Grand Marsh, Wisconsin Weather Forecast Discussion

778
FXUS63 KARX 270434
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
1130 PM CDT Fri Sep 26 2025
.KEY MESSAGES...
- High pressure will provide dry weather through much of next
  week. As a result, the forecast is dry with enhanced chances
  of warmer-than-normal temperatures.
&&
.DISCUSSION...
Issued at 1236 PM CDT Fri Sep 26 2025
Tonight and Saturday
A 500 mb shortwave trough will move through the region late tonight
and Saturday morning. This system will have little moisture to work
with, so other than a wind shift there will no impact to the
sensible weather. With increasing winds and shallow boundary layer
moisture tonight, the fog potential looks very low. Low
temperatures tonight will be in the 50s tonight and high
temperatures will range from the mid-70s to lower 80s.
Saturday night through Thursday
In the wake of the system tonight and Saturday, a 500 mb ridge of
high pressure will build across the Upper Mississippi River Valley
and eventually the Canadian Prairies. If Imelda comes into the
southeast United Sates early next week, a Rex Block would gradually
develop. This will keep the forecast dry through this time period.
Even if does not develop, the strong 500 mb ridge will keep the area
dry. High temperatures will range from the mid-70s to lower 80s for
this time period. Currently, the high temperatures for
Wednesday and Thursday are in the lower and mid-70s. If these
trends continue, these temperatures will have to be eventually
raised into the 75th percentile which ranges from the mid-70s to
lower 80s.
&&
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1130 PM CDT Fri Sep 26 2025
CIGS: SKC/SCT through the period with some high level (15-20kft)
clouds attached to a passing trough/cool front today. Some threat
for low stratus at KLSE Sunday morning.
WX/vsby: only concern is for the potential fog/low stratus at KLSE
the next few mornings. T/Td spreads, sfc winds, and the depth of the
light wind layer, will be the main factors to keep an eye on. As of
now, RAP/NAM suggest the vert wind speeds will be too brisk to
support fog late Sat night/Sun morning - but could lighten up enough
for 300 ft stratus to spread across KLSE. Something to watch.
WINDS: winds will swing west/northwest with the passage of the cool
front this morning. Some increase to around 10+ kts post the front,
but those settle down Sat evening as a sfc high moves back in.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Boyne
AVIATION.....Rieck

NWS ARX Office Area Forecast Discussion