542
FXUS63 KDMX 311955
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
255 PM CDT Sun May 31 2026

.KEY MESSAGES...

- Few lingering showers, isolated non-severe storms, in northern
  Iowa this afternoon. Some continue to produce efficient
  rainfall.

- There is a low chance for a few severe storms this evening
  into tonight, but the question is if storms can develop. If
  storms do develop, gusty winds, hail, and locally heavy
  rainfall will be the main threats.

- Monday is favoring drier conditions with capping in place to
  limit if not prevent storms. However, similar to Sunday, if
  storms can develop, a few severe storms with hail or gusty
  winds are possible.

- High pressure drifts southward through the Great Lakes into
  the Ohio Valley, which pushes rain and storm chances west of
  the state Tuesday and Wednesday and perhaps Thursday. Highs
  above normal in the 80s.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 253 PM CDT Sun May 31 2026

Morning rainfall has continued to slowly lift northward with
occasional storms/lightning. Some areas, especially towards northern
Blackhawk into southern Bremer Counties have seen some decent
rainfall of at least 1" where showers/storms have repeatedly
tracked, but isolated locations of 1-2"+. The bulk of the rainfall
activity has largely ended for this afternoon in that area, but will
certainly be keeping an eye on this area and similarly central
Butler County for any hydro issues that may occur should any
additional storms develop and track over this area tonight.

On that note, cloud cover and the rainfall has kept conditions
cooler in northern into portions of northeast Iowa. Meanwhile,
conditions have started to clear and warm in western into southern
Iowa. While in the north and northeast temperatures are in the 60s,
in the west and south, temperatures have warmed into the 80s with
dew points largely in the 50s-60s making it feel muggy. As has been
discussed over the last several days and would be expected given the
warm, humid conditions noted in areas that have also seen sunshine,
additional storm development is the main forecast challenge through
the evening. With minimal forcing in Iowa and a cap seen in forecast
soundings with mid level warm and dry air, storm development is not
a certainty. We are starting to see a cu field develop in the south
and west but largely not expecting any storms to take off and
sustain before 00Z. The area to watch is back in eastern Nebraska
where a boundary appears to be stalled out. This is the most likely
location for storms to develop if they can break through the cap,
which per soundings, is not as stout as further east. Instability is
plentiful but shear remains weaker making it more difficult for
storms to maintain. CAMs have started to come into some agree with
storms firing in eastern Nebraska between 00-3Z and moving east into
Iowa after, maybe reaching our western area around 06Z but would be
on a weakening trend so confidence in eastern extent (should these
storms actually develop) is not high. Timing and the expected
weakening trend make severe storms unlikely overall, but a stronger
storm could have some hail or gusty winds. Pwats do remain over 1.5"
so will continue to see the potential for locally heavy rainfall
with any storms that do develop and track into our area. Storm
motions remain slow, though albeit a little faster than say
yesterday, around 20 knots. QPF guidance is in better agreement with
totals over 1" in eastern Nebraska/far western Iowa, but should
storms maintain, could see some localized 1-2"+, maybe 2-3" on the
high end, but this high end does not seem likely given the questions
on storm maintenance.

Upper lows over Montana and just off the Northeast U.S. coast will
keep upper riding in place to start the new work week. After a dry
morning, some weak shortwave energy may move in later Monday
afternoon into Monday evening but QPF fields are sporadic in
bringing much of any QPF into our area (largely to our west) which
aligns with the better moisture to our south and then west later
Monday into early Tuesday morning. CAMs have varying ideas of
kicking of storms again Monday afternoon and evening. Global models
(NAM, GFS) have also started a drying trend later Monday. Not too
dissimilar from today, if a storm could develop, it would be in an
environment characterized by ample instability but with varying
ideas in the amount of shear present with the GFS/NAM around
30-40 knots and the Euro closer to 25-30 and mostly offset with
the higher shear values from the higher instability values. This
to say should a storm get going, it could become strong to
severe with hail or gusty winds, but trends are certainly on the
drier side Monday with plenty of mid to upper level dry air
capping off the atmosphere making it difficult for storms to
develop. The potential thing to watch, however, is what occurs
further west in Nebraska tomorrow night and if any storms can
maintain into Tuesday morning. CAMs and global models remain in
decent agreement that activity fades before it gets into central
Iowa (and even into Iowa for the most part). Thus, we keep
another conditional threat for storms Monday but even more so
than tonight, most areas may remain dry.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Issued at 253 PM CDT Sun May 31 2026

Warm conditions continue this week with highs in the 80s. A Great
Lakes high looks to keep conditions dry Tuesday into Wednesday with
storm chances returning later in the week as the upper ridge finally
breaks down. By the end of the week, temperatures may warm further
as southwest flow kicks in with additional storm chances into the
weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1241 PM CDT Sun May 31 2026

Mix of MVFR and VFR ceilings ongoing early this afternoon with a
few IFR CIGs in northwest Iowa. Expect these MVFR CIGs to become
more SCT over the next couple hours with clearing also occurring
in southwest Iowa and expected to continue east-northeast with
time this afternoon. Morning showers/storms have largely moved
north of TAF sites with the exception of KFOD. Additional
isolated shower/storm development remains possible late this
afternoon into evening but confidence in occurrence or impacts
far too low to include any mentions in TAFs. Some guidance also
hints at fog development into Monday morning with associated
lowering CIGs/Visbys. Have started to address with SCT MVFR CIGs
but confidence is not there for dropping visibilities as fog
development may not occur should showers/storms develop, or even
with the additional cloud cover that could move into the state
tonight. Winds out of the south to southeast today become light
and variable tonight before settling out of the east later on
Monday.

&&

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

&&

$$

SHORT TERM...05
LONG TERM...05
AVIATION...05