236
FXUS63 KDMX 300426
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1126 PM CDT Wed May 29 2024

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

.KEY MESSAGES...

* Pleasant conditions prevail into tomorrow

* Shower/storm chances ooze in later Thursday through Friday. Severe
  threat very low.

* Additional/periodic shower/storm chances into next week, but model
  spread makes details hazy.

&&

.DISCUSSION...
Issued at 231 PM CDT Wed May 29 2024

Surface high pressure continues to dominate the region this
afternoon, yielding an abundantly pleasant and sunny day. As the
inverted surface ridge slowly slides eastward, currently light
and variable winds will gradually give way to light
southeasterly winds this evening and overnight with highs
topping out in the low to mid 70s for most.

Western trough along the US-Canada border will quickly push upper
level ridging above and across the region tonight, in conjunction
with southern stream shortwave energy approaching. Those combined
will work to provide our next opportunity for a few showers/storms
latter Thursday and through Friday. The overall severe risk remains
very low with best ingredients/opportunities shunted southward.
Deterministic synoptic models have begun hinting at more of a split
scenario for precip coverage with strongest forcing centered
northward into SD/ND/MN and southward over KS/MO/OK/AK between the
two aforementioned waves. This has also begun to be reflected within
ensemble guidance. As such, greatest uncertainty in precipitation
coverage and amounts lies over, you guessed it, Iowa. Have nominally
scaled bag PoPs, but did not get too aggressive with it just yet.

Additional shortwave energy moving through the developing zonal
upper flow pattern will allow for periodic shower/storm chances
through the weekend and potentially into/through the middle of next
week. PoPs are inevitably too prolonged within the forecast, but
model discrepancies in handling of the shortwaves lends to degraded
confidence in higher or drier windows for PoPs at the moment.
Similar to the Thur/Fri system above, the severe threat appears
quite low for the most part. Out on Day 6/7, deterministic guidance
is in fair agreement of an upper trough dragging a cold front across
the region, which may provide our next severe opportunity as Gulf
moisture is also forecast to return to the area early-mid next week.
Lots of time for details to change/shift though, but something to
casually watch.

Temperatures through the forecast period will see a warming trend
after Friday with high temperatures surging into the 80s by Sunday
and into next week. Tuesday currently shapes up to be the warmest of
days with progged 850mb temps into the teens deg C, including a shot
at touch 90 if forecast trends warmer.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1124 PM CDT Wed May 29 2024

VFR conditions prevail through the current TAF period. Showers
and storms develop across western Iowa late Thursday afternoon
and evening, but latest model trends continue to suggest that
this activity will make very slow eastward progression and may
not reach any of the forecast terminal sites through 06z Friday.
Opted not to include any TS mention prior to 06z Friday for
now, but will need to be reassessed in future TAF updates.

&&

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

&&

$$

DISCUSSION...Curtis
AVIATION...Martin