Ankeny, Iowa 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

644
FXUS63 KDMX 250850
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
250 AM CST Thu Dec 25 2025

.KEY MESSAGES...

- Foggy Christmas morning with some visibility improvement,
  though fog may linger in portions of western Iowa through
  much of today. Widespread fog tonight with a 60% chance of
  dense fog over northwest into parts of north central Iowa.

- Cloudy, mild with drizzle possible at times today and tonight.

- Turning much colder with stronger, gusty winds and snow
  showers developing on Sunday as a cold front blasts through
  the state.

&&

.DISCUSSION...
Issued at 250 AM CST Thu Dec 25 2025

Merry Christmas! It is a foggy Christmas morning across much of
the state with visibilities generally lowest at or under a mile
over the western half of the state with 1 to 2 miles over
eastern Iowa. The stratus is likely aiding in mitigating more
widespread dense fog (<1/4 mile visibility). In addition, light
northeasterly surface winds are ushering in lower dewpoints and
the question becomes how much and where does this aid visibility
improvements. Latest guidance would suggest our far eastern
forecast area along roughly Highway 63 and more so points east
would have improvements toward or after sunrise and may need to
end the current advisory early in those areas. Farther west, the
denser fog may persist and will be assessing extending the
advisory for areas over central Iowa, particularly west of
roughly I-35 in the coming hours. It is possible that a portion
of northwest or north central Iowa will not remain quite foggy
so will monitor trends for further extension in time today.

Outside of the fog, low level saturation will persist meaning our
stratus clouds will as well. The moisture depth is generally below a
1km through much of this morning; however, that looks to change as
isentropic lift returns increasing the moisture depth starting later
this afternoon into this evening. Thus, have added patchy drizzle in
this time frame along with a buffer of several hours on either side.
It will also be mild today and have continued to adjust temperatures
away from the initial National Blend of Models (NBM) to the 25th
percentile for highs and the 75th for lows lessening the overall
diurnal range in this cloudy, dreary pattern. Whatever fog does not
dissipate during the day will return tonight and likely be
widespread into the daylight hours of Friday morning. The biggest
question is whether it will necessitate a dense fog advisory with
the stratus not going anywhere either. The latest HREF places 60%
chance of visibilities below a quarter mile roughly along and north
of Highway 20 over much of northwest into parts of north central
Iowa.

Friday will offer some brighter skies, but just to southwest Iowa as
the low level inversion remains in place along with the moisture
beneath it. Whatever sunshine is seen on Friday will likely be gone
by Saturday as the inversion remains in place and the next round of
isentropic lift moves into the state. Conditions will remain mild
Friday and Saturday, but may need to shrink diurnal ranges similar
to as was done on Christmas Eve and Christmas Day/yesterday and
today in areas that will remain cloudy, especially on Saturday. Will
also have to keep an eye on fog potential for Friday night and
Saturday morning, though winds do increase slightly overnight from
around or under 5 mph to 5 to 10 mph by sunrise Saturday.

A big pattern change will occur as an amplified, sharp shortwave
trough moves from the West Coast Friday night and through the state
Sunday night. This trough will send a potent cold front through the
state bringing much colder air, especially after this mild stretch,
along with increasing winds. High temperatures Saturday to Sunday
will be 15 to 25 degrees lower. The winds from the northwest may
reach advisory levels later Sunday with forecast soundings showing
top of mixed layer winds near 40 knots/45 mph. As has been discussed
the last few days, deterministic and ensemble guidance has pointed
to at least some light QPF on Sunday and the NBM has finally caught
onto this trend. This will likely be in the form of snow showers,
which combined with the gusty winds could make for tricky post-
Christmas travel on Sunday. Monday and Tuesday mornings will be cold
with single digits to around 10 degrees above zero for lows over
northern Iowa, but conditions will moderate back to seasonal levels
for the final days of 2025.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1041 PM CST Wed Dec 24 2025

Widespread dense fog is expected to prevail across all
terminals, with visibilities down to 1/4 mile or less at times
at least through 12-15z before improving for a short time. Low
clouds however are expected to remain throughout much of the
forecast period, keeping IFR/LIFR conditions before fog once
again develops later Thursday afternoon to evening. Winds remain
light through Thursday, increasing slightly up to 10 knots from
the southeast by the afternoon into the evening. These winds do
introduce some uncertainty in the extent of fog towards the end
of the period, so have included mentions directly at the
terminals but kept from mentions of dense fog at this time, and
will continue to assess and update as needed.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM CST this morning for IAZ004>007-
015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097.

&&

$$

DISCUSSION...Ansorge
AVIATION...Bury