Day 1 Severe Weather Outlook

Valid 031300Z – 041200Z

…THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY FROM CENTRAL
AL TO CENTRAL GA…AND TONIGHT ACROSS CENTRAL TX…

…SUMMARY…
Thunderstorms with damaging winds and a couple of tornadoes will be
possible today across parts of Alabama/Georgia, as well as the
corridors from West Virginia to New Jersey and into North Carolina.
Additional severe storms with large hail and damaging winds are
expected tonight, mainly across central Texas.

…Central AL to central GA today…
Though the more obvious shortwave trough in the northern stream will
pass north of this area today, an organized cluster of storms is
moving into west central AL this morning in association with a 40-45
kt segment of the low-level jet and enhanced warm advection. This
cluster could pose an increasing threat for damaging gusts and a
couple of tornadoes from central AL into central GA today, as the
low levels destabilize with surface heating in cloud breaks and some
continued low-level moistening with boundary-layer dewpoints in the
low-mid 60s. Embedded bowing segments and supercells will be
supported by modest buoyancy (MLCAPE of 500-1000 J/kg), effective
bulk shear in excess of 50 kt, and locally enhanced SRH with the
low-level jet segment.

…NC area this afternoon/evening…
The remnant outflow and southern fringe of a weakening MCV over
WV/western VA this morning will interact with the returning
moisture/warm front across central NC this afternoon. Wind profiles
will be supportive of organized severe storms, but buoyancy will
likely remain marginal. As such, will expand 5% wind threat into NC
for a broken band of storms along the boundary this
afternoon/evening.

…Central Appalachians to Mid-Atlantic this afternoon/evening…
A northern stream shortwave trough will translate from the MS Valley
to the OH Valley today, and reach the Mid-Atlantic and New England
tonight. An associated surface cyclone will deepen from the lower
Great Lakes into New England, while a trailing cold front moves
eastward off the Mid-Atlantic coast by early tonight. In the wake
of weakening morning convection and a remnant MCV near southern WV,
a few cloud breaks and some low-level warming/moistening will
contribute to weak buoyancy in advance of the cold front from WV
into parts of PA/VA this afternoon/evening. Broken bands of storms
will be possible this afternoon along the front, and the convection
will spread east-northeastward toward NJ by late evening. Assuming
sufficient near-surface destabilization, wind profiles will favor
organized bowing segments and supercells with some threat for
isolated damaging gusts and a tornado or two.

…Edwards Plateau into central TX tonight…
A deep, closed midlevel low over Sonora will move eastward to the TX
Big Bend by early Wednesday morning. Surface cyclogenesis is
expected across central TX in advance of the midlevel trough, along
a stalled front. The warm sector across south TX is likely to
remain capped today, but increasing forcing for ascent will begin to
interact with the northwest edge of the unstable warm sector this
evening near DRT, and then storms will increase in
coverage/intensity overnight near the path of the surface cyclone
and immediately north of the surface front. A mixed storm mode of
cells and clusters is expected, in an environment supportive of
supercells with MUCAPE greater than or equal to 1000 J/kg and
effective bulk shear greater than 50 kt. Large hail will be the
main threat with elevated storms well north of the front, while
damaging gusts and perhaps a tornado will be possible with storms
along the surface front/north edge of surface warm sector.

…East TX/LA/southern MS early Wednesday morning…
A gradual increase in low-level flow/warm advection is expected
overnight along the stalled front from TX to LA/southern MS.
Slightly elevated thunderstorm development will become more probable
after about 09z, with the stronger storms capable of producing
isolated large hail just before the end of the period.

..Thompson/Jewell.. 03/03/2020

$$

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