darkskys25
Member
SPC notes a lot of uncertainty in their discussion. Seems to think this is very conditional. I agree:
Forecast Discussion
SPC AC 111735
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 PM CDT Sat Apr 11 2020
Valid 121200Z - 131200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
LOUISIANA THROUGH SOUTHEAST ARKANSAS...MISSISSIPPI INTO CENTRAL AND
NORTHERN ALABAMA
Farther south, moderate to locally strong instability is forecast to
develop along/south of the warm frontal position, which will be
modulated by the impact of outflow from any early convection
described above. Midlevel flow will increase to 70-100 kt as a
south-southwesterly low-level jet intensifies into the 40-60 kt
range. These wind profiles combined with ample instability (MLCAPE
of 1500-3000 J/kg) will support the potential for intense
supercells. Any surface-based initiation along and east of a
pseudo-dryline moving into western LA by late afternoon could evolve
into one or more long-tracked supercells capable of producing strong
tornadoes, large hail, and damaging wind gusts. The extent of
development within the warm sector remains somewhat uncertain, given
the presence of a capping inversion and generally subtle foci for
initiation.
While the conditional risk of all severe hazards will be quite high
if supercells develop, uncertainty remains regarding how convection
will evolve from the morning into the afternoon. Any remnant outflow
related to early convection will determine the northern extent of
the higher-end tornado potential, and some guidance suggests the
potential for elevated convection within a midlevel moist plume
across the warm sector during the afternoon, which could either
dampen the severe potential, or evolve into surface-based convection
with a substantial severe threat. Given these factors, there is too
much uncertainty to upgrade the ongoing outlook at this time.
Forecast Discussion
SPC AC 111735
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 PM CDT Sat Apr 11 2020
Valid 121200Z - 131200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
LOUISIANA THROUGH SOUTHEAST ARKANSAS...MISSISSIPPI INTO CENTRAL AND
NORTHERN ALABAMA
Farther south, moderate to locally strong instability is forecast to
develop along/south of the warm frontal position, which will be
modulated by the impact of outflow from any early convection
described above. Midlevel flow will increase to 70-100 kt as a
south-southwesterly low-level jet intensifies into the 40-60 kt
range. These wind profiles combined with ample instability (MLCAPE
of 1500-3000 J/kg) will support the potential for intense
supercells. Any surface-based initiation along and east of a
pseudo-dryline moving into western LA by late afternoon could evolve
into one or more long-tracked supercells capable of producing strong
tornadoes, large hail, and damaging wind gusts. The extent of
development within the warm sector remains somewhat uncertain, given
the presence of a capping inversion and generally subtle foci for
initiation.
While the conditional risk of all severe hazards will be quite high
if supercells develop, uncertainty remains regarding how convection
will evolve from the morning into the afternoon. Any remnant outflow
related to early convection will determine the northern extent of
the higher-end tornado potential, and some guidance suggests the
potential for elevated convection within a midlevel moist plume
across the warm sector during the afternoon, which could either
dampen the severe potential, or evolve into surface-based convection
with a substantial severe threat. Given these factors, there is too
much uncertainty to upgrade the ongoing outlook at this time.
