Severe Storm Outlook Narrative (AC)
Issued by NWS

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609
ACUS02 KWNS 131732
SWODY2
SPC AC 131731

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 PM CDT Sun Jul 13 2025

Valid 141200Z - 151200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN
NEW ENGLAND TO THE MID ATLANTIC AND THE NORTHERN ROCKIES/PLAINS...

...SUMMARY...
Isolated strong to severe thunderstorms are possible across portions
of the northern Plains/Rockies and across the Mid Atlantic and
Southern New England Monday.

...Mid Atlantic to southern New England...
Weak troughing at the northern periphery of the subtropical ridge
will shift northward across parts of the Northeast Monday. At the
surface, a wind shift/weak front will move from the eastern Great
Lakes into the upper OH/St Lawrence Valley by early afternoon. A
very warm and humid air mass is in place east of the front with
dewpoints in the 70s F expected. Despite some lingering cloud cover,
diurnal heating should support moderate destabilization over much of
the Northeast. Widespread thunderstorm activity is expected along
and ahead of the surface boundary from northern VA into southern NY.
Slight enhancement of the flow aloft to near 20 kt from the
approaching shortwave could be enough to foster some longer-lived
clusters with damaging gust potential from northern VA into southern
NY. Elsewhere across the East, confidence in storm coverage/damaging
wind potential is lower, but any stronger storms will remain cable
of damaging outflow gusts from heavily water-loaded downdrafts.

...Northern Rockies and Plains...
An upper trough, forecast to emanate from southern Canada, will move
eastward over the northern Rockies/Plains Monday and Monday night.
Ascent from this feature will overspread a weak cold front and lee
trough/low, that will serve as a focus for scattered thunderstorms
through afternoon and evening. Along the southern fringes of
enhanced westerly flow aloft, a mix of multicells and transient
supercells is expected. Modest surface moisture and deep
boundary-layer mixing will support moderate buoyancy atop inverted-v
structures favorable for damaging gusts and some hail with storms
from northern WY into the western Dakotas.

Late in the evening and into the overnight hours, low-level warm
advection and continued ascent from the upper trough are expected to
intensify along and north of the cold front from eastern MT into ND.
A belt of strong mid-level flow (35-50 kt) will overlap with
elevated destabilization north of the front. While not overly
robust, sufficient buoyancy (MUCAPE ~1000 J/kg) and elongated
hodographs should support a few organized elevated storms (including
supercell structures) capable of isolated hail.

...Southeast States...
A seasonably warm and moist air mass will again reside across much
of the southeastern US beneath broad subtropical ridging aloft.
Scattered to numerous storms expected Monday afternoon and evening
amid strong diurnal heating and weak background ascent. With PWATs
near or exceeding two inches and moderate buoyancy, a few stronger
thunderstorm clusters may develop. With weak vertical shear below 15
kt, organized storms on a widespread basis are not expected. Still,
sporadic damaging gusts from wet microbursts are possible.

..Lyons.. 07/13/2025

$$