Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 307

May 19, 201115 counties in New Jersey; 18 counties in New York; 26 counties in Pennsylvania

The Storm Prediction Center issued this severe thunderstorm watch at May 19, 2011, 12:20 PM EDT for 15 counties in New Jersey; 18 counties in New York; 26 counties in Pennsylvania. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
May 19, 2011, 12:20 PM EDT (16:20 UTC)
Expired
May 19, 2011, 8:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 59 counties

Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Albany County, NY, Broome County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Delaware County, NY, Greene County, NY, Orange County, NY, Otsego County, NY, Rockland County, NY, Schenectady County, NY, Schoharie County, NY, Schuyler County, NY, Steuben County, NY, Sullivan County, NY, Tioga County, NY, Tompkins County, NY, Ulster County, NY, Berks County, PA, Bradford County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Dauphin County, PA, Delaware County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Sullivan County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, York County, PA

The radar

The Binghamton radar (KBGM), 78 km from the middle of the area, began a volume at 16:22 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 19, 1:29 PM EDTSevere Thunderstorm WarningPHIBerks61 min
May 19, 1:41 PM EDTSevere Thunderstorm WarningCTPColumbia, Lebanon, Northumberland, Schuylkill49 min
May 19, 2:22 PM EDTSevere Thunderstorm WarningPHIBerks41 min
May 19, 3:12 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton63 min
May 19, 3:37 PM EDTSevere Thunderstorm WarningPHIWarren53 min
May 19, 3:43 PM EDTFlash Flood WarningBGMChemung4 hr
May 19, 4:06 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester54 min
May 19, 4:12 PM EDTFlash Flood WarningBGMSteuben3 hr
May 19, 4:20 PM EDTSevere Thunderstorm WarningPHIHunterdon, Warren55 min
May 19, 4:39 PM EDTFlash Flood WarningPHIHunterdon, Warren4 hr
May 19, 5:08 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Sussex, Warren50 min
May 19, 6:18 PM EDTFlash Flood WarningBGMPike, Wayne2 hr
May 19, 7:33 PM EDTFlash Flood WarningALYDutchess, Ulster5 hr
May 19, 7:34 PM EDTSevere Thunderstorm WarningPHIAtlantic, Camden, Cumberland, Gloucester56 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 4.3 hours before the alert went out and 202 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 2011-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 joules per kilogram.LCLLFCEL10008507005003002001001 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 2011-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 square meters per square second.19395878Sfc1 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
11 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
491 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
103 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 19, 10:47 AM EDTMesoscale DiscussionSPCBergen, Essex, Hudson, Hunterdon, Mercer, Middlesex and 6 more88 min
May 19, 2:17 PM EDTMesoscale DiscussionSPCAtlantic, Bergen, Burlington, Camden, Cumberland, Essex and 12 more58 min
May 19, 5:02 PM EDTMesoscale DiscussionSPCBergen, Burlington, Camden, Essex, Gloucester, Hudson and 9 more58 min

Nearby

Severe Thunderstorm Watches in Pennsylvania, 2011Severe Thunderstorm Watches in New York, 2011Severe Thunderstorm Watches in New Jersey, 2011Every severe thunderstorm watch 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.