Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS02 KWNS 241720
SPC AC 241720
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1120 AM CST Fri Feb 24 2017
Valid 251200Z - 261200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
MID-ATLANTIC INTO WESTERN NEW YORK...
Thunderstorms potentially capable of mainly isolated damaging winds
are forecast from the Mid-Atlantic states northward through western
New York on Saturday.
...Mid-Atlantic States through eastern New York...
Upper trough initially situated from the Great Lakes through the
Tennessee Valley will advance east northeast into the Mid-Atlantic
and Northeast States Saturday. The attendant surface low will move
from the Great Lakes into southeast Canada while trailing cold front
continues east, reaching the Atlantic seaboard by early evening. A
line of convection including thunderstorms will likely be ongoing
from the southern Appalachians into the Lower Great Lakes region.
This activity will be embedded within strong unidirectional south
southwesterly deep-layer winds, and storms may pose an ongoing
threat for a few instances of strong to damaging wind gusts as they
continue east through the marginally unstable atmosphere. Further
weakening of the convection is expected over the southern
Appalachians where the line will not be as strongly forced. However,
greater potential for diabatic warming and stronger destabilization
of the boundary layer will exist from northern MD through VA where
mlcape up to 800 j/kg is possible, and storms will likely redevelop
along and just ahead of the cold front. This activity will also pose
at least a modest risk for isolated damaging wind gusts as it
continues toward the coast. Given the potential limiting factors
imposed by the expected marginal thermodynamic environment, will
maintain marginal risk category this outlook, but an upgrade to
slight risk might be warranted in day 1 updates.