901
FXUS63 KDMX 020832
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
332 AM CDT Sat May 2 2026

.KEY MESSAGES...

- Frost and Freeze headlines remain through sunrise this
  morning, then improving temperatures in the low to mid 60s.

- Light shower activity possible in northeast half of Iowa late
  tonight into Sunday morning. Dry the remainder of the day.

- Increasing potential for showers and storms later Monday,
  with isolated strong/severe storms possible south into the
  evening.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 332 AM CDT Sat May 2 2026

A quiet but chilly early morning is panning out largely as expected,
with much of the area under clear skies and light winds, leading to
efficient radiational cooling and temperatures plummeting into the
30s. Values are coldest over northern to central Iowa in the 32-36
degree range. Clouds that were overhead the state yesterday are
still lingering over southeastern Iowa though, which has led to
temperatures much warmer yet in the 40s. Despite this, the
expectation is that these stubborn clouds should slowly track
southeast out of the area over the next hour or so, allowing for
temperatures to drop rather quickly into the 30s before sunrise
occurs. Therefore have made no change to current frost/freeze
headlines this morning, which will remain in effect until 8am. Winds
shift westerly into this afternoon as the area of surface high
pressure centered over eastern Nebraska shifts south out of the area
through the day, with mostly sunny skies through the afternoon that
will lead to warming temperatures in the low to mid 60s. Surface
winds shift further southwest into the night through Sunday morning,
allowing for warm air advection to increase into Iowa. Overnight
lows for this reason, along with increasing cloud cover will allow
for milder low temperatures in the upper 40s to low 50s.

The shift to WAA is a response ahead of the next shortwave within
the midlevel northwest flow pattern, which is expected to descend
across the Midwest by Sunday. A trailing cold front related to this
wave is expected to reach into northwest Iowa in the early morning
hours, dropping southeastward across the state before making a full
passage by the early afternoon. Notable forcing for lift ahead of
the front, along with some saturation in the mid-levels is featured,
which CAM guidance continues to try generating reflectivities late
tonight through mid-morning Sunday, mainly over the northeast half
of the state. However, a closer look at model soundings shows the
presence of a deep layer of pronounced low level dry air that is
lingering from the high pressure that departed the state earlier in
the day, which will likely greatly limit rainfall potential at the
surface. Sprinkles or very light rain in areas where better
precipitation loading could occur, at best, would be possible, but
otherwise most areas should remain dry. Despite the shift to
northwesterly surface winds behind the departing front into the
afternoon, incoming 850mb temperatures with the approaching western
CONUS ridge will allow for highs to reach into the upper 60s to low
70s. There remains a signal for redevelopment of showers and even
some storms into the evening, but by then the front is well south
into northern to central Missouri, so any potential for additional
activity continues to diminish and have left the forecast dry for
the remainder of the day. Otherwise, another area of high pressure
will quickly pass across the state through the evening, leading to
gradually shifting winds back southwesterly into Monday, keeping
overnight lows on the milder side in the mid to upper 40s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 332 AM CDT Sat May 2 2026

The warming trend will peak Monday as the warm air settles overhead,
with highs expected to top out in the mid to upper 70s. While
conditions are expected to remain dry through the afternoon, a
stronger system dropping across the Upper Midwest will send another
cold front across Iowa through the day, which will eventually lead
to shower and storm development by the evening. Model guidance
indicates development of this shower/storm activity to occur largely
over southern and eastern Iowa, where the better saturation and
forcing near the boundary is located per NAM, though comparison with
the GFS/Euro has this boundary placed over north central Iowa by the
evening. Certainly some timing differences that will need to be
sorted out over the next few days, though it is safe to say at this
time that at least somewhere in Iowa will see showers and storms to
some degree. There is the inclusion of a Marginal Risk for isolated
severe storms in far southern Iowa into Missouri/Illinois in the SPC
Day 3 outlook, which is reasonable considering the presence of
instability values around 1000-1500 J/kg and shear values over 35
knots in these areas.

By Tuesday, this boundary is suggested to stall somewhere over
southern Iowa or northern Missouri, with an overall decreasing trend
in activity through the morning before redevelopment is indicated in
the afternoon to evening as peak heating occurs. Overall uncertainty
in exact coverage and timing is present this far out considering the
inconsistency in guidance earlier in the week with this
boundary, so will be something to keep an eye on. Otherwise,
high temperatures will be several degrees lower as values are
only expected in the upper 50s across the forecast area. The
pattern by midweek is trending on the cool side, with additional
rain chances as a deepening longwave trough arrives over the
Central Plains. It is worth noting though that there is no
signal for severe weather at this time with this activity, given
the instability axis being shunted much further south of the
state.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1046 PM CDT Fri May 1 2026

VFR conditions prevail through the period, as scattered to
broken cloud cover around 8 to 10 kft continues to drift
southeastward and dissipate. Winds will be light and somewhat
variable overnight, generally out of the north to northwest.
Winds become westerly and increase some in the morning, but
remain generally around 10 kts. A few sprinkles are possible
north tomorrow evening, but have kept out of TAFs at this time.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Freeze Warning until 8 AM CDT this morning for IAZ004>007-
015>017-023>028-033>037-044>047.
Frost Advisory until 8 AM CDT this morning for IAZ038-039-
048>050-057>062-070>075-081>086-092>097.

&&

$$

SHORT TERM...Bury
LONG TERM...Bury
AVIATION...Dodson