Severe Thunderstorm Warning 103, NWS Des Moines, IA

Area Forecast Discussion
National Weather Service Des Moines IA
207 PM CDT Thu Apr 23 2026

.KEY MESSAGES...

- A line of severe storms will move across Iowa late afternoon
  and evening. A few non-severe showers and storms possible
  ahead of the main line. The line of storms will have wind as
  the primary hazard, though tornadoes and hail are possible.

- Cooler Friday through the weekend. Multiple rounds of showers
  and thunderstorms possible this weekend and early next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 207 PM CDT Thu Apr 23 2026

A few spotty showers have developed in the moist plume extending
into Iowa, though have been fairly sort lived with little mechanism
to sustain development. Meanwhile, convection has fired along and
just ahead of the cold front pushing across Nebraska and into
western Iowa. This will push across Iowa this evening, reaching the
I-35 corridor around 7-9pm and pushing east after midnight. There
was some concern that prefrontal convection would prevent more
robust development with the main line of storms. While this has not
yet materialized, the widespread stratus has put a bit of a damper
on instability. There is little DCAPE out there and with moist
soundings through the low levels, that may prevent better cold pool
development except in northern Iowa where there is drier air in
place. This would impact wind potential with the line as it blows
through. A pool of 2500+ J/kg SBCAPE is in place across western to
central Iowa with the Creston sounding showing 1900+ ECAPE as some
may not be realized due to entrainment. Shear is largely parallel to
the boundary. This could limit some of the tornado threat unless a
bowing section can take better advantage of line normal shear.
Tornado threat would be highest with initial convection that is
more likely to be surface based, along with the low LCLs around
500m. Hail concerns will also be greatest with initial discrete
convection when lapse rates are steeper around 7-8 C/km. As the
line grows upscale with column moistening and pushes east later
this evening threats will start to diminish.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 207 PM CDT Thu Apr 23 2026

Relatively cooler conditions settle in Friday through the weekend
and much of the upcoming week. While cooler that recent days,
average highs this tie of year are in the mid 60s, so temperatures
will be closer to what is "typical" for this time of year. The
pattern remains active This weekend and next week as several
embedded shortwave eject east from a longwave trough parked across
Alberta and Saskatchewan. The first is rather weak and may skim the
area on Saturday. Then a more robust wave lifts out of Missouri
towards the area on Sunday. This will interact with the main
longwave trough finally digging east Sunday into Monday. As this
interacts with the system lifting out of Missouri thunderstorms
are expected into Iowa. Placement of the warm sector will
impact severe threats into Iowa and will be better determined in
the next few days.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1234 PM CDT Thu Apr 23 2026

MVFR stratus is in place across the area as the atmosphere
saturates today. Scattered showers and thunderstorms are
expected to develop north and east this afternoon ahead of a
line of severe storms set to push across the state later this
afternoon and evening. Periods of IFR conditions are possible as
this primary line pushes thorugh. Behind the line winds shift
to out of the northwest. Conditions improve back to VFR
overnight and on Friday morning.

&&

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

&&

SHORT TERM...Hagenhoff
LONG TERM...Hagenhoff
AVIATION...Hagenhoff

Hazardous Weather Outlook
National Weather Service Des Moines IA
444 AM CDT Thu Apr 23 2026

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-240945-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun-
Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene-
Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper-
Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union-
Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-
Appanoose-Davis-
444 AM CDT Thu Apr 23 2026

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...Today and tonight

There is a Slight Risk (level 2 of 5) for severe weather over most
of Iowa. Damaging wind is the main threat. Tornadoes and large
hail will also be possible, mainly early in the event in western
and southwestern Iowa, with the threat diminishing and storms move
east. Locally heavy rainfall and ponding may also occur.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Additional thunderstorms possible Sunday night into Monday. There
is a Slight Risk for severe weather Monday.

.SPOTTER INFORMATION STATEMENT...

Spotters may be needed Thursday into Thursday night.