Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0225 AM CDT Wed May 15 2019
Valid 171200Z - 181200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS CENTERED OVER
CENTRAL NEBRASKA AND WEST TEXAS...
...SUMMARY...
Severe storms are expected across parts of the Plains, mainly from
Nebraska southward into west Texas. Very large hail and a few
tornadoes are possible. Scattered severe hail is also possible
across southern South Dakota, as well as across parts of Ohio and
West Virginia.
...Synopsis...
A large upper trough will move across the Rockies with strong
southwesterly flow aloft overspreading the Plains. Height
falls/cooling aloft will enhance lift, and a moist, unstable air
mass will develop through the period.
Consensus is for low pressure to develop over the CO/KS/NE region,
with a stationary front stretching from northern NE across IA, IL,
OH and WV. Meanwhile, a sharp dryline will develop across western NE
and KS into the eastern OK and TX Panhandles and west TX where it
will remain overnight. Strengthening southerly winds over the Plains
will bring mid 60s F dewpoints north across the entire warm sector,
which will result in areas of strong instability. Lift related to
the aforementioned boundaries should result in a few concentrated
areas of severe storms,
with very large hail and few tornadoes
possible.
Elsewhere, sufficient instability will develop along the eastern
extent of the stationary front, beneath modest west/northwest flow
aloft which may support isolated severe storms during the day.
..
.Northern Plains...
Daytime heating, cooling aloft and moisture advection will result in
2000-2500 J/kg MLCAPE ahead of the low and south of the stationary
front. By late afternoon, wind profiles will favor supercells
producing very large hail and tornadoes as SRH increases late in the
day. Numerous storms are possible along the front eventually, and
this could result in a severe MCS with both damaging wind and hail
threat.
North of the front, large hail is possible across much of SD,
northwest IA and southwest MN as the low-level jet maintains strong
elevated instability.
.
..Southern Plains...
Strong instability will develop along the dryline with daytime
heating and dewpoints increasing into the mid 60s F. A capping
inversion will exist east of the dryline, with development expected
where heating is strongest. Ample deep-layer shear along with
increasing SRH late in the day and overnight will support supercells
capable of very large hail and a few tornadoes. Storms may not move
very far east until overnight when a larger complex of storms is
forecast from southwest TX into southwest OK, with all modes of
severe possible.