296
ACUS01 KWNS 141959
SWODY1
SPC AC 141957

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0257 PM CDT Mon Jul 14 2025

Valid 142000Z - 151200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MID-ATLANTIC AND THE NORTHERN PLAINS...

...SUMMARY...
Strong to severe thunderstorms are possible across parts of the
northern Plains as well as the Mid-Atlantic States this afternoon
into tonight. Isolated strong to severe thunderstorms are possible
across the East, Mid-South, southeast Arizona, and Florida.

...20z Update...
The previous outlook remains on track and no significant changes
were made with this update. Towering cumulus/initial storm
development is underway across the higher terrain of WY and, as
remaining CINH as shown on the 18z Rapid City Sounding is removed
via diurnal heating, additional development is expected in the
vicinity of the Black Hills. Storms should tend to evolve into
clusters/line segments while moving east this afternoon and evening.
Very steep low- and mid-level lapse rates and dry low levels above
the boundary layer will result in a damaging wind risk, and an
isolated potential for severe hail with isolated stronger storms.

Across the mid-Atlantic, thunderstorms continue to develop and move
east within a very moist/moderately unstable air mass. Please refer
to Mesoscale Convective Discussion 1668 for the latest short-term
thinking regarding convective evolution in this area.

..Bunting.. 07/14/2025

.PREV DISCUSSION... /ISSUED 1135 AM CDT Mon Jul 14 2025/

...Mid-Atlantic into the Northeast...
A belt of stronger mid-level flow extends from the north-central
CONUS/south-central Canadian Prairies through the Northeast, with
some modest cyclonic curvature. A more defined shortwave trough is
currently progressing into the Upper OH Valley/central Appalachians,
along the southern periphery of the belt of stronger, broadly
cyclonic flow. Showers and isolated thunderstorms are currently
ongoing just ahead of this shortwave.

Expectation is for this shortwave trough to continue
eastward/northeastward throughout the day, with the modest upper
troughing farther north shifting eastward as well. A reservoir of
ample low-level moisture (i.e. dewpoints in the low to mid 70s) is
in place ahead of this shortwave. This low-level moisture will
support airmass destabilization and moderate buoyancy this afternoon
despite widespread cloudiness and tempered daytime heating.
Thunderstorm development is anticipated as large-scale ascent
attendant to the approaching shortwave (and larger upper trough)
moves into the region. Additionally, recent surface analysis places
a trough axis from the northern NY/VT border southwestward through
central PA. Low-level convergence along this axis could augment the
large-scale ascent. All of these factors will act to support
scattered to numerous thunderstorms this afternoon.

While mid-level flow and related deep-layer shear are both expected
to remain fairly modest, some of this convection could congeal into
multiple loosely organized clusters. Steepened low-level lapse rates
and water loaded downdrafts could support isolated strong to
damaging winds as thunderstorms spread generally eastward through
the afternoon and evening. Highest thunderstorm coverage and
greatest relative chance for damaging gusts is expected from eastern
PA through central VA.

...Northern Plains to Northern Minnesota...
Satellite imagery shows a vorticity maximum drifting slowly across
the central Intermountain West. Large-scale ascent attendant to this
vorticity maximum will augment low-level convergence along a
sharpening lee trough, likely resulting in enough lift to promote
thunderstorm development across eastern WY during the late
afternoon. This area is on the southern periphery of a belt of
stronger westerlies, and there appears to be just enough westerly
flow aloft for updraft organization and persistence into the better
moisture and buoyancy farther east. As such, there is a risk for
strong to severe gusts within this deeply mixed airmass throughout
the afternoon and evening.

Thunderstorm development also appears possible along a surface
trough that arcs from western MT to a low in southwest SD. A
conditional severe risk exists with any storms that develop near the
surface low over ND this afternoon, but the greater thunderstorm
coverage is anticipated later this evening and overnight as warm-air
advection across the frontal zone strengthens. Elevated
thunderstorms are also expected tonight as an
upper trough overspreads the northern Rockies. Given ample shear and
buoyancy, isolated hail is possible in both of these regions
tonight.

...Eastern GA into the FL Peninsula...
Ample low-level moisture and robust diurnal heating will result in
strong buoyancy from eastern GA southward across the entire FL
Peninsula this afternoon. A modest cyclone drifting westward towards
the GA/FL coast will interact with this airmass, contributing to
widespread thunderstorm development this afternoon. Convection
should develop along/near the Atlantic Coast before spreading
south-southwestward and inland across much of the FL Peninsula this
afternoon/evening. Several clusters capable of producing isolated
strong to severe winds are possible.

...AZ...
High pressure over the southern Great Basin will contribute to
around 20-25 kt of northeasterly mid-level flow across southern AZ
this afternoon. This mid-level flow will take storms that develop
across the higher terrain southwestward into the deeply mixed
boundary layer over southeast AZ. A few strong to severe gusts are
possible, but overall coverage will likely be sparse.

...South-Central/Southeast TX into the Mid-South...
A trio of MCVs is apparent on radar and satellite imagery this
morning. One is centered over Real and Uvalde Counties in the TX
Hill Country, with another over Denton and Collin Counties in north
TX, and the third farther north over northeast AR. At least
scattered thunderstorms are possible this afternoon/evening with
each of these MCVs as they progress eastward/northeastward. Vertical
shear will be weak, but discrete storm propagation along the
stronger outflows could result in occasionally strong/damaging
downbursts.

$$