Severe Storm Outlook Narrative (AC)
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000
ACUS02 KWNS 211722
SWODY2
SPC AC 211721

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1221 PM CDT Thu Mar 21 2024

Valid 221200Z - 231200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
CENTRAL GULF COAST AND SOUTH FLORIDA...

...SUMMARY...
One or two clusters of strong thunderstorms may impact portions of
southern Florida and the Keys Friday into Friday evening,
accompanied by at least some risk for damaging winds and a brief
tornado. More isolated strong to severe thunderstorm development may
impact central and northeastern Gulf coastal areas into Friday
night.

...Southeast States...

An upper trough within southern stream flow located over eastern
OK/TX Friday morning will migrate east across the Southeast U.S.
through early Saturday morning. Stronger deep-layer flow associated
with the subtropical jet will mostly remain over the Gulf, though
some stronger flow will impinge on the central Gulf Coast while also
overspreading FL. 30-40 kt west/southwesterly flow within the warm
conveyor ahead of the trough will support ongoing clusters of storms
early in the period and through much of the evening across portions
of the Southeast. At the surface, a weak low will shift east near
the central Gulf Coast through the day before lifting northeast into
GA overnight. This will maintain a cool/dry airmass inland from the
coast, especially across MS/AL, with some modest moisture return
ahead of the low across the FL Peninsula into GA.

While CAMs guidance varies in location and timing of convective
features, the overall consensus is that one cluster of storms over
the western Gulf will likely affect south FL and the Keys during the
morning into early afternoon. Meanwhile another cluster will likely
traverse east in the vicinity of the central Gulf Coast during the
morning and afternoon. Another round of thunderstorms associated
with an eastward-advancing cold front may then move across northern
FL/southern GA after 06z while continued convection associated with
warm advection impacts the coastal Carolinas during the nighttime
hours.

How much destabilization can occur ahead of any of the
aforementioned clusters of convection remains uncertain given
limited diurnal heating, and generally modest mid and low-level
lapse rates. Where/if stronger destabilization occurs, vertical
shear characterized by 0-6 km effective shear magnitudes near 40 kt
will support organized cells. Strong to locally damaging gusts will
be the main hazard with this activity, though small hail or a brief
spin-up also may be possible very near the coast.

..Leitman.. 03/21/2024

$$


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