143
FXUS63 KDMX 222048
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
248 PM CST Sat Nov 22 2025

.KEY MESSAGES...

- Mild and dry weather continues into Sunday.

- Rainy and dreary Monday into Monday night, then much cooler by the
latter half of next week.


&&

.DISCUSSION...
Issued at 247 PM CST Sat Nov 22 2025

Upper air pattern early this afternoon shows a closed upper low that
has been slow to move across southern CA and the northern Baja
Peninsula. This feature will influence our weather locally in the
coming days, but closer to home, a weaker shortwave aloft has
developed an associated sfc low in western Ontario with a weak front
extending through the Upper Midwest into IA. This front is having
little impact across the state aside from a band of high clouds,
which should push south as we head into this evening. With the sfc
low moving east and sfc high pressure to our south expanding
northward into tonight, this should give us another good setup for
radiational cooling with mostly clear skies and light winds. Can`t
entirely rule out some patchy fog in the morning, especially in low-
lying and typical fog prone areas, but impacts should be limited.
Another pleasant day is on tap for Sunday, perhaps a few degrees
cooler behind today`s weak front, but otherwise looking pretty
similar. A low-amplitude ridge at 500mb ahead of the aforementioned
low in addition to low-level winds returning southerly should still
keep mild temperatures and sunny skies in play with highs reaching
the mid to upper 50s.

Sunday night into Monday, the upper low looks to eject out of the
Four Corners region and move northeast across the Central Plains.
Isentropic lift and moisture advection increase ahead of the system
Monday morning, helping to increase rain chances across Iowa.
Coverage should become more widespread from west to east
through the balance of the morning hours, per the latest CAM
guidance, with likely PoPs continuing through the afternoon.
PoPs decrease from west to east during the evening and
especially overnight with the upper trough axis pushing the main
area of ascent east after midnight. Rain amounts look light
overall, with most ensemble solutions producing a quarter inch
or less across the area. A few outliers give up to a half inch
of QPF, but that appears to be a 20% chance or less at any given
location. Additionally, there`s little to no instability to
work with to produce any thunderstorms, so that would help keep
amounts light as well.

Not far behind the Monday system, a Pacific shortwave trough is
progged to become more amplified as it traverses across the Northern
Plains and Upper Midwest. There remain some small differences in the
timing and strength of that system as it does so, which results in
some difference among solutions in how far south any associated
precip will develop. The latest forecast has increased PoPs slightly
across northern IA Tuesday, which seems reasonable. Depending on
timing of the system, there could be some snowflakes mixing in with
rain toward the evening as cold air advects in. This should have
little to no impact with only a few hundredths of QPF, but trends
will be something to watch at least. The main story with this system
will be the strong CAA bringing in a much cooler and drier air mass,
which sticks around through the end of next week. Highs are forecast
to drop into the 30s Wednesday onward with lows dipping into the
teens and 20s. Dry weather is forecast Wednesday through Friday with
northwest flow aloft.

To give an early look at the long range into next weekend, models do
show a trough in the western CONUS, which could produce a low
pressure system somewhere in the region. It`s far too early to get
any more detailed than that, as we really need to see more run-to-
run consistency closer to the time frame in question to get a handle
on how this may impact the local area.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1111 AM CST Sat Nov 22 2025

VFR conditions will prevail through the TAF period. Southwest
winds this afternoon will turn to northwest later this evening,
then go light and variable by Sunday morning. There is a low
probability of fog, less than 20 percent, mainly at DSM and OTM
around sunrise Sunday. Have not included it in the TAFs at this
range, but will monitor for subsequent issuances in case
probabilities rise and warrant inclusion.

&&

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

&&

$$

DISCUSSION...CP
AVIATION...Lee