Alert archive / New Jersey / Flash Flood Warnings in 2009

Flash Flood Warning 20, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 29, 2009, 6:44 PM EDT for Middlesex County, Somerset County, New Jersey. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 29, 2009, 6:44 PM EDT (22:44 UTC)
Expired: Jul 29, 2009, 9:46 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Middlesex County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 66 km from the middle of the area, began a volume at 22:47 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, 10.7 hours before the alert went out and 129 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 
WGUS51 KPHI 292244
FFWPHI
NJC023-035-300245-
/O.NEW.KPHI.FF.W.0020.090729T2244Z-090730T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
644 PM EDT WED JUL 29 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN MIDDLESEX COUNTY IN NORTHERN NEW JERSEY...
  THIS INCLUDES THE CITIES OF...PERTH AMBOY...NEW BRUNSWICK...
  EAST CENTRAL SOMERSET COUNTY IN NORTHERN NEW JERSEY...

* UNTIL 1045 PM EDT

* AT 642 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED   
HEAVY RAINFALL OVER PORTIONS OF THE THE WARNED AREA CAPABLE OF 
PRODUCING FLASH FLOODING.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  MIDDLESEX...COLONIA AND CARTERET

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 4057 7420 4055 7424 4048 7427 4046 7426
      4044 7452 4048 7447 4050 7447 4054 7453
      4058 7450 4060 7431 4059 7429 4060 7423
      4059 7420

$$

KRUZDLO

1 follow-up statement

000 
WGUS71 KPHI 300146
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
946 PM EDT WED JUL 29 2009

NJC023-035-300154-
/O.CAN.KPHI.FF.W.0020.000000T0000Z-090730T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SOMERSET NJ-MIDDLESEX NJ-
946 PM EDT WED JUL 29 2009

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHERN MIDDLESEX
AND EAST CENTRAL SOMERSET COUNTIES...

ALTHOUGH MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TONIGHT, NO 
NEW FLOODING IS EXPECTED.

LAT...LON 4057 7420 4055 7424 4048 7427 4046 7426
      4044 7452 4048 7447 4050 7447 4054 7453
      4058 7450 4060 7431 4059 7429 4060 7423
      4059 7420

$$

KRUZDLO

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, 1:35 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Somerset	55 min
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, 6:50 PM EDT	Areal Flood Advisory	PHI	Morris	94 min
Jul 29, 7:31 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth	30 min

Nearby

Flash Flood Warnings in New Jersey, 2009 Every flash flood 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.