ACUS01 KWNS 301306
SWODY1
SPC AC 301304

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0804 AM CDT Tue Jul 30 2024

Valid 301300Z - 311200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE
MIDDLE MISSOURI VALLEY/MIDWEST...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
NORTHERN/CENTRAL PLAINS TO THE SOUTHEAST...

...SUMMARY...
Severe storms are expected today into tonight across a broad area
from eastern Nebraska and Iowa into parts of the Midwest, Tennessee
Valley and southern Appalachians, with swaths of damaging winds
possible within this corridor. Severe storms are also possible
across parts of the northern Plains.

...Central Plains/Upper Midwest to OH/TN Valleys...
Very challenging meteorological scenario with highly variable
guidance as far as MCS development/disposition today. However, a
rather favorable set of ingredients will generally coincide,
spanning east/northeast Nebraska into Iowa, northern Missouri and
western Illinois, and to some extent even farther southeastward into
the Tennessee Valley. Very strong buoyancy will exist within this
MCS/outflow-reinforced corridor, with a strong elevated mixed layer
-- yet not overly warm aloft for the season -- atop a moist boundary
layer. Seasonally strong west-northwesterly winds aloft will also
reside in this general corridor, with potential for multiple
east/southeastward-moving MCSs today and tonight. Swath of damaging
wind gusts (potentially in excess of 75 mph) are plausible.

With a remnant thunderstorm cluster across Illinois, some
re-intensification of this convection may occur across the lower
Ohio Valley toward the Tennessee Valley, with a modestly strong
northwesterly flow regime and ample downstream instability. Isolated
to scattered damaging wind should be the primary threat.

Meanwhile, multiple thunderstorm clusters across Siouxland this
morning from southeast South Dakota into northwest/western Iowa may
continue to pose a severe risk, with some potential that these
storms could merge/organize later today along the instability
gradient. There is also potential that additional storm development
may occur by late afternoon/early evening across northern
Nebraska/far southern South Dakota near a surface low/troughs, with
these storms potentially increasing and evolving into an MCS
tonight, aided by a nocturnally strengthening low-level jet.

...Northern Plains...
Weak height falls amid moderate to strong instability may lead to
widely scattered thunderstorm development along a surface
trough/dryline across the Dakotas this afternoon. Moderate
westerlies should support moderate deep-layer vertical shear around
30-35 kt, sufficient for a few organized storms capable of both
large hail and damaging gusts.

...Northern New York to northern New England...
Moderate buoyancy may develop this afternoon from northern New York
into northern New England. While storm coverage remains somewhat
uncertain, deep-layer shear and relatively cool temperatures aloft
could support a couple modestly organized storms capable of locally
damaging wind, and possibly some hail.

...Mid-Atlantic vicinity...
A mid/upper-level trough and possibly an MCV will move across the
Mid Atlantic vicinity later today. Scattered thunderstorm
development is expected by afternoon from northern Virginia into
parts of Pennsylvania. While there is some uncertainty regarding the
extent of heating and destabilization, a couple stronger
cells/clusters may become capable of producing isolated damaging
winds.

..Guyer/Grams.. 07/30/2024

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