LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1232 AM CDT Sat Mar 18 2023
Valid 181200Z - 191200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not forecast Saturday.
...Florida...
Strong northern-stream upper trough will shift east across the Great
Lakes during the day1 period as 100+kt 500mb speed max translates
off the southern New England Coast, increasing to near 140kt by
19/12z. In the wake of this feature, strong surface anticyclone will
build south across the Plains, ultimately dominating the CONUS east
of the Rockies. Leading edge of this air mass will force a cold
front into the central FL Peninsula later this afternoon, then to
the Keys by the end of the period.
Early this morning, most concentrated convection extends ahead of
the front across southeast GA along with a nearly north-south band
approaching the central FL Gulf Coast. Scattered convection will
likely persist along/ahead of the boundary into the early part of
the period, but aside from a few strong updrafts, this activity is
not expected to be severe. Latest model guidance suggests modest
boundary-layer heating ahead of the cold front by late morning with
surface temperatures forecast to rise into the lower 80s by 18z.
Convective temperatures will be breached shortly thereafter and
isolated thunderstorms should develop along the boundary. While
SBCAPE values could exceed 1000 J/kg, modest lapse rates and
seasonally weak surface-6km bulk shear do not favor organized
updrafts, especially given the expected weak low-level convergence.
While a few robust updrafts could evolve, the prospect for severe
wind, and/or hail appear too low to warrant severe probabilities.
..Darrow/Lyons.. 03/18/2023
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