FXUS63 KARX 082341
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
641 PM CDT Wed Jul 8 2026

.KEY MESSAGES...

- Clusters of storms developing over southern Minnesota into
  western Wisconsin advance southeast this evening. Some storms
  may be severe and produce locally heavy rainfall of (1-3"),
  mainly west of the Mississippi River.

- Quieter weather for the remainder of the week with a 20-30%
  chance of afternoon storms for Thursday.

- Cooler for the end of the week with warmth returning early
  next week.

&&

.DISCUSSION...
Issued at 100 PM CDT Wed Jul 8 2026

This Afternoon: Severe Weather and Heavy Rain Risk

A convective complex that moved through central Minnesota 
gradually decayed and shifted northward through the morning 
hours as it ran into a more stable airmass, with the back edge 
of the anvil shield serving as the trigger for new convective 
development around noon as return southerly flow streamed up 
through the Siouxland. These cells have already grown into a 
multi-cell complex with additional cells developing further 
upstream along I-90. Given the earlier initiation timeframe and 
continued convective debris lingering over the forecast area, 
concerns area shifting more towards a heavy rain threat vs. 
severe threat with these storms. 

There looks to be a period before 00Z where storms could train 
along the I-90 corridor in southeastern Minnesota before the 
convective cold pools take over and propagate to the southeast,
which should result in the convective complex sagging southward
as well. Multiple runs of the HRRR through the day have been 
focusing the QPF axis of 1-3 inches (with some pixels of 4-5 
inches) between I-35 and Highway 52 in southeast Minnesota and 
far northeast Iowa, an area that remains saturated from last 
week's deluge. Given these trends, have issued a flood watch for
much of the area west of the Mississippi River through midnight
tonight.

There severe threat remains on the table, but will probably be 
more focused west of the Mississippi River (maybe even closer to
I-35) where there will be better recovery of the airmass. There
is some southeastward elongation in the 1-5-km hodographs that 
could support some storms organization, but with cells already 
growing upscale into clusters, severe weather will likely be 
focused in narrow corridors where the convective cold pools can 
organize. As the storms become more outflow dominant in the 
evening, the severe weather threat should wane.


Thursday Afternoon: Scattered Showers and Storms

Cooler and slightly less humid air filters southward on 
Thursday in the wake of this afternoon's storms, but vertical 
thermal profiles will still support pulse convection during the 
afternoon with MLCAPE values of 1500-2000 J/kg and little to no 
inhibition. Shear profiles and forcing will be weak and 
therefore storms will struggle to organize. Very localized heavy
rainfall of 1-2 inches would be the main threat with these 
storms given their slower storm motions.


Cool End to the Week, Warmer Next Week

Upper level ridging builds in for the weekend and into early 
next week, keeping the threat for rainfall at bay while at the 
same time pumping heat northward into the northern CONUS. At 
this point, the warmest temperatures are progged to be more over
High Plains with the Upper Mississippi River Valley falling 
under a weak east to southeasterly flow under or just west of 
the surface high pressure reflection. This may act to temper 
temperatures and dewpoints compared to locations further west, 
though to the exact degree is less certain. Highs are still 
forecast to reach into the upper 80s to low 90s no matter how 
you slice the forecast, making it feel solidly like summer. The 
ridge flattens around midweek, but how fast it amplifies earlier
in the week will dictate whether this flattening brings 
convection down into our region or if the storms stay to the 
north and we remain under the heat. The various ensembles groups
remain in their respective camps on how this will unfold with 
no clear leaning one way or another.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 641 PM CDT Wed Jul 8 2026

A cold front will move through southeast Iowa and southwest 
Wisconsin between now and 11 pm. Once this occurs, the threat
for severe weather and flooding will end. Areas of fog will be
found overnight. This will produce areas of IFR/MVFR ceilings 
and visibilities through 09.14z.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...Flood Watch until midnight CDT tonight for MNZ086>088-094>096.
IA...Flood Watch until midnight CDT tonight for IAZ008>011-018-019.

&&

$$

DISCUSSION...Skow
AVIATION...Boyne