Alert archive / New Jersey / Tornado Warnings in 2009

Tornado Warning 13, NWS Philadelphia/Mount Holly

October 24, 2009Hunterdon County, New Jersey

NWS Philadelphia/Mount Holly issued this tornado warning at Oct 24, 2009, 6:31 PM EDT for Hunterdon County, New Jersey. It was in force for 10 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
Oct 24, 2009, 6:31 PM EDT (22:31 UTC)
Expired
Oct 24, 2009, 6:41 PM EDT
In force
10 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Hunterdon County, NJ

The radar

The Philadelphia radar (KDIX), 70 km from the middle of the area, began a volume at 22:33 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 nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.5 hours before the alert went out and 176 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 12:00Z on 2009-10-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 74 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 12:00Z on 2009-10-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 282 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
74 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
485 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
282 m²/s²
0-3 km storm-relative helicity
325 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
WFUS51 KPHI 242231
TORPHI
NJC019-242300-
/O.NEW.KPHI.TO.W.0013.091024T2231Z-091024T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
631 PM EDT SAT OCT 24 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL HUNTERDON COUNTY IN NORTHWEST NEW JERSEY...

* UNTIL 700 PM EDT

* AT 630 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
  SERGEANTSVILLE...OR 16 MILES NORTHWEST OF TRENTON...MOVING
  NORTHEAST AT 25 MPH.

* THE TORNADO WILL BE NEAR...
  SAND BROOK BY 640 PM EDT...
  FLEMINGTON BY 650 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 4053 7486 4043 7477 4035 7491 4045 7501
TIME...MOT...LOC 2231Z 240DEG 23KT 4040 7494

$$

RNS
1 follow-up statement
000 
WWUS51 KPHI 242241
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
641 PM EDT SAT OCT 24 2009

NJC019-242250-
/O.CAN.KPHI.TO.W.0013.000000T0000Z-091024T2300Z/
HUNTERDON NJ-
641 PM EDT SAT OCT 24 2009

...THE TORNADO WARNING FOR SOUTH CENTRAL HUNTERDON COUNTY IS
CANCELLED...

THE RADAR NO LONGER SHOWS STRONG ROTATION WITH THE STORM. HOWEVER, 
A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT.

LAT...LON 4053 7486 4043 7477 4035 7491 4045 7501
TIME...MOT...LOC 2240Z 240DEG 23KT 4042 7487

$$

RNS

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 24, 4:49 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Somerset, Sussex, Warren4 hr
Oct 24, 6:19 PM EDTSevere Thunderstorm WarningPHISalem26 min
Oct 24, 6:28 PM EDTSevere Thunderstorm WarningPHIHunterdon, Somerset47 min
Oct 24, 7:16 PM EDTFlash Flood WarningPHIHunterdon, Morris, Somerset3 hr
Oct 24, 7:24 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Gloucester, Middlesex, Monmouth, Ocean and 1 more3 hr

Nearby

Tornado Warnings in New Jersey, 2009Every tornado warning in 2009Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.