Alert archive / Pennsylvania / Mesoscale Discussions in 2021
Mesoscale Discussion 1276
The Storm Prediction Center issued this mesoscale discussion at Jul 13, 2021, 9:12 PM EDT for 13 counties in New York; 16 counties in Pennsylvania. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- Jul 13, 2021, 9:12 PM EDT (01:12 UTC)
- Expired
- Jul 13, 2021, 10:45 PM EDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 375
All 29 counties
Broome County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Oswego County, NY, Schuyler County, NY, Seneca County, NY, Tioga County, NY, Tompkins County, NY, Bradford County, PA, Carbon County, PA, Columbia County, PA, Juniata County, PA, Lackawanna County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Union County, PA, Wyoming County, PA
The radar
The Binghamton radar (KBGM), 41 km from the middle of the area, began a volume at 01:11 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.
The nearest sounding before it
Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 1.2 hours before the alert went out and 222 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 883 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -60 m²/s²
- 0-3 km storm-relative helicity
- -49 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
535
ACUS11 KWNS 140112
SWOMCD
SPC MCD 140112
NYZ000-PAZ000-140245-
Mesoscale Discussion 1276
NWS Storm Prediction Center Norman OK
0812 PM CDT Tue Jul 13 2021
Areas affected...Central/eastern New York and Pennsylvania
Concerning...Severe Thunderstorm Watch 375...
Valid 140112Z - 140245Z
The severe weather threat for Severe Thunderstorm Watch 375
continues.
SUMMARY...An organized line of convection will be capable of
strong/damaging wind gusts for another hour or two before
encountering stable air within the Adirondacks and Delaware River
Valley. No additional watches are expected this evening.
DISCUSSION...A line of thunderstorms across central New York into
central Pennsylvania has become somewhat more organized within the
last 1-2 hours as cold pools have congealed. This has allowed
portions of the line to surge out, which is most evident in
north-central Pennsylvania. Occasional wind damage has been reported
with one measured gust on the NY Mesonet of 78 mph at the Penn Yan
site at 8:40 PM EDT. There is a narrow corridor of remaining buoyant
airmass ahead of the line. Strong/damaging winds remain possible
likely for another hour or two, particularly with any more
pronounced bowing segments. Storms moving into the Adirondacks and
Delaware River Valley will encounter much more stable surface
conditions. Storms will quickly weaken as that occurs. No additional
watches are expected this evening.
..Wendt.. 07/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...BGM...BUF...CTP...
LAT...LON 41027550 40807576 40577629 40387711 40477783 41397730
42817698 43857713 44067648 43817603 43277537 41847525
41027550Nearby
Mesoscale Discussions in Pennsylvania, 2021Mesoscale Discussions in New York, 2021Every mesoscale discussion in 2021
Sources
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.