Ottumwa, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

558
FXUS63 KDMX 041833
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
133 PM CDT Mon May 4 2026

.KEY MESSAGES...

- Cold front moving across Iowa today. Thunderstorms expected
  far south into MO late afternoon, then light showers across
  central and southern Iowa overnight into Tuesday morning.

- Cooler the next few days with highs in the 60s. Overnight
  lows in the 30s to 40s may result in frost concerns, mainly
  Tuesday night/Wednesday morning and Wednesday night/Thursday
  morning.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 133 PM CDT Mon May 4 2026

A cold front is pushing across Iowa today and will be the focus for
weather impacts over the next 24 hours. So far today the front has
made it approximately halfway across the state, moving northwest to
southeast. Temperatures in central and southern Iowa ahead of the
front are in the upper 70s to low 80s while area behind the front
have been in the mid to upper 60s. Meanwhile a plume of gulf
moisture is pushing north. This will intersect with the cold front
as it continues to sink south. Based on the speed of the front today
and current placement, expect that initiation along the front will
occur in far southeast Iowa and quickly pushing outside the area
late this afternoon. Gusty winds are the primary hazard with storms
that do develop, given very dry low levels with inverst-v soundings.
Deep mixing ahead of initiation has allowed for gusts of 25-35
mph this afternoon. Should the front slow down and a more robust
cell develop in the area as better moisture is allowed a bit
further north, that cell could also develop hail. Again, based
on the timing of the front, expect that most severe activity
will be southeast of the area this evening.

The secondary front with cooler air pushes into the area this
evening and overnight. This will bring a period of post-frontal
showers to the area. These are already seen on satellite and radar
across South Dakota into Minnesota. Scattered light showers will
pass across northern Iowa this evening, becoming more widespread in
central to southern Iowa overnight, lingering south through Tuesday
morning. Much cooler air settles across the area Tuesday with highs
in the 50s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 133 PM CDT Mon May 4 2026

With much colder air in place the threat for frost/freeze is back
through the middle of this week. Tuesday night-Wednesday morning
(low 30s north) and Wednesday night-Thursday morning (widespread mid
30s) are the coldest, though both nights still have complications
from cloud cover. As the main trough axis starts to shift east
late week warmer air will shift into the area with mid 60s
returning Thursday and Friday. A quick moving and rather weak
embedded shortwave may try to sneak across the area Thursday or
Friday bringing light rain to the area, however there are timing
differences at this time amongst EC/GEFS guidance that make
refining the timeframe a challenge. A more robust trough looks
to move across the midwest Sunday into Monday and will provide
the next window for showers and thunderstorms.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1225 PM CDT Mon May 4 2026

VFR conditions are expected at all terminals throughout this TAF
period, with gusty winds, wind shifts and precipitation chances
expected overnight into tomorrow. A cold front is going to pass
through Iowa this afternoon through the evening, causing a wind
shift at all terminals by sunset. Winds will shift from being
southwesterly ahead of the front to northwesterly behind the
front. Wind gusts of 25-30kts are possible through sunset,
though gusts could linger with any showers that form. At OTM,
PROB30 mentions of thunderstorms were introduced as the front
makes it to southern Iowa with low confidence in the northern
coverage of thunderstorms. Otherwise, behind the front a band of
showers is expected to form across central Iowa. Timing and the
exact location of where the showers form leads to PROB30s being
introduced at FOD and ALO, while more certainty leads to
prevailing showers at DSM and OTM tonight through early Tuesday
morning.

&&

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

&&

$$

SHORT TERM...Hagenhoff
LONG TERM...Hagenhoff
AVIATION...Hagenhoff/Rotter