030
FXUS63 KDMX 071138
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
638 AM CDT Fri Jun 7 2024

 ...Updated for the 12z Aviation Discussion...

.KEY MESSAGES...

- Possible strong storms mainly southwest Iowa this evening into
early Saturday.

- Additional on and off chances for showers and non-severe storms
this weekend

- More of an active trend into the work week, with temperatures
becoming very warm by mid-late week

&&

.DISCUSSION...
Issued at 409 AM CDT Fri Jun 7 2024

A very quiet morning across Iowa to start the day, with an area of
high pressure sitting overhead. Per satellite imagery, cloudless
skies can be seen, which will aid to cool down temperatures through
the rest of the early morning into the 50s. Temperatures currently
are sitting in the 50s to low 60s, paired with light winds primarily
out of the southwest. The aforementioned high pressure is expected
to glide out of the region later this morning, which is expected to
be followed by an approaching shortwave into the afternoon/evening.
Despite CAMs and some deterministic guidance suggesting some initial
rain shower activity into the afternoon across northern into central
Iowa, model soundings indicate dry low levels which will make it
quite difficult for much if any accumulations to occur. Otherwise,
the primary focus remains later on into this evening as the
shortwave tracks across the southwest portion of Iowa, paired with a
strengthening low level jet and increased moisture return into the
region as dew points increase into the upper 50s to 60s, which will
result in a complex of showers and thunderstorms to develop and push
mainly across south/southwest Iowa into early Saturday. Despite
lower CAPE values under 1000 J/kg, significant bulk shear
values of 50+ kts and mid level lapse rates around 7 C/km, along
with fairly dry low levels look to pose mainly a threat for
damaging winds and at least a possibility for some isolated
larger hail, though the best potential for any strong to severe
storms looks to be further south and west where conditions are
more favorable. Heavy rainfall with these storms are also on the
table, given deep warm cloud levels and PWATs around 1.50
inches. Total rainfall amounts continue to vary given some
slight differences in the track of this system in terms of where
the heaviest rain may fall, with totals generally under an inch
and the highest values occurring near or just south of the
IA/MO border.

As the lingering MCS tracks further southeast into MO and beyond, a
following frontal boundary dropping into northern Iowa looks to
bring the chance for additional light rain and a few weak storms
through Saturday morning. A period of dry weather is expected into
the afternoon before redevelopment of showers and non-severe storms
are expected into Saturday evening. By Sunday, mainly dry conditions
look to occur through at least the afternoon, before another
boundary per model guidance drops south into the state. However,
model consistency in terms of coverage becomes a bit more uncertain,
as the Euro keeps the area dry while high pressure quickly drops in
from the north, while the GFS and Name have more widespread showers
and even storms Sunday evening into Monday as a developing system
pivots across the region and the aforementioned high pressure
remains further north. Will have to keep an eye on this given the
differences, but nonetheless, a period of active weather looks to
remain into early next week.

For the upcoming work week, outside of the lingering activity on
Monday, additional chances for showers and storms are suggested,
though still remain more uncertain as models continue to show varied
solutions ranging from completely dry weather to more widespread
activity within the larger scale northwest flow. This trend
unfortunately lingers through Thursday, before a more defined
thermal ridge over the western CONUS tracks into the Midwest region
by the end of the week. Overall details regarding specific timing
and impacts with the previously mentioned active weather should
become more clear in the coming days, so please stay tuned as more
information becomes available. Regarding temperatures, the beginning
of the work week starts out more on the comfortable side with highs
through the 70s, before gradually turning warmer Wednesday and
especially into the end of the work week as highs are expected in
the upper 80s to low 90s.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 638 AM CDT Fri Jun 7 2024

VFR conditions remain this morning and are expected over the
next several hours across the terminals. Clouds will begin to
increase around and after 18z, which may come with a small
chance for light rain across mainly the northern terminals.
However, given uncertainty due to low level dry air, decided to
leave out and will continue to monitor. Showers and storms
however are more likely after 00z this evening, mainly impacting
KDSM and KOTM. Heavy downpours at times may allow for periods
of lower visibilities. Otherwise, will see low ceilings arrive
with widespread MVFR conditions and possibly isolated IFR
conditions into Saturday morning.

&&

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

&&

$$

DISCUSSION...Bury
AVIATION...Bury