002
FXUS63 KDMX 200444
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1144 PM CDT Sun May 19 2024

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

.KEY MESSAGES...

- Active pattern to persist through early next week with
  multiple rounds of thunderstorms, some of which may be severe

- Tuesday carries the most widespread and high impact severe
  weather potential with widespread Enhanced Risk (3/5)

- Storms will likely be accompanied by heavy rain through
  Tuesday as moisture increases

&&

.DISCUSSION...
Issued at 247 PM CDT Sun May 19 2024

Progressive pattern continues through early this week with
multiple shortwave troughs lifting northeast across IA.
Periodic thunderstorms will be the result with varying severe
weather threats, some of which will depend upon overnight
convection and the impact on insolation/instability.

Elevated storms have been pesky today, maintaining for longer
and stronger than most models had indicated. The more organized
updrafts have hugged a MUCAPE gradients thats draped across
southern IA. Convection has been isolated and weaker elsewhere.
Expect this trend to continue for the remainder of the
afternoon. Looking upstream, satellite clearly depicts next
shortwave accelerating across the high plains, with convection
erupting in advance. This shortwave tracks across the state
later today and overnight, providing the next potential (this
evening) for severe convection give sufficient deep layer shear
and instability. Thunderstorms will linger through the
overnight; although severe threat decreases later this evening.

Shortwave trough moves east of the CWA on Monday morning, likely
providing a relative minimum in storm chances immediately in its
wake, sometime around midday. Even so, surface boundary will
remain draped across the state and when combined with SBCAPE
values of 2000-2500 j/kg will provide the potential for another
round of afternoon/early evening convection. Coverage/strength
will depend on how quickly the morning shortwave departs and how
much destabilization can occur behind.

Attention then shifts to Tuesday as the strongest shortwave of
the period takes aim on the Midwest during diurnal heating.
Latest guidance tracks the surface low pressure into NW IA or S
MN by mid-afternoon. Parameters are progd be more than
sufficient for severe in the warm sector with SBCAPEs progd
3000+ j/kg and deep layer shear of 50-60 knots. There is some
questions on timing and location of synoptic features, which
will dictate where storms initiate and resultant impact on
severity. As always, the devils in the details, which will
become more clear in the next 24-36 hours.

The system departs quickly Tuesday night, giving way to a couple
of drier days on Wednesday and Thursday. More storm chances
returning by the end of the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1144 PM CDT Sun May 19 2024

A line of showers and storms continues east of I-35 early this
morning and is expected to move out of the area over the next
few hours. However, a large cluster of additional showers and
storms are expected to lift north across the state after 06z,
which will allow for active weather to continue through much of
the morning. Periods of lower ceilings and reduced visibilities
from heavier rainfall with these storms may allow for MVFR
conditions at times. A drying period looks to occur by late
morning through the afternoon, before additional showers and
storms look to move into the area towards the evening. Specific
mention of timing and location of storms Monday evening remain
unclear and will largely depend on the previous storm evolution,
which will be monitored closely. Winds will gradually shift
south/southwesterly with slightly breezy winds through the
daylight hours.

&&

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

&&

$$

DISCUSSION...Hahn
AVIATION...Bury