24/06/2023
Jun 23, 2023 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Fri Jun 23 07:30:36 UTC 2023 (20230623 0730Z Day 3 shapefile | 20230623 0730Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0730 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 91,965 12,438,478 Columbus, OH...Nashville, TN...Cincinnati, OH...Louisville, KY...Lexington-Fayette, KY...
MARGINAL 167,473 21,098,929 Indianapolis, IN...Memphis, TN...Cleveland, OH...Toledo, OH...Fort Wayne, IN...
Probabilistic Graphic
20230623 0730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 3 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SIG SEVERE 43,924 6,910,460 Nashville, TN...Cincinnati, OH...Louisville, KY...Lexington-Fayette, KY...Clarksville, TN...
15 % 92,167 12,293,187 Columbus, OH...Nashville, TN...Cincinnati, OH...Louisville, KY...Lexington-Fayette, KY...
5 % 167,560 21,356,610 Indianapolis, IN...Memphis, TN...Cleveland, OH...Toledo, OH...Fort Wayne, IN...
SPC AC 230730
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 AM CDT Fri Jun 23 2023
Valid 251200Z - 261200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID MISSISSIPPI...OHIO AND TENNESSEE VALLEYS...
...SUMMARY...
A severe threat will be likely across parts of the mid Mississippi,
Ohio and Tennessee Valleys on Sunday. Large hail, wind damage and
perhaps a couple tornadoes will be possible.
...Mid Mississippi, Ohio and Tennessee Valleys...
An upper-level trough will move eastward across the north-central
states on Sunday, as a 60 to 70 knot mid-level jet translates
eastward across the mid Mississippi Valley. At the surface, a low
will move into the western Great Lakes as a cold front advances
southeastward into the mid Mississippi Valley. Ahead of the front,
surface dewpoints in the low to mid 70s F will contribute to a
corridor of moderate to strong instability by early afternoon from
western Tennessee into central and northern Kentucky. During the
afternoon, convection is forecast to first initiate on the northern
edge of the stronger instability, with storms moving eastward across
the Ohio Valley during the mid to late afternoon. Convective
coverage should continue expanding across the region during the
early evening, with a band of storms moving east-southeastward into
the central Appalachians, and southeastward into the Tennessee
Valley. MCS development will be possible across parts of the Ohio
and Tennessee Valleys.
The mid-level jet will move into the Ohio Valley during the
afternoon, enhancing large-scale ascent and creating moderate
deep-layer shear. NAM forecast soundings near Cincinnati during the
late afternoon have 0-6 km shear in the 40 to 45 knot range with
some directional shear present in the low levels. In addition,
MLCAPE is forecast to peak in the 3000 to 4000 J/kg range. This
combined with mid-level lapse rates near 7 C/km should be favorable
for supercells with large hail. Hailstones greater than 2 inches in
diameter will be possible. Wind damage will also possible with
supercells and the more intense line segments. In addition, 0-3 km
storm-relative helicity is forecast to increase into the 300 to 350
m2/s2 range, suggesting that a tornado threat may also develop. The
severe threat could be upgraded to Enhanced Risk in later outlooks,
if model runs continue to show a greater coverage of severe threat
Sunday afternoon and evening.
Further to the west, a severe threat will also be possible in parts
of the Ozarks Sunday afternoon. Although a potential will exist for
isolated large hail and wind damage, weaker large-scale ascent and
warm temperatures in the mid-levels should keep convective coverage
more isolated
