Alert archive / New York / Mesoscale Discussions in 2011

Mesoscale Discussion 979

May 26, 201121 counties in New York; 19 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at May 26, 2011, 11:55 AM EDT for 21 counties in New York; 19 counties in Pennsylvania. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
May 26, 2011, 11:55 AM EDT (15:55 UTC)
Expired
May 26, 2011, 1:30 PM EDT
In force
95 min
Issued by
the Storm Prediction Center
All 40 counties

Broome County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Delaware County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Lewis County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Otsego County, NY, Schoharie County, NY, Schuyler County, NY, Seneca County, NY, Tioga County, NY, Tompkins County, NY, Warren County, NY, Bradford County, PA, Clinton County, PA, Columbia County, PA, Dauphin 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, Tioga County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA

The radar

The Binghamton radar (KBGM), 22 km from the middle of the area, began a volume at 15:59 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 3.9 hours before the alert went out and 199 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.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2011-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2011-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 274 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1004 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
274 m²/s²
0-3 km storm-relative helicity
327 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

376 
ACUS11 KWNS 261555
SWOMCD
SPC MCD 261555 
NYZ000-PAZ000-261730-

MESOSCALE DISCUSSION 0979
NWS STORM PREDICTION CENTER NORMAN OK
1055 AM CDT THU MAY 26 2011

AREAS AFFECTED...CNTRL PA INTO UPSTATE NY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 261555Z - 261730Z

STRONG BOUNDARY LAYER HEATING IS OCCURRING OVER MUCH OF PA AND NY
WELL AHEAD OF PRIMARY FORCING ASSOCIATED WITH UPPER TROUGH OVER THE
OH VALLEY.  IN THE ABSENCE OF SIGNIFICANT CLOUD COVER IT APPEARS
VERY STEEP LOW LEVEL LAPSE RATES WILL SOON CONTRIBUTE TO DEEP
BOUNDARY LAYER THERMALS AND WITH TIME A MATURING CU FIELD THAT
SHOULD LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT...ESPECIALLY OVER
THE HIGHER TERRAIN FROM CNTRL PA INTO UPSTATE NY. 
ADDITIONALLY...DEEP LAYER SHEAR PROFILES FAVOR SUPERCELL DEVELOPMENT
AND LOW LEVEL MOISTURE IS SUCH THAT ISOLATED TORNADOES MAY ACCOMPANY
THE MORE ORGANIZED CELLS.  VERY LARGE HAIL MAY ALSO BE NOTED GIVEN
THE INSTABILITY OBSERVED.  THIS ENVIRONMENT IS BECOMING INCREASINGLY
FAVORABLE FOR SEVERE DEVELOPMENT AND A TORNADO WATCH MAY BE ISSUED
BY 18Z.

..DARROW.. 05/26/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BTV...ALY...PHI...BGM...BUF...CTP...

LAT...LON   40527795 43007688 44437458 43577343 41727518 40327654
            40527795

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 12:29 PM EDTTornado WatchSPCClinton, Essex, Franklin, St. Lawrence8 hr
May 26, 2:16 PM EDTTornado WatchSPCAlbany, Broome, Cayuga, Chemung, Chenango, Cortland and 26 more8 hr
May 26, 2:57 PM EDTMesoscale DiscussionSPCAlbany, Broome, Chemung, Chenango, Clinton, Cortland and 20 more63 min
May 26, 5:49 PM EDTMesoscale DiscussionSPCSullivan56 min
May 26, 6:06 PM EDTSevere Thunderstorm WatchSPCAllegany, Cattaraugus, Chautauqua, Erie, Livingston, Ontario and 1 more6 hr
May 26, 6:41 PM EDTMesoscale DiscussionSPCAlbany, Broome, Chenango, Cortland, Delaware, Essex and 16 more64 min
May 25, 8:14 PM EDTMesoscale DiscussionSPCCrawford, Lawrence, Mercer2 hr
May 26, 2:37 AM EDTMesoscale DiscussionSPCBeaver, Lawrence83 min
May 26, 2:53 PM EDTTornado WatchSPCAdams, Bedford, Blair, Centre, Clinton, Columbia and 20 more7 hr

Nearby

Mesoscale Discussions in New York, 2011Mesoscale Discussions in Pennsylvania, 2011Every mesoscale discussion in 2011

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.