Mesoscale Discussion 0071
NWS Storm Prediction Center Norman OK
0347 PM CST Sun Feb 18 2018
Areas affected...Parts of west Texas
Concerning...Severe potential...Watch unlikely
Valid 182147Z - 182245Z
Probability of Watch Issuance...5 percent
SUMMARY...At least isolated strong to severe storm development
appears possible during the 4-6 PM CST time frame, with severe hail
and locally strong wind gusts the primary potential hazards.
DISCUSSION...Weak to moderate destabilization is ongoing near the
dry line across west Texas, with continued boundary layer heating
and mixing. Latest RAP output suggests CAPE is now on the order of
500-1000 J/kg. Low-level convergence appears weak, and mid/upper
forcing for ascent unclear, but inhibition appears to be in the
process of becoming increasingly negligible. At least isolated
thunderstorm development does not appear out of the question within
the next hour or two, probably near or west/southwest of Midland,
based on latest visible imagery.
Given favorable deep layer shear beneath southwesterly mid-level
flow on the order of 40-50 kt, any sustained convection could take
on a supercell structures. This probably would be accompanied by at
least the risk for severe hail and localized strong surface gusts,
before boundary layer instability wanes after nightfall.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 31250339 32360272 33110158 33120058 32100184 31550236
30670330 30880347 31250339