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000
FXUS63 KDMX 221739
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1239 PM CDT Mon Apr 22 2024

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

.KEY MESSAGES...

- Windy today with increasing south to southwest winds. Isolated
  showers north and east this afternoon into early evening.

- Scattered showers in far southern Iowa tonight with cooler and
  breezy conditions on Tuesday.

- More active Thursday night through the weekend. The potential
  exists for several rounds of convection. Severe weather is
  possible along with heavy rainfall during this time.

&&

.DISCUSSION...
Issued at 342 AM CDT Mon Apr 22 2024

Surface riding is departing early this morning with light southwest
flow across the state.  There may still be some potential for
isolate frost in areas of the east but this should remain limited
given the wind and temperatures.  Otherwise, the upper low in
southern Canada approaches northern United States later today.  An
associated surface trof approaches the state today with a rapidly
tightening pressure gradient.  Winds from the south to southwest are
forecast to increase quickly by late morning and persist into the
afternoon prior to passage of the trof axis.  Mixing deepens into
the afternoon with some transport of higher momentum air to the
surface however this may be modified somewhat by the ongoing lift
associated with the system.  However, sustained winds as well as
gusts are likely to approach if not exceed wind advisory criteria at
times during the afternoon and have hoisted an advisory during this
time.  Otherwise, models have generally backed off on showers in the
north and east this afternoon into the evening and have dropped PoPs
to isolated coverage during this time.

The trof is sluggish to depart tonight as additional moisture feeds
north into the boundary.  Another wave rides along the boundary and
with renewed lift, scattered showers and a few isolated storms are
expected into southern Iowa overnight although models are indicating
the bulk of precipitation remains just south of the state in
Missouri where the deeper low level convergence is located.
Otherwise, the main cold front associated with the system arrives
into northern Iowa toward daybreak on Tuesday. This cooler air
filters across the state on Tuesday and have done some downward
adjustment to temperatures and it may not be enough.  Otherwise,
windy conditions continue from the northwest along with the threat
of a few showers in the north and east by afternoon underneath the
southwest edge of the upper low.

The upper pattern is still expected to change for the later half of
the week into next weekend with a more active weather scenario.
Strong theta-e advection into Thursday night and early Friday should
lead to convection developing across portions of Iowa during the
night and persisting into Friday morning.  Additional convection is
likely to redevelop into Friday afternoon and evening as the surface
low passes northwest of the state.  The potential for severe storms
exists during this entire period with elevated storms on Thursday
night and a better potential for surface based convection on Friday.
As of right now, Saturday appears to be relatively quiet prior to
the next surge of moisture and convection on Saturday night thru
early Monday with additional severe threat during this time.  In
addition, the several rounds of convection have the potential to
produce heavy rainfall across portions of the state and some
responses on area rivers. Still plenty of time to hammer out the
details at this point.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1239 PM CDT Mon Apr 22 2024

Main concern is wind through 01z as strong winds and gusts from
south will continue until boundary layer decouples. Most sites
relax aft 01z, though some will remain above 12kt ambient.
Mid level VFR cigs approach and move through region tonight,
generally above 070. Other than a few passing showers, nothing
of significance expected. Have left VC for now. Winds expected
to increase again aft 14-15z Tues with northwest winds 15G22
through end of period north; progressing south aft 18z. /rev

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 5 PM CDT this afternoon for IAZ004>007-
015>017-023>028-033>039-044>049-057>061-070>073-081>083-
092>094.

&&

$$

DISCUSSION...Cogil
AVIATION...REV