Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0242 PM CDT Wed May 15 2024
Valid 152000Z - 161200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE TX
PANHANDLE INTO NORTHWEST OK AND SOUTH KS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN SC AND SOUTHERN
NC...
...SUMMARY...
Severe thunderstorms are expected across the southern Plains this
afternoon and evening, accompanied by severe wind gusts, large hail,
and perhaps a tornado or two. Scattered severe thunderstorms are
also possible into early evening across parts of the Carolinas.
...20Z Update...
Two appreciable changes were made to the outlook. First, the level
2-SLGT risk across FL has been removed in the wake of the primary
convective clusters having moved off the coast. Isolated
thunderstorms may redevelop this evening into tonight, so the level
1-MRGL risk has been maintained for now. The other adjustment was to
add a small 2 percent tornado area in southwest MN where an arc of
low-topped convection has developed ahead of a shortwave trough and
attendant surface cyclone in SD. A brief tornado remains possible
along the edge of mid 50s surface dew points where temperatures have
warmed into the middle 60s to low 70s. This potential should be
short-lived as the corridor of modest low-level SRH shifts
northeastward away from the meager buoyancy plume emanating north
from the Mid-MO Valley.
..Grams.. 05/15/2024
.PREV DISCUSSION... /ISSUED 1130 AM CDT Wed May 15 2024/
...Carolinas this afternoon/evening...
Along and south of a slow moving front across southern NC, surface
heating in cloud breaks and boundary-layer dewpoints of 65-70 F are
contributing to MLCAPE of 1500-2000 J/kg and minimal convective
inhibition. Thunderstorm development is expected by early afternoon
along/south of the front into the warm sector, in advance of
embedded perturbations rotating around the southeast periphery of a
midlevel trough approaching the southern Appalachians. Mostly
straight hodographs with effective bulk shear of 35-50 kt will favor
a mix of organized clusters and/or supercells capable of producing
large hail of 1-1.75 inches in diameter and damaging winds of 60-70
mph.
...Central FL today...
Convection is ongoing along and north of a diffuse outflow boundary
across central FL, as well as upstream over the eastern Gulf of
Mexico. VWPs from TBW/MLB/JAX show largely unidirectional,
west-southwesterly wind profiles with straight hodographs, in an
environment with MLCAPE of 2000-3000 J/kg. Central FL will be along
the southern periphery of the southern Appalachians midlevel trough
with modest forcing for ascent near its peak this afternoon. It
appears the strongest storms, which will include a mix of
supercells/clusters, will tend to remain along the southern fringe
of the ongoing convection, with more uncertainty farther north based
on more extensive cloud cover. The strongest storms will be capable
of producing large hail up to 1.5 inches in diameter and 60-70 mph
outflow winds.
...Southern Plains this afternoon into tonight...
A shallow, moist boundary layer is returning to south TX, but areas
farther to the north will rely on residual low-level moisture and
evapotranspiration from moist soil and green vegetation to boost
boundary-layer dewpoints into the 50s/low 60s. Weak perturbations
will move eastward from northern NM and CO toward the TX
Panhandle/northwest OK/KS, along a weak front from central KS to the
TX Panhandle. Strong surface heating along and south of the front
will drive a deepening mixed layer, while there will be sufficient
moisture/steep midlevel lapse rates to support MLCAPE of 1000-2000
J/kg. The moderate buoyancy and inverted-V profiles will favor
hybrid microbursts with severe outflow winds of 60-80 mph,
especially with any organized clusters/high-based supercells and
storm mergers. Large hail of 1-2 inches in diameter will be
possible with any persistent supercells or favorable storm mergers.
The tornado threat will be tempered by modest low-level moisture.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/T6xZMN
