507
ACUS02 KWNS 231730
SWODY2
SPC AC 231729

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1229 PM CDT Mon Sep 23 2024

Valid 241200Z - 251200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
CENTRAL AND EASTERN KENTUCKY...

...SUMMARY...
Isolated to scattered severe thunderstorms are possible on Tuesday
across portions of the Ohio and Tennessee Valleys into the
central/southern Appalachians.

...Synopsis...
A lead shortwave trough will be moving through parts of the Ohio
Valley Tuesday morning with a stronger mid-level jet digging
southward through the central Plains. Trends in model guidance have
suggested a stronger large-scale trough across the Midwest over the
last few cycles. However, the surface pattern still remains a point
of uncertainty. At least a weak surface low is expected to be
positioned near the Illinois/Indiana border Tuesday morning. The
exact position and evolution are not clear, but a general movement
to the north-northeast is expected. This will aid in slowly pushing
an effective warm front north in Indiana/Ohio/western Pennsylvania.
Farther to the west, a secondary, weak surface low is forecast to
develop in the Texas Panhandle/western Oklahoma. A weak cold front
will push southward as mid-level jet/trough moves south and
eastward, respectively.

...Central/Eastern Kentucky...
Confidence in scattered storm coverage has increased. While some
activity may be ongoing early Tuesday, model guidance generally
suggested that at least broken heating is possible. Additional
storms are expected along/ahead of the cold front during the
afternoon. While mid-level lapse rates will not be overly steep,
40-50 kts of effective shear should lead to organized storms capable
of wind damage and isolated large hail. 15% wind probabilities have
been limited to where the highest confidence in  scattered storm
coverage is. Some adjustments are still possible as details
regarding low-level destabilization becomes more apparent.

...Mid-South into southern Appalachians...
While low/mid-level forcing will be weaker in these areas, shear
will still be strong enough to support organized convection along
the cold front and within the higher terrain. Mid-level lapse rates
will be modest, but a moist airmass (dewpoints in the upper 60s to
perhaps low 70s F) will support 1500-2000 J/kg MLCAPE where heating
occurs. Damaging winds are likely the primary threat, but effective
shear of 40-45 kts will also support some risk of large hail with
the strongest storms.

...Lower Great Lakes Vicinity...
Uncertainty in the track of the surface low and effective warm front
complicate the forecast for this region. Some guidance is more
aggressive in destabilizing the boundary layer in the wake of early
day activity. Wind profiles will support supercells capable of
damaging winds and large hail. Forecast soundings show enlarged
low-level hodographs near the effective warm front. While the
tornado threat will be conditional on the degree of destabilization
and overall storm evolution, a supercell interacting with the
boundary could produce a brief tornado.

...Western Oklahoma Vicinity...
Some model guidance develops convection along the cold front and
moves it southward through western Oklahoma. Moisture will likely be
limited which will likely limit storm intensity if any form at all.
Gusty winds and small hail could occur with strong northwesterly
flow and cold temperatures aloft. Uncertainty is too high to
introduce probabilities at this time.

..Wendt.. 09/23/2024

$$