Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
SPC AC 231241
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0741 AM CDT Tue May 23 2023
Valid 231300Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS
AFTERNOON/EVENING FROM THE SOUTH PLAINS INTO CENTRAL TX...
Isolated very large hail and damaging gusts will be possible this
afternoon/evening from South Plains into central Texas. Additional
strong to severe thunderstorms will be possible across Florida and
the northern Great Basin.
...South Plains into central TX this afternoon/evening...
Overnight convection dissipated early this morning over central TX,
with only subtle hints of lingering convective outflow. The surface
pattern today will consolidate into a loose baroclinic zone from
northwest TX to the South Plains, southeast of a weak lee cyclone
near the TX/NM border. Aloft, a series of weak perturbations will
crest the ridge over NM and move southeastward toward the TX
Panhandle by this evening. Surface heating and convergence/ascent
along the baroclinic zone will support thunderstorm development by
mid afternoon in a loose northwest-southeast band near the front,
and storms will subsequently move southeastward through late
Midlevel lapse rates will be a little steeper today (near 8 C/km)
compared to yesterday, and low-level moisture will be the same or
slightly greater (58-64 F dewpoints). MLCAPE is expected to reach
2000-3000 J/kg by mid-late afternoon along the front with minimal
convective inhibition. Vertical shear will be sufficient for
supercells given 25-30 kt midlevel westerly flow atop low-level
east-southeasterly flow, with effective bulk shear of 30-40 kt and
relatively straight hodographs. The initial, more discrete
supercells will be capable of producing isolated very large hail of
2 to 3 inches in diameter, while the threat for damaging winds of
60-75 mph will increase as convection grows upscale into one or more
clusters. Any tornado threat will rely on favorable storm
interactions, and/or locally curved hodographs close to the front
this evening, at the same time upscale growth into clusters is
...FL this afternoon...
Similar to yesterday, a weak midlevel trough persists over MS/AL/GA,
with a diffuse surface front across north FL. Surface heating will
drive local sea breeze circulations south of the front, with storm
formation expected from the FL Panhandle into the peninsula by
early-mid afternoon. Moderate buoyancy and effective bulk shear of
25-30 kt will favor a mix of semi-organized multicells and some
low-end supercells. The strongest storms will be capable of
producing isolated damaging downburst winds of 50-60 mph, while
steeper lapse rates aloft (in the hail growth zone) compared to
yesterday may support isolated, marginally severe hail.
...Northeast NV to southeast ID this afternoon/evening...
A midlevel low will form over OR, and heights will rise over the
northern Plains, allowing flow to back to south-southwesterly from
NV into ID. On the east edge of the stronger flow with the OR low,
surface heating will result in steep low-level lapse rates and
SBCAPE of 500-1000 J/kg this afternoon from northeast NV into
southeast ID. Scattered multicell clusters are expected in this
zone, with the potential for isolated strong-severe outflow gusts of
50-60 mph given the moderate buoyancy, effective bulk shear near 25
kt, and inverted-V profiles with DCAPE approaching 1000 J/kg.
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