SPC Jan 8, 2024 0700 UTC Day 2 Convective Outlook

[NorthGeorgiaWX]

SPC 0700Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1146 PM CST Sun Jan 07 2024

Valid 091200Z - 101200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TUESDAY ACROSS
PARTS OF SOUTHEASTERN ALABAMA...NORTHERN FLORIDA...PARTS OF THE
CAROLINA PIEDMONT AND THE CAROLINA COASTAL PLAIN...

...SUMMARY...
Severe thunderstorms may impact much of the eastern Gulf and
southern Atlantic Coast states Tuesday, accompanied by a risk for
very strong and damaging wind gusts and a few strong tornadoes.

...Synopsis...
Within the prevailing split flow across the eastern mid-latitude
Pacific, it still appears that mid/upper ridging will undergo
amplification through this period.  As this occurs, mid-level
troughing is forecast to begin to dig across Pacific Northwest, and
a strong downstream trough, initially approaching the Mississippi
Valley, likely will remain progressive. 

Strong cyclogenesis appears likely to proceed from the Mississippi
Valley through much of the eastern U.S., with the center of the
primary surface cyclone generally forecast to track from east
central Missouri through lower Michigan by late Tuesday night. 
Models indicate that the mid/upper trough axis will take on a
negative tilt while pivoting northeast of the Mississippi Valley,
with difluent flow aloft overspreading much of the Southeast. 
Further intensification of lower/mid-tropospheric wind fields may
include 50-90+ kt southerly to southwesterly flow in the 850-700 mb
layer overspreading much of the eastern Gulf/southern Atlantic Coast
region during the day Tuesday, accompanied by a moistening warm
sector.

...Southeast...
Associated with the strong synoptic forcing for ascent, a strong to
severe squall line, perhaps closely preceded by discrete supercell
development, may be ongoing ahead of an eastward surging cold front
across parts of central/southern Alabama into the north central Gulf
of Mexico at 12Z Tuesday.  With at least a continuing corridor of
sufficient pre-frontal destabilization, the forcing for ascent
likely will maintain this convective development across much of the
eastern Gulf/southern Atlantic Coast region by Tuesday evening.

While inflow off the Atlantic into the Carolinas will contribute to
pre-frontal low-level moistening even if the Gulf moist inflow
becomes cut off, relatively warm layers aloft with weak lapse rates
model likely will tend to at least limit the degree of
boundary-layer destabilization.  However, latest forecast soundings
from both the 03Z Rapid Refresh and NAM do appear to suggest that
thermodynamic profiles immediately ahead of the line will continue
to become at least marginally sufficient to maintain a line of
surface-based or near surface-based storms.  

It is still possible that the line of convection may undergo at
least some weakening across parts of Georgia and Florida during the
morning or early afternoon, before intensifying once again across
the Carolinas.  However, given mean winds forecast on the order of
60-70+ kts in the lowest 6 km, downward mixing of higher momentum
may remain sufficient to support widespread strong, damaging wind
gusts.  Given the strong to extreme low-level shear, developing
meso-vortices within the line may pose a risk for tornadoes.

Within the moistening return flow off the Atlantic, there is at
least some signal within convection allowing guidance of increasing
potential for discrete supercell development across the Carolina
coastal plain by late Tuesday afternoon, aided by large-scale ascent
associated with warm advection ahead of the squall line.  In the
presence of potentially very large, clockwise-curved low-level
hodographs, this may be accompanied by the risk for a couple of
strong tornadoes.

It remains unclear how much of a focus a remnant baroclinic zone,
extending through much of the eastern Georgia and Carolina Piedmont,
may become for severe thunderstorm development.

..Kerr.. 01/08/2024

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