|Mesoscale Discussion 1314|
< Previous MD Next MD >
Mesoscale Discussion 1314
NWS Storm Prediction Center Norman OK
0631 PM CDT Fri Aug 17 2018
Areas affected...Parts of eastern Pennsylvania and northern New
Jersey into the lower Hudson Valley
Concerning...Severe Thunderstorm Watch 340...
Valid 172331Z - 180100Z
The severe weather threat for Severe Thunderstorm Watch 340
SUMMARY...Storms may continue to produce frequent cloud to ground
lightning, with increasing potential for damaging wind gusts
possible into the 8-10 PM EDT time frame.
DISCUSSION...A small but sustained cluster of vigorous thunderstorms
now northwest of Philadelphia PA seems to provide the most
substantive continuing severe weather potential through 00-02Z.
Within surface troughing across the northern Mid Atlantic region,
the boundary layer air mass ahead of it remains warm, very moist and
characterized by moderately large CAPE in excess of 2000 J/kg.
Inflow of this air provides potential for further intensification of
this convection, along with the possible evolution of a
strengthening surface cold pool. Perhaps aided by modest vertical
shear associated with a belt of 20-30 kt southwesterly lower/mid
tropospheric flow, this could still be accompanied by an increasing
risk for damaging wind gusts north of Philadelphia through northern
New Jersey and portions of the lower Hudson Valley this evening.
Otherwise, thunderstorm activity elsewhere across severe
thunderstorm watch 340 and surrounding areas seems likely to
gradually diminish with decreasing severe weather potential.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 40957505 41337454 41167374 40187411 39797522 40077580
Top/All Mesoscale Discussions/Forecast Products/Home