202
FXUS63 KDMX 072344
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
644 PM CDT Fri Aug 7 2026

 ...Updated for the 00z Aviation Discussion...

.KEY MESSAGES...

- Scattered thunderstorms through early this evening. A few
  severe storms remain possible.

- Mostly dry tonight into Saturday.

- Additional thunderstorm chances late Saturday night into
  Sunday.

- Active weather will persist through much of next week.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 243 PM CDT Fri Aug 7 2026

Thunderstorms are ongoing over north central Iowa in advance of a
boundary that is moving in from the northwest. MLCAPE values of 2000-
3000 J/kg along with mid-level lapse rates at 8-8.5 C/km have led to
strong initial updrafts with 65 dBZ over 20 kft occurring. The
primary storm initialization is on a pre-frontal trough that has
extended into northern Iowa from west to east. Expect much of the
activity this afternoon to remain associated with the current storm
cluster with the potential for some additional development back
west/southwest along the pre-frontal trough. These storms will
maintain a damaging wind and large hail threat through the remainder
of the afternoon as the entire system settles south/southeast. These
storms should exit south into Missouri by early this evening.

The remainder of tonight into much of Saturday is expected to be
dry. Much drier dew points will settle into the state behind the
boundary with dew point values falling into the low 50s north to low
to mid 60s south. Deep layer drying will also be occurring which
will further support the dry forecast.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 243 PM CDT Fri Aug 7 2026

Return flow begins Saturday night as high pressure moves to the
east of the state. Strong theta- e advection and an increasing
low level jet of 40-45 kts will lead to increasing instability
and thunderstorm chances.

Upper high pressure over Hudson Bay combined with upper high
pressure over the Four Corners region, will lead to progressive
westerly flow over much of the northern CONUS with periodic embedded
short waves passing across Iowa. This flow will also keep a surface
boundary in the Midwest area and resulting in several chances for
thunderstorms before Canadian high pressure arrives early next week.
PWAT values of 1.50-2.00" will be common during active storm periods
that could lead to an aggregate heavy rain threat through the week.
Temperatures will be seasonal and mainly in the 80s through midweek
the gradual cooling as the Canadian high pressure approaches for the
end of next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 644 PM CDT Fri Aug 7 2026

Lingering areas of MVFR ceilings are expected to remain over the
next few hours near and behind the passing boundary that is
over central Iowa. Storm potential largely remains near/at KOTM
before 03z, before dry conditions are expected to return for
all sites. Patchy fog is possible mainly at the eastern
terminals where residual moisture from the rain, plus light
winds and clearing skies are expected, with less confidence
further west where drier conditions are noted. Northwest winds
are expected to shift southeasterly across the forecast area
after 12-15z Saturday, with VFR conditions expected through the
remainder of the current TAF period.

&&

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

&&

$$

SHORT TERM...Donavon
LONG TERM...Donavon
AVIATION...Bury