304
FXUS63 KDMX 241153
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
653 AM CDT Fri Jul 24 2026

 ...Updated for the 12z Aviation Discussion...

.KEY MESSAGES...

- Light rain passing through central Iowa on Friday. Last
  pleasant day for quite some time.

- Dangerous heat builds in over the weekend with a heat advisory
  issued for Saturday. Extreme Heat Watch issued Sunday through
  Monday.

- Additional showers and storms are possible later this weekend
  into early next week, with some potential for severe weather.
  Timing and location will be better determined in the coming
  days.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 149 AM CDT Fri Jul 24 2026


Make sure you get out and enjoy Friday, as it will be the last day
with comfortable temperatures for quite some time. As we kick off
Friday morning, light showers will continue to spread across
northern Iowa, with temperatures sitting in the mid-60s.
Showers will continue to drift to the south as we progress
through the morning. We will maintain precipitation chances
along the Iowa/Missouri border through sunset tonight. Highs on
Friday will top out in the mid to upper 70s under a mostly
cloudy sky. Rain will eventually move out and ridging begins to
build in, ending our pleasant streak of beautiful days.
Summertime heat looks to return starting on Saturday, and it
will return with a vengeance.

Ensemble guidance gives a strong signal that dangerous heat is
building in on Saturday. With persistent southerly flow and
crops in peak evapotranspiration, dew points will have no
trouble climbing into the mid 70s and perhaps at times reaching
the upper 70s over the weekend. Temperatures are expected to
climb into the upper 80s to lower 90s across the state. The
highest confidence for highs in the 90s will be over the western
half of the state on Saturday, as we mix down some of those
warmer temperatures to the west. For this reason, a heat
advisory has been issued for the western and central parts of
Iowa Saturday, as heat indices will push the 105 mark in several
spots. Reasons for keeping it out of the eastern half of the
area include:
first, we won`t have as warm of temperatures to mix down; and
second, guidance hints at smoke returning to central Iowa on
Saturday, which may play a small factor in keeping highs
slightly lower and preventing higher heat index values.

With dew points and hot temperatures, our atmosphere will be very
unstable. However, 850 mb temperatures of 20 degrees celsius or
higher will put much of central Iowa under a strong cap. If storms
manage to fire along the thermal ridge to the east, there will be
enough energy to produce a few strong storms, but the capping should
generally hold over our area. Given the conditional for severe
storms, a marginal risk has been issued over far northeast Iowa.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 240 PM CDT Thu Jul 23 2026

As the thermal ridge nudges further eastward into the weekend and
early next work week, a stronger push of low-level southwesterly
flow will bring warmer and more humid air into the Central Plains.
This pattern shift will allow for temperatures to rise significantly
with values through the 90s, especially Sunday and Monday. Dewpoint
values topping out through the 70s, paired with these temperatures,
will lead to heat index values near 100-105+ degrees over western
Iowa Saturday, and much of the area Sunday and Monday. The upper
level northwesterly flow into Iowa though in relation to the closer
proximity of the thermal ridge will also introduce additional
chances for showers and thunderstorms, particularly into Sunday
morning and again late Sunday into Monday. Smoke also could limit
highs a bit Saturday as guidance suggests a return through the day.
All important things to watch over the coming days, but at least in
terms in heat headlines, the potential is certainly there for some
areas of Central Iowa. The warm and moist airmass Sunday through
early next week will bring about to a substantial increase in
instability and favorable shear profiles to reintroduce severe
weather potential as various shortwaves round this ridge into
the Midwest. At this time, guidance suggests, as mentioned
earlier in this paragraph, early Sunday morning and especially
late Sunday into Monday morning with the increasing LLJ into
Iowa to be possible targets for some potential severe weather,
with the SPC highlighting north/northeast Iowa in a 15% risk.
Will keep a close eye on this over the coming days as details
become more clear. The thermal ridge by midweek next week moves
very little, with Iowa still in the ring of fire as additional
waves are indicated in long term guidance to pass through,
keeping the pattern more on the active side.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 639 AM CDT Fri Jul 24 2026

Light showers are pushing through central Iowa this morning
impacting KFOD, KDSM, and KOTM terminals. Showers will begin to
clear over the next couple of hours at these terminal sites.
Clouds will begin to thicken this afternoon and ceilings will
drop across all terminal sites. KDSM and KOTM will see ceilings
drop to MVFR restrictions around 20z. Clouds will continue to
lower tonight into early tomorrow morning. Confidence is high
that all terminal sites will hit IFR restrictions around 06z.
LIFR will be possible, but confidence is not high enough to
introduce it at this time.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon Saturday to noon CDT Sunday for
IAZ004>006-015-016-023>025-033>036-044>048-057>060-070>073-081-
082-092-093.
Extreme Heat Watch from Sunday afternoon through Monday
evening for IAZ004>007-015>017-023>028-033>039-044>050-057>062-
070>075-081>086-092>097.

&&

$$

SHORT TERM...TDR
LONG TERM...Bury
AVIATION...TDR