Alert archive / New Jersey / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 128, NWS Philadelphia/Mount Holly

July 17, 2009Hunterdon County, Morris County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2009, 8:51 PM EDT for Hunterdon County, Morris County, Somerset County, New Jersey. It was in force for 54 min. 4 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 17, 2009, 8:51 PM EDT (00:51 UTC)
Expired
Jul 17, 2009, 9:45 PM EDT
In force
54 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Hunterdon County, NJ, Morris County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 86 km from the middle of the area, began a volume at 00:53 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 17, 8:55 PM EDTTSTM WND DMGWhite House Station, NJTREES DOWN IN READINGTON TOWNSHIP.
Jul 17, 9:01 PM EDTTSTM WND GST 44Somerville, NJA 44 MPH THUNDERSTORM WIND GUST WAS MEASURED AT THE SOMERVILLE AIRPORT.
Jul 17, 9:08 PM EDTTSTM WND DMG2 W Raritan, NJTREES AND WIRES DOWN IN BRANCHBURG TOWNSHIP.
Jul 17, 9:10 PM EDTTSTM WND DMGBernardsville, NJTREES DOWN.

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, 0.9 hours before the alert went out and 156 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 2009-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1160 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 2009-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 square meters per square second.1939587897Sfc1 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
1160 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
625 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.6

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 180051
SVRPHI
NJC019-027-035-180145-
/O.NEW.KPHI.SV.W.0128.090718T0051Z-090718T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
851 PM EDT FRI JUL 17 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN MORRIS COUNTY IN NORTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF MORRISTOWN...
  SOMERSET COUNTY IN NORTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF SOMERVILLE...
  EASTERN HUNTERDON COUNTY IN NORTHWEST NEW JERSEY...

* UNTIL 945 PM EDT

* AT 850 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
  CLOVERHILL...OR 11 MILES SOUTHWEST OF SOMERVILLE...AND MOVING
  NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  FLAGTOWN AROUND 900 PM EDT...
  WHITE HOUSE STATION AND BRIDGEWATER AROUND 910 PM EDT...
  PEAPACK AND GLADSTONE AND FAR HILLS AROUND 925 PM EDT...
  BASKING RIDGE AROUND 930 PM EDT...
  CHESTER AROUND 935 PM EDT...
  SUCCASUNNA AROUND 940 PM EDT...

LAT...LON 4090 7474 4078 7438 4041 7470 4047 7494
TIME...MOT...LOC 0051Z 204DEG 26KT 4049 7479

$$

KRUZDLO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 8:12 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer96 min
Jul 17, 9:17 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Somerset, Sussex, Warren3 hr
Jul 17, 9:21 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex54 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 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.