Alert archive / New Jersey / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 217, NWS Philadelphia/Mount Holly

August 21, 2009Sussex County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 21, 2009, 2:34 PM EDT for Sussex County, New Jersey. It was in force for 63 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 21, 2009, 2:34 PM EDT (18:34 UTC)
Expired: Aug 21, 2009, 3:37 PM EDT
In force: 63 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Sussex County, NJ

The radar

The Philadelphia radar (KDIX), 143 km from the middle of the area, began a volume at 18:36 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

Time	Report	Where	Remark
Aug 21, 2:40 PM EDT	HAIL 0.25	5 Nne Pellettown, NJ	PEA SIZED HAIL REPORTED WITH HEAVY RAIN AND FREQUENT LIGHTNING IN WANTAGE.
Aug 21, 2:45 PM EDT	TSTM WND DMG	Andover, NJ	TREES AND WIRES DOWN IN SEVERAL LOCATIONS, INCLUDING ANDOVER.

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.

Issued	Product	Office	Lasted
Aug 21, 11:28 AM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 6.6 hours before the alert went out and 160 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2197 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 740 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 138 m²/s²
0-3 km storm-relative helicity: 158 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 7.7

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 211834
SVRPHI
NJC037-211945-
/O.NEW.KPHI.SV.W.0217.090821T1834Z-090821T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
234 PM EDT FRI AUG 21 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SUSSEX COUNTY IN NORTHWEST NEW JERSEY...
  THIS INCLUDES THE CITY OF NEWTON...

* UNTIL 345 PM EDT

* AT 233 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
  HIGH POINT...OR 6 MILES SOUTHEAST OF MONTAGUE...AND MOVING
  NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  HIGH POINT AROUND 240 PM EDT...
  8 MILES NORTHWEST OF VERNON VALLEY AROUND 245 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 FRIDAY
EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4124 7445 4121 7441 4092 7478 4109 7497
      4114 7493 4115 7491 4129 7481 4134 7475
      4135 7471 4135 7468
TIME...MOT...LOC 1834Z 229DEG 24KT 4127 7468

$$

NIERENBERG

1 follow-up statement

000 
WWUS51 KPHI 211937
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
337 PM EDT FRI AUG 21 2009

NJC037-211945-
/O.CAN.KPHI.SV.W.0217.000000T0000Z-090821T1945Z/
SUSSEX NJ-
337 PM EDT FRI AUG 21 2009

...THE SEVERE THUNDERSTORM WARNING FOR SUSSEX COUNTY IS CANCELLED...

THE THUNDERSTORMS THAT PROMPTED THE WARNING HAVE MOVED OUT OF THE 
AREA.

LAT...LON 4124 7445 4121 7441 4092 7478 4109 7497
      4114 7493 4115 7491 4129 7481 4134 7475
      4135 7471 4135 7468
TIME...MOT...LOC 1935Z 229DEG 24KT 4154 7427

$$

NIERENBERG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 6:11 AM EDT	Coastal Flood Statement	PHI	Atlantic, Cape May, Monmouth, Ocean	9 hr
Aug 21, 2:41 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex, Warren	3 hr
Aug 21, 2:47 PM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 10 more	35 hr
Aug 21, 3:12 PM EDT	High Surf Advisory	PHI	Atlantic, Cape May, Monmouth, Ocean	53 hr
Aug 21, 4:13 PM EDT	Severe Thunderstorm Warning	PHI	Salem	77 min
Aug 21, 4:16 PM EDT	Special Marine Warning	PHI		59 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2009 Every 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.