Mesoscale Discussion 1010
NWS Storm Prediction Center Norman OK
0125 PM CDT Tue Jun 13 2017
Areas affected...Portions of southern New England...southeast
Concerning...Severe potential...Watch possible
Valid 131825Z - 132100Z
Probability of Watch Issuance...40 percent
SUMMARY...The area is being monitored for some severe thunderstorm
potential through the afternoon and into the evening. Uncertainty
exists regarding the anticipated severe coverage, though the
issuance of a Severe Thunderstorm Watch will be possible across
portions of the region.
DISCUSSION...Temperatures have warmed into the lower 90s from
northern NJ and southeast NY and across southern New England, while
the dewpoints have held in the middle/upper 60s. This is
contributing to 1500-2000 J/kg of MLCAPE with little capping.
Meanwhile, along the periphery of subtle midlevel speed maxima
crossing northern NY into adjacent New England, and along subtle
confluence axes farther south from northeast PA to southern New
England, ascent has been sufficient to support initial towering
cumulus and isolated thunderstorm development.
Thunderstorms will likely increase in number and intensity during
the next few hours as diurnal heating continues. A mix of weak
supercell structures, and loosely organized convective clusters, may
eventually evolve and spread eastward. This will be supported by
sufficient deep shear aided by 25-30 kt westerly winds around 4-5 km
above ground indicated by the Albany VAD wind profile.
Present indications are that severe coverage could be lacking, owing
to the lack of stronger deep ascent/shear overlapping with the
moderate buoyancy. However, with at least isolated to widely
scattered severe hail/wind possible -- especially as convection
develops into southern New England -- Watch issuance will be
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 41207482 41977388 42427114 41827028 41457053 41097161
40887261 40767437 41207482