Ottumwa, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

827
FXUS63 KDMX 250344
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1044 PM CDT Sun May 24 2026

 ...Updated for the 06z Aviation Discussion...

.KEY MESSAGES...

- Marginal Risk for severe weather in northwest Iowa for
  tonight. Hail will be the main threat.

- Marginal Risk for severe weather in northern and northwest
  Iowa for Monday afternoon/evening. Hail and damaging winds
  both possible.

- Extended forecast trending more dry for the work week, but
  precipitation builds back in to start next weekend.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 228 PM CDT Sun May 24 2026

A quite and fair Sunday featured little to no clouds. Highs this
afternoon will eclipse 80 degrees most everywhere. 12z CAM guidance
simulated showers and storms in northwest Iowa this afternoon and
evening, the culprit being storms that initiated in Nebraska and
South Dakota. These storms have yet to materialize out there, so
have continued to hedge towards the later arrival. The Marginal Risk
for storms tonight remains tucked just west, focused more with the
instability axis. The low-level relative wind max will be pulled
into northern Iowa throughout Monday, extending the timeframe of
showers and storms at least through late morning. Shower and storm
chances have be introduced further south as a few could form on the
eastern edge of the instability axis. A Marginal Risk was added in
for Monday afternoon as destabilization pushed MUCAPE north of 2000
J/kg with deep layer shear of around 30kts. Hail will be the main
risk, with damaging wind potential in the daytime hours. Storm
motion will be slow, and the Corfidi vectors start pointing to the
west after dark. Locally heavy rain exceeding 2" will be possible
with storms.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 228 PM CDT Sun May 24 2026

The moisture axis responsible for Monday`s storms will be ushered
north by the building ridge. The blocking pattern still favors highs
in the 80s, and now trends favor the moisture profile keeping
southwest of the area for most of this week. Models diverge on how
to handle the arrival of high pressure this weekend, which will
affect where the moisture pool will move. A more eastward shift like
the ECMWF`s would mean active weather, whereas a more centered,
faster solution like the GFS spells an extension of seasonal, dry
conditions.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1044 PM CDT Sun May 24 2026

Showers and storms are moving over north central Iowa late this
evening and will continue to be off and on over the next several
hours. Have prevailed showers with TEMPO TSRA at FOD and MCW
where confidence is highest in precipitation. While trends are
downward, have maintained PROB30 at ALO. Otherwise, there could
be low level wind shear as low level winds increase, but too
sporadic and spotty to include at any terminal. Surface winds
will increase and become gusty on Memorial Day, especially later
in the morning through the afternoon with sustained winds above
12 knots. These winds will decrease after sunset. There could
be an isolated storm in northern Iowa in the latter half of the
period, but confidence well below level to include.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...Jimenez
LONG TERM...Jimenez
AVIATION...Ansorge