ACUS01 KWNS 041627
SWODY1
SPC AC 041625

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1125 AM CDT Sun May 04 2025

Valid 041630Z - 051200Z

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

...SUMMARY...
Scattered severe thunderstorms are expected across parts of eastern
New Mexico and west Texas this afternoon and evening. Large to very
large hail, isolated severe wind gusts, and possibly a tornado or
two may occur.

...New Mexico and West Texas...
Large-scale ascent will increase this afternoon across NM and the
southern High Plains as strong difluence aloft associated with an
upper low over northwest Mexico and the Southwest moves eastward.
Steep lapse rates aloft atop modest low-level moisture will act in
tandem with daytime heating to foster up to 1000-1250 J/kg of MLCAPE
across eastern NM and far west TX by mid afternoon. While low-level
southeasterly flow will initially be modest, various RAP/NAM
forecast soundings show substantial veering and some strengthening
with height at mid/upper levels. Resultant long/straight hodographs
aloft and strong deep-layer shear will likely support a few
supercells with an attendant threat for large to very large hail (up
to 1.5-2.5 inches in diameter). Isolated severe wind gusts may also
occur as this convection spreads slowly eastward across eastern NM
into parts of west TX through the evening. Although low-level
moisture will remain modest, a southeasterly low-level jet is also
expected to gradually strengthen this evening, which should support
enough 0-1 km SRH for a tornado or two with any sustained supercell.
These thunderstorms will eventually weaken with eastward extent into
west TX as MLCIN gradually increases by mid/late evening.

...Upper Ohio Valley/Mid-Atlantic to the Carolinas...
An expansive closed mid/upper-level low will remain centered over
the OH/TN Valleys today. A belt of stronger south-southwesterly
mid-level winds will overspread parts of the upper OH Valley and
southern Mid-Atlantic through this evening. This enhanced flow along
with upper-level difluence should provide sufficient large-scale
ascent for isolated to scattered convection this afternoon across
parts of OH into WV and western PA. Low-level moisture will remain
somewhat limited across this area, with surface dewpoints generally
in the low to mid 50s. Even with filtered daytime heating, poor
lapse rates aloft should keep any more than weak instability from
developing. Various RAP forecast soundings across this region also
show flow backing with height aloft, which lends considerable
uncertainty regarding convective organization. While an isolated
damaging wind/hail threat may exist, the overall environment should
keep the severe threat fairly marginal.

A somewhat separate area of convection may develop this afternoon
across eastern NC into VA, generally along/ahead of a weak surface
front. While these thunderstorms will have access to greater
low-level moisture, both instability and deep-layer shear are
expected to remain modest. Still, some risk for damaging winds and
hail should exist with any cells or clusters that can develop,
before this activity gradually weakens through the evening with the
loss of daytime heating.

...Florida...
Scattered showers and thunderstorms are ongoing across parts of the
southern/central FL Peninsula. A subtropical upper-level jet should
continue to aid thunderstorm development across the FL Peninsula
through the afternoon. But, persistent cloud cover and poor lapse
rates aloft noted on area 12Z soundings may hinder destabilization
to some degree. Even so, a rather moist low-level airmass exists
along/south of a front over north FL/far southeast GA, and even
modest further heating should support sufficient instability for
surface-based convection. With weak low-level flow gradually veering
to westerly and strengthening at mid/upper levels, this activity
should have enough deep-layer shear for modest updraft organization.
Thunderstorms may preferentially form on/near the Atlantic Coast sea
breeze this afternoon while posing an isolated threat for severe
hail, damaging winds, and perhaps a brief tornado.

...Eastern Idaho into Southern Montana...
As a mid-level trough moves eastward over western Canada and the
northern Rockies, scattered thunderstorms should develop this
afternoon and evening across eastern Idaho into southwest Montana.
This region will have steep mid-level lapse rates and cool
temperatures aloft associated with the shortwave trough. Deep-layer
shear is expected to remain modest, but a couple of stronger cores
with small hail and gusty winds could still occur.

..Gleason/Squitieri.. 05/04/2025

$$



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