Mesoscale Discussion 1271

Issued

Jul 13, 2021, 4:07 PM EDT (20:07 UTC)

Expired

Jul 13, 2021, 6:00 PM EDT

In force

113 min

Issued by

the Storm Prediction Center

Concerning

Severe thunderstorm watch 375

The Buffalo radar (KBUF), 111 km from the middle of the area, began a volume at 20:08 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

227 
ACUS11 KWNS 132007
SWOMCD
SPC MCD 132007 
NYZ000-PAZ000-MDZ000-WVZ000-OHZ000-132200-

Mesoscale Discussion 1271
NWS Storm Prediction Center Norman OK
0307 PM CDT Tue Jul 13 2021

Areas affected...Portions of the Northeast

Concerning...Severe Thunderstorm Watch 375...

Valid 132007Z - 132200Z

The severe weather threat for Severe Thunderstorm Watch 375
continues.

SUMMARY...The severe threat continues across WW 375, with damaging
winds the main threat.

DISCUSSION...Regional satellite/radar depicts a few isolated storms
over portions of southern New York and vicinity. Updrafts have
largely been transient thus far, likely due to modest mid-level
lapse rates amid abundant shear. However, recent scans/imagery
suggest the intensity of these storms may be increasing somewhat as
low-level lapse rates over the region remain supportive for
convective development amid a weak cap.

Farther west, a cluster of severe storms has emerged across portions
of western Pennsylvania, with several damaging wind reports. This
band of convection appears to be associated with a mid-level
short-wave evident at 700 mb. Short-term convection-allowing models
suggest these storms should continue moving northeast into western
portions of the watch area across northwest Pennsylvania and
southwestern New York. Additional storm development is possible
along the southern flank of the line as the mid-level wave and
associated ascent progresses through the region for the remainder of
the afternoon and evening.  Damaging winds remain the primary
hazard, but severe hail and a tornado or two are possible,
particularly with any discrete/supercell modes that may emerge.

..Karstens.. 07/13/2021

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

ATTN...WFO...BTV...ALY...BGM...BUF...CTP...LWX...PBZ...RLX...
CLE...

LAT...LON   43367468 41887520 39987740 38917963 39288052 40248038
            41408100 42338091 43107943 43457919 43637868 44397586
            44067485 43367468

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The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.