SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1120 AM CST Sat Feb 11 2023
Valid 121200Z - 131200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EARLY SUNDAY
ACROSS PORTIONS OF NORTH CAROLINA COASTAL AREAS...
...SUMMARY...
Strong thunderstorms posing some risk for severe weather may
approach, and perhaps spread across, portions of North Carolina
coastal areas Sunday morning into early Sunday afternoon, mainly
near Outer Banks vicinity.
...Synopsis...
Blocking has become a bit more prominent within the mid/upper flow
across the southern mid- and subtropical Pacific, near and to the
east and north of the Hawaiian Islands. Around the northern
periphery of this regime, a number of progressive short wave troughs
are embedded within a strong belt of westerlies extending more or
less zonally downstream of the northern mid-latitude Pacific, across
the Canadian/U.S. border vicinity. This includes one forecast to
dig east-southeast of the Canadian Rockies through northwestern
Ontario and the upper Great Lakes region by late Sunday night, and
another across the British Columbia/Pacific Northwest coast.
Within an initially more amplified branch across the southern
mid-latitudes, it appears that the center of a significant mid-level
low, currently digging along the California coast, will bottom out
to the west of northern Baja, before turning inland Sunday night and
reaching southwestern Arizona by 12Z Monday. A similar, but deeper,
downstream low is forecast to migrate from the Georgia Piedmont
across and offshore of the southern Mid Atlantic coast.
In association with the lead perturbation, a significant cold front
likely will have advanced through much of the Gulf of Mexico and
south/east of the Florida Peninsula and Keys by the beginning of the
period. Secondary surface cyclogenesis may gradually be underway
near the North Carolina coast, but it appears that the more rapid
deepening may not occur until later Sunday through Sunday night,
offshore of the Mid Atlantic coast.
In the wake of the developing cyclone and trailing cold front,
generally dry and/or stable conditions will prevail across much of
the nation.
...North Carolina coast vicinity...
Based on consideration of the various model output, the potential
for severe thunderstorm development near and inland of coastal areas
early Sunday still appears rather low. This will mostly depend on
the evolution of the surface frontal wave/low, which remains a bit
uncertain, but could perhaps include a strongly sheared and unstable
warm sector boundary layer spreading inland across portions of
coastal areas. If this occurs, it probably would be accompanied by
a risk for organized severe convection, including supercells.
...Southwest...
It appears that stronger destabilization supportive of convection
capable of producing lightning, beneath a mid-level cold core
including 500 mb temperatures of -28 to -30 C, probably will remain
initially offshore of southern California coastal areas. However,
Sunday afternoon into Sunday night this may change with cooling
aloft along and east of the Peninsular Ranges through the lower
Colorado Valley. Destabilization within a downstream warm advection
regime across the Mogollon Rim into Colorado Plateau may also become
marginally sufficient for scattered weak thunderstorm development.
..Kerr.. 02/11/2023
Read more