SPC AC 151729
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CST Fri Feb 15 2019
Valid 161200Z - 171200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
Severe thunderstorms are not expected across the U.S. Saturday
through Saturday night.
Models are maintaining the evolution of large-scale troughing that
should broaden as it develops inland across much of the western and
central United States. This will occur downstream of a mid-level
ridge forecast to amplify further during this period, across the
eastern Pacific into Alaska, the Yukon, Northwest Territories, and
adjacent portions of northern British Columbia.
...Pacific Coast region...
Models suggest midlevel impulses will either weaken as they move
inland across northern and central CA, while an additional banner of
vorticity remains located off the WA, OR, to central CA coasts.
While forcing for ascent associated with the inland-moving feature
will be weak, models suggest marginal destabilization could support
weak thunderstorm activity, given lingering very cold mid-level air
mass across parts of northern and central CA.
...NC/SC to Tennessee Valley region...
Southern stream flow is expected to strengthen this forecast period,
becoming oriented southwesterly from northern Mexico to the central
and southern Appalachians region, as the aforementioned large-scale
troughing evolves. Low-level warm air advection associated with a
couple of progressive mid-level perturbations, embedded within the
southern stream, will result in weak, elevated destabilization.
This should promote convective showers early in the forecast period,
as a lead shortwave trough is forecast to move east of the Carolinas
Saturday afternoon, while additional elevated convection will be
possible late Saturday night from portions of northern AL into TN,
attendant to a weak, fast-moving impulse. Forecast soundings
suggest MUCAPE around or below 100 J/kg and rooted generally between
750-850 mb should have a low probability to produce lightning, as
most of the buoyancy will not become deep enough for charge
separation. This thermodynamic analysis is true for the early day
and late Saturday night convection.
...MAXIMUM RISK BY HAZARD...
Tornado: <2% - None
Wind: <5% - None
Hail: <5% - None
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z