Mesoscale Discussion 1494
NWS Storm Prediction Center Norman OK
0205 PM CDT Sat Jul 04 2026
Areas affected...Portions of southern NY...north-central/northeast
PA...and northern NJ
Concerning...Severe potential...Watch likely
Valid 041905Z - 042130Z
Probability of Watch Issuance...80 percent
SUMMARY...The area is being monitored for an increasing risk of
severe thunderstorms this afternoon. The primary concern is damaging
wind gusts. A watch is likely.
DISCUSSION...The latest visible satellite imagery indicates an
east/west-oriented band of deepening boundary-layer cumulus across
northern PA -- within a zone of broadly confluent low-level flow.
Thunderstorms should continue increasing in coverage and intensity
within this zone over the next few hours, given ample diurnal
heating/destabilization of a moist air mass (upper 60s to lower 70s
dewpoints). Steepening low-level lapse rates and around 30-40 kt of
unidirectional shear should promote several organized clusters
capable of producing scattered damaging wind gusts through the
afternoon. An additional focus for severe thunderstorms is evident
downstream of Lake Ontario, where an MCV and related thunderstorms
will continue eastward into the diurnally destabilizing air mass.
These storms will also pose a risk of damaging wind gusts as they
intercept the unstable air.
..Weinman/Hart.. 07/04/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OKX...ALY...PHI...BGM...BUF...CTP...
LAT...LON 42977639 42777539 42467446 42187406 41587395 40947431
40367544 40567693 40847778 41257819 41787840 42167828
42557787 42847717 42977639
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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