MD 0596 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR THE TEXAS EDWARDS PLATEAU VICINITY
Mesoscale Discussion 0596
NWS Storm Prediction Center Norman OK
0158 PM CDT Sat Apr 22 2023
Areas affected...the Texas Edwards Plateau vicinity
Concerning...Severe potential...Watch likely
Valid 221858Z - 222100Z
Probability of Watch Issuance...80 percent
SUMMARY...The initiation of scattered thunderstorms, including one
or two developing supercells, appears possible by 3-5 PM CDT. These
storms will pose a risk for large hail, locally strong surface
gusts, and at least some potential for a tornado.
DISCUSSION...Beneath modestly steep mid-level lapse rates,
lower-level lapse rates are becoming very steep in response to
insolation and deepening boundary-layer mixing. This is focused
either side of a sharpening dryline wrapping into a weak surface low
to the northwest of San Angelo. East of the dryline, boundary-layer
moisture remains characterized by mid/upper 50s surface dew points,
but it appears that this is sufficient to support mixed-layer CAPE
in excess of 1000 J/kg.
Attempts at deepening boundary-layer based convective development
are ongoing near the surface low center, as well as within, at least
initially, a bit more elevated warm advection regime
east-southeastward into areas northeast of San Angelo. As
inhibition for boundary-layer parcels erodes further with additional
heating and large-scale ascent, it appears that thunderstorms may
initiate as early as 20-22Z, before increasing and intensifying
through the remainder of the afternoon.
Although low-level wind fields are generally modest to weak, strong
deep-layer shear beneath at least broadly cyclonic, 50+ kt flow
around 500 mb is sufficient for organized severe convection. The
evolution of one or two sustained supercells is possible, which
probably will be accompanied by a risk for large hail, locally
strong surface gusts, and at least some risk for producing a
tornado, while slowly propagating southeastward.
..Kerr/Hart.. 04/22/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...SJT...
LAT...LON 31920077 31959974 31819919 31329829 30899911 31079988
30910090 31430064 31920077
