Alert archive / New Jersey / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 254, NWS Philadelphia/Mount Holly

August 18, 2011Hunterdon County, Mercer County, New Jersey; Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 18, 2011, 8:31 PM EDT for Hunterdon County, Mercer County, New Jersey; Bucks County, Montgomery County, Pennsylvania. It was in force for 59 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
Aug 18, 2011, 8:31 PM EDT (00:31 UTC)
Expired
Aug 18, 2011, 9:30 PM EDT
In force
59 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Hunterdon County, NJ, Mercer County, NJ, Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 00:31 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
Aug 18, 8:35 PM EDTHAIL 0.88Horsham, PA
Aug 18, 8:50 PM EDTHAIL 0.75Furlong, PA

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.5 hours before the alert went out and 194 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 2011-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1443 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, Brookhaven, NY at 00:00Z on 2011-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 85 square meters per square second.1939Sfc1 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
1443 J/kg
Mixed-layer CIN
-43 J/kg
Mixed-layer LCL
871 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
85 m²/s²
0-3 km storm-relative helicity
155 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.

078 
WUUS51 KPHI 190031
SVRPHI
NJC019-021-PAC017-091-190130-
/O.NEW.KPHI.SV.W.0254.110819T0031Z-110819T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
831 PM EDT THU AUG 18 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WEST CENTRAL MERCER COUNTY IN CENTRAL NEW JERSEY...
  SOUTH CENTRAL HUNTERDON COUNTY IN NORTHWEST NEW JERSEY...
  CENTRAL BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  EAST CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 930 PM EDT

* AT 827 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  AMBLER...OR 10 MILES NORTH OF PHILADELPHIA...AND MOVING NORTHEAST
  AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WILLOW GROVE AROUND 845 PM EDT...
  HATBORO AROUND 850 PM EDT...
  IVYLAND AROUND 900 PM EDT...
  8 MILES SOUTHEAST OF DOYLESTOWN AROUND 905 PM EDT...
  RICHBORO AROUND 920 PM EDT...
  NEWTOWN...6 MILES WEST OF WOODSIDE...7 MILES WEST OF YARDLEY AND 7
  MILES SOUTH OF NEW HOPE AROUND 930 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4045 7494 4023 7476 4011 7522 4021 7532
TIME...MOT...LOC 0030Z 239DEG 12KT 4015 7519

$$

HEAVENER
3 follow-up statements
457 
WWUS51 KPHI 190053
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
853 PM EDT THU AUG 18 2011

PAC091-190103-
/O.CAN.KPHI.SV.W.0254.000000T0000Z-110819T0130Z/
MONTGOMERY PA-
853 PM EDT THU AUG 18 2011

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MONTGOMERY COUNTY
IS CANCELLED...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

LAT...LON 4015 7506 4022 7517 4029 7520 4045 7494
      4023 7476 4023 7477
TIME...MOT...LOC 0053Z 239DEG 12KT 4019 7510

$$

NJC019-021-PAC017-190130-
/O.CON.KPHI.SV.W.0254.000000T0000Z-110819T0130Z/
HUNTERDON NJ-MERCER NJ-BUCKS PA-
853 PM EDT THU AUG 18 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR CENTRAL BUCKS...WEST CENTRAL MERCER AND SOUTH CENTRAL HUNTERDON
COUNTIES...

AT 848 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR WARMINSTER HEIGHTS...OR 12 MILES NORTH OF
PHILADELPHIA...MOVING NORTHEAST AT 15 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  IVYLAND BY 900 PM EDT...
  8 MILES SOUTHEAST OF DOYLESTOWN BY 905 PM EDT...
  CHURCHVILLE BY 915 PM EDT...
  RICHBORO AND VILLAGE SHIRES BY 920 PM EDT...
  NEWTOWN GRANT...NEWTOWN...WOODBOURNE AND 6 MILES WEST OF WOODSIDE
  BY 930 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4015 7506 4022 7517 4029 7520 4045 7494
      4023 7476 4023 7477
TIME...MOT...LOC 0053Z 239DEG 12KT 4019 7510

$$

HEAVENER
955 
WWUS51 KPHI 190116
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
916 PM EDT THU AUG 18 2011

NJC019-021-PAC017-190130-
/O.CON.KPHI.SV.W.0254.000000T0000Z-110819T0130Z/
HUNTERDON NJ-MERCER NJ-BUCKS PA-
916 PM EDT THU AUG 18 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR CENTRAL BUCKS...WEST CENTRAL MERCER AND SOUTH CENTRAL HUNTERDON
COUNTIES...

AT 914 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR NEWTOWN GRANT...OR 14 MILES WEST OF TRENTON...MOVING
NORTHEAST AT 15 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEWTOWN GRANT...NEWTOWN...6 MILES WEST OF WOODSIDE AND 7 MILES WEST
  OF YARDLEY BY 930 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4019 7494 4027 7507 4035 7510 4045 7494
      4024 7478
TIME...MOT...LOC 0115Z 239DEG 12KT 4023 7502

$$

HEAVENER
350 
WWUS51 KPHI 190133
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
933 PM EDT THU AUG 18 2011

NJC019-021-PAC017-190141-
/O.EXP.KPHI.SV.W.0254.000000T0000Z-110819T0130Z/
HUNTERDON NJ-MERCER NJ-BUCKS PA-
933 PM EDT THU AUG 18 2011

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL BUCKS...WEST CENTRAL
MERCER AND SOUTH CENTRAL HUNTERDON COUNTIES HAS EXPIRED...

