- Day Three
acus02 kwns 221714
Storm Prediction Center ac 221713
Day 2 convective outlook
National Weather Service Storm Prediction Center Norman OK
1213 PM CDT sun Oct 22 2017
Valid 231200z - 241200z
..there is a marginal risk of severe thunderstorms from eastern
Georgia to the mid-Atlantic...
A few strong to marginally severe storms are expected from eastern
Georgia to the mid-Atlantic Monday afternoon into the overnight
hours. The primary threat will be damaging wind gusts.
..Georgia and the Carolinas...
A pronounced mid-level shortwave trough, now crossing East Texas,
will progress eastward to the southeast US on Monday, gradually
acquiring a more negative tilt as a powerful upper jet evolves
southeastward over the central/northern plains. In response to the
southeastern impulse, a surface front will push towards the Atlantic
Seaboard, while southerly flow ahead of the front brings mid/upper
60s dew points northward across parts of the Carolinas.
Near/along the front, a broken line of convection will likely be
progressing east across Alabama, Georgia, and the Florida Panhandle
early in the day. As the line encounters greater moisture and
related surface-based buoyancy across eastern Georgia and South
Carolina by afternoon, modest strengthening of convection is
probable. Forecast deep-layer wind fields suggest a potential for
small bowing segments and occasional embedded circulations within
the broader line of storms. However, strengthening anvil-layer flow
may cast considerable cloud cover/precipitation downstream during
the day, stunting low-level destabilization and tempering the severe
threat. Nonetheless, the potential remains for a few damaging gusts
and perhaps a tornado, and some parts of the marginal risk
(especially across SC and far eastern ga) could require an upgrade
if a greater potential for heating/destabilization becomes apparent.
A broken line of shallow/thin convection will race eastward across
Virginia through the overnight, with showers and thunderstorms
approaching the Delmarva by early Tuesday morning. Destabilization
will be even weaker here than it will be over the southeast, and
surface-based parcels may have only 100-300 j/kg of MLCAPE to
utilize during the overnight hours. However, 50-60 kt of 850mb flow
will overspread parts of the region towards 03-09z. In turn, more
organized convective elements may sufficiently enhance downward
momentum Transfer for isolated damaging gusts late Monday night.