From Dumas Walker@21:1/175 to All on Tue Jul 9 08:22:00 2024
ACUS01 KWNS 091237
SWODY1
SPC AC 091236
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0736 AM CDT Tue Jul 09 2024
Valid 091300Z - 101200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN
KENTUCKY AND SOUTHERN INDIANA...
...SUMMARY...
Several tornadoes are possible today over the lower Ohio Valley in
association with the remnants of Beryl.
...Lower Ohio Valley/Mid Mississippi Valley...
Water-vapor imagery this morning shows a progressive mid-level
shortwave trough moving east across the lower MO Valley/Ozarks.
This mid-level trough is forecast to reach Lake Michigan/Indiana by
late tonight. The remnants of Beryl will move across the mid
Mississippi and lower Ohio Valleys today. Ahead of the associated
surface low, morning surface analysis indicates a reservoir of lower
70s deg F dewpoints from the IN/OH/KY tri-state south/southwest into
the Mid South ahead of the low. Surface streamlines show a warm
frontal zone extending east-northeast from the low. The warm front
will advance northward to near the OH River by mid afternoon and
serve as a focus for severe thunderstorm potential.
Despite considerable cloud cover this morning, significant cloud
breaks south of the warm front and pockets of heating will
destabilize the airmass from the mid MS Valley to the OH Valley.
Moderate buoyancy is forecast to develop in the vicinity of the warm
front and to its south over parts of KY/TN. Models imply, and this
notion is supported by morning observational trends, that a couple
of convective bands will preferentially favor storm development
today. Widely scattered to scattered thunderstorms are forecast to
develop within a moderately unstable airmass (1000-1500 J/kg
MLCAPE). Forecast hodographs will become enlarged --especially in
the warm frontal zone where backed low-level flow will reside-- as a
30-40 southerly 850-mb LLJ overspreads the OH Valley during the afternoon/evening. One or more bands of quasi-discrete supercells
are forecast with tornado potential greatest in a southwest to
northeast corridor paralleling the OH River this afternoon into the
evening.
...New England...
A low-amplitude trough at mid-levels will move eastward across
Quebec and New England during the period. Heating of a seasonably
moist airmass by afternoon will aid in the development of scattered thunderstorms. A few organized multicells and perhaps a transient
supercell or two, will pose an isolated risk for 50-65 mph gusts and
large hail.