454
FXUS63 KDMX 100509
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1109 PM CST Sun Nov 9 2025

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

.KEY MESSAGES...

- Breezy this afternoon, with north northwest winds gusting to
  30-35 MPH, before diminishing this evening. A few lingering
  flurries, with a chance of snow showers in eastern Iowa.

- Dry and quiet from Monday through Friday, with steadily
  warming temperatures reaching the 60s by late in the week.

&&

.DISCUSSION...
Issued at 153 PM CST Sun Nov 9 2025

An elongated 500 MB trough currently stretches from just east
of Hudson Bay down to Wisconsin, with one lobe of vorticity
rounding its southwestern lobe over extreme eastern Iowa and
adjacent Wisconsin/Illinois tonight. At the surface, the low
pressure center that crossed our region yesterday has moved
eastward into the Great Lakes, while a ridge of high pressure
is building down the Dakotas and High Plains this afternoon.
The pressure gradient between these two systems is producing
breezy north northwest winds across Iowa, augmented by cold air
advection enhanced by the approach of the aforementioned mid-
level trough. Wind gusts to 30-35 MPH will be the norm for
a couple more hours before winds gradually abate this evening
and tonight. Meanwhile, satellite imagery depicts areas of low
stratocumulus clouds moving southward from Minnesota, with a
few sites are reporting associated flurries. The cloud depth is
shallow without much moisture indicated by soundings, so no
accumulation is anticipated and will maintain isolated flurries
in the forecast accordingly. This evening into early tonight,
as the lobe of vorticity aloft swings by near the eastern Iowa
border, several short-range models do show the development of
weak instability and higher potential for brief relatively
intense snow showers, however, all indications are that this
potential will remain just east of our forecast area. We will be
monitoring in case any such snow showers do impact our eastern
counties, but even then no real accumulation would be
anticipated and the primary sensible effects would be briefly
reduced visibility. One other fly in the ointment for tonight`s
forecast is temperatures. The northwestern sections of our
service area have fresh snow cover on the ground and winds will
be diminishing overnight, with is a classic setup for
temperatures bombing after sunset. However, this potential will
be mitigated by at least intermittent cloud cover as well as the
fact that while winds will be lighter overnight, they will still
be organized and not calm. Nevertheless, have taken forecast
hourly and minimum temperatures down a couple of degrees over
the snow pack to account for potentially more efficient
radiational cooling.

On Monday the 500 MB trough will begin to move away eastward,
placing Iowa beneath generally west northwesterly steering flow for
most of the coming week. With the High Plains surface ridge
translating eastward over the Midwest on Monday it will remain cool,
but with much lighter winds and mostly sunny skies. Thereafter, the
ensuing synoptic pattern will lend itself to alternating periods of
brief surface ridging/troughs, with steadily moderating temperatures
and little to no chance for additional precipitation. By the end of
the week many areas will see highs in the 60s. However, on Friday a
deep 500 MB trough will be digging over the western U.S.,
subsequently migrating eastward, and will likely bring a return of
precipitation chances sometime around the end of the week or next
weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1050 PM CST Sun Nov 9 2025

Pesky marginal MVFR CIGS persist for portions of the state at
this hour. These will continue to be possible at KDSM and KOTM
for the first hour of this TAF cycle before lifting. Elsewhere
cloud decks have been above the 3000 feet VFR threshold. Northwest
winds will gradually lessen into Monday, before becoming more
westerly, then southwesterly towards the end of the TAF cycle.

&&

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

&&

$$

DISCUSSION...Lee
AVIATION...Hahn