176
FXUS63 KDMX 081652
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1152 AM CDT Sat Jun 8 2024

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

.KEY MESSAGES...

- Lingering chances for on and off showers and weak storms today

- Dry and pleasant Sunday and Monday; "cooler" temperatures

- On and off chances for showers and storms through the upcoming
  work week

&&

.DISCUSSION...
Issued at 352 AM CDT Sat Jun 8 2024

Less active early this morning across Iowa, as radar returns show
the departing MCS tracking across Missouri. However, on the heels of
this departing system is a weak boundary that is currently over far
southern Minnesota into northern Iowa, with light rain and a few
weak storms ongoing. As this boundary drops into the state,
expecting to see continued chances for light rain showers and some
weak storm activity this morning, mainly affecting areas of northern
and eastern Iowa, with low end CAPE values despite more
appreciable bulk shear values around 30-40 kts. Temperatures
this morning have been quite warm given the remaining surge of
warm air advection while the weakening low level jet remains
overhead, with temperatures in the upper 60s to low 70s across
the southern to central portions of the state, while northern
Iowa sits in the upper 50s to mid 60s. Expecting some cooling
yet over the next few hours of a couple degrees in most areas,
before warming as highs reach into the mid 70s to low 80s. Into
the late afternoon to evening, a secondary wave is expected to
track across the Central Plains, leaving additional chances for
mainly light rain showers and non- severe storms given a similar
environmental setup (higher shear but fairly low CAPE), though
more concentrated over central into southern Iowa. This is
reflected in the SPC Day 1 outlook highlighting mainly a general
thunder threat over Iowa.

Into this evening, behind the departing wave, high pressure is
expected to make its way into the region, which will allow for
mainly dry weather conditions tonight and through Sunday. Highs in
the upper 70s to low 80s are expected, along with mostly sunny skies
and slightly breezy northwest winds, especially over northeastern
Iowa. The start of the work week is expected to remain on the
pleasant side, with guidance showing the high pressure system
pushing directly over the state, before sliding further southeast
ahead of the next system. By Tuesday morning, a low pressure system
over the Dakotas into southern Canada is suggested to bring a
frontal boundary across Iowa. However, the overall forcing
mechanisms look rather weak, despite the increasing southwest flow
and resultant warm air advection as well as increasing theta-e
advection. No severe weather is expected at this time, though will
be keeping an eye on this potential over the next several days.

With the upper level west/northwest flow pattern remaining
persistent over the region through Thursday, a few additional
waves passing through the region look to affect at least parts
of Iowa, which will allow for continued chances for on and off
showers and thunderstorms. In terms of severe weather potential,
Wednesday looks more favorable given better parameter space,
though differences among models in track and intensity remain,
so will not be getting into specific details at this time. Close
monitoring will continue with confidence in the details
gradually increasing. Warmer temperatures are expected mid to
late week given the gradual arrival of a thermal ridge tracking
out of the northwestern CONUS and into the Midwest. Highs as a
result are expected in the upper 80s to low 90s.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 1152 AM CDT Sat Jun 8 2024

A few lingering MVFR ceilings at the start of the period at ALO
and OTM will give way to VFR conditions, which should then
prevail through the period. A fleeting sprinkle or brief shower
could occur this afternoon or early this evening at FOD, DSM, or
OTM if it can overcome the dry subcloud air. With chances
remaining at or less than 10%, have maintained a dry forecast.

&&

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

&&

$$

DISCUSSION...Bury
AVIATION...Ansorge