ACUS02 KWNS 221728
SPC AC 221727
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1227 PM CDT Mon Apr 22 2019
Valid 231200Z - 241200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR SOUTHEAST
NEW MEXICO INTO PORTIONS OF WESTERN...CENTRAL AND NORTH TEXAS...
Severe thunderstorms capable of producing isolated large hail and
wind damage are expected across parts of southeast New Mexico and
Texas on Tuesday afternoon and evening. Additional strong storms may
produce isolated gusty winds and small hail from northern Kentucky
into southwest Pennsylvania Tuesday afternoon and evening.
...Southern High Plains and Vicinity...
A cutoff low centered over northwest Mexico/southern Arizona will
migrate east/southeast toward the Rio Grande Valley/southern Rockies
by Wednesday morning. A weak surface low/frontal wave will extend
east/northeast from southeast NM into southern MO during the
morning, and the front will only slowly sag southward through the
evening before advancing southward more quickly overnight. Ahead of
the front, southeasterly low level flow will advect Gulf moisture
north/northeast across much of TX into southern OK. Low to mid 60s
dewpoints beneath 7-8 C/km lapse rates and 40+ kt effective bulk
shear will support supercells along/ahead of the front. Storms are
expected to develop during the afternoon and increase in coverage
during the evening as ascent increases across the southern Plains.
Initial storm development is expected near higher terrain of western
TX and southeast NM. Isolated convection will likely be ongoing on
the cool side of the front across the TX South Plains/Panhandle into
western OK at the beginning of the period. As the cold front becomes
reinforced by this activity and the warm sector destabilizes during
the afternoon, additional storms are expected to develop across the
Permian Basin northeastward into north Texas. This convection may
remain discrete initially but should transition into bowing line
segments during the evening. As the cold front surges southward
during the nighttime hours, convection may become undercut and
severe threat should diminish after 06z. Any cells that remain
discrete Tuesday afternoon/evening will pose a threat for large hail
and damaging winds. As convection takes on more linear modes, the
hail threat should diminish.
...Northern KY into southwest PA...
A northern stream shortwave trough will move across the Great Lakes
and toward the Mid-Atlantic and southern Ontario/Quebec on Tuesday.
This will bring a band of enhanced mid-to-upper level flow across
portions of the mid/upper Ohio Valley vicinity. Modest low level
moisture (mid/upper 50s F dewpoints) beneath 6.5-7.5 C/km midlevel
lapse rates will be adequate for weak destabilization (500-1000 J/kg
MLCAPE) by afternoon ahead of an eastward progressing cold front. A
few strong storms will be possible along the front and a few
strong/locally damaging wind gusts and small hail could accompany
these stronger cells into early evening.
...MAXIMUM RISK BY HAZARD...
Tornado: 5% - Slight
Wind: 15% - Slight
Hail: 15% - Slight