SPC AC 231945
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0245 PM CDT Thu May 23 2019
Valid 232000Z - 241200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS EASTERN TX
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROMT THE TX
SOUTH PLAINS TO CENTRAL KS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS CHESAPEAKE BAY
Severe storms with large hail, damaging wind and tornadoes will
continue today over a part of the central and southern Plains and
from the Ohio Valley into parts of the Mid-Atlantic.
A few changes have been made to the 1630z outlook.
1) Focused higher severe probs ahead of maturing squall line over
MD/VA. Convection has recently increased in intensity across
northern VA/MD. This activity has renewed along the leading edge of
an old MCS carcass where low-level lapse rates have increased as
temperatures warmed into the 80s. Damaging winds should be noted
along this squall line as it progresses toward the lower Chesapeake
2) Extended severe probs west along decaying outflow into northern
KY. Early-day MCS that progressed across the OH Valley has forced an
outflow boundary across northern KY. This boundary should serve as
the focus for convection to spread east over the next few hours.
3) Nudged 15% hail probs northwest across western KS. Scattered
elevated convection is rapidly developing/spreading north across
western KS. Hail is the primary risk and 15% severe probability has
been adjusted accordingly to account for this evolution.
.PREV DISCUSSION... /ISSUED 1130 AM CDT Thu May 23 2019/
A large upper trough is present today over the western states, with
a vigorous shortwave trough rotating northeastward into western NM.
The large-scale lift and midlevel height falls associated with this
feature will overspread parts of the southern high Plains this
afternoon. Meanwhile, a very moist and unstable air mass has become
established across much of the TX Panhandle, with dewpoints in the
upper 60s over much of the area. Visible satellite imagery suggest
the potential for relatively strong afternoon heating over the
region, setting the stage for intense thunderstorm development.
Present indications are that elevated convection capable of large
hail will remain possible along and north of the surface boundaries
over the northern TX Panhandle, OK Panhandle and southwest KS.
These storms would primarily pose a hail risk through the day.
Please refer to MCD #751 for further details.
Intense surface-based initiation is expected along the dryline over
the western TX Panhandle by mid afternoon, with supercells likely.
These storms will track north-northeastward across the ENH and MDT
risk areas, and will be capable of very large hail and strong
tornadoes. It is unclear how long the storms will maintain discrete
supercell mode, with all model solutions tending toward quasi-linear
modes during the evening as storms track into northwest OK and
southern KS. This will increase the risk of damaging winds.
Over south-central KS, rapid recovery of the surface air mass will
provide a favorable zone for thunderstorm development and
maintenance this afternoon and evening. A few supercells are
possible with an inherent tornado/large hail threat. But perhaps
more likely are bowing structures capable of damaging winds. This
activity may persist much of the evening and spread eastward into
parts of northwest MO before weakening.
...NY into Mid Atlantic Region...
A fast moving line of thunderstorms is tracking across central PA,
and extends southwestward into WV. This line may intensify this
afternoon as it approaches the east coast, with a risk of locally
damaging wind gusts. Please refer to MCD #750 for further details.
In the wake of the first line, multiple lines and clusters of
thunderstorms are expected to form across parts of western/central
PA into northern WV. Fast flow aloft and sufficient time to heat
will result in a favorable environment for a few severe storms
capable of damaging wind gusts and some hail. These storms will
track eastward and approach the east coast by dark. While damaging
winds are the main threat, an isolated tornado or two cannot be
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z