SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1251 PM CDT Fri Jun 16 2023
Valid 171200Z - 181200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS
OKLAHOMA...AND PORTIONS OF SURROUNDING STATES......
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN
PARTS OF MISSISSIPPI/ALABAMA/GEORGIA AND MUCH OF FLORIDA...
...SUMMARY...
Severe thunderstorms are expected across portions of the central and
southern Great Plains Saturday through Saturday night, with
additional strong to severe thunderstorms expected from the central
Gulf Coast region into much of Florida.
...Synopsis...
Moderately strong southern-stream flow will persist across the
southern U.S. Saturday, with one trough within this stream to move
across the Southeast, and a second to shift out of the Rockies and
into the Kansas/Oklahoma area later in the period. Meanwhile in the
northern stream, lows are forecast to reside over western Canada and
the Northeast U.S. through the period.
At the surface, a baroclinic zone will remain generally in place
east-to-west across the Southeast and Gulf Coast states and into
Texas, while a second/weak front shifts southeastward across the
Plains through Sunday morning.
...Southeastern Colorado southeastward to the Ozarks and Arklatex...
Daytime heating of a moist boundary layer near and south of the
remnant surface front is expected across the southern Plains area
Saturday, and to a somewhat lesser degree northward into Colorado
and Kansas ahead of a weaker/secondary front, which will result in
moderate to strong destabilization across a large area. This will
result in diurnal development of storms -- across portions of the
southeastern Colorado area during the afternoon, and in more
limited/uncertain degree southward along a west Texas dryline, where
capping will be stronger.
Developing storms are expected to quickly intensify given the
thermodynamic environment, and with moderately strong westerly
mid-level flow persisting atop the area, supercells are expected,
accompanied by potential for very large hail and damaging winds.
With time, one or more areas of convection will likely grow upscale,
with some CAMs suggesting two separate clusters evolving (one moving
southeastward out of Colorado and a second across central/northern
Texas), while others suggest one larger MCS evolving (across the
southern Kansas/Oklahoma area as a southwesterly low-level jet
intensifies during the evening). In any case, any upscale growth
should enhance potential for very strong/damaging winds, given the
background kinematic environment. As such, an upgrade to enhanced
risk is being introduced at this time, which will likely require
refinement as the scenario becomes a bit more clear with time.
Risk will likely continue through the evening and into the overnight
hours, as the convection propagates eastward/east-southeastward
toward southern Missouri/Arkansas/northern Louisiana later in the
period.
...Southern portions of Mississippi/Alabama/Georgia and into much of
Florida...
A complex scenario is forecast across parts of Southeast Saturday,
as ongoing convection is expected across parts of Florida, and
perhaps portions of the central Gulf Coast states, near and south of
the remnant surface front lying west-to-east across the region.
Away from early/ongoing convection and associated cloud cover,
diurnal destabilization of the moist boundary layer will support
additional/widespread convective development, aided by the
southeastward advance of mid-level short-wave troughing across the
Southeast states.
While narrowing down specific corridors of potentially greater
severe-weather coverage is difficult at this time, the broadly
favorable kinematic environment combined with moderately strong
deep-layer flow (40 to 60 kt in the 850 to 500 mb layer) that will
spread across the region in conjunction with the aforementioned
mid-level troughing suggests risk for hail and damaging winds, and
possibly a tornado or two, with episodic storms/storm clusters
across this area through most if not all of the period.
..Goss.. 06/16/2023
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