807
FXUS63 KDMX 271009
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
409 AM CST Thu Nov 27 2025

.KEY MESSAGES...

- Cold and dry conditions through Thanksgiving and the first
  half of Friday.

- Snow moves into the area Friday late afternoon and evening,
  continuing through Saturday before tapering off overnight
  Saturday. Widespread impactful snow is expected with travel
  impacts likely this weekend.

- Bitter cold settles in Sunday and early next week with highs
  in the teens to low 20s and lows in the single digits to
  near/below 0 degrees.

&&

.DISCUSSION...
Issued at 408 AM CST Thu Nov 27 2025

A quiet but chilly day is in store for Thanksgiving today as high
pressure remains over the region. High temperatures today are
expected to top out in the upper 20s north to mid 30s south, with
partly to mostly sunny skies and slightly breezy winds gusting to 20-
25 mph out of the northwest.

While Friday starts out dry and quiet, a mid-level trough and
associated system is still on track to pass southeastward out of the
northwestern CONUS and into the Central Plains by Friday evening
into the start of weekend. Moderate warm air advection ahead of this
system along with a rather strong push of mid and low-level moisture
is expected into Iowa Friday afternoon and especially by the evening
into Saturday morning, paired with favorable forcing for efficient
lift over the area. This will result in increasing snow chances (70-
90%) Friday evening into Saturday from west to east, becoming
widespread across Iowa Saturday where highest probabilities are
expected (90-100%). By Saturday, the deformation zone along with a
band of frontogenetical forcing is expected to setup over Iowa,
while deepening of the surface low occurs just to the east. In terms
of latest trends, the shift of the system southward per the most
recent guidance continues to push the rain-snow line further south,
now near the IA/MO border if not just beyond this. However,
particularly over southwest Iowa, a rather deep isothermal
layer near to just above freezing has introduced the potential
for freezing rain and therefore a minor ice accumulation
possibility, so this change is reflected in the current
forecast. The southward shift in this system also means that
overall probabilities for higher snowfall accumulations have
also shifted southward. More specifically, ensemble guidance now
has all of Iowa in a 50% chance or higher of 4 inches or more
over, with similar probabilities for all areas except far
southeast Iowa for 6+ inches. The highest chances (>90%)
generally remain north of I-80 as of this morning. As the
overall confidence on widespread significant accumulating snow
continues to grow as the event nears, coordination with
surrounding offices has led to the issuance of a Winter Storm
Watch across the entire CWA, starting Friday evening all the way
through early Sunday. Significant travel impacts will occur
with these forecast snow amounts, so please be extra cautions
and consider altering any travel plans as widespread hazardous
conditions are likely.

As the system slowly departs late Saturday and especially Sunday
morning, snowfall is expected to gradually diminish, though
lingering travel impacts are expected to remain given these snowfall
amounts and resulting snow cleanup. High pressure out of Canada will
arrive following this departing system, which will bring an even
colder airmass with it, resulting in frigid temperatures through
early next week as highs are expected in the teens to 20s, while
lows fall in the single digits and even near to below zero in
northern Iowa.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1042 PM CST Wed Nov 26 2025

MVFR stratus has become more expansive than any guidance would
have indicated impacting MCW and ALO as forecast, but it did
expand far enough as FOD. Have continued using more
observational trends for the forecast, which would suggest
clearing by before sunrise at MCW and ALO. For FOD, there is an
upstream area of stratus feeding down that may keep restrictions
past sunrise, but confidence is medium at best. While there
could be another brief period of MVFR ceilings at MCW or ALO
toward midday on Thanksgiving Day, confidence is too low to
include at this time. DSM and OTM will have VFR conditions
through the period. After diminishing tonight, winds from the
northwest will become breezy in the afternoon before
diminishing in the evening.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Friday evening through late Saturday
night for IAZ004>007-015>017-023>028-033>039-044>050-057>062-
070>075-081>086-092>097.

&&

$$

DISCUSSION...Bury
AVIATION...Ansorge