518
FXUS63 KDMX 040353
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1053 PM CDT Wed Jun 3 2026

 ...Updated for the 06z Aviation Discussion...

.KEY MESSAGES...

- Dry conditions continue through tonight; then storms arrive
  far northwest after midnight.

- Marginal Risk (level 1 out of 5) of severe weather Thursday
  afternoon/evening.

- Rain/storm chances continue into Friday evening with the
  possibility of severe weather and heavy rain. Slight Risk per
  SPC.

- Temperatures return to the upper 80`s over the weekend.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 257 PM CDT Wed Jun 3 2026

Dry, warm, and breezy conditions are common across Central Iowa
today, with afternoon temperatures as of 2pm in the upper 70s
to low 80s and south/southeasterly winds gusting to 20-25 mph,
while areas on northern Iowa have seen higher gusts at times up
to 30-35 mph. The synoptic setup responsible for this weather
features a large area of ridging and associated surface high
pressure that is centered over the Ohio Valley, with its
influence remaining across Iowa, while further west, a trough is
moving across southern Saskatchewan/Manitoba. The high pressure
area will continue to allow for dry conditions through the rest
of today, though will continue to depart eastward into the
evening/Thursday morning. Will see a noticeable change as
moisture return as it increases across western Iowa tonight,
which will continue to translate further north and east over the
next few days and generally bring a more active pattern across
Iowa into the weekend.

The first chance for showers and storms in the short term will
come from a boundary in relation to the Canadian trough
mentioned above, which is slated to arrive into northwest Iowa
after midnight tonight and drop southeast into the state through
the morning. Showers and storms are expected to arrive in
relation to this boundary, but will be on a weakening trend as
they track out of the Dakotas/Nebraska. The parameter space over
Iowa features instability values less than 500 J/kg and shear
values under 25 knots, which should keep any storms that linger
into Iowa below severe limits. With dry air still over much of
central and eastern Iowa, any showers and storms will generally
struggle to maintain themselves as well, but could hold the
potential for gusty non-severe winds as they collapse.

By late Thursday morning and especially the afternoon,
destabilization becomes widespread overhead, with instability
values around 1000-2000 J/kg, paired with shear values around
25-30 knots as temperatures rise through the 80s. These
conditions, paired with the arrival of a shortwave moving
northeast across Iowa and further forcing for lift into the
evening by the strengthening low level jet will allow for
scattered showers and storm chances to return across western and
southern Iowa, increasing in coverage through the evening as
this activity tracks northeastward. The primary hazards of
concern will be hail and gusty winds, though heavy rain
continues to be increasingly likely as well where storms pass
through, given very favorable PWATS of 1.6-1.7 inches moving
over much of the area. Though soils over much of the state are
dry, quick accumulations of 1-2+ inches could easily occur where
stronger storms setup. A Slight Risk per WPC has been
introduced over portions of southwest/western Iowa to account
for this potential.

Highest dewpoints in the mid to upper 60s arrive over much of
Iowa into Friday as moisture advection from the Gulf becomes
maximized. Showers and storm coverage look to remain through the
majority of Friday morning as the low level jet slowly fades,
especially over southern Iowa. While the severe risk is lessened
during the morning hours given more limited instability
overhead, storms are still expected to occur. Drying conditions
return briefly, but will see storm chances return once again
Friday afternoon and especially the evening as another mid-level
shortwave is expected to pass across the Upper Midwest, with an
associated defined cold front arriving into Iowa. This west to
east boundary will be the feature responsible for yet another
period of showers and thunderstorms, which will gradually track
south/southeast with the passing boundary through Friday night.
Higher instability values ahead of this feature around 2000+
J/kg, shear values up to 30-35 knots and steep lapse rates of
7-8 C/km overhead will lead to the highest potential for strong
to severe storms. A Slight Risk for severe weather remains
across much of the forecast area per SPC given this parameter
space, where all hazards are possible. Heavy rain given similar
PWAT values and slower storm movement will introduce additional
concerns for 1+ inch amounts where stronger and repeated storms
move through.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 257 PM CDT Wed Jun 3 2026

Showers and thunderstorms are expected to continue into
Saturday morning, mainly over southern Iowa in relation to where
the frontal boundary is progged to generally stall for the day.
While most areas look to be dry for much of the day, additional
showers and storms look to redevelop over parts of southern
Iowa in relation to the lingering aforementioned front by the
evening. Confidence however on exact placement is on the low end
at this time, as models such as the GFS push this boundary near
the IA/MO border into northern Missouri by Saturday evening.
Certainly some placement differences to keep an eye on over the
coming days. The pattern Sunday and beyond looks to remain on
the more active side as additional wave pass through the area,
along with slightly warmer temperatures overhead. More specific
details however on timing and location of showers and storms
will be better known in the coming days as models better capture
these features.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1052 PM CDT Wed Jun 3 2026

Showers and thunderstorms in northwest Iowa tonight will
diminish as they head southeastward, but there is a low
probability (30%) of TSRA at FOD and MCW by around sunrise.
Otherwise, expect more widespread SHRA/TSRA spreading across the
area Thursday afternoon through evening, with a higher
probability of reduced visibility and possibly ceilings at all
terminals during that time. Have used extended PROB30 groups to
convey this in the 06Z TAFs, but expect refinement in future
issuances.

&&

.HYDROLOGY...
Issued at 631 PM CDT Wed Jun 3 2026

Flash flood concerns exist over at least the next few days,
primarily between Thursday afternoon and Friday night. WPC
introduced a slight risk for the western CWA in their Day 2
Excessive Rainfall Outlook update this afternoon. (See the WPC
Excessive Rainfall Discussion for details.) Flash flooding may
occur from heavy rainfall amounts or the sheer rainfall
intensities since the activity has the potential to be efficient
rainfall producers. The greatest risk of any flash flooding
would be in cities and towns.

The risk of river flooding over the next 10 days is minimal
(generally less than 10-20%), however minor to moderate within-
bank rises are possible in basins that receive heavier rainfall.

&&

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

&&

$$

SHORT TERM...Bury
LONG TERM...Bury
AVIATION...Lee
HYDROLOGY...Zogg