Alert archive / New Jersey / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 154, NWS Philadelphia/Mount Holly

July 29, 2009Burlington County, Mercer County, New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 29, 2009, 5:09 PM EDT for Burlington County, Mercer County, New Jersey; Bucks County, Pennsylvania. It was in force for 66 min. 1 report 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 29, 2009, 5:09 PM EDT (21:09 UTC)
Expired
Jul 29, 2009, 6:15 PM EDT
In force
66 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Philadelphia radar (KDIX), 42 km from the middle of the area, began a volume at 21:12 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 29, 5:30 PM EDTTSTM WND DMGWillingboro, NJTREES AND WIRES DOWN.

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 29, 12:49 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.2 hours before the alert went out and 136 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 2009-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1577 joules per kilogram.LCLLFCEL10008507005003002001001 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 2009-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
1577 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
745 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 292109
SVRPHI
NJC005-021-PAC017-292215-
/O.NEW.KPHI.SV.W.0154.090729T2109Z-090729T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
509 PM EDT WED JUL 29 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...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHWESTERN BURLINGTON COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 615 PM EDT

* AT 509 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR WILLINGBORO...OR 13 MILES EAST OF
  PHILADELPHIA...AND MOVING NORTHEAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BURLINGTON AROUND 515 PM EDT...
  BRISTOL...FLORENCE AND JACKSONVILLE AROUND 520 PM EDT...
  LEVITTOWN AROUND 525 PM EDT...
  BORDENTOWN AROUND 530 PM EDT...
  WHITE HORSE...TRENTON AND EWING AROUND 535 PM EDT...
  MERCERVILLE-HAMILTON SQUARE AROUND 540 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS 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 800 PM EDT
WEDNESDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4037 7477 4025 7459 3989 7488 3999 7501
TIME...MOT...LOC 2109Z 217DEG 29KT 4004 7490

$$

EBERWINE
1 follow-up statement
000 
WWUS51 KPHI 292138
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
538 PM EDT WED JUL 29 2009

NJC005-021-PAC017-292215-
/O.CON.KPHI.SV.W.0154.000000T0000Z-090729T2215Z/
MERCER NJ-BUCKS PA-BURLINGTON NJ-
538 PM EDT WED JUL 29 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR EXTREME NORTH CENTRAL BURLINGTON...SOUTHEASTERN BUCKS AND MERCER
COUNTIES...

AT 536 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL.

THIS STORM WAS LOCATED NEAR WHITE HORSE...OR NEAR TRENTON...MOVING
NORTHEAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  EDINBURG AND LAWRENCEVILLE BY 545 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
WEDNESDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4021 7484 4037 7477 4025 7459 4010 7471
TIME...MOT...LOC 2138Z 216DEG 30KT 4022 7469

$$

EBERWINE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 10:15 AM EDTFlash Flood WatchPHIHunterdon, Mercer, Middlesex, Morris, Somerset, Sussex and 1 more17 hr
Jul 29, 12:55 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Somerset65 min
Jul 29, 1:30 PM EDTAreal Flood AdvisoryPHIMorris, Somerset3 hr
Jul 29, 1:35 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Somerset55 min
Jul 29, 1:56 PM EDTSevere Thunderstorm WarningPHISussex64 min
Jul 29, 2:10 PM EDTTornado WarningPHISussex65 min
Jul 29, 2:21 PM EDTAreal Flood AdvisoryPHIMiddlesex3 hr
Jul 29, 2:32 PM EDTFlash Flood WarningPHISussex6 hr
Jul 29, 2:50 PM EDTFlash Flood WarningPHIMiddlesex4 hr
Jul 29, 3:52 PM EDTFlash Flood WarningPHIMorris, Somerset4 hr
Jul 29, 5:48 PM EDTSpecial Marine WarningPHI57 min
Jul 29, 5:55 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Mercer, Middlesex, Salem4 hr
Jul 29, 6:11 PM EDTSevere Thunderstorm WarningPHICumberland26 min
Jul 29, 6:26 PM EDTSevere Thunderstorm WarningPHIAtlantic, Camden, Gloucester38 min
Jul 29, 6:42 PM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Mercer and 4 more3 hr
Jul 29, 6:42 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden39 min
Jul 29, 6:44 PM EDTFlash Flood WarningPHIMiddlesex, Somerset3 hr
Jul 29, 6:50 PM EDTAreal Flood AdvisoryPHIMorris94 min
Jul 29, 7:31 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth30 min
Jul 29, 11:48 AM EDTSevere Thunderstorm WarningPHIBucks, Chester, Montgomery72 min
Jul 29, 12:12 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton78 min
Jul 29, 1:51 PM EDTFlash Flood WarningPHICarbon, Monroe9 hr
Jul 29, 2:04 PM EDTSevere Thunderstorm WarningPHIMonroe56 min
Jul 29, 2:11 PM EDTTornado WarningPHICarbon, Monroe34 min
Jul 29, 5:28 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Northampton40 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.