Alert archive / New Jersey / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 151, NWS Philadelphia/Mount Holly

July 29, 2009Middlesex County, Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 29, 2009, 1:35 PM EDT for Middlesex County, Somerset County, New Jersey. It was in force for 55 min. 3 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 29, 2009, 1:35 PM EDT (17:35 UTC)
Expired: Jul 29, 2009, 2:30 PM EDT
In force: 55 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 64 km from the middle of the area, began a volume at 17:35 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
Jul 29, 2:10 PM EDT	TSTM WND GST 70	Edison, NJ	70 MPH WIND GUST WITH TREES AND BRANCHES DOWN.
Jul 29, 2:13 PM EDT	HAIL 1	South Plainfield, NJ	QUARTER SIZE HAIL.
Jul 29, 2:15 PM EDT	HAIL 0.88	Skillman, NJ	PEA TO NICKEL SIZE HAIL ON SKILLMAN/HILLSBOROUGH BORDER.

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
Jul 29, 12:49 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 5.6 hours before the alert went out and 138 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: 594 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 646 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 104 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.8

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 291735
SVRPHI
NJC023-035-291830-
/O.NEW.KPHI.SV.W.0151.090729T1735Z-090729T1830Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
135 PM EDT WED JUL 29 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN MIDDLESEX COUNTY IN NORTHERN NEW JERSEY...
  THIS INCLUDES THE CITIES OF...PERTH AMBOY...NEW BRUNSWICK...
  SOUTHERN SOMERSET COUNTY IN NORTHERN NEW JERSEY...

* UNTIL 230 PM EDT

* AT 132 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR SKILLMAN...OR 12 MILES NORTH OF TRENTON...
  AND MOVING NORTHEAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ROCKY HILL AROUND 140 PM EDT...
  BELLE MEAD AROUND 145 PM EDT...
  KENDALL PARK AND SOUTH BRUNSWICK AROUND 150 PM EDT...
  MILLSTONE AROUND 155 PM EDT...
  NORTH BRUNSWICK AROUND 200 PM EDT...
  SOMERSET AROUND 205 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
WEDNESDAY EVENING FOR NORTHWESTERN NEW JERSEY AND EASTERN
PENNSYLVANIA.

&&

LAT...LON 4034 7460 4039 7463 4043 7476 4066 7447
      4063 7440 4059 7444 4060 7432 4059 7429
      4059 7428 4058 7425 4052 7425
TIME...MOT...LOC 1735Z 244DEG 22KT 4040 7470

$$

EBERWINE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 10:15 AM EDT	Flash Flood Watch	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset, Sussex and 1 more	17 hr
Jul 29, 12:55 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Somerset	65 min
Jul 29, 1:30 PM EDT	Areal Flood Advisory	PHI	Morris, Somerset	3 hr
Jul 29, 1:56 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	64 min
Jul 29, 2:10 PM EDT	Tornado Warning	PHI	Sussex	65 min
Jul 29, 2:21 PM EDT	Areal Flood Advisory	PHI	Middlesex	3 hr
Jul 29, 2:32 PM EDT	Flash Flood Warning	PHI	Sussex	6 hr
Jul 29, 2:50 PM EDT	Flash Flood Warning	PHI	Middlesex	4 hr
Jul 29, 3:52 PM EDT	Flash Flood Warning	PHI	Morris, Somerset	4 hr
Jul 29, 5:09 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer	66 min
Jul 29, 5:48 PM EDT	Special Marine Warning	PHI		57 min
Jul 29, 5:55 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer, Middlesex, Salem	4 hr
Jul 29, 6:11 PM EDT	Severe Thunderstorm Warning	PHI	Cumberland	26 min
Jul 29, 6:26 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Camden, Gloucester	38 min
Jul 29, 6:42 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Mercer and 4 more	3 hr
Jul 29, 6:42 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden	39 min
Jul 29, 6:44 PM EDT	Flash Flood Warning	PHI	Middlesex, Somerset	3 hr
Jul 29, 6:50 PM EDT	Areal Flood Advisory	PHI	Morris	94 min
Jul 29, 7:31 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth	30 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.