267
FXUS63 KDMX 082005
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
305 PM CDT Mon Jun 8 2026

.KEY MESSAGES...

- Isolated patchy fog possible northeast tonight into early Tuesday

- Hot and humid Tuesday, with a Heat Advisory in effect for portions
  of western and southern Iowa.

- An active week ahead with a larger system bringing strong to
  severe storms to the area Tuesday through Thursday. Strongest
  storms are expected on Wednesday.


&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 259 PM CDT Mon Jun 8 2026

Dry conditions have returned to the greater majority of the state
this afternoon, though a few isolated spotty rain showers are
occurring over northern and eastern Iowa. This activity is in the
vicinity of the ongoing MCV that continues to swirl over eastern
Iowa as of this writing, which is tied to the upper level trough
that is over the region. The expectation is that this system will
continue to very slowly depart for the rest of the afternoon and
especially the evening as the upper wave translates further
northeastward, which will lead to dry conditions. Warm and humid
conditions are noted across central Iowa this afternoon, thanks to
the increase in sunshine occurring over the western two thirds of
Iowa, which is seen on satellite from the areas of cumulus overhead.
Temperatures as a result have been allowed to increase into the
upper 70s to mid 80s, paired with humid conditions from recent
rainfall overhead, with values in the upper 60s to low 70s. This
lingering moisture will be something to watch, especially over
northeast Iowa tonight into Tuesday morning, which paired with light
winds could allow for some patchy fog development to occur.
Confidence is lower further west and south where conditions have
been dry longer, as well as the presence of upper level clouds which
could limit development altogether. Something we will certainly be
keeping an eye on. Otherwise, while most if not all guidance keeps
Iowa dry tonight into Tuesday morning, at least a few models
indicate the MCS potential as mentioned in previous discussion to
possibly bleed into far southern Iowa as this system passes out of
eastern Kansas and Nebraska into northern Missouri. Have therefore
included low PoPs to the far southern CWA to mention this potential,
with the overall potential remains quite low (<30%). The main
concerns would be gusty winds, while the threat for heavy rain
remains into Missouri.

Through Tuesday, a deepening trough is expected to pass slowly
across the western CONUS, with a developing surface low pressure
system on the lee side of the Rockies. As Iowa is on the eastern
fringe of this upper level feature, the low level flow pattern will
become southwesterly, ushering even warmer and humid air by mid to
late morning. Afternoon high temperatures are forecast to peak into
the low to mid 90s, with feels like values in the 100 to 105 degree
range by late morning through the afternoon across much of western
and southern Iowa. Therefore, have issued a Heat Advisory for these
areas that will be in effect from 1pm to 9pm Tuesday. Into the
evening hours, a boost in warm air advection wing convection ahead
of the aforementioned system is indicated mainly over central to
northern Iowa, along with a strengthening low level just over the
western Central Plains. Shear values around 30 knots and instability
values around 1500+ J/kg will be favorable for strong to severe
storms. If storms can break through the elevated warm layer, the
main concerns with any storms will be large hail and gusty winds,
given DCAPE values over 1500 J/kg and steep lapse rates up to 8-8.5
C/kg. Storms should diminish in coverage into Wednesday.

By Wednesday morning, the aforementioned trough is expected to arrive
over the western portions of the Upper Midwest and Central Plains,
with a surface cold front slated to track across the state later in
the day. At this time, guidance generally indicates convection
developing in the afternoon and continue through the evening as
forcing increases into Iowa from the strengthening low level jet.
Temperatures in the low to mid 90s once again, along with dewpoints
in the upper 60s to low 70s will boost instability values during
this time period over 4000 J/kg, paired with shear around 40 knots,
steep lapse rates around 7.5 C/kg and DCAPE values around 1500 J/kg.
All hazards are on the table, including large hail, damaging winds
and tornadoes. On the hydro side, high PWATS around 2 inches
overhead will be concerning as well, which would indicate efficient
rainers with this activity. Flooding concerns overall are limited,
with any highest potential over the south where soil moistures are
highest given recent activity. Details will continue to be refined
over the next several forecast packages.&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Issued at 259 PM CDT Mon Jun 8 2026

The pattern remains on the active side Thursday, with lingering
showers and storms mainly over southern and eastern Iowa as the
frontal boundary gradually departs the state. A brief reprieve is
indicated later in the morning, then another surface low over
Southern Plains within the larger western CONUS trough moves into
the region. Latest model guidance such as the NAM shows that this
system tracking directly over Iowa Thursday afternoon through the
evening, with warm frontal showers and storms indicated during the
morning followed by additional activity later in the afternoon into
the evening. Severe weather looks possible with this activity as
well.

Following the frontal passage, dry conditions look to return for
some time. The upper level low pressure is signaled to deepen
further as it circulates over the Upper Midwest into Canada. This
flow pattern overhead will lead to slightly cooler and less humid
conditions, with highs in the low to mid 80s and dewpoints in the
50s. Long range members begin to diverge more by the weekend, as the
GFS keeps conditions on the dry side before the next system arrives
later Sunday, while the Euro passes a few subtle waves across Iowa
that keep at least low chances for showers/storms at times. While
variations like these are normal this far out, details should become
more clear in the coming days, so stay tuned for that.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1246 PM CDT Mon Jun 8 2026

MVFR and isolated IFR ceilings persist across much of the area
this afternoon, though should improve within a few hours or so
across the west and closer to early evening further east as
ceilings lift. Isolated showers were near KALO, and are
otherwise spotty in nature over portions of the area but should
decrease in coverage over the next few hours as well. Winds will
remain light and generally variable in nature into tonight,
before switching southeasterly after sunrise and turning breezy.
There is a signal for fog development, especially northeast
early Tuesday morning, so have included at least at KALO and
KMCW at this issuance and will continue to monitor trends.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM to 9 PM CDT Tuesday for IAZ015-023-
033>035-044>047-057>060-070>073-081>083-092>094.

&&

$$

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