377
FXUS63 KDMX 262331
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
631 PM CDT Thu Sep 26 2024

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

.KEY MESSAGES...

- Extended period of tranquil and dry weather with above normal
  temperatures into Monday.
- Cooler temperatures arrive by Tuesday but dry conditions
  persist.

&&

.DISCUSSION...
Issued at 331 PM CDT Thu Sep 26 2024

Quiet weather persists across the state this afternoon with ridge
axis across the southeast.  Otherwise, the dry atmosphere warmed
nicely with plenty of sunshine this afternoon.  Anticipate the
tranquil conditions to persist tonight as the surface ridge begins
to actually retrograde as the eastern upper low and Hurricane Helene
interact.  Patchy fog may once again develop toward daybreak given
the light winds and ample radiational cooling although dont
anticipate this becoming problematic.

The overall pattern is dominated by the large upper low absorbing
Helene and holding nearly stationary in the lower Ohio River Valley
thorugh the weekend.  Iowa remains on the backside of this large
circulation with northeast winds but generally clear skies.  Some
clouds may back into the east third or so of the state during the
weekend, but otherwise relatively sunny conditions are expected
during the day.  Temperatures continue with decent diurnal ranges
with a relatively dry airmass in place and limited clouds. A
stronger shortwave drops southeast into the Upper Midwest by Monday
of next week.  The bulk of forcing and associated lift remain well
north of Iowa with relatively little moisture in the state.
Therefore, the chances of precipitation with this system remains
north of the state.  However, a decent push of colder air is
expected by Tuesday with temperatures dropping to or below normal,
if only for a day or two.  Warmer air returns quickly into midweek
once again ahead of another fast moving shortwave which arrives by
late in the work week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 625 PM CDT Thu Sep 26 2024

VFR conditions ongoing and expected to continue through the TAF
period. However, we continue to monitor trends for any isolated
patchy fog around daybreak Friday, but confidence far to low to
include any mentions at any one TAF site. Light and variable
winds tonight become out of the northeast and increase during
the daytime Friday, the strongest winds/gusts in the southeast
towards KOTM.

&&

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

&&

$$

DISCUSSION...Cogil
AVIATION...KCM