038
ACUS02 KWNS 211731
SWODY2
SPC AC 211730

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 PM CDT Tue May 21 2024

Valid 221200Z - 231200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
TEXAS AND SOUTHEAST OKLAHOMA ACROSS THE OZARKS AND TOWARD THE
MISSOURI BOOTHEEL...

...SUMMARY...
Severe thunderstorms posing a risk for damaging gusts and hail will
be possible from central Texas into the Ohio Valley and lower Great
Lakes area on Wednesday. The greatest threat of damaging hail and
wind is forecast from north Texas across the Ozarks.

...Synopsis...
A broad zone of moderate to strong southwest flow will stretch from
the Plains to the Great Lakes, with the primary shortwave trough
affecting the upper MS Valley and Great Lakes through 00Z. This wave
will eject northeastward into Ontario and Quebec thereafter, with
various convectively enhanced disturbances trailing southwestward
within the southwest flow toward Texas.

At the surface, low pressure near Lake Superior early Wednesday will
fill as it occludes into Ontario, with a cold front roughly from
lower MI into southern MO and into northwest TX by midday. Ahead of
this front, ample moisture will exist from TX into the lower OH
Valley, with various rounds of severe thunderstorms throughout the
period.

...Southern Plains into the Ozarks and Mid South...
Severe regimes are forecast on both sides of the synoptic front,
beginning early on Wednesday.

Scattered storms are expected early Wednesday morning over parts of
OK, and expanding into southern MO. Here, forecast soundings show
extreme elevated instability, along with very favorable hodographs
supporting splitting elevated hail storms. Northeast winds north of
the front beneath moderate southwest flow will result in lengthy
hodographs and good effective-layer storm relative inflow. While the
precise corridor is difficult to place, it will likely be just north
of the surface front, with potential swaths of significant damaging
hail.

Western portions of the front into northwest TX will also favor
relatively early development, with steep lapse rates aloft and
lengthy hodographs again favoring damaging hail. As heating occurs
ahead of the boundary, additional storms will develop across
northern TX, producing damaging hail and areas of damaging winds. A
couple tornadoes will be possible, especially if the boundary
briefly stalls or robust cells develop along old outflows. Given
that the boundary is roughly parallel to the flow aloft, a prolonged
splitting hail storm event will be possible, from the Red River
region across the Ozarks.

Additional clusters of storms are likely to develop and translate
south/southeast across AR and into western TN/MS where ample
moisture and instability will favor areas of damaging wind and hail.

...OH Valley into PA/NY...
Although the region will be well ahead of the main upper wave,
gradual height falls are forecast to occur atop the moistening air
mass ahead of the cold front. Strong heating will lead to an
uncapped air mass, with weak but sufficient lift timed with peak
heating.  Scattered cells are forecast from the OH River toward the
southern shores of Lakes Erie and Ontario by around 21Z, and modest
veering with height may support a few longer lived cells capable of
hail spreading east.

..Jewell.. 05/21/2024

$$