323
ACUS01 KWNS 121247
SWODY1
SPC AC 121246

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0746 AM CDT Sun May 12 2024

Valid 121300Z - 131200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
CENTRAL/EAST TEXAS TO LOUISIANA...

...SUMMARY...
Scattered strong to severe storms are possible today and tonight
across east/southeast Texas to western and central Louisiana. Large
hail, locally damaging winds, and a couple tornadoes are possible.
More isolated strong to severe storms will be possible across parts
of the central and southern High Plains into central Texas, and also
across the upper Great Lakes region.

...Central/east Texas to the lower Mississippi Valley...
A front, roughly oriented west/northwest to east/southeast, will
transition northward as a warm front across central/southeast Texas
and southern Louisiana through the afternoon and evening. Associated
with warm/moist advection, elevated scattered showers and
thunderstorms are ongoing this morning well to the north of the
surface reflection of the front. There is some potential that this
activity could intensify and organize into the afternoon, possibly
including some elevated supercells in the presence of moderate
buoyancy and strong shear in the cloud-bearing layer. Large hail and
locally strong winds could occur.

Stronger heating/destabilization near and immediately south of the
northward-shifting front may support surface-based storm development
near the boundary into the afternoon, potentially from south-central
into southeast Texas including the coastal plain. Rich low-level
moisture, moderate to strong buoyancy, and sufficient deep-layer
shear would support supercells, with the possibility for all hazards
including a tornado risk as well as large hail and damaging winds.

There will be potential for forward-propagating clusters to evolve
by late afternoon into this evening across far southeast Texas into
Louisiana, with at least some severe risk continuing tonight
particularly near and immediately south of the effective warm front.


...Texas Edwards Plateau/Low Rolling Plains and High Plains...
While richer moisture will stay confined to central/south Texas, a
narrow corridor of moderate destabilization will be possible along
the surface trough/effective dryline from the Texas South Plains
vicinity northward into western Kansas.

Greater storm coverage is expected across the northern portion of
this corridor across western Kansas, in closer proximity to the
primary mid/upper-level trough. Cool temperatures aloft and steep
lapse rates will support a hail threat with the strongest storms.
However, with weak low-level flow and only modest deep-layer shear,
convection is expected to be only be weakly organized.

Farther south, deep-layer flow/shear will increase southward along
the dryline into the Oklahoma/Texas Panhandles and the Texas South
Plains. Ongoing early day thunderstorms and the potential for
lingering low-level cloud cover are key factors of uncertainty for
the extent and likelihood of near-dryline deep convection later
today. Pending a scattering of lingering clouds and adequate diurnal
destabilization, at least isolated supercell development is
plausible along the dryline during the afternoon, with an attendant
threat of large hail and locally gusty winds. This scenario
currently appears most probable across the Concho Valley vicinity
and Edwards Plateau late this afternoon and early evening.

...Upper Great Lakes...
Moisture will likely remain rather limited across the upper Great
Lakes vicinity in advance of the cold front, However, strong heating
will support some destabilization, with MLCAPE potentially
increasing into the 500-1000 J/kg range. Moderate west-northwesterly
midlevel flow will support some potential for organized convection,
and a few stronger cells/clusters may pose a threat for localized
severe gusts and perhaps some hail this afternoon and evening.

..Guyer.. 05/12/2024

$$