Alert archive / New Jersey / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 137, NWS Philadelphia/Mount Holly

July 20, 2008Warren County, New Jersey; Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 20, 2008, 8:48 PM EDT for Warren County, New Jersey; Northampton County, Pennsylvania. It was in force for 42 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
Jul 20, 2008, 8:48 PM EDT (00:48 UTC)
Expired
Jul 20, 2008, 9:30 PM EDT
In force
42 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Warren County, NJ, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 107 km from the middle of the area, began a volume at 00:51 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 20, 8:55 PM EDTTSTM WND DMG3 Nne Wilson, PAA LARGE TREE WAS BLOWN DOWN IN FORKS TOWNSHIP.
Jul 20, 8:55 PM EDTTSTM WND GST 673 Nne Wilson, PAA THUNDERSTORM WIND GUST OF 67 MPH WAS REPORTED IN FORKS TOWNSHIP. THE MEASUREMENT WAS VIA AN ANEMOMETER.

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, 0.8 hours before the alert went out and 189 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 2008-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 254 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 2008-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 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
254 J/kg
Mixed-layer CIN
-143 J/kg
Mixed-layer LCL
1155 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
162 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 210048
SVRPHI
NJC041-PAC095-210130-
/O.NEW.KPHI.SV.W.0137.080721T0048Z-080721T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
848 PM EDT SUN JUL 20 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  SOUTHWESTERN WARREN COUNTY IN NORTHWEST NEW JERSEY...

* UNTIL 930 PM EDT

* AT 846 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
  WILSON...OR ABOUT NEAR EASTON...AND MOVING EAST AT 27 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ALPHA BY 855 PM...
  HARMONY BY 900 PM...
  6 MILES SOUTH OF ROXBURG AND 9 MILES SOUTH OF BELVIDERE BY 905
  PM...
  PLEASANT VALLEY...WASHINGTON...BRASS CASTLE AND 8 MILES SOUTH OF
  OXFORD BY 915 PM...

THUNDERSTORMS ARE CAPABLE OF PRODUCING HEAVY RAINFALL WHICH MAY
RESULT IN LOCALIZED AREAS OF FLOODING. DO NOT DRIVE IN AREAS WHERE
WATER IS CROSSING THE ROAD.

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.

LAT...LON 4087 7493 4072 7497 4064 7514 4061 7530
      4077 7536
TIME...MOT...LOC 0048Z 266DEG 24KT 4069 7523

$$

EBERWINE
1 follow-up statement
000 
WWUS51 KPHI 210109
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
909 PM EDT SUN JUL 20 2008

PAC095-210119-
/O.CAN.KPHI.SV.W.0137.000000T0000Z-080721T0130Z/
NORTHAMPTON PA-
909 PM EDT SUN JUL 20 2008

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL NORTHAMPTON COUNTY IS
CANCELLED...

LAT...LON 4076 7496 4074 7496 4073 7497 4067 7507
      4067 7509 4064 7515 4080 7509 4081 7495
TIME...MOT...LOC 0109Z 266DEG 24KT 4070 7505

$$

NJC041-210130-
/O.CON.KPHI.SV.W.0137.000000T0000Z-080721T0130Z/
WARREN NJ-
909 PM EDT SUN JUL 20 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR SOUTH CENTRAL WARREN COUNTY...

AT 908 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 PLEASANT VALLEY...OR 9 MILES EAST OF EASTON...MOVING
EAST AT 28 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  PLEASANT VALLEY...WASHINGTON AND BRASS CASTLE BY 915 PM EDT...

LAT...LON 4076 7496 4074 7496 4073 7497 4067 7507
      4067 7509 4064 7515 4080 7509 4081 7495
TIME...MOT...LOC 0109Z 266DEG 24KT 4070 7505

$$

EBERWINE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 5:20 AM EDTCoastal Flood StatementPHIAtlantic, Cape May, Monmouth, Ocean24 hr
Jul 20, 8:17 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery58 min
Jul 20, 9:22 PM EDTSevere Thunderstorm WarningPHIChester23 min
Jul 20, 9:29 PM EDTSevere Thunderstorm WarningPHIDelaware, Montgomery32 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2008Severe Thunderstorm Warnings in Pennsylvania, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.