645
FXUS63 KDMX 042030
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
230 PM CST Tue Nov 4 2025

.KEY MESSAGES...

- Breezy northwest wind gusting 25-35+ mph Wednesday morning
  into afternoon. Continued breezy conditions Thursday through
  the rest of the week, varying in direction each day.

- Robust system Friday through the weekend will bring much
  colder air into the area, along with the potential for rain
  and snow on Saturday.

&&

.DISCUSSION...
Issued at 230 PM CST Tue Nov 4 2025

Surface low pressure is centered west of the area over Nebraska and
South Dakota early this afternoon. This orientation has placed Iowa
in the warm sector with southerly flow into the area, pushing
temperatures back through the 60s this afternoon. Dry low levels
have allowed for deeper afternoon mixing and gusts of 20-25 mph have
been common at sites across the area. As the low pressure passes
north of the area and continues east, a cold front will sweep across
the Iowa overnight and through Wednesday. Winds will shift to out of
the northwest with the passage and increase with a 6-12 hour
window for breezier northwest winds as this occurs, beginning
very early Wednesday morning. The combination of a tightening
pressure gradient, subsidence, and strong cold air advection
into the area will result in gusts of 25-35+ mph through the
morning. By afternoon high pressure will shift into the area,
helping to diminish the winds later in the day. With the cold
air advection into the area, temperatures on Wednesday will be
about 10 degrees cooler than today, in the 50s.

Breezy conditions remain the theme of the week with several waves
across the area. Next up will be a wave passing north of the area on
Thursday, with southerly flow within the warm sector. This will push
temperatures a few degrees warm on Thursday compared to Wednesday.
At the same time, another day with deeper mixing will result in
breezy southerly flow around 20-25 mph across the area. That surface
low passing north of the area will deepen as it moves east, tapping
into gulf moisture Thursday night into Friday morning with the
trailing cold front. Current trajectory has this phasing occurring
across eastern Iowa and moreso Illinois. This may allow for light
rain to clip eastern portions of the area as the system shifts east.
Precipitation clears out Friday morning, leaving the rest of the day
dry. Model soundings show quickly drying low levels in place on
Friday, allowing for yet another day of deep mixing and breezy
northwest winds behind the system gusting 20-25 mph.

By Friday late afternoon to evening another lobe of vorticity
rotates across the area, pulling a first push of cooler air into the
area overnight. Overnight the robust low drops out of Montana and
into the midwest, reaching Iowa on Saturday morning. As it moves
across the area expect strong cold air advection with
temperatures likely falling through the day. Current model
tracks place the surface low moving south of the area and the
deformation zone with band of precipitation across Iowa. What
kind of precipitation? Rain. Snow. Both. The number of GFS and
Euro ensemble members with snow have increased from yesterday
to day, helping to nudge up confidence in accumulating snow on
Saturday. Expect that there will likely be a transition from
snow to rain then back to snow through the day. Timing and
speed of the cold front will influence those precipitation types
and the subsequent amounts of each. Exact amounts are uncertain
at this time, as is the placement of the band of any potential
snow that may fall on Saturday. Note that the 12z GFS and 06z EC
were in good timing agreement, though the is 12z EC faster.
While uncertainty in the details remains, confidence is
increasing in a rain/snow mix across Iowa on Saturday with a
band of accumulating snow possible somewhere across the
northern half of the state. Details will be refined over the
next several days. It is also clear that temperatures fall of
behind the system with highs in the 30s Sunday and perhaps
cracking 40 degrees again by next Monday. Anyone with outdoor
plans this weekend should monitor for changes to the forecast.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1125 AM CST Tue Nov 4 2025

VFR conditions will prevail through the period. Breezy south to
southeast winds this afternoon will gust to around 20 kts before
diminishing at sunset. Then overnight winds will shift to out of
the northwest, becoming breezy again. The area of strongest
winds will move across the area from northwest to southeast
through the early morning into afternoon. Winds increase with
gusts over 20 kts between 06-09z, with gusts of 25-30+ kts
beginning 12-15z. Gusts will taper off through the afternoon
beyond the current TAF period.

&&

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

&&

$$

DISCUSSION...Hagenhoff
AVIATION...Hagenhoff