Alert archive / Pennsylvania / Tornado Warnings in 2011

Tornado Warning 8, NWS Philadelphia/Mount Holly

May 23, 2011Bucks County, Lehigh County, Northampton County, Pennsylvania; Hunterdon County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this tornado warning at May 23, 2011, 7:58 PM EDT for Bucks County, Lehigh County, Northampton County, Pennsylvania; Hunterdon County, Warren County, New Jersey. It was in force for 32 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 23, 2011, 7:58 PM EDT (23:58 UTC)
Expired
May 23, 2011, 8:30 PM EDT
In force
32 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Hunterdon County, NJ, Warren County, NJ, Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 109 km from the middle of the area, began a volume at 00:03 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 was reported inside it

TimeReportWhereRemark
May 23, 8:15 PM EDTFUNNEL CLOUDLower Nazareth Twp, PA
May 23, 8:20 PM EDTTSTM WND GST 68Forks Twp, PA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 12.0 hours before the alert went out and 153 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, Phillips Aaf/Abe, MD at 12:00Z on 2011-05-23Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phillips Aaf/Abe, MD at 12:00Z on 2011-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -35 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
530 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
-35 m²/s²
0-3 km storm-relative helicity
11 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.

096 
WFUS51 KPHI 232358
TORPHI
NJC019-041-PAC017-077-095-240030-
/O.NEW.KPHI.TO.W.0008.110523T2358Z-110524T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
758 PM EDT MON MAY 23 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF EASTON...
  EXTREME WEST CENTRAL HUNTERDON COUNTY IN NORTHWEST NEW JERSEY...
  SOUTHWESTERN WARREN COUNTY IN NORTHWEST NEW JERSEY...
  NORTH CENTRAL BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 830 PM EDT

* AT 754 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
  NORTHAMPTON...OR 8 MILES NORTH OF ALLENTOWN...MOVING EAST AT 20
  MPH.

* THE TORNADO WILL BE NEAR...
  BATH BY 810 PM EDT...
  BETHLEHEM BY 815 PM EDT...
  NAZARETH AND 6 MILES NORTH OF HELLERTOWN BY 820 PM EDT...
  OLD ORCHARD AND TATAMY BY 825 PM EDT...
  GLENDON...WILSON...EASTON AND FORKS BY 830 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING UP 
TO TWO INCH SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 4074 7505 4052 7512 4063 7557 4080 7552
TIME...MOT...LOC 2357Z 283DEG 19KT 4070 7547

$$
1 follow-up statement
292 
WWUS51 KPHI 240024
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
824 PM EDT MON MAY 23 2011

PAC017-077-240034-
/O.CAN.KPHI.TO.W.0008.000000T0000Z-110524T0030Z/
LEHIGH PA-BUCKS PA-
824 PM EDT MON MAY 23 2011

...THE TORNADO WARNING FOR NORTH CENTRAL BUCKS AND EAST CENTRAL
LEHIGH COUNTIES IS CANCELLED...

LAT...LON 4071 7508 4056 7515 4057 7520 4060 7519
      4062 7520 4059 7526 4061 7537 4076 7530
TIME...MOT...LOC 0024Z 283DEG 19KT 4067 7529

$$

NJC019-041-PAC095-240030-
/O.CON.KPHI.TO.W.0008.000000T0000Z-110524T0030Z/
WARREN NJ-HUNTERDON NJ-NORTHAMPTON PA-
824 PM EDT MON MAY 23 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 830 PM EDT FOR SOUTH
CENTRAL NORTHAMPTON...EXTREME WEST CENTRAL HUNTERDON AND SOUTHWESTERN
WARREN COUNTIES...

AT 820 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED NEAR PALMER HEIGHTS...
OR NEAR EASTON...MOVING EAST AT 20 MPH.

THE TORNADO WILL BE NEAR...
  OLD ORCHARD...GLENDON...WEST EASTON AND WILSON BY 830 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 4071 7508 4056 7515 4057 7520 4060 7519
      4062 7520 4059 7526 4061 7537 4076 7530
TIME...MOT...LOC 0024Z 283DEG 19KT 4067 7529

$$

PO

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 23, 5:35 PM EDTSpecial Weather StatementPHIDelaware, Philadelphia55 min
May 23, 5:47 PM EDTSpecial Weather StatementPHIBerks43 min
May 23, 6:21 PM EDTSpecial Weather StatementPHIBerks, Chester, Montgomery54 min
May 23, 6:30 PM EDTSpecial Weather StatementPHICarbon, Northampton60 min
May 23, 7:22 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton38 min
May 23, 7:30 PM EDTTornado WarningPHICarbon, Lehigh, Monroe, Northampton30 min
May 23, 11:07 AM EDTSpecial Weather StatementPHIAtlantic53 min

Nearby

Tornado Warnings in Pennsylvania, 2011Tornado Warnings in New Jersey, 2011Every tornado warning in 2011Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.