936
FXUS63 KDMX 111745
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1245 PM CDT Mon Aug 11 2025

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

.KEY MESSAGES...

- Patchy fog this morning.

- A few storms possible (20-40% chance) again today into
  tonight, mainly south or southeast. Severe weather is not
  expected, but a few funnel clouds may once again be possible
  this afternoon.

- Transition to drier weather through midweek.

&&

.UPDATE...
Issued at 338 AM CDT Mon Aug 11 2025

Patchy fog has been observed in portions of western, northern, and
eastern Iowa so far early this morning with reduced visibilities at
times. Most sites that have seen fog have had visibilities bounce up
and down precluding the need, as of this issuance, for any SPS or
fog headline products with the transient nature of the fog so far
through the early morning hours. Will continue to monitor closely
through the night but any lingering fog will dissipate within a few
hours after sunrise this morning.

Otherwise, rest of forecast for today is largely on track with
scattered showers and storms returning to mainly southern Iowa from
later this morning into tonight as the low and associated boundary
driving storms over KS early this morning lifts north to northeast
towards and into the state, lingering until late tonight before
it gets pushed back southward as another boundary moves across
from the north on Tuesday. For those that even have rain/storm
chances today, it won`t be raining all day in any location,
with many areas staying dry. No severe storms are expected today
so main hazard with any storms that occur is lightning.
However, as noted below, a few funnel clouds may be possible
again this afternoon in primarily southern Iowa. Areas far
north to northwest may have some haze aloft from wildfire smoke
this afternoon into tonight but impacts at the surface seem more
minimal. Except for a few glancing showers or isolated storms
primarily east as the boundary to the north moves across on
Tuesday, forecast is mainly dry through the rest of the midweek
period with temperatures in the 80s.

&&

.DISCUSSION...
Issued at 237 PM CDT Sun Aug 10 2025

Weak surface boundary, which is still somewhat non-descript from the
morning convection disruption, is extending from near to Decorah and
through the Des Moines metro and the to the southeast of
Omaha/Council Bluffs. A remnant MCV is also moving into central Iowa
from the overnight convection and the combination of the MCV and the
boundary have led to conditions favorable for a few funnel clouds
associated new updrafts with near surface vorticity, light winds and
sufficient 0-3 km CAPE for stretch the vorticity vertically. The
potential for actual tornadoes to occur is low. We have a Special
Weather Statement out for funnel potential. Otherwise, the threat
for heavy rainfall that could produce flash flooding has diminished
therefore, the Flash Flood Watch has been cancelled.

The showers and storms will gradually move off the east and south
this evening and overnight and will lead to a mostly dry period. A
few showers and storms are possible on Monday, especially south as
weak instability lingers. There is a window for more funnel
potential in the afternoon similar to today, over southern Iowa.
Iowa will be in the long wave trough Monday night and transition to
northwest flow Tuesday. This will lead to drier conditions but also
will bring the potential for more wildfire smoke to move over the
state, especially over northern Iowa. The northwest flow will begin
to relax and transition to zonal flow on Wednesday then 500 mb
height rises occur for the end of the week as sub-tropical high
pressure becomes re-established into Gulf Coast region. It is
possible northern Iowa gets caught in the ring of fire MCS tracks
late in the week and into the weekend. Otherwise, typical summer
weather with highs in the mid 80s to low 90s and humid.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1241 PM CDT Mon Aug 11 2025

Band of precipitation in southern Iowa is lifting northward but
is expected to continue a weakening trend this afternoon. Light
rain could reach KDSM but not anticipating and restrictions
associated with the light rain. A great chance for
thunderstorms arrives this evening and overnight with KDSM/KOTM
having the greatest potential to be impacted. MVFR cigs may also
develop as well in those areas which may linger into Tuesday
morning. The wind will remain light through much of the period
though thunderstorm outflow may bring gusts overnight.

&&

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

&&

$$

UPDATE...05
DISCUSSION...Donavon
AVIATION...Donavon