THE STORM THAT PROMPTED THE WARNING HAS GREATLY WEAKENED AND 
THEREFORE THE WARNING HAS BEEN ALLOWED TO EXPIRE.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

LAT...LON 4019 7494 4027 7507 4035 7510 4045 7494
      4024 7478
TIME...MOT...LOC 0116Z 239DEG 12KT 4023 7502

$$

HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 8:11 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester64 min
Aug 18, 8:26 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester112 min
Aug 18, 8:48 PM EDTSpecial Weather StatementPHIWarren57 min
Aug 18, 8:48 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean57 min
Aug 18, 8:59 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex, Warren61 min
Aug 18, 9:48 PM EDTSevere Thunderstorm WarningPHIHunterdon, Middlesex, Morris, Somerset, Warren57 min
Aug 18, 9:53 PM EDTSevere Thunderstorm WarningPHIAtlantic, Cape May, Cumberland, Salem67 min
Aug 18, 9:57 PM EDTSevere Thunderstorm WarningPHIMorris43 min
Aug 19, 12:19 AM EDTSpecial Marine WarningPHI26 min
Aug 19, 12:19 AM EDTSpecial Weather StatementPHICape May41 min
Aug 19, 12:50 AM EDTSpecial Weather StatementPHICumberland, Salem40 min
Aug 19, 1:14 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Mercer and 1 more3 hr
Aug 19, 1:31 AM EDTSpecial Weather StatementPHICumberland, Gloucester, Salem59 min
Aug 19, 2:28 AM EDTSpecial Weather StatementPHICamden, Cumberland, Gloucester, Salem47 min
Aug 19, 2:48 AM EDTSpecial Weather StatementPHIMonmouth, Ocean57 min
Aug 19, 3:06 AM EDTAreal Flood AdvisoryPHIAtlantic, Cape May, Cumberland114 min
Aug 19, 3:21 AM EDTAreal Flood AdvisoryPHIMiddlesex, Monmouth, Ocean114 min
Aug 19, 6:24 AM EDTSpecial Weather StatementPHIMercer, Middlesex36 min
Aug 19, 6:37 AM EDTSpecial Weather StatementPHIMiddlesex23 min
Aug 19, 1:34 PM EDTSpecial Marine WarningPHI41 min
Aug 19, 2:39 PM EDTSpecial Marine WarningPHI96 min
Aug 19, 3:23 PM EDTSpecial Marine WarningPHI67 min
Aug 19, 4:05 PM EDTSpecial Weather StatementPHICamden55 min
Aug 19, 4:15 PM EDTSpecial Marine WarningPHI90 min
Aug 19, 4:29 PM EDTSevere Thunderstorm WarningPHIWarren61 min
Aug 19, 4:32 PM EDTAreal Flood AdvisoryPHISussex, Warren2 hr
Aug 19, 4:38 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden67 min
Aug 19, 4:42 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Salem4 hr
Aug 19, 5:12 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Sussex, Warren78 min
Aug 19, 5:27 PM EDTAreal Flood AdvisoryPHIMonmouth, Ocean111 min
Aug 19, 5:29 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean50 min
Aug 19, 5:47 PM EDTSpecial Marine WarningPHI118 min
Aug 19, 5:49 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Middlesex, Morris, Somerset104 min
Aug 19, 5:59 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Morris, Somerset80 min
Aug 19, 6:14 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Mercer, Salem65 min
Aug 19, 6:24 PM EDTSevere Thunderstorm WarningPHIMorris28 min
Aug 19, 6:54 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth31 min
Aug 18, 8:08 PM EDTSpecial Weather StatementPHIBerks67 min
Aug 19, 12:02 AM EDTSpecial Weather StatementPHIChester58 min
Aug 19, 4:00 AM EDTAreal Flood WarningPHIDelaware4 hr
Aug 19, 1:46 PM EDTSevere Thunderstorm WarningPHIMonroe59 min
Aug 19, 2:35 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe70 min
Aug 19, 2:38 PM EDTAreal Flood AdvisoryPHICarbon, Monroe3 hr
Aug 19, 2:57 PM EDTFlash Flood WarningPHICarbon, Monroe3 hr
Aug 19, 3:47 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe58 min
Aug 19, 4:52 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton53 min
Aug 19, 5:35 PM EDTSevere Thunderstorm WarningPHIChester55 min
Aug 19, 5:39 PM EDTAreal Flood AdvisoryPHIChester, Delaware3 hr
Aug 19, 5:42 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery48 min
Aug 19, 5:45 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia3 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2011Severe Thunderstorm Warnings in Pennsylvania, 2011Every severe thunderstorm warning 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.