477
FXUS63 KDMX 071728
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1228 PM CDT Sun Jul 7 2024

 ...Updated for the 18z Aviation Discussion...

.KEY MESSAGES...

- Scattered showers/storms today into tonight.
- Isolated/Scattered afternoon convection expected Monday into
  Wednesday.
- Warming late in the forecast as western ridge edges toward the
  Midwest.

&&

.DISCUSSION...
Issued at 403 AM CDT Sun Jul 7 2024

Spotty convection remains over portions of central Iowa this morning
as low level moisture transport remains directed into the state
early this morning. There has been some locally heavy rainfall with
areas near Tama and Marshalltown over an inch.  CAMs continue to
have isolated/scattered convection into the morning in southern and
central Iowa as the low level flow remains directed into the state
along with weak instability.  Meanwhile, another shortwave drops
through the Dakotas and into Nebraska today.  This helps to bring
another round of lift into the state by this afternoon into tonight.
Instability climbs with MUCAPEs above 1000 J/KG by early afternoon
with convection expanding as the wave approaches. Some of the 06Z
CAMS have indicated the potential for higher wind gusts,
particularly in the southeast where there are slight inverted-v
soundings.  Localized heavy rainfall is also possible but the
overall threat for increased flooding or flash flooding remains
relatively low given the progression of the bulk of the activity
later today into tonight.

The broad upper trof remains in place into the early portion of the
week as Beryl comes ashore on the Texas coast and heads northeast.
The trof axis is expected to be nearly overhead on Monday with
daytime heating providing some weak instability by afternoon.  This
should support some isolated convection during the peak heating
hours over the north half to two-thirds of the state.  Temperatures
remain below normal with extensive cumulus field developing by
afternoon as well.  Similar conditions exist on Tuesday as the
remnants of Beryl move into the lower Midwest and toward the Ohio
River Valley although the coverage is expected to be less given
generally less forcing.  By Wednesday, both GFS and Euro indicate a
decent shortwave dropping south toward the state which should
encourage the development of afternoon convection once again.

Some transition in the pattern is anticipated by late in the work
week with the upper trof finally lifting northeast and upper ridging
in the western United States expanding east into the Plains.  Warmer
air is expected to push back into Iowa by Friday and into next
weekend with readings likely heading back towards the 90s.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1227 PM CDT Sun Jul 7 2024

Main concern today into the evening is timing and coverage of
showers/storms. Instability increases aft 20z with gradual
filling in of showers/scat storms between 21 to 00z in the west
and southeast. Weak boundary entering western Iowa will add
some shear to equation aft 00z. Prior to that, mainly late
afternoon/evening instability storms. Main impacts will be lower
vsby and wind gusts. A few storms may bring gusts to 45kts or
slightly higher. Confidence in location low; but favored mainly
for southern TAF sites DSM/OTM and perhaps up toward ALO prior
to 04z. Will update as needed for stronger VRB gusts in storms.
Some vsby issues may develop around 10z Monday as well. /rev

&&

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

&&

$$

DISCUSSION...Cogil
AVIATION...REV