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510
FXUS63 KDMX 110446
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1146 PM CDT Mon Jun 10 2024

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

.KEY MESSAGES...

- Pleasant this afternoon and tonight.

- Showers (few storms) Tuesday morning followed by afternoon
  redevelopment which may bring a few strong to marginally
  severe storms during the afternoon to early evening hours,
  mainly in the northeast quadrant of the area, and with the
  primary threats of gusty winds and hail.

- Active weather pattern continues Wednesday and Thursday with
  additional chances for strong to severe storms.

- Continued warming into midweek as highs reach into the 90s.

- Slightly cooler/drier Friday but heat and storm chances
  return for the weekend.

&&

.DISCUSSION...
Issued at 331 PM CDT Mon Jun 10 2024

Rest of Today Through Tuesday:

Today`s the last more comfortable and pleasant day for the next
several - get outside and enjoy it!

High pressure that has been drifting through the region today
departs tonight with winds gradually switching to be out of the
southwest through the evening hours. With much warmer temperatures
to the west given the upper ridging in place through much of the
western U.S., temperatures will be warmer overnight west as warm air
advection increases with better radiational cooling far east leading
to a 10+ degree temperature gradient west to east overnight. Clouds
also start to increase overnight west to parts of central as the
shortwave trough and associated frontal boundary cross from the
Upper Plains into the Upper Midwest. Scattered showers start to form
in the warm air advection wing ahead of the approaching boundary as
moisture increases towards the early morning hours Tuesday northwest
with these showers and possibly a few non-severe storms making their
way northwest to southeast into around midday. Coverage may decrease
with southern extent as forecast soundings reveal much less moisture
to work with limiting overall precipitation in general far south or
making it harder to reach the ground with ample dry air to overcome.

The boundary moves through during the afternoon hours bringing the
opportunity for some redevelopment during a few hour window on
Tuesday afternoon to early evening, mainly near to east of I-35 and
north of I-80, which is roughly the location of the SPC Day 2
Marginal (1 out of 5) Risk. Although forcing is overall fairly weak,
if everything comes together a few strong to marginally severe
storms are possible with gusty winds and hail the primary threats,
though the instability gradient of CAPE values >1000 J/kg is fairly
narrow and dependent on atmospheric recovery and overcoming a CAP
evident in some soundings. A few models are much more robust with
the extent of warming/moisture with dew points in the upper 50s or
even 60s which would lead to higher CAPE values to go along with the
35-40+ knots of 0-6 km bulk shear. Given the overall parameter
space, coverage is likely to be isolated with any lingering storms
moving out of the area by mid to late evening. Temperatures will be
noticeably warmer and more humid Tuesday as we start our warming
trend through mid week with highs generally in the 80s.

Wednesday/Thursday:

Warm air advection amplifies further on Wednesday as mid-level flow
remains out of the southwest and much stronger moisture transport
surges dew points into the 60s. This will create a warm, humid, and
unstable environment allowing for better storm organization along a
surface boundary as it moves through MN/SD and eventually into Iowa.
Some questions remain in the speed of this frontal boundary which
will determine the location for any more organized storms Wednesday
afternoon/evening and again on Thursday afternoon and evening as
storms reinitiate along the boundary further south on Thursday
in another warm and unstable environment. With mesoscale details
helping to drive the ultimate threats and locations both days,
stay tuned for additional updates but the SPC has a Slight Risk
(2 out of 5) clipping the area north on Wednesday and in the
south on Thursday with an environment certainly supportive of
strong to severe storms both days. As noted above, both days
will be warm and humid with highs in the 80s to 90s and heat
indices nearing 100 far south Thursday.

Friday and Beyond:

A break in the action is expected on Friday with a slightly cooler
and drier forecast, though still in the 80s, before more storm
chances and heat return for the weekend as we return to the upper
80s to 90s by Sunday.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
-- Changed Discussion --
Issued at 1144 PM CDT Mon Jun 10 2024

Cigs will increase overnight and lower. Cigs are still expected
to remain mostly VFR through the period. Showers and a few
thunderstorms are possible late tonight and again by late
afternoon, over mainly northern Iowa. A brief MVFR cig with the
precipitation is possible vicinity of KMCW. Light southeast wind
to start the period will become more southerly later tonight and
turn southwest during the day Tuesday.
-- End Changed Discussion --

&&

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

&&

$$

DISCUSSION...KCM
AVIATION...Donavon