ZCZC SPCSWOMCD ALL
ACUS11 KWNS 261809 
SPC MCD 261809 
NJZ000-PAZ000-DEZ000-MDZ000-262015-

Mesoscale Discussion 0452
NWS Storm Prediction Center Norman OK
0109 PM CDT Fri Apr 26 2019

Areas affected...southeastern Pennsylvania...northern Maryland and
Delaware...southwest New Jersey

Concerning...Tornado Watch 105...

Valid 261809Z - 262015Z

The severe weather threat for Tornado Watch 105 continues.

SUMMARY...Storms will rapidly develop and evolve over the next
several hours, with damaging winds and a tornado or two possible.
The greatest tornado threat area appears to be from northern
Maryland into southeast Pennsylvania between 18-22Z.

DISCUSSION...Storms are increasing in coverage along the cold front
from central PA into central VA, and just to the east near the warm
front. These storms will continue to evolve as they proceed east
into an unstable and warming air mass, with increasing large-scale
lift aiding organization as well. Given the motion of the front, the
entire event may clear the coast by 00Z.

The 16Z IAD sounding shows 0-2 km mean winds in excess of 40 kt,
along with effective SRH over 200 m2/s2. This is favorable for
damaging winds, as well as occasional rotation in storms. Shear
profiles are stronger farther north into PA, where effective SRH is
in excess of 300 m2/s2 just on the cool side of the warm front.
Meanwhile, an axis of warmer air continues to mix northward into
southeast PA. This appears to be the most favorable area for a
tornado, either with any leading cells that develop and/or with cold
front/QLCS activity. Wind damage is possible with any storm.

..Jewell.. 04/26/2019

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

ATTN...WFO...PHI...BGM...CTP...LWX...

LAT...LON   40947592 40677529 40307486 39907460 39627449 39367449
            39107464 39027481 39027517 39097565 39107639 39087682
            39147710 39377737 39717756 39977769 40277777 40487759
            40767709 40947646 40947592 

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