941
FXUS63 KDMX 031911
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
211 PM CDT Thu Sep 3 2026

.KEY MESSAGES...

- Scattered showers and thunderstorms across northern Iowa this
  afternoon will gradually diminish into the evening hours.
  Gusty winds are possible but more robust severe storms are
  not expected.

- Additional scattered showers and thunderstorms develop in
  northeast Iowa early Friday morning and lasting into the
  afternoon.

- Heat and humidity continues into this weekend. The Heat
  Advisory has been extended through Saturday evening and
  expanded a row of counties north to include the Highway 30
  Corridor.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 211 PM CDT Thu Sep 3 2026

Scattered showers and thunderstorms have persisted across
northern into central Iowa into this afternoon, fueled in part
by a low level jet that has lasted well beyond what could be
called "nocturnal". This has finally begun to fade early this
afternoon, but storms continue along the theta e gradient that
is draped across northern Iowa. Expectation is for storms to
gradually taper off into the early evening hours, as has been
the case the last few days. While dewpoints are high, some dry
air is still in place in the low levels of soundings and could
result in gusty winds with any collapsing cells. The
precipitation across northern Iowa has created much cooler
temperatures in rain-impacted areas with temperatures in the
mid 70s while the rest of the state has quickly warmed into the
upper 80s and low 90s already this afternoon. With dewpoints in
the 70s this has sent the heat index into the upper 90s to low
100s in central and southern Iowa.

Once again expect overnight and early morning thunderstorms to
developing Iowa, this time associated with a weak shortwave
that will slide along the thermal ridge from Minnesota into
Wisconsin and into Illinois on Friday. A few stronger storms are
possible with the extra forcing associated with the shortwave,
however this is expected to remain mostly east of the area.
Convection that trails into parts of northeast Iowa should be
aways from the better forcing with less of a severe threat.
Gusty winds would be the primary concern for any stronger cells
that do develop on Friday.

With convection shifted east the heat and humidity on Friday will be
able to surge farther north into the state. As such, have
expanded the Heat Advisory a row of counties farther north to
include the highway 30 corridor. Heat indicies from 100-105 are
possible in the afternoon. Similarly on Saturday, convection
looks to remain on the Fringes of the state and so the Heat
Advisory has also been extended in time out through Saturday
evening. As we think about the upcoming holiday weekend and any
outdoor plans, be sure to continue to exercise appropriate heat
safety measures including hydrating properly, taking breaks in
the shade, and avoiding strenuous activity.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 211 PM CDT Thu Sep 3 2026

A more robust trough will move east across the northern US from
Sunday into early next week. This will renew the periodic scattered
thunderstorms chances each day while also helping to squash the
thermal ridge. We will not see substantial cooling, however
temperatures Sunday into early next week should be at least a
few degrees cooler than what we have seen this week. The ridge
does look to rebuild for the middle to end of next week. Heat
and humidity along with continued scattered thunderstorm chances
looks to be the story for at least another week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1231 PM CDT Thu Sep 3 2026

Scattered showers and thunderstorms are across northern and
western Iowa this afternoon and will persist for the next
several hours. These will continue to impact KFOD and KMCW while
other sites are expected to remain clear. The rest of the TAF
period features VFR conditions with light south-southwest wind.
Scattered showers and thunderstorms are possible in northeast
Iowa Friday morning but are not expected to impact TAF sites. If
coverage expands, most likely impacts would be at KMCW/KALO.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM Friday to 7 PM CDT Saturday for
IAZ044>050.
Heat Advisory until 7 PM CDT Saturday for IAZ057>062-070>075-
081>086-092>097.

&&

$$

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