Area Forecast Discussion
Issued by NWS Des Moines, IA

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055
FXUS63 KDMX 271802
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
102 PM CDT Mon Apr 27 2026

.KEY MESSAGES...

- Cool front sweeping eastward across the area this afternoon,
  bringing scattered thunderstorms mainly to northeastern and
  eastern sections. The overall severe weather threat has
  diminishes, but a few severe storms may still be possible with
  hail and strong winds the primary threats.

- Notably cooler weather will prevail for the remainder of the
  week beyond this afternoon. It will be breezy for a period
  later today into tonight, after which it will be generally
  quiet for several days with just sporadic light rain chances.

- The cooler weather will result in low temperatures ranging in
  the 30s to lower 40s each remaining night this week. Frost and
  freeze impacts will be dependent on wind speeds and degree of
  cloud cover each night.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 102 PM CDT Mon Apr 27 2026

A well-advertised cool front is currently making its way
eastward across central Iowa. It is accompanied by a few showers
and thunderstorms right along the boundary, but thankfully,
overnight/morning convection over Missouri has pushed the axis
of surface instability much farther south, toward the St. Louis
area, and with it the highest severe weather threat for this
afternoon. Nevertheless, a dry slot has spread into our eastern
counties today and destabilization is occurring, with SBCAPE
analyzed at around 2000 J/KG just ahead of the front. This
should allow for a lingering threat of severe weather in our
area, mostly our eastern and northeastern counties, in the form
of hail and gusty winds. The front and associated storms will
clear our eastern boundary by around 3 PM or so, but behind the
boundary strong west northwest winds are anticipated for several
hours as a relatively tight pressure gradient moves through,
with stratus also spreading into the area from Minnesota and
South Dakota. This will make for a cool, cloudy, and blustery
evening across most of Iowa.

Later tonight and Tuesday, a surface high pressure ridge will
build from the northern High Plains southeastward into Iowa,
sustaining the cooler weather and gradually diminishing north
northwesterly breezes. However, broad cyclonic flow will remain
in place aloft, with a shortwave impulse rounding the base of
the flow over Nebraska and Iowa late Tuesday into Tuesday night.
Forecast soundings indicate a near-surface dry layer, but
deepening saturation and modest forcing for ascent above that.
Several model solutions depict light, patchy QPF across our
area, mainly our southern counties around Tuesday afternoon, and
there is some chance for light showers or sprinkles if they can
penetrate the low-level dry layer without evaporating. Have
increased POPs into the 10-20% range accordingly, to get a light
rain mention, but the chance for any accumulation greater than
0.01" is spotty at best. Temperatures will fall into the mid to
upper 30s in some of our northern and western areas both tonight
and Tuesday night, however, cloud cover and organized surface
wind fields should prohibit any frost formation or impacts.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 102 PM CDT Mon Apr 27 2026

Surface high pressure will continue to dominate Iowa`s weather
from Wednesday through at least Friday night, resulting in a
continuation of cool and generally quiet conditions. However,
similar to Tuesday/Tuesday night, between Wednesday afternoon
and Thursday evening a couple more shortwave impulses will
translate through the broadly cyclonic flow aloft, providing
additional chances for light rain or sprinkles at times. A few
brief thunderstorms may even be possible around Thursday
afternoon as a more pronounced shortwave moves overhead, but
even then instability is meager and no severe or impactful
weather would be expected. For now have carried slight chance
(20%) PoPs Thursday afternoon across about the southern half of
Iowa to account for this, but kept Wednesday afternoon through
Thursday morning free of precipitation mention as confidence is
lower then. This may change in future forecast updates.
Meanwhile, temperatures are likely to fall into the mid/upper
30s across portions of the area again on Wednesday night,
Thursday night, and Friday night, and if clear skies and
light/calm winds prevail at any of those times then frost/freeze
impacts may occur. These details will be sussed out in future
forecast cycles as confidence increases.

Next weekend Iowa will remain beneath northwesterly flow aloft,
but the surface high will finally move off to our southeast and
allow for slow moderation of temperatures. By Sunday forecast
highs are in the upper 60s to lower 70s. The weather for the
weekend appears overall quiet, especially Saturday, but by
Sunday some low (20-30%) chances for rain and thunderstorms may
return.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1230 PM CDT Mon Apr 27 2026

A cool front will move across the area in the next few hours,
bringing scattered SHRA/isolated TSRA to at least northern
areas, along with winds shifting from SSW to WNW and increasing
behind the front. In addition, a large area of low ceilings
behind the front will surge into the area tonight, resulting in
widespread MVFR conditions with pockets of IFR ceilings
(FL007-010). This will improve later Tuesday morning, toward the
end of the 18Z TAF period, as the clouds slowly lift and clear
out.

&&

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

&&

$$

SHORT TERM...Lee
LONG TERM...Lee
AVIATION...Lee