993
FXUS63 KARX 262323
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
623 PM CDT Thu Jun 26 2025

.KEY MESSAGES...

- Today, severe thunderstorms possible again this afternoon,
  with a few tornadoes & heavy rain as the primary threats.
  Please stay weather aware in case watches and warnings are
  issued for your area.

- This weekend, another round of strong to severe storms possible
  Saturday night into Sunday.

- Next week, drier conditions are expected across the region.

&&

.DISCUSSION...
Issued at 1246 PM CDT Thu Jun 26 2025

TODAY...the main concern this afternoon into this evening is the
another round of thunderstorms capable of producing a few tornadoes,
as well as heavy rain and the potential for flooding. Please stay
weather aware in case watches and warnings are issued for your area.

An upper level wave was located across the Missouri River Valley,
with precipitation downstream of the trough axis across the eastern
Dakotas and Minnesota. Late morning satellite imagery with a RAP
surface analysis showed a surface low approaching western Iowa, with
mostly clear skies and easterly winds ahead of it. A warm front was
becoming better defined near I-90, and this will set the stage for
another severe weather threat this afternoon.

By early this afternoon, instability around 2000 to 3000 j/kg will
be in place south of this warm front, and the aforementioned upper
level trough be enough lift to develop storms. In addition, the
veered wind profile along the warm front will be favorable for
rotating storms. Forecast sounding show nearly 300 m2/s2 of 0-2km
helicity, along with low cloud bases. The combination of instability
and wind shear should lead to at least a few storms capable of
producing tornadoes. The Storm Prediction Center has lifted the
severe weather outlook northward, and now the slight risk and
tornado threat are centered across the local area. In addition to
the severe threat, heavy rain will also accompany these storms, and
if storms were to track across the same region, then amounts in
excess of 3 inches would be possible. A flash flood watch was issued
for counties along and near I-90. The timing for these storms are
this afternoon and evening, with storms expected to be east of the
region by midnight tonight.

TONIGHT THROUGH TUESDAY...Rain will exit the region overnight, but
forecast soundings show low clouds lingering through Friday morning,
before clearing out later in the day as weak high pressure builds
across the region. On Friday night storms will develop over the
Dakotas, but they should fall part before the reach the tri-state
area. By Saturday, southerly flow will return across the region,
with hot and humid conditions expected over the weekend. Additional
thunderstorm chances are possible Saturday night, and again Sunday
into Sunday night. The instability and shear profiles would once
again support strong to severe storms.

Looking ahead, the current southwest flow of the jet stream will
transition to zonal flow this weekend, and eventually northwest flow
next week. That will bring in some drier air, with dewpoints, back
in the lower 60s. Temperatures will be slightly above the seasonal
average for early July, with highs in the lower 80s. This pattern
favors drier weather, but cant completely rule out and
precipitation, so have generally 10 to 20 percent chances in the
forecast.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 623 PM CDT Thu Jun 26 2025

Main taf concerns are thunder chances early in the period and
IFR/LIFR conditions tonight into Friday at both RST/LSE taf sites.
Showers and storms associated with a cold front will continue to
move across the area this evening. Thunder will be possible at LSE
taf through 02z Friday. The better instability has moved east of RST
taf site and showers are expected through the early evening hours.
Behind the surface front...low level moisture and weak winds aloft
will allow for a stratus deck to form tonight. Bufkit soundings show
ceilings lower into the IFR/LIFR overnight. Have kept IFR condition
at LSE taf site and lowered RST taf site into LIFR condition
through Friday morning. Due daytime heating and surface ridge
building into the area...ceilings will slowly improve and maybe
improve to VFR conditions after 18z Friday at both taf sites.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Flood Watch until 4 AM CDT Friday for WIZ041>044-053>055.
MN...Flood Watch until 4 AM CDT Friday for MNZ086>088-094>096.
IA...Flood Watch until 4 AM CDT Friday for IAZ008>011.

&&

$$

DISCUSSION...JRB
AVIATION...DTJ