Area Forecast Discussion
Issued by NWS Des Moines, IA

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010
FXUS63 KDMX 271115
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
615 AM CDT Mon Jul 27 2026

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

.KEY MESSAGES...

- Dangerously hot conditions persist through Monday.

- Strong to severe storms are still possible Monday morning but
  confidence remains low.

- Slightly less warm and humid conditions are expected Tuesday
through mid to late work week, with largely dry weather  expected
until Thursday/Friday.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 250 AM CDT Mon Jul 27 2026

We are in the waiting game as guidance continues to suggest
convection is still possible through early this morning. The
environment is highly unstable across all of central Iowa but a
very strong H850 cap is limiting any storm ignition. Something
to watch overnight will be a low level jet that begins to ramp
up and push into us from the west. This could provide just
enough lift to fire storms and with how unstable the environment
will be, a few storms could be strong to severe. The primary
concerns will be damaging winds and some hail.

Otherwise, the main story is going to be another round of dangerous
heat across central Iowa. Another day with heat indices near 110F
are expected. One thing to keep an eye on as we head into the late
morning hours will be a boundary that forms in northern Iowa.
Moisture pooling ahead of the boundary will push dew points well
into the mid to upper 70s. The combination of highs in the mid to
upper 90s and high dew points will push heat indicies over 110
across central Iowa during peak heating. An Extreme Heat Warning
will be in effect for most of central Iowa while in portions of
northwest Iowa will be under a heat advisory. Heat indices are only
expected to climb into the mid to upper 90`s in northwest Iowa as
dry air gets ushered in behind the boundary. As the boundary tracks
farther south into Iowa through the afternoon, showers and storms
will be possible along it. However, once again a strong cap will be
in place, potentially inhibiting widespread convection.

Monday night into Tuesday will have another potential for showers
and storms across western Iowa. A shortwave disturbance will help
initiate storms across central Nebraska. Confidence is low that
storms will be able to sustained themselves as they will enter
a low shear and low instability environment. As of right now,
have kept the forecast dry.

High pressure starts to build in on Tuesday which will drop out dew
points along with our high temperatures. Highs are expected to
top out in the upper 80s with dew points in the upper 60s to low
70s ending our stretch of dangerous heat!

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 247 PM CDT Sun Jul 26 2026

While another weak wave could bring another low potential for
rain in the western Central Plains Wednesday morning, a more
potent wave is signaled to descend on the eastern fringe of the
upper western ridge in the late work week, bringing some
potential for more widespread shower and storm activity then.
Specific details will be better known in the coming days as more
data becomes available from additional model members.
Temperatures look to trend cooler into next weekend, with
average highs in the low to mid 80s and dewpoints in the 60s,
which will be a welcome break from the previous heat.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 607 AM CDT Mon Jul 27 2026

VFR conditions to prevail through the end of this TAF period.
Winds today will shift from a southwest flow to more of a
northerly flow by this afternoon. A boundary will slide through
causing the wind shift as well as a slim shower or storm chance
in southern Iowa but confidence is too low to issue prob30
groups at this time. Behind this boundary smoke from Canadian
wildfires will also spread in and could reduce visibility at
times, especially at the northern terminals. Have maintained 6SM
FU groups at all sites accordingly, and will continue to assess
the potential for any reductions below 6SM to see if this needs
to be adjusted in later TAF updates.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 10 PM CDT this evening for IAZ004>007-
015>017-023>026-033-044.
Extreme Heat Warning until 10 PM CDT this evening for IAZ027-
028-034>039-045>050-057>062-070>075-081>086-092>097.

&&

$$

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