SPC May 22, 2025 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0737 AM CDT Thu May 22 2025

Valid 221300Z - 231200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTHERN
PORTIONS OF TEXAS AND SOUTHERN OKLAHOMA...

...SUMMARY...
Severe storms are possible across parts of the southern Plains this
afternoon and evening. Large hail is the main threat, along with
severe gusts.  A few instances of 2+ inch diameter hail are
possible.

...Southern Plains...
Weak short-wave ridging will shift into the central High Plains
later today and mid-level heights are forecast to rise from the
southern Rockies into the northern Plains.  As this occurs, a
synoptic front draped across OK will sag south and sharpen over the
TX South Plains/southern OK by mid-late afternoon.  Strong heating
south of the boundary will contribute to a moderately to very
unstable airmass.  Scattered thunderstorms will likely evolve and
mature within this steep lapse-rate environment with 0-6km bulk
shear around 40kt.  Wind profiles favor supercells and hodographs
suggest very large hail is likely with the most robust updrafts.
Severe gusts are possible with the stronger downdrafts and upscale
growth into a couple of thunderstorm clusters is forecast during the
evening as this activity moves into northwest/north-central TX
during the evening hours.

...Southern/Eastern Florida...
Seasonally cool 500-mb temperatures (-8 to -10 deg C) and moderately
steep mid-level lapse rates are forecast equatorward of a
large-scale eastern U.S. upper trough.  Deep westerly flow favors an
east coast sea breeze, and this should be where convection focuses
as temperatures warm through the upper 80s and lower 90s.  Localized
severe gusts and large hail are the primary threats with this
diurnally driven convection.

...Central High Plains...
The aforementioned mid-level ridge and an eastward-migrating
mid-level trough over the northern Rockies will favor southeasterly
low-level upslope flow into the central High Plains.  Modest
moisture coupled with strong heating will yield 250-750 J/kg SBCAPE
by mid afternoon east of the Front Range.  Recent model runs of the
HRRR show a dearth of storm coverage, but the 00z HREF implies at
least isolated storms.  Elongated straight-line hodographs will
support east-southeastward moving storms within an environment
featuring steep 700-500 mb lapse rates (8 deg C/km).  A couple of
stronger storms may result in an isolated risk for large hail/severe
gusts.

..Smith/Marsh.. 05/22/2025

StormPrep