SPC Dec 9, 2023 0700 UTC Day 2 Convective Outlook

[NorthGeorgiaWX]

SPC 0700Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1243 AM CST Sat Dec 09 2023

Valid 101200Z - 111200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE FL
PANHANDLE TO THE DELMARVA...

...SUMMARY...
Isolated severe thunderstorms will be possible through Sunday
evening across parts of the Southeast States, mainly in the form of
sporadic damaging winds and a few brief tornadoes.

...Synopsis...
An amplified, positive-tilt upper trough from ON to east TX at 12Z
Sunday will take on a neutral to slight negative tilt as a basal
shortwave impulse rapidly ejects across the Deep South to the Lower
Mid-Atlantic States. Intense mid-level southerlies will become
asymmetrically confined ahead of the trough by early morning Monday.
Surface cyclogenesis will occur from the central/southern
Appalachians across the Northeast into southern New England, with
greater deepening during the latter half of the period.

...FL Panhandle to the Delmarva...
Overall scenario appears similar to prior days with a broad swath of
low-probability tornado and severe thunderstorm wind evident from
Sunday morning to evening across the Southeast States. A mesoscale
corridor of greater tornado/wind threat may be highlighted in later
outlooks, seemingly within the eastern SC to southeast VA vicinity. 


A swath of showers and embedded thunderstorms will likely be ongoing
12Z Sunday from western/central VA to the FL Panhandle, within the
warm conveyor ahead of a surface cold front steadily progressing
eastward. Morning severe potential should generally be confined to
the FL/GA portion of the risk area, where mid 60s surface dew points
should be more common ahead of the early-day convection. Diurnal
diabatic heating is still expected to be muted, with extensive
low-level moistening and resultant cloudiness anticipated. Consensus
of guidance still suggests that a separate low-level warm theta-e
advection regime from the western Atlantic will aid in a secondary
swath of convective development by late morning into the afternoon
across the eastern Carolinas. A corridor of somewhat greater surface
heating may occur between both regimes which could yield a mesoscale
area of MLCAPE from 500-1000 J/kg. Otherwise, amid weak mid-level
lapse rates, much of the region should hold with MLCAPE at or below
500 J/kg. Low-level hodographs will be more favorably enlarged from
the Carolinas northward. Should this become coincident with greater
than meager buoyancy, a level 2-SLGT risk may be warranted for
Sunday afternoon.

More prominent strengthening of low-level southerlies will occur on
Sunday night as cyclogenesis intensifies. However, the thermodynamic
environment may be mostly to completely overturned by this time
frame, given widespread convection. Guidance varies substantially in
whether scant to meager surface-based buoyancy can still linger
ahead of the cold front, mainly across eastern NC. Should this
occur, a brief tornado/damaging-wind threat may be  sustained
through late evening.

..Grams.. 12/09/2023

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