the 30.12z GEFS and ECENS, progged storm
motions of 25 mph or greater and progressive nature of the upper
trough should keep things from getting too dicey despite potential
for high rain rates. Thus, flood risks at this time would focus on
urban locations with poor drainage.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 527 AM CDT Tue Jul 1 2025

VFR conditions expected for the next 24 hours. Light west winds will
become more northwesterly through the morning, picking up to around
10 kts at the terminals by this afternoon. Winds are then expected
to decrease into the evening and back to the west/southwest
overnight.

&&

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

&&

$$

DISCUSSION...Ferguson
AVIATION...Barendse