Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 145, NWS Philadelphia/Mount Holly

July 23, 2008Bucks County, Pennsylvania; Mercer County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 23, 2008, 2:55 PM EDT for Bucks County, Pennsylvania; Mercer County, New Jersey. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 23, 2008, 2:55 PM EDT (18:55 UTC)
Expired
Jul 23, 2008, 3:30 PM EDT
In force
35 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Mercer County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 53 km from the middle of the area, began a volume at 18:57 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.

The watch it was issued in

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

IssuedProductOfficeLasted
Jul 23, 2:34 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.9 hours before the alert went out and 133 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 2008-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1012 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 2008-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -61 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
1012 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
980 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
-61 m²/s²
0-3 km storm-relative helicity
-48 m²/s²
Significant tornado parameter
-0.4
Supercell composite
-7.5

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 231855
SVRPHI
NJC021-PAC017-231930-
/O.NEW.KPHI.SV.W.0145.080723T1855Z-080723T1930Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
255 PM EDT WED JUL 23 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL MERCER COUNTY IN CENTRAL NEW JERSEY...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 330 PM EDT

* AT 253 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  LANGHORNE...OR ABOUT 9 MILES EAST OF WILLOW GROVE...AND MOVING
  NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  LANGHORNE...LEVITTOWN AND RICHBORO BY 300 PM...
  NEWTOWN BY 310 PM...
  WOODSIDE BY 315 PM...
  TRENTON BY 320 PM...
  EWING AND WASHINGTON CROSSING BY 325 PM...

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 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 1000 PM WEDNESDAY
EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW JERSEY AND
SOUTHEAST PENNSYLVANIA.

LAT...LON 4034 7498 4027 7463 4008 7490 4015 7503
TIME...MOT...LOC 1855Z 212DEG 17KT 4015 7493

$$

IOVINO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 3:51 AM EDTFlash Flood WatchPHIBerks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more25 hr
Jul 23, 4:23 AM EDTAreal Flood AdvisoryPHIBucks, Chester, Montgomery3 hr
Jul 23, 2:58 PM EDTSevere Thunderstorm WarningPHIBucks47 min
Jul 23, 3:30 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia60 min
Jul 23, 3:58 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery62 min
Jul 23, 4:27 PM EDTSevere Thunderstorm WarningPHIChester, Delaware38 min
Jul 23, 4:47 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton58 min
Jul 23, 5:03 PM EDTSevere Thunderstorm WarningPHIBucks57 min
Jul 23, 5:13 PM EDTSevere Thunderstorm WarningPHIBucks62 min
Jul 23, 7:00 PM EDTSevere Thunderstorm WarningPHIDelaware60 min
Jul 23, 7:48 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Montgomery, Philadelphia57 min
Jul 23, 3:02 AM EDTSpecial Marine WarningPHI58 min
Jul 23, 2:44 PM EDTSevere Thunderstorm WarningPHICumberland, Salem46 min
Jul 23, 3:26 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Somerset64 min
Jul 23, 4:03 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset57 min
Jul 23, 4:09 PM EDTTornado WarningPHIMiddlesex, Somerset36 min
Jul 23, 4:51 PM EDTAreal Flood WarningPHIMiddlesex, Somerset105 min
Jul 23, 7:10 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset35 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2008Severe Thunderstorm Warnings in New Jersey, 2008Every severe thunderstorm warning in 2008

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.