SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0253 PM CDT Sun May 01 2022
Valid 012000Z - 021200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF WESTERN TEXAS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE SOUTHERN HIGH PLAINS INTO CENTRAL TEXAS...
...SUMMARY...
Severe thunderstorms are still expected across the southern High
Plains into central Texas, beginning around mid-afternoon and
persisting through tonight. Damaging gusts, very large hail, and a
few tornadoes are all possible.
...20Z Update...
The primary change made to this outlook was to add 30 percent wind
probabilities across portions of southwest Texas. Here, clustering
or potential upscale growth of hail-laden storm cores in a steep low
and mid-level lapse rate environment may encourage intense cold pool
development via hydrometeor melting/evaporating processes, with a
locally higher density of severe gusts possible. Otherwise,
supercells that can prolong their inflow dominant phase and remain
discrete are still expected to pose a large hail/tornado threat,
with some of the largest stones potentially reaching 2-4 inches in
diameter (please see MCD 0607 for more details).
2 percent tornado probabilities were also added along the OH/PA
border. While convective development remains in question, any storms
that form may benefit from the locally backed surface winds across
the area, where RAP forecast soundings show modest low-level
hodograph curvature. Given adequate buoyancy, any cells that can
mature may briefly become transient-supercellular and a brief
tornado cannot be ruled out. Please see MCD 0609 for more details.
..Squitieri.. 05/01/2022
.PREV DISCUSSION... /ISSUED 1120 AM CDT Sun May 01 2022/
...Southern Plains...
Current surface analysis shows a reservoir of rich low-level
moisture in place over south and central TX. Southeasterly
low-level winds will transport this air mass northwestward, with
rapid moistening and destabilization of the boundary layer across
west TX and eastern NM this afternoon and evening. Relatively strong
heating and only a weak capping inversion is expected to lead to
several supercells developing across the area by mid-afternoon.
Storms will first form along the retreating warm front from the
Permian Basin into the Hill Country. Deep-layer shear profiles will
promote discrete supercell structures, while low-level winds are
sufficient for the risk of a few tornadoes through the afternoon and
evening. However, very large hail is expected to be the primary
risk with storms in this corridor.
Later this afternoon and evening, the development of discrete storms
including supercells will occur farther north across the western TX
panhandle into northeast NM and even southeast CO. These storms
will be in a drier boundary-layer environment, but very steep lapse
rates and the strength of the mid/upper level winds will be
conducive for very large hail formation and perhaps a tornado or
two.
...VA/NC...
Full sunshine is occurring this morning across much of southern VA
and northern NC, where dewpoints in the upper 50s and lower 60s will
yield MLCAPE values of 1500-2000 J/kg. Scattered thunderstorms
currently over the mountains of extreme southwest VA and east TN
will spread eastward and intensify this afternoon as they encounter
the unstable air. This should lead to scattered strong to severe
storms, capable of damaging winds and hail. Activity will track
eastward roughly along the NC/VA border through the early evening.
Read more CHECK UPDATE ZOOM GRAPHIC
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