SPC MD 1217

MD 1217 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN OKLAHOMA AND PORTIONS OF ADJACENT STATES

Mesoscale Discussion 1217
NWS Storm Prediction Center Norman OK
0353 PM CDT Sun Jul 02 2017

Areas affected...Eastern Oklahoma and portions of adjacent states

Concerning...Severe potential...Watch unlikely 

Valid 022053Z - 022300Z

Probability of Watch Issuance...20 percent

SUMMARY...Any marginal severe hail threat probably will begin to
diminish as storms further increase in coverage and consolidate over
eastern Oklahoma late this afternoon.  However, the risk for strong
wind gusts approaching or briefly exceeding severe limits could
continue to increase.  At this point, the probability for a watch
issuance still seems low, but trends will continue to be monitored.

DISCUSSION...Vigorous thunderstorm development is well underway, now
mostly east of the Interstate 35 corridor of central Oklahoma.  This
is occurring in the presence of weak inhibition, where a pocket of
slightly cooler mid-level temperatures lingers ahead of a remnant
mesoscale convective vortex,  on the eastern periphery of a plume of
warmer and more strongly capping elevated mixed layer air slowly
advecting east of the high plains.  

Insolation within a very moist boundary layer air mass characterized
by mid/upper 70s surface dew points is contributing to large CAPE
across much of eastern Oklahoma, with greatest potential instability
focused roughly between the Interstate 44 and 40 corridors.  Deep
layer mean westerly flow is generally less than 20 kt across this
region, but veering wind profiles with height may be contributing to
vertical shear marginally conducive to the evolution of an organized
convective system.

Given this environment, considerable further upscale convective
growth appears possible through the 23-01Z time frame, accompanied
by a gradual consolidation and strengthening of convectively
generated cold pools.  It may not be out of the question that this
could coincide with the evolution of another lower/mid tropospheric
vortex, and a rear inflow jet that could support an increasing risk
for strong surface gusts that could approach or briefly exceed
severe limits through early evening.

..Kerr/Hart.. 07/02/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LZK...SHV...TSA...ICT...OUN...

LAT...LON   36849675 37039616 36439504 36089454 35509356 34959395
            34669470 34119544 33949644 34289669 35229614 35999617
            36849675 

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