Sattre, Iowa Weather Forecast Discussion

561
FXUS63 KARX 141035
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
535 AM CDT Sun Sep 14 2025
.KEY MESSAGES...
- Summer heat and humidity hangs around for the start of the
  week, with a transition back to seasonable temperatures for
  the latter part of the week.
- Low probability (10-20%) risk for storms west of the
  Mississippi River tonight into Monday.
- Better shot of widespread showers and storms comes Wednesday
  afternoon through Thursday (40-50%).
&&
.DISCUSSION...
Issued at 355 AM CDT Sun Sep 14 2025
Summertime Warmth through Midweek
The current sultry airmass moves little over the coming days
with a downstream blocking ridge keeping it stuck in place. The
end result will be continued heat and humidity with highs in the
80s and dewpoints in the 60s to low 70s. Any storms and clouds
on Monday may locally temper high temperatures, which is
reflected in the NBM high temperature grid west of the
Mississippi River. By midweek, the aforementioned ridge flattens
and shifts just slightly to the east, allowing for cyclonic
flow to overspread the region and bring cooler air and repeated
chances for showers and storms, which will have the effect of
bringing temperatures back to near normal for the end of the
week.
Low Risk of Storms Tonight into Monday
A ribbon of 800-700-mb 335-K theta-e air slowly migrates
eastward from north-central Iowa this afternoon to the
Mississippi River by midday Monday before dissipating. Forecast
soundings show that this increase in saturation may be just
enough to generate isolated to scattered storms between Sunday
night and Monday afternoon, mainly along and west of the
Mississippi River. As is to be expected in such a conditional
pattern, the convective allowing models are highly variable in
whether any storms form and their exact coverage. Despite MUCAPE
values of around 500-1000 J/kg, shear profiles will be complex,
resulting in a limited severe weather threat. However, with
ample moisture in play (PWATS around 90% of climatology), any
slower moving or training cells will be capable of producing
efficient rainfall and amounts of 1-2+ inches could fall in a
short time.
Midweek Storms
The shift in the synoptic pattern midweek presents the best
opportunity for widespread showers and storms to affect the
region. A closed upper low then pivots over the region from
Thursday till Saturday, keeping the risk for scattered showers
in play through the end of the week. With there being little in
the way of synoptic surface forcing mechanisms during this
pattern change, the mesoscale details of the timing and coverage
of this convection for the middle to end of the week will be
better refined in the coming days.
&&
.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 531 AM CDT Sun Sep 14 2025
An expanding field of IFR/LIFR stratus and fog is pushing
westward across the Mississippi River north of PDC as of 11Z
and will continue to expand to the WNW, affecting mainly areas
northeast of a SYN to OVS line through 14-16Z this morning.
Patchy fog also formed further to the west and likewise burns
off by mid-morning. Look for VFR conditions for the rest of the
TAF period with winds from the southeast around 5-10 kts. There
is a low probability of high-based storms after 06Z west of the
Mississippi River.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Skow
AVIATION...Skow

NWS ARX Office Area Forecast Discussion