156
FXUS63 KDMX 082327
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
627 PM CDT Wed Oct 8 2025

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

.KEY MESSAGES...

- After near normal temperatures today, a period of above normal
  temperature for at least the next week.

- Winds pick up Thursday, with highest gusts over northwestern
  Iowa. Elevated fire weather conditions are expected over
  northwest Iowa with these winds due to lower RH values and
  dry crops.

- A slight chance (15-30%) for rain showers mainly central to
  eastern Iowa late Thursday into Friday. A few weak storms are
  also possible.

&&

.DISCUSSION...
Issued at 252 PM CDT Wed Oct 8 2025

Rest of Today and Tonight... High pressure over the Great Lakes
continues to be the main driver of the weather over the Upper
Mississippi Valley. This has given us continued clear skies
(outside of the diurnal cumulus) and light winds. This is also
why we have seen efficient raditional cooling overnight. The
best area of this cooling will shift where it was over northern
Iowa this past morning to northeast Iowa tonight into tomorrow
morning. While frost cannot be ruled out, it looks most likely
much farther east closer to the Mississippi River.

Thursday... On Thursday the Great Lakes high will continue to
move out to the east. With this motion another system will begin
to move in from the west. This will allow for increasing winds
from the tightening pressure gradient. Any frontal or
shortwaves aloft have their timing later in the day into
tomorrow night with respect to rain chances. So the daytime
should be dry and windy. Nothing near a critical fire weather
level, but high enough for some concern. This is especially true
for agriculture, as the GFDI Agriculture values are elevated
during the day tomorrow. As we head into the evening and
overnight a shortwave should provide enough broad lift to
support the chance for showers and maybe some isolated
thunderstorms. The main question here is if the depth of the
saturation will be enough for showers or storms. If the
saturation depth is enough, there is enough elevated
instability for a few elevated thunderstorms overnight. High
resolution guidance suggests a better setup to our north with a
more isolated chance across Iowa.

Friday into Next Week... Higher pressure to move in Friday into
Saturday providing more a mild and dry start to the weekend. By
Sunday another frontal passage (late day to overnight) provides
the next chance for rain. Looking into the NBM percentiles there
remains a spread. 50th percentile and lower keeps us dry with
75th and above providing widespread rain chances. Hopefully as
start to get into the high resolution window this can be
resolved better. Right now low NBM PoPs appear to be the best
approach. This pattern repeats multiple times over the next week
due to spread within global ensembles.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 627 PM CDT Wed Oct 8 2025

VFR conditions will persist through the period. High VFR clouds
will move into western Iowa Thursday afternoon, reaching
central Iowa sites late in the period. South wind will also
increase tomorrow with highest gusts west and less east. Sites
KFOD/KMCW will see gusts of around 20kts beginning late
morning, reaching KDSM/KOTM by 18z. Stronger winds are not
expected to reach to KOTM and have been excluded from TAFs at
this time.

&&

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

&&

$$

DISCUSSION...NC
AVIATION...Hagenhoff