SPC May 4, 2025 1300 UTC Day 1 Convective Outlook

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0750 AM CDT Sun May 04 2025

Valid 041300Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NEW
MEXICO AND FAR WEST TEXAS...

...SUMMARY...
Strong to potentially severe storms are expected across east-central
and southeast New Mexico and far west Texas this afternoon and
evening, with a threat for large hail, isolated severe wind gusts,
and possibly a tornado. Other strong to locally severe storms are
possible from Florida northward into the Mid-Atlantic and Allegheny
Plateau.

...New Mexico/West Texas...
In advance of the upper trough over the Southwest Deserts,
increasing height falls and strongly diffluent flow aloft will
overspread a modestly moist boundary layer with prevalent 40s to
near 50F surface dewpoints. Beneath steep mid-level lapse rates,
upwards of 500-1000 J/kg MLCAPE is expected by late afternoon.
Scattered thunderstorms are expected across northern into
east-central New Mexico, with more isolated storms expected into far
southeast New Mexico and west Texas. Wind profiles veering with
height and increasing mid-level southwesterly winds will provide
sufficient deep-layer shear for storm organization, including the
probable development of a few supercells. Large hail and localized
severe wind gusts will be possible. In addition, enlarging low-level
hodographs and gradually improving low-level moisture could support
a tornado or two if any mature supercells can persist through late
afternoon into the evening.

...Florida...
A cluster of storms across the north-central Peninsula, and to a
lesser extent across the south-central Peninsula, may pose a
localized severe risk as they continue eastward today. Existing
cloud cover may tend to somewhat mute more robust heating, but
gradual destabilization should still occur particularly along the
east coast, which will also probably influence storm development.
Effective shear of 25-30 kt will support potentially organized
storms capable of hail and isolated damaging gusts, and some tornado
threat may exist particularly in the vicinity of the sea breeze or
any other boundaries.

...Allegheny Plateau into the Carolinas...
East of the semi-stacked/closed low, cloud breaks and cold
temperatures aloft should support modest diurnal destabilization
across parts of Ohio and West Virginia into western Pennsylvania.
Storm development should be aided one or more low-amplitude
vorticity maxima rotating around the midlevel cyclone amidst
diffluent flow aloft. Low-level winds are expected to remain rather
weak, but modestly veering wind profiles and moderate mid-level flow
could support some storm organization, if sufficient buoyancy can be
realized. Hail and locally gusty winds could accompany the strongest
storms, and a corridor of higher severe probabilities (Slight Risk
caliber) may be warranted if a scenario with somewhat greater
destabilization appears likely.

Farther south into the Carolinas and parts of the Mid-Atlantic
region, somewhat stronger diurnal heating is expected, and MLCAPE
may increase to near/above 1000 J/kg. However, storm coverage is
more uncertain, with a notable mid-level dry slot and only weak to
modest large-scale ascent expected with southward extent. Any storms
that can mature within this environment could become modestly
organized with a threat of isolated hail and damaging gusts. 

...Eastern Idaho/southwest Montana...
Scattered storm development is expected this afternoon and evening
across eastern Idaho into southwest Montana, within an environment
characterized by cool temperatures aloft and steep lapse rates.
Deep-layer shear will be relatively modest, but a few stronger
storms with small hail and gusty winds could occur. Subsequent
outlooks will reevaluate the need for a potential introduction of
low-end severe probabilities.

..Guyer/Jewell.. 05/04/2025

StormPrep