012
FXUS63 KDMX 300503
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1103 PM CST Sat Nov 29 2025

 ...Updated for the 06z Aviation Discussion...

.KEY MESSAGES...

- Moderate to heavy snow continues this afternoon, tapering off
  this evening across Iowa.

- Winds increase this evening and into Sunday morning, gusting
  35+ mph. Blowing snow will reduce visibility and impact travel
  into Sunday.

- Colder Sunday into next week with highs in the teens to
  around 20 degrees. Lows in the single digits on either side of
  zero.

- Additional light snow Monday brings 1-2" to southern Iowa.

&&

.DISCUSSION...
Issued at 216 PM CST Sat Nov 29 2025

The surface low is centered across northwest Missouri this afternoon
with the northwestern side deformation zone stretching across Iowa.
A band of heavy snow with high snow rates and visibility under 1/4
mile is currently set up across the Des Moines metro and east
towards Grinnell. This has resulted in a number of accidents on the
interstate already this afternoon. Light to moderate snow
continues to fall across much of the rest of the state. The
edge of precipitation has reached western portions of Iowa.
Heaviest snow is ongoing and expected to last another couple
hours, tapering off from west to east through this late
afternoon and evening. Totals have been highest along the
Highway 20 corridor so far today with widespread reports of
8-12+ inches. North and south of this corridor amounts ranging
from 3-8 inches have been common. Expect another 2-4 inches of
additional snow through the rest of this event.

As snow tapers off today northwest winds will increase with
subsidence and strong cold air advection behind the system as
the pressure gradient remains enhanced. Soundings indicate
25-35+ kts through the boundary layer overnight, tapering off
Sunday morning. Despite falling snow ending, the layer of fresh
powder for today will still be easily blowable, reducing
visibility and blowing back onto previously cleared roads. Winds
diminish midday Sunday as the low pushes further east, and
clouds clear out. Lighter winds and sunshine should help with
snow removal efforts on Sunday. Even so, much colder air
filters in behind this system with highs on Sunday in the teens
to near 20 degrees on Sunday with the wind making it feel more
like 0 degrees. Overnight lows will fall to the single digits
and below zero but the wind will die off and should not result
in much of a wind chill.

On Monday an upper level wave dropping across the Rockies will
undergo lee cyclogenesis and eject across the central plains.
The low is set to track across Missouri with the northern
deformation zone passing over southern Iowa. GFS soundings
across southern to central Iowa show a deep isothermal layer
within the dendritic growth zone for several hours on Monday.
And while omega is modest during this period, the deep DGZ
should allow for larger dendrite growth and enhance snow ratios.
Areas south of I-80 may see an additional 1-2" Monday. A few
subtle waves pass across the area this week, but with little
available moisture the forecast is dry. The most notable impact
of these waves will be periods of colder air pulled across Iowa.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1101 PM CST Sat Nov 29 2025

BLSN and 30kt gusts will be the main concern for the next 6
hours. Localized IFR vsbys possible, but will be short-lived.

Trends with clouds have been more optimistic given the
dissipation of stratus over western Iowa, so have reduced
coverage for sites like KFOD and KDSM. Elsewhere, stratus will
lift to MVFR and will prevail for much of the period.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 AM CST Sunday for IAZ004>007-
015>017-023>028-033>039-044>050-057>062-070>075.

&&

$$

DISCUSSION...Hagenhoff
AVIATION...Jimenez