339
FXUS63 KDMX 051735
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1135 AM CST Thu Nov 5 2026

 ...Updated for the 18z Aviation Discussion...

.KEY MESSAGES...

- Cloudy today. Breezy with patches of drizzle in the morning,
  then diminishing winds and dry conditions later today.

- Generally cool and mostly cloudy conditions persist into
  Friday, then some clearing and a steady warming trend from the
  weekend into early next week.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 202 AM CST Thu Nov 5 2026

A large gyre centered over Wisconsin and far northeastern Iowa
is gradually pushing eastward this morning as it is swept out by
a trough moving across Hudson Bay and Ontario. A large stratus
shield surrounding the gyre blankets all of Iowa and neighboring
states, with its western and southern edges currently from
extreme southeastern South Dakota, down across far eastern
Nebraska, and over to far northern Missouri. Meanwhile, a
surface trough is moving southeastward through Iowa, and behind
it modestly gusting northwest winds are pushing in. The
temperature is not falling much, however, due to the thick cloud
cover in place. A few pockets of drizzle also continue to move
through, but are steadily fading out as the gyre begins to
depart.

A surface ridge will later build down the region later today and
tonight, lying right over Iowa on Friday and bringing lighter
and eventually calm winds to end the week. The primary forecast
challenge is determining how long the low cloud cover will
persist, as that will significantly impact temperatures over the
next couple of days. Satellite imagery currently shows the large
stratus shield over Iowa is barely moving. Some of the global
models, primarily the GFS, indicate the clouds will gradually
move out tonight (that is, Thursday night) as the trough departs
and the ridge builds in. However, these solutions are not
realizing that there is currently an even larger low stratus
field spilling rapidly from southern Canada into the northern
High Plains within the surface ridge. The high-res solutions are
picking up on this, as these clouds will arrive in our area
later today and reinforce/enlarge the stratus shield across the
region. The 06Z HRRR, in particular, is very well initialized
with current cloud cover and blankets the entire region in low
ceilings through the end of its run Friday night. There are some
indications of breaks at times, especially in northeastern Iowa
late Friday, but overall it is likely cloudy conditions will
prevail for the next couple of days. This is also supported by
forecast soundings, such as the RRFS which depicts a persistent
shallow saturated layer right into Saturday morning. In light of
this trend, have maintained high temperatures today on the
cooler side of guidance, but the practice of lowering daytime
highs and warming overnight lows may need to extend through
Friday night as we continue to assess the cloud potential.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 202 AM CST Thu Nov 5 2026

By Saturday morning the old gyre covering the region early this
morning will have moved into the northeastern U.S., while a
compact but energetic 500 MB shortwave on its heels crosses
near the Minnesota/Canada border and another lobe deepens near
the Arizona/Mexico border. A weak mid-level trough stretching
between these systems will move overhead will help push the
surface ridge lying over the region early Saturday
southeastward, bringing a brief return of southerly flow to our
forecast area. Forecast soundings also indicate the departure of
the ridge may finally clear the low cloud shield out, as
discussed in the short term section above. Thereafter, Iowa will
enter a west northwesterly steering flow regime in the first
half of next week, generally supporting dry weather with a
series of rapid and weak surface troughs and ridges and steady
airmass modification. By early next week, on any days where
there is sunshine and southerly flow ahead of an approaching
trough, temperatures may rebound well into the 60s before being
moderated again.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1132 AM CST Thu Nov 5 2026

IFR to MVFR conditions are still prevailing across much of
Central Iowa as stratus continues to build in behind a departing
surface low. While there`s breaks in the clouds leading to VFR
observations, the widespread cloud deck is IFR to MVFR. Gradual
improvement is expected toward the end of the TAF window where
VFR conditions could be achieved as surface high pressure builds
into the region. Winds are forecast to remain strong out of the
north-northwest before diminishing toward the overnight.

&&

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

&&

$$

SHORT TERM...Lee
LONG TERM...Lee
AVIATION...Vorst