939
FXUS63 KDMX 022040
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
240 PM CST Tue Dec 2 2025

.KEY MESSAGES...

- Snow, freezing drizzle possible through the day Wednesday.
  Minimal snow accumulations, but any ice accumulations may
  collect on untreated surfaces.

- High temperatures on Wednesday occur in the morning, then fall
  into the teens by the afternoon.

- Bitter cold temperatures Thursday. Lows Thursday morning will
  be in the subzero teens, wind chills in the subzero twenties.

&&

.DISCUSSION...
Issued at 230 PM CST Tue Dec 2 2025

The surface high moved off this morning and southwest flow took its
place. Aloft, an approaching wave has turned 850mb flow to
southwesterly as well, even advecting in temperatures above
freezing in the southwest. The flow will continue to chip away
at the stratus`s territory in eastern Iowa. As the trough nears,
advection neutralizes overnight in the south, and a weak
boundary starts to pass over northern Iowa. This boundary
connects two cyclones, one in the Hudson Bay and the other in
the desert Southern Plains, the distance a hint that synoptic
forcing is nebulous and moisture transport is limited to what
is carried along the front. Precipitation will be transient and
light. Soundings lose ice introduction quickly and hang on to
sub-DGZ saturation for a time post-frontal. Have added in
mention of freezing drizzle for tomorrow. Impacts would be
limited due to the low QPF, but the drizzle could create some
slick spots as the front dives south Wednesday.

The bigger story is the cold air that follows behind. Highs on
Wednesday will be achieved in the morning--notice they`re not too
dissimilar from the day`s low temperatures. Cooling intensifies once
the sun sets under clear skies and snow pack, plus the weak winds
under a surface high directly overhead. Lows on Thursday morning
will be below zero for much of the state, coldest in the north. The
lack of winds will spare us from extreme wind chills, but we will
still have a window of values at or below -20 degrees in northern
Iowa. After a recovery into the teens above zero for highs,
southwest winds return and hold temperatures roughly in place
Thursday night, then boost highs back towards 30 degrees Friday.

An upper low will stall over the Hudson Bay and lock Iowa in
northwest flow for the extended forecast, a pattern typically
featuring rounds of shortwaves and temperatures that lean below
average. The first wave will arrive Friday and affect mostly the
northeast with light snow. There`s evidence of another feature on
Saturday that will drag a cold front with it and cool Sunday highs
down. Forcing beyond this point will be better handled as we get
closer to time.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1141 AM CST Tue Dec 2 2025

Fog and stratus have been stubborn to clear out of KMCW and
KALO, but both should see restrictions lift within the next hour
or two. MVFR cigs return along a front tonight. Terminals could
see a mix of light snow and freezing rain, but the duration
would be limited. Accumulation appears limited to none at this
time. Left precipitation chances out of most sites due to lack
of impacts anticipated, but will continue to evaluate in later
issuances.

&&

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

&&

$$

DISCUSSION...Jimenez
AVIATION...Jimenez