069
ACUS01 KWNS 271958
SWODY1
SPC AC 271957

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0257 PM CDT Mon May 27 2024

Valid 272000Z - 281200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF THE
EAST COAST STATES...AND OVER THE SOUTHERN PLAINS...

...SUMMARY...
Severe thunderstorms remain possible across from parts of the
Northeast southward across the Mid-Atlantic and into the Southeast
this afternoon. More isolated activity is possible through this
evening across much of central and eastern Texas, as well as
southwest Oklahoma and the mid/upper Mississippi Valley.

...20Z Changes...
Just a minor adjustment of the western edge of the risk areas across
the East as scattered storms continue to develop within the moist
pre-frontal air mass. Areas of locally stronger low-level shear may
favor a brief/weak tornado over parts of the Mid Atlantic. See
mesoscale discussion 1016 for more information.

For the Southern Plains, extended the Slight Risk southwestward
toward the Rio Grande Valley. Visible imagery shows increasing
cumulus and hot temperatures should aid storm development with
locally severe hail or wind gusts.

Farther north into OK, concerns are growing for an early morning
hail event as elevated instability develops northward across the 12Z
day1/day2 outlook time frame. While most of the development is
expected after 12Z, a few storms may produce hail earlier. As such,
have brought low hail probabilities/Marginal Risk farther north,
however, this does not necessarily mean hail will be small.

..Jewell.. 05/27/2024

.PREV DISCUSSION... /ISSUED 1145 AM CDT Mon May 27 2024/

...Eastern States/Southeast...
An initial ongoing focus for severe potential is across Georgia near
an outflow boundary and in the wake of an MCV across the Carolinas
Piedmont as of midday. Regional WSR-88D VWPs are sampling
supercell-favorable wind profiles across this region, with
additional storm development/intensification as the air mass
modifies/destabilizes across Georgia/South Carolina/southeast
Alabama. Another favored zone of severe storm development, including
supercells, may occur across eastern North Carolina/southeast
Virginia this afternoon near, or in the immediate wake of, the MCV,
in the presence of a very moist and strongly unstable boundary
layer.

Farther north, a broad north-south zone of severe thunderstorm
potential exists near, or more so in the immediate lee of, the
Appalachians. For additional details, see Mesoscale Discussion 1013.
Sufficient deep-layer shear and buoyancy will support potential for
both supercells and organized multicells in lines or clusters.
Damaging winds are expected to be the most common risks, but large
hail is also possible, along the potential for a couple of tornadoes
regionally.

...Southern Plains including North/Central Texas...
Isolated to scattered thunderstorm development is possible across a
broad part of North/central Texas by mid/late afternoon. Large hail
and damaging winds gusts are the greatest concerns in the presence
of large buoyancy and supercell-favorable deep-layer shear. The most
probable area for potentially intense deep convection will be near
the stalled/slow-moving front and east of the dryline, including a
corridor across North Texas/Big Country into central Texas including
the Concho Valley and Hill Country vicinity. Surface dewpoints
commonly in the 70s F and steep mid-level lapse rates will support
4000-5000 J/kg MLCAPE. A few small clusters could evolve by evening.
Later tonight, additional elevated/potentially severe storms will
probably form across western/southern Oklahoma and western North
Texas to the north of the surface front.

...Midwest including Iowa/Illinois...
A clipper-type shortwave trough over southern Minnesota and northern
Iowa this morning will continue southeastward today toward the Great
Lakes. Low-level moisture (50s F surface dewpoints) and overall
buoyancy will be limited in the wake of the primary cold front
approaching the Appalachians, but adequate moisture in the presence
of steepening low/mid-level lapse rates could yield some storms
capable of strong/gusty winds and possibly some hail during the
mid/late afternoon through early evening.

$$