790
FXUS63 KDMX 301857
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
157 PM CDT Tue Sep 30 2025

.KEY MESSAGES...

- Warm and dry through the end of the week. Becoming breezy
  Friday through the weekend.

- Precipitation chances return to the area by Sunday.

&&

.DISCUSSION...
Issued at 157 PM CDT Tue Sep 30 2025

High clouds have spread across much of Iowa this afternoon where a
plume of midlevel moisture has lifted into the area, sandwiched
between a trough to the west and the high central and east that
continues to dominate the upper level pattern this week. The primary
impact has been a couple degree reduction in temperatures so
far today, though highs remain in the 80s and well above
average. In areas with less cloud cover, daytime heating has
allowed for deeper mixing and breezier gusts near 20 mph. As an
embedded shortwave passes north of the area this plume of
moisture will gradually shift across and east of the area
through Wednesday with continued high clouds. Even so, we will
continue to see warm temperatures into the mid to upper 80s. By
Thursday to Friday (and into Saturday), temperatures may brush
the low 90s.

The western US trough finally approaches the area this weekend. The
first influence will be the tightening pressure gradient across the
area, accompanied by dry low levels and deep mixing. Model soundings
indicate parts of northern Iowa with gusts of 35+ kts and into
central Iowa gusts of 25-30 kts. Have increased winds through
Saturday and into Sunday to account for this, though further
adjustments are likely in the days to come. While not in the
realm of headline criteria (for wind or fire), these breezier
conditions will heighten fire weather conditions this weekend
with the harvest well underway.

As has been discussed the past few discussions, the blocking high
and eastern US tropical systems have slowed the progression of the
western US trough. And while this should finally come to an end this
weekend, the onset has slowed another 12-24 hrs with recent guidance
delaying precipitation into Iowa until Sunday.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1233 PM CDT Tue Sep 30 2025

VFR conditions will persist through the TAF period. High clouds
remain in place across the area, especially towards western
Iowa. Areas without cloud cover have seen deeper mixing this
afternoon with gusts near 20 kts, however most TAF sites are
clouded in and less likely to see gusts so have kept from TAFs
at this time.

&&

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

&&

$$

DISCUSSION...Hagenhoff
AVIATION...Hagenhoff