Mesoscale Discussion 1770
NWS Storm Prediction Center Norman OK
1033 AM CDT Sat Jul 29 2023
Areas affected...southern New England into parts of eastern New York
and far northern New Jersey
Concerning...Severe potential...Watch likely
Valid 291533Z - 291730Z
Probability of Watch Issuance...80 percent
SUMMARY...A steady increase in thunderstorm coverage is expected
through the afternoon, with locally strong wind gusts becoming more
likely as the airmass destabilizes. WW issuance will likely be
needed.
DISCUSSION...Latest visible satellite loop shows partly sunny
conditions across southern New England and into parts of eastern New
York and vicinity. Daytime heating through late morning has
supported modest destabilization, which will continue into the
afternoon given dewpoints in the upper 60s to low 70s. As an MCV
now crossing eastern Lake Erie continues to shift eastward, expect
storm coverage to increase as afternoon mixed-layer CAPE values rise
into the 1000 to 1500 J/kg range.
While low-level flow is forecast to remain weaker as compared to
areas farther south, mid-level westerlies near 30 kt will support
potential for organized storms and some upscale growth into
small-scale bands. Locally strong/damaging wind gusts are expected
with the strongest storms, through the afternoon hours, and this
potential appears sufficient that WW issuance will likely be
required in the next hour.
..Goss/Thompson.. 07/29/2023
...Please see www.spc.noaa.gov for graphic product