680
ACUS01 KWNS 071630
SWODY1
SPC AC 071629

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Fri Jun 07 2024

Valid 071630Z - 081200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE
CENTRAL PLAINS...

...SUMMARY...
Severe thunderstorms are expected across the central Plains
especially from mid/late afternoon through evening. Damaging winds
and large hail are the primary threats.

...Central Plains including Nebraska/Kansas to western Missouri...
Scattered elevated thunderstorms are ongoing across southern South
Dakota, and in a more isolated sense across central Nebraska. A
mid-level speed max/subtle shortwave trough over Wyoming and the
nearby north-central High Plains this morning will continue
east-southeastward, overspreading a warm sector later today that
will narrow northward across north-central Nebraska near a deepening
surface low and evolving triple point. This is where surface-based
thunderstorm development will become increasingly likely by
mid-afternoon (circa 20z across north-central Nebraska).

As surface dewpoints climb through the lower 60s F, upwards of
2000-2500 J/kg MLCAPE will reside in this corridor by peak heating.
Intense storm development including supercells can initially be
expected in the presence of 50+ kt effective shear, highlighted by
50-80 kt mid/high-level west-northwesterly flow. Instances of very
large hail (baseball size plausible) may occur, potentially also
with some tornado risk, although low-level winds/SRH will not be
overly strong diurnally (roughly pre-00z).

Storms are expected to merge/congeal through early evening as they
progress southeastward, likely growing upscale into a well-organized
MCS that will evolve across south-central/southeast Nebraska and
northern Kansas, and into western/northern Missouri and southwest
Iowa by late evening/overnight. Scenario will be aided by a
nocturnally strengthening southwesterly low-level jet and
increasingly robust warm/moist advection. A corridor of potentially
widespread damaging winds and wind-driven hail is expected.

...Southwest Kansas and Texas/Oklahoma Panhandles...
High-based thunderstorms are expected to develop through mid/late
afternoon near a south-central High Plains surface low and adjacent
surface trough/diffuse dryline. This development will be associated
with a hot/deeply mixed boundary layer with temperatures in the
90s/lower 100s F. These storms will progress into a region of
somewhat greater moisture and instability through early evening,
with storm organization potentially aided in proximity to moderately
strong northwesterly flow aloft. At least isolated severe storms can
be expected, with severe-caliber wind gusts and bouts of large hail
possible.

...Great Basin...
A shortwave trough is readily evident in water vapor imagery near
the western Nevada/California border vicinity at late morning. Ample
insolation and PW values between 0.50-1.00 inch may potentially
support upwards of 750-1000 J/kg MLCAPE this afternoon, especially
across a broad portion of northern/central Nevada into southern
Idaho and northern Utah. As thunderstorms diurnally increase in
coverage and intensity, and low-level lapse rates steepen, effective
shear generally 30-35 kt may allow for some sustained/organized
multicells, with severe-caliber wind gusts possible with the
strongest storms.

..Guyer/Gleason.. 06/07/2024

$$