393
FXUS63 KDMX 022345
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
645 PM CDT Wed Sep 2 2026

 ...Updated for the 00z Aviation Discussion...

.KEY MESSAGES...

- Scattered storms persist across northern Iowa this afternoon.
  Additional scattered thunderstorms develop in northern Iowa
  Thursday morning. The pattern continues with morning storms
  expected in parts of northern Iowa each morning through at
  least Saturday.

- Heat and humidity continues this week and through the weekend.
  Hottest conditions in southern to central Iowa where a Heat
  Advisory is in effect through at least Friday.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 243 PM CDT Wed Sep 2 2026

Scattered thunderstorms have persisted across north central
Iowa all morning and into this afternoon. Storms were fueled
through the morning by the low level jet, which is only just
beginning to diminish after 18z. Those storms have continued to
bubble along the theta e gradient in place and are expected to
continue into the afternoon. The severe threat is low, however
storms could create gusty winds as soundings show dry air
through the low levels.

Storms redevelop across northern Iowa once again early Thursday
morning and are expected to percolate along the theta e gradient
through midday. The low level jet axis is expected to be oriented
west of the area and that will help to reduce forcing into the area.
With very little shear available severe chances are low, though some
gusty winds are possible with stronger cores. The story
continues with overnight/early morning storms developing into
Friday morning as well. This round will be aided by a weak
embedded shortwave rounding the thermal ridge and providing
additional forcing. The track of this embedded wave is expected
to track across Minnesota and slide south across Wisconsin and
into Illinois, skimming into northeast Iowa but largely missing
Iowa to the east. Damaging winds are the primary concern storms
developing on Friday morning and continuing into the afternoon
with that shortwave.

Heat continues this week and the heat advisory has been extended
through Friday evening. The large thermal ridge dominating the
central US extended through the southern portions of Iowa,
allowing heat indicies to reach the upper 90s to low 100s each
afternoon. There is little in the way of overnight relief as
low remain muggy and in the upper 70s to near 80. In fact, Des
Moines has broken warmest minimum temperatures records multiple
times this week and may continue to do so this week. From
central to northern Iowa storms along the peripheral of the
ridge have kept temperatures lower.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 243 PM CDT Wed Sep 2 2026

Nocturnal and morning convection, mainly across northern Iowa, is
expected to continue each day through at least Sunday morning. With
only modest forcing severe chances each day are fairly low. The next
more organized convection chance is not until early next week and
that will help to squash the ridge and bring at least some relief to
temperatures for a few days. Until then, heat continues this weekend
with heat indicies in the upper 90s to low 100s across southern and
into central Iowa. With the holiday weekend coming up it is
important to remember heat safety for any outdoor plans that are in
place. Minimize time outside, hydrate, and take breaks in the shade.
By late week the thermal ridge looks to rebuild with heat and
humidity lifting back north into the area, along with continued
scattered storm chances.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 640 PM CDT Wed Sep 2 2026

Showers continue to fester near KALO, but have not produced
lightning over the past two hours, so made added a TEMPO for
showers. VFR expected with showers. Showers and storms will
return over northern Iowa late tonight and may linger near KMCW
and KALO similar to what occurred today. Storms will offer a
window of MVFR vsbys, but VFR cigs are expected to prevail
through the period.

&&

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

&&

$$

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