936
FXUS63 KDMX 031752
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1152 AM CST Tue Mar 3 2026

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

.KEY MESSAGES...

- Light rain and drizzle at times from later today through
  Wednesday, mainly in southern Iowa. Little accumulation or
  impact during this time.

- Warming through the week, with thunderstorm chances arriving
  Thursday night into Friday.

&&

.UPDATE...
Issued at 208 AM CST Tue Mar 3 2026

Light rain has fallen across northern Iowa overnight as
anticipated, with air and road temperatures remaining at or
just above freezing and preventing any ice accumulation. The
rain will gradually depart to the east this morning, but skies
will remain mostly cloudy with stratus currently covering most
of the region and have nudged high temperatures down just a tad
today. There is still some potential for drizzle indicated by
forecast soundings in southern Iowa during the day, however it
will be fighting lingering dry air layers in the column that
have so far been winning for the most part the last couple of
days, so have limited POPs to only 30-40% for drizzle in our
southern counties, with no real accumulation or impact.

Tonight a band of frontogenetical forcing will enhance prospects
for light rain across northern Missouri and into southern Iowa
once again. Most model output keeps this potential in Missouri
however, or just scraping our southern counties, with only the
NAM depicting a farther north solution where rain gets up to
around Highway 30. With some modest support for little drizzle
have maintained at least 20% POPs up to near Highway 20, but
shunted higher (40%+) POPs south of I-80 overnight. In any
event, temperatures should remain above freezing where any
drizzle or light rain falls and no impacts are anticipated. With
skies expected to remain mostly cloudy to cloudy tonight, at
least outside of our northern counties, have bumped low
temperatures up just a bit.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 256 PM CST Mon Mar 2 2026

The stratus has been scattering over southwest into central Iowa
this afternoon. The scattering and thinning of the stratus is
beginning to expand into eastern Iowa as well. A more pronounced
area of stratus extends from Kansas to the Ohio Valley and it is
this area of clouds that will lift northward overnight as return
flow increases later tonight into Tuesday. Surface cyclogenesis is
ongoing over eastern Colorado and north along the lee side of the
Rockies. It is this system will lift a warm front north from Texas.
An area of precipitation is beginning to develop over southern South
Dakota and northern Nebraska. Cloud bases in that region remain AOA
6 kft and much of the precipitation is evaporating prior to reaching
the surface. The forcing associated with this system as it moves
east, will move across northern Iowa tonight. A few deterministic
models are trying to saturate profiles over northern Iowa but given
the stratus clearing ongoing and mainly a Pacific moisture source,
this is likely overdone. A few solutions suggest a seeder/feeder
setup with the mid-level cloud based hydrometeors feeding stratus
below. Again, the the stratus field has been eroding and it may not
fill in again until the Missouri stratus lifts north. Expect some
liquid precipitation to occur over northern Iowa. At this time, the
primary precipitation type looks to be rain as higher dew points
continue to advect northward along with a warming low level profile.
Any precipitation amounts should be light and will continue to
monitor for any icing potential should temperatures remain cooler
than expected. Areas of drizzle may develop with the stratus
advancement northward as some weak vertical ascent develops at times
late tonight and into Tuesday. The stratus steering flow turns from
southerly to northeasterly during the afternoon. That will likely
keep cloud skies over central and southern Iowa therefore have
cooled high temperatures.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 256 PM CST Mon Mar 2 2026

The broad westerly upper level flow will persist through much of the
week with one open upper level system passing through Wednesday and
Wednesday night. This system will bring precipitation chances to
southeast Iowa and it may include isolated thunderstorms. The main
system to monitor remains the system at the end of the week. Strong
Gulf flow lifting north may bring dew points into the low 60s
into southern Iowa by Friday. This system may bring elevated
storms across the state Thursday night into Friday morning. Will
continue to monitor storm potential and details.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1152 AM CST Tue Mar 3 2026

MVFR and IFR conditions will prevail at all terminals throughout
the period. Guidance shows a potential brief window for some
VFR clearing over MCW and ALO, but confidence is low in duration
of any clearing. At ALO, fog is expected tomorrow morning with
other sites remaining largely free of fog, thus have removed the
mention at MCW. Trends for fog will be monitored with later TAF
issuances. Tomorrow morning into the afternoon there is a
potential for drizzle at OTM. Confidence in the northern extent
of drizzle currently hinders its probabilities.

&&

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

&&

$$

UPDATE...Lee
SHORT TERM...Donavon
LONG TERM...Donavon
AVIATION...Rotter/Ansorge