SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1232 PM CDT Mon Jun 12 2023
Valid 131200Z - 141200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN TEXAS
EASTWARD ACROSS THE GULF COAST STATES...
...SUMMARY...
Corridors of severe thunderstorms are expected throughout the period
Tuesday, from parts of the southern Plains eastward across the
Southeast. Large hail and damaging winds will be the primary
concern.
...Synopsis...
An upper low will move slowly eastward across the Upper Great Lakes
on Tuesday, contributing to height falls along the East Coast.
Meanwhile, a weak upper ridge will exist over the Southwest, with a
belt of strong mid to upper level westerlies from the southern
Plains into the Southeast.
At the surface, 60+ dewpoints will remain roughly from TX/OK
eastward to the Atlantic Coast, with 70+ dewpoints from TX eastward
across the northern Gulf Coast and FL. Drier air will exist across
much of the MO/Upper MS/OH Valleys owing the cooling influence of
the upper low. However, weak low pressure is expected over Lower MI,
with at least weak instability developing in that region.
Otherwise, a mean surface boundary will extend roughly from northern
TX eastward to GA/SC, reinforced by bouts of convection and outflow.
This general zone, beneath the favorably strong westerlies aloft,
will be the primary focus for severe storms throughout the period on
Tuesday.
...TX eastward into GA/SC...
Clusters of storms are expected throughout the period, and the
influence of antecedent convection will have an impact on where the
greatest threat corridors develop. At this time, it appears that
storms will be ongoing from parts of MS, AL into GA and eventually
SC during the day, with one or more clusters possible. Heating of a
moist air mass will contribute to MLCAPE of 2000-3000 J/kg in spots,
with deep-layer effective shear around 50 kt. This will favor large
hail and swaths of damaging wind, perhaps very large hail. The
proportion of supercells may depend on whether outflow scour much of
the warm sector.
To the west, large-scale lift may be reduced in the wake of the
systems passing to the east, with midlevel subsidence found in some
forecast soundings. However, very strong instability will remain in
place from TX into the lower MS Valley, and strong heating and
convergence along any residual boundaries will provide a focus for
storms during the afternoon. Very large hail may occur along with
locally damaging gusts, from northeast TX into northern LA.
Although locally higher-end hail potential will exist,
predictability is a bit low to provide higher severe probabilities
at this time.
...Southeast CO into the OK/TX Panhandles...
Residual moisture, surface heating and the influence of a
low-amplitude wave will lead to storms forming over southeast CO and
northeast NM during the afternoon. Strong high-level flow atop weak
southerly winds will lead to cells moving in a southeastward
direction, producing hail and locally gusty winds. These storms will
likely encounter increased CIN from western OK into northwest TX,
with lessening threat there overnight.
...Central IN into western OH...
Westerly surface winds and heating will lead to a narrow plume of
steeper low-level lapse rates from IL into southern IN and OH, with
temperatures in the 70s F. Dewpoints will generally be in the 40s to
near 50 F, and this may contribute to weak instability during the
peak heating hours. The combination of mixing of 30 kt flow at 850
mb and increasing precipitation during the afternoon could lead to
gusty winds. At this time, the threat for severe does not appear
high enough to introduce low wind probabilities. Any cellular
convection could result in small/sub-severe hail as well.
..Jewell.. 06/12/2023
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