MD 0689 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR PORTIONS OF CENTRAL/NORTHERN TX INTO SOUTH-CENTRAL OK
Mesoscale Discussion 0689
NWS Storm Prediction Center Norman OK
0308 PM CDT Sat May 06 2023
Areas affected...portions of central/northern TX into south-central
OK
Concerning...Severe potential...Watch likely
Valid 062008Z - 062215Z
Probability of Watch Issuance...80 percent
SUMMARY...Vigorous thunderstorm development is expected by
21-23z/4-6pm CDT. Very large hail and scattered damaging gusts will
be the main hazards associated with these storms through this
evening. A severe thunderstorm watch will likely be needed in the
next couple of hours.
DISCUSSION...An expanding cumulus field from near San Angelo TX
northeast toward Wichita Falls TX is becoming increasingly agitated
this afternoon. Strong heating along a dryline has resulted in
temperatures from the upper 80s to low 90s. To the east of the
dryline, surface dewpoints from the upper 60s to low 70s F beneath
very steep midlevel lapse rates (greater than 8 C/km) are
contributing to MLCAPE values around 2500-3000 J/kg. 19z objective
analysis indicated capping is also rapidly eroding. Thunderstorms
are expected to develop close to the dryline by 22z/5 pm CDT. Given
strong instability and favorable lapse rates, intensification may
occur fairly rapidly. Deep-layer flow is relatively modest, but
vertically veering wind profiles with some increase in midlevel
southwesterly flow by 23-00z will result in effective shear
magnitudes around 25-30 kt.
Very large hail (to around 3 inch diameter) will be possible,
especially early in storm evolution. Steep low-level lapse rates
also may promote strong downburst winds. Wind potential also may
increase with time/eastward extent if some upscale development into
forward-propagating clusters/bowing segments occurs, as some some
short term hi-res guidance suggests.
..Leitman/Hart.. 05/06/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...OUN...SJT...LUB...
LAT...LON 31349948 31379990 31510025 31630048 31880061 32240065
32600044 33849920 34599830 34799790 34859744 34779708
34619683 34389674 34089672 33929676 32839740 32559755
32009798 31469882 31349936 31349948
