640
ACUS01 KWNS 060551
SWODY1
SPC AC 060550

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Thu Jun 06 2024

Valid 061200Z - 071200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE NORTHEAST...MID ATLANTIC...FLORIDA PENINSULA...AND PARTS OF
THE SOUTHERN PLAINS...

...SUMMARY...
Isolated strong to potentially severe thunderstorms will be possible
later today across parts of central and south Florida, parts of the
Mid Atlantic into the Northeast, and also from the Texas Panhandle
into western Oklahoma.

...Mid Atlantic/Northeast...

Latest water-vapor imagery depicts a notable upper trough over the
upper Great Lakes region, shifting east in line with latest model
guidance. 500mb speed max is forecast to translate across the
northern OH Valley into western NY by 18z, and 30-60m 12hr height
falls will spread across much of western PA/NY by peak heating.
Modest boundary-layer heating is expected ahead of this feature
which will result in a narrow corridor of MLCAPE on the order of
1000 J/kg from northeast PA into portions of upstate NY. Forecast
soundings suggest convective temperatures will be breached by 17z
and scattered thunderstorms should evolve along/ahead of the surging
cold front. While deep-layer shear is not expected to be
particularly strong, mid-level flow should be sufficient for some
organization and gusty winds are the primary risk with storms by mid
day.

Farther south across VA/NC, influence of Great Lakes trough will be
minimal but instability should be strong with MLCAPE values possibly
approaching 2000 J/kg prior to convective initiation. Deep
west-southwesterly flow and surface-6km bulk shear around 20kt may
permit some updraft organization. Gusty winds will be the primary
concern with thunderstorms that form after 18-19z across the
southern Mid Atlantic.

...Florida...

Seasonally cool 500mb temperatures will be noted across the FL
Peninsula today with values near -10C across northern FL. Weak
westerly flow at mid levels should encourage convection to
concentrate along the eastern Peninsula and solenoidal influences
will prove instrumental in robust convection by early afternoon.
With MLCAPE around 3000 J/kg and steep lapse rates, hail and wind
may be noted with the strongest storms.


...TX Panhandle/Western OK...

Upper ridge is expected to hold across the southwestern US through
the day1 period. This position will ensure northwesterly flow across
the southern High Plains with 500mb flow possibly approaching 30kt.
In addition to very steep lapse rates, PW values will be quite high
with readings of 1.5-2" from the eastern TX Panhandle into northern
OK. This corridor is coincident with a weak surface boundary that
should serve as the focus for convective initiation. NAM forecast
sounding southeast of GAG at 21z exhibits MLCAPE around 4000 J/kg
with 35kt surface-6km bulk shear and negligible CINH. Convection
should evolve near this wind shift after 21z than propagate
south-southwest into the eastern TX Panhandle. If sufficient
convection forms such that a substantial cold pool evolves, there
may be a need for a SLGT risk to account for potentially organized
wind event. Will maintain low probabilities at this time due to
storm coverage uncertainty.

..Darrow/Lyons.. 06/06/2024

$$