Area Forecast Discussion
Issued by NWS Des Moines, IA

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000
FXUS63 KDMX 012324
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
624 PM CDT Sat Oct 1 2022

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

.DISCUSSION.../Tonight through Saturday/
Issued at 212 PM CDT Sat Oct 1 2022

Key Messages:

-Mild temperatures continue
-Rain chances Wednesday, cool temperatures and wind follow

A stagnant weather pattern continues today with a visible omega
block on water vapor imagery. This is made from the mid level low in
the northern Rockies as well as the remains of Ian on the east
coast. A low-level thermal ridge has built up in the west, advecting
in air with H850 dew point depressions of ~15C. Combined with dry
easterly winds from a surface high, the rain that has shown up on
radar most of the day has seldom reached the ground, only producing
light sprinkles if anything. A similar outcome is expected tomorrow
except with even less moisture available.

The surface high near the Great Lakes will also remain in place over
the next few days, continuing to provide the cool, dry easterlies
that are keeping high temperatures cooler in central Iowa.
Southwesterlies aloft, however, will continue to create a warm nose
that will limit the mixed layer height over the next few days. This
should keep our surface dew points from plummeting further in the
afternoon hours. Upper-level energy will propagate from the west
and break the blocking pattern. As the low moves closer to the
state, uniformed southwesterly winds will make Tuesday the warmest
day of the week. A front will move through on Wednesday along
with the low, bringing the best chances of rain for the week. The
amount of low- level moisture is still in question as the remnants
of Ian continue to cut off flow from the Gulf. If Ian moves
offshore faster, the chances of rain Wednesday will likely be
higher.

Breezy northerly winds will arrive Thursday behind the dry passage
of a more prominent cold front. The CAA will push Friday morning
temperatures into the 30s, making frost possible again. Low
temperatures in northern counties may fall into the upper 20s.
Northwest winds aloft along with a descending surface high will keep
us dry and close to seasonal next weekend.

&&

.AVIATION.../For the 00Z TAFS through 00Z Sunday evening/
Issued at 622 PM CDT Sat Oct 1 2022

Sprinkles remain possible vicinity of KMCW but VFR conditions and
east/southeast wind less than 12kts will prevail through the
period.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

DISCUSSION...Cogil/Jimenez
AVIATION...Donavon


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