Alert archive / New Jersey / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 142, NWS Philadelphia/Mount Holly

July 26, 2009Burlington County, Mercer County, Middlesex County, New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 26, 2009, 8:16 PM EDT for Burlington County, Mercer County, Middlesex County, New Jersey; Bucks County, Pennsylvania. It was in force for 59 min. 3 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
Jul 26, 2009, 8:16 PM EDT (00:16 UTC)
Expired
Jul 26, 2009, 9:15 PM EDT
In force
59 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Burlington County, NJ, Mercer County, NJ, Middlesex County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 43 km from the middle of the area, began a volume at 00:15 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
Jul 26, 8:25 PM EDTTSTM WND DMGHamilton Square, NJTREE DOWN ON HOUSE.
Jul 26, 8:30 PM EDTTSTM WND DMGWhite Horse, NJTWO 50 TO 80 FOOT TREES COMPLETELY UPROOTED IN WHITE HORSE/YARDVILLE.
Jul 26, 8:40 PM EDTHAIL 0.25Hamilton, NJPEA SIZE HAIL IN HAMILTON TWP.

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

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 26, 3:51 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.3 hours before the alert went out and 175 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, Brookhaven, NY at 00:00Z on 2009-07-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 807 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 00:00Z on 2009-07-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 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
807 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
210 m²/s²
Significant tornado parameter
0.4
Supercell composite
5.8

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 270016
SVRPHI
NJC005-021-023-PAC017-270115-
/O.NEW.KPHI.SV.W.0142.090727T0016Z-090727T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
816 PM EDT SUN JUL 26 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MERCER COUNTY IN CENTRAL NEW JERSEY...
  THIS INCLUDES THE CITY OF TRENTON...
  SOUTHWESTERN MIDDLESEX COUNTY IN NORTHERN NEW JERSEY...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTH CENTRAL BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 915 PM EDT

* AT 812 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  FLORENCE...OR 7 MILES SOUTH OF TRENTON...AND MOVING NORTHEAST AT 25
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BORDENTOWN AROUND 820 PM EDT...
  WHITE HORSE AND TRENTON AROUND 830 PM EDT...
  MERCERVILLE-HAMILTON SQUARE AROUND 840 PM EDT...
  EDINBURG...WINDSOR AND 6 MILES SOUTHEAST OF LAWRENCEVILLE AROUND
  850 PM EDT...
  PRINCETON AROUND 900 PM EDT...
  6 MILES NORTHWEST OF CLEARBROOK PARK AROUND 910 PM EDT...

THIS STORM HAS BEEN BACKBUILDING ACROSS NORTHERN BURLINGTON COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES GREATEST KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 PM EDT
SUNDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4037 7477 4031 7445 4003 7486 4007 7492
TIME...MOT...LOC 0015Z 212DEG 17KT 4013 7474

$$

GORSE
1 follow-up statement
000 
WWUS51 KPHI 270040
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
840 PM EDT SUN JUL 26 2009

NJC005-PAC017-270048-
/O.CAN.KPHI.SV.W.0142.000000T0000Z-090727T0115Z/
BUCKS PA-BURLINGTON NJ-
840 PM EDT SUN JUL 26 2009

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL BURLINGTON AND
SOUTHEASTERN BUCKS COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM HAS MOVED OUT OF THE AREA, THEREFORE THE 
WARNING HAS BEEN CANCELLED. WIND DAMAGE WAS REPORTED IN MANSFIELD 
TOWNSHIP AND BORDENTOWN IN BURLINGTON COUNTY.

A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 1100 PM EDT 
SUNDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 4037 7477 4031 7445 4016 7472 4019 7474
TIME...MOT...LOC 0038Z 212DEG 17KT 4022 7467

$$

NJC021-023-270115-
/O.CON.KPHI.SV.W.0142.000000T0000Z-090727T0115Z/
MERCER NJ-MIDDLESEX NJ-
840 PM EDT SUN JUL 26 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM EDT
FOR SOUTHWESTERN MIDDLESEX AND EASTERN MERCER COUNTIES...

AT 838 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR MERCERVILLE-HAMILTON SQUARE...OR NEAR TRENTON...MOVING
NORTHEAST AT 20 MPH.

THIS STORM PRODUCED WIND DAMAGE IN NORTHERN BURLINGTON COUNTY.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  6 MILES SOUTHEAST OF LAWRENCEVILLE BY 845 PM EDT...
  EDINBURG AND WINDSOR BY 850 PM EDT...
  PRINCETON JUNCTION...PRINCETON AND HIGHTSTOWN BY 900 PM EDT...
  6 MILES NORTHWEST OF CLEARBROOK PARK BY 910 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 PM EDT
SUNDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4037 7477 4031 7445 4016 7472 4019 7474
TIME...MOT...LOC 0038Z 212DEG 17KT 4022 7467

$$

GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 26, 9:57 PM EDTAreal Flood AdvisoryPHIMercer, Middlesex, Morris, Somerset2 hr
Jul 27, 2:46 PM EDTSpecial Marine WarningPHI89 min
Jul 27, 2:58 PM EDTSpecial Marine WarningPHI92 min
Jul 27, 4:10 PM EDTSpecial Marine WarningPHI2 hr
Jul 27, 4:25 PM EDTSevere Thunderstorm WarningPHICape May54 min
Jul 27, 6:25 PM EDTSpecial Marine WarningPHI95 min
Jul 26, 8:26 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh, Northampton37 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2009Severe Thunderstorm Warnings in Pennsylvania, 2009Every severe thunderstorm warning in 2009

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.