SPC Dec 9, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

SPC 1930Z Day 3 Outlook

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0111 PM CST Mon Dec 09 2024

Valid 111200Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN
NORTH CAROLINA TO SOUTHERN NEW ENGLAND...

...SUMMARY...
Strong to isolated severe thunderstorms are possible along and ahead
of a cold front from the Mid-Atlantic into the Florida Peninsula on
Wednesday.

...Synopsis...
As a strong mid-level trough becomes negatively tilted across the
eastern CONUS, a surface low will deepen as it moves north along the
spine of the Appalachians and tropospheric flow will strengthen
across much of the East Coast. As the surface low deepens, a cold
front will sharpen and move quickly east through the period and move
into the Atlantic by late Wednesday afternoon/early evening. 

...Eastern North Carolina to southern New England...
As the surface low deepens and the cold front sharpens, expect a
strongly forced convective line to develop during the morning near
the Appalachian Mountains and strengthen as it moves east by late
morning to early afternoon. Low 60s dewpoints ahead of this front
will lead to marginal instability 100-300 J/kg MLCAPE ahead of the
line. However, despite the weak instability, this line may have some
threat for damaging wind gusts given the strength of the kinematic
field. A 130 knot mid-level jet streak and a 75 knot low-level jet
will overspread the warm sector during the late morning to early
afternoon which will provide a large reservoir of high momentum air
which may mix to the surface within the strongly forced line. A
marginal risk has been added to address this threat. Some low-level
stability is possible along the immediate coast due to the cold
shelfwaters. However, given the strength of the flow and how
strongly forced the line will likely be, some damaging wind threat
could still exist into areas with this marine influence.

..Bentley.. 12/09/2024

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