Alert archive / Pennsylvania / Tornado Watches in 2011

Tornado Watch 701

July 29, 2011Bergen County, Passaic County, Sussex County, New Jersey; 4 counties in New York; 5 counties in Pennsylvania

The Storm Prediction Center issued this tornado watch at Jul 29, 2011, 5:03 PM EDT for Bergen County, Passaic County, Sussex County, New Jersey; 4 counties in New York; 5 counties in Pennsylvania. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jul 29, 2011, 5:03 PM EDT (21:03 UTC)
Expired
Jul 29, 2011, 8:20 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Bergen County, NJ, Passaic County, NJ, Sussex County, NJ, Orange County, NY, Putnam County, NY, Rockland County, NY, Westchester County, NY, Lackawanna County, PA, Luzerne County, PA, Monroe County, PA, Pike County, PA, Wayne County, PA

The radar

The Binghamton radar (KBGM), 122 km from the middle of the area, began a volume at 21:03 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 29, 5:11 PM EDTTornado WarningBGMPike49 min
Jul 29, 5:22 PM EDTTornado WarningOKXOrange, Rockland, Westchester38 min
Jul 29, 5:34 PM EDTSevere Thunderstorm WarningOKXOrange41 min
Jul 29, 5:39 PM EDTSevere Thunderstorm WarningBGMPike, Wayne36 min
Jul 29, 5:57 PM EDTTornado WarningOKXRockland, Westchester33 min
Jul 29, 5:59 PM EDTSevere Thunderstorm WarningPHISussex61 min
Jul 29, 6:16 PM EDTSevere Thunderstorm WarningOKXPassaic44 min
Jul 29, 6:26 PM EDTTornado WarningOKXWestchester34 min
Jul 29, 6:49 PM EDTSevere Thunderstorm WarningOKXOrange, Rockland, Westchester27 min
Jul 29, 6:56 PM EDTSevere Thunderstorm WarningOKXBergen, Passaic34 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, 9.1 hours before the alert went out and 169 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 2011-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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 2011-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 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
695 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

347 
WWUS20 KWNS 292102
SEL1
SPC WW 292102
NJZ000-NYZ000-PAZ000-300300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 701
NWS STORM PREDICTION CENTER NORMAN OK
505 PM EDT FRI JUL 29 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       NORTHERN NEW JERSEY
       FAR SOUTHEAST NEW YORK
       FAR NORTHEAST PENNSYLVANIA

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 505 PM UNTIL
1100 PM EDT.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 25 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 5 MILES NORTHWEST OF
WILKESBARRE PENNSYLVANIA TO 25 MILES SOUTH SOUTHEAST OF
POUGHKEEPSIE NEW YORK.  FOR A COMPLETE DEPICTION OF THE WATCH SEE
THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 699...WW 700...

DISCUSSION...A NARROW CORRIDOR OF ENHANCED TORNADO POTENTIAL HAS
DEVELOPED ALONG WARM FRONT RETREATING NWD.  ONGOING SUPERCELLS WILL
BE CAPABLE OF PRODUCING A COUPLE OF TORNADOES AS THEY INTERACT WITH
THE WARM FRONT LATE THIS AFTERNOON INTO EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 29030.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 29, 12:57 PM EDTMesoscale DiscussionSPCBergen, Essex, Hudson, Hunterdon, Morris, Passaic and 4 more2 hr
Jul 29, 2:40 PM EDTSevere Thunderstorm WatchSPCBergen, Burlington, Camden, Essex, Gloucester, Hudson and 11 more8 hr
Jul 29, 4:40 PM EDTMesoscale DiscussionSPCBergen, Burlington, Camden, Essex, Hudson, Hunterdon and 10 more95 min
Jul 29, 6:17 PM EDTMesoscale DiscussionSPCSalem88 min
Jul 29, 3:31 AM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Erie, Wyoming89 min
Jul 29, 3:56 AM EDTSevere Thunderstorm WatchSPCAllegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston and 1 more5 hr
Jul 29, 2:06 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Bedford, Blair, Butler and 9 more84 min

Nearby

Tornado Watches in Pennsylvania, 2011Tornado Watches in New York, 2011Tornado Watches in New Jersey, 2011Every tornado 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.