551
FXUS63 KDMX 190450
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1050 PM CST Tue Nov 18 2025

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

.KEY MESSAGES...

- Cloudy conditions with a light mist/fog persists today into
  tonight.

- Mostly cloudy skies on Wednesday, with temperatures warming
  through Thursday.

- Rain chances in far southern Iowa Thursday night into Friday,
  although guidance continues to trend drier for Iowa.

&&

.DISCUSSION...
Issued at 243 PM CST Tue Nov 18 2025

The main wave that brought rain and thunderstorms to the area last
night has all but departed the area this afternoon, leaving stratus
and some drizzle/mist in it`s wake. Some areas in southern Iowa have
managed to remain clear through the morning, but the persistent
stratus deck continues to leak southward and will eventually span
much of the area. High pressure is filling in behind the wave
tonight, keeping winds light and temperatures cool. Additional fog
development will be possible with the light winds and moist
conditions, but the stout cloud deck will work to negate radiational
cooling. For this reason, not expecting significant fog development,
barring any unexpected breaks in the cloud deck.

Surface high pressure continues to dominate the pattern on Wednesday
morning, but return flow on the back side of the high will flip
winds to more southerly during the day. This will bring warmer
temperatures up into the area, and begin to push out the stratus
from the southwest. Unfortunately, this will be a slow process,
keeping conditions cloudy for most of the area through the day
Wednesday. Skies will clear out some on Thursday morning, with
temperatures warming into the 50s to near 60.

Flow will steadily flip to more northerly on Thursday as a weak
boundary is pulled through the area by the northern stream trough
passing through Canada. This wave will be well displaced from Iowa,
but will still manage to pull cooler, drier air into the state
through the end of the week. This will have implications on the
precipitation forecast late in the week, as guidance continues to
trend drier for Thursday night into Friday. Due to the presence of
the northern stream wave and associated high pressure, the southern
stream wave and precipitation is struggling to lift up into the
state, keeping most of the rain chances south of the area. NBM
continues to lag behind this trend, still bringing at least low end
rain chances up to highway 80 corridor. This is likely overdone,
with the greatest likelihood for rainfall being along the
Iowa/Missouri border and south.

Another northern stream wave will eventually pass through the area
over the weekend, boosting temperatures into the 50s through the
weekend and into early next week. More rain chances could return by
Monday but it`s still too far out to get attached to any one
solution.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1049 PM CST Tue Nov 18 2025

Widespread low stratus will remain overhead through the morning
and into the afternoon across the terminals, which will result
in continued IFR and even LIFR categories for the next several
hours. These conditions are being amplified by increasing
patchy to localized dense fog covering much of central Iowa,
where visibilities down to 1-3 miles may occur at times, with
highest chances over northern Iowa through the morning before
gradually dissipating. Isolated drizzle may also occur at times
early on given the abundance of low level saturation along with
low cloud bases. Due to uncertainty on the overall timing and
coverage of the lower visibilities due to fog, and at times
drizzle potential, amendments are expected at times as
conditions evolve. Otherwise, winds will be light through the
period, gradually turning southerly later in the day.

&&

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

&&

$$

DISCUSSION...Dodson
AVIATION...Bury