Alert archive / New Jersey / Flash Flood Warnings in 2009

Flash Flood Warning 53, NWS Philadelphia/Mount Holly

August 22, 2009Mercer County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 22, 2009, 6:02 PM EDT for Mercer County, New Jersey. It was in force for 4 hr. 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
Aug 22, 2009, 6:02 PM EDT (22:02 UTC)
Expired
Aug 22, 2009, 10:00 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Mercer County, NJ

The radar

The Philadelphia radar (KDIX), 43 km from the middle of the area, began a volume at 22:02 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
Aug 22, 7:25 PM EDTHEAVY RAIN 04 Nw Hamilton Square, NJ2.28 IN 69 MINUTES / 3.24 TODAY - COCORAHS LAWRENCE TWP.
Aug 22, 7:50 PM EDTFLASH FLOODHamilton Square, NJ3.33 TODAY. WIDESPREAD ROAD FLOODING. MANY STALLED CARS.
Aug 22, 7:50 PM EDTHEAVY RAIN 05 W Hamilton Square, NJ2.6 INCHES IN PAST 1.5 HOURS.

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 12:00Z, 10.0 hours before the alert went out and 171 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 2009-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1060 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 2009-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 square meters per square second.193958Sfc1 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
1060 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
620 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 222202 RRA
FFWPHI
NJC021-230200-
/O.NEW.KPHI.FF.W.0053.090822T2202Z-090823T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
602 PM EDT SAT AUG 22 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  MERCER COUNTY IN CENTRAL NEW JERSEY...
  THIS INCLUDES THE CITY OF TRENTON...

* UNTIL 1000 PM EDT

* AT 600 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN IN THE WARNED AREA WHICH WILL RESULT IN FLASH      
  FLOODING...ESPECIALLY ON ROADS AND IN URBANIZED AREAS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  PENNINGTON...PRINCETON...AND LAWRENCEVILLE

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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. 

&&

LAT...LON 4023 7481 4033 7489 4038 7475 4025 7452
      4019 7459 4017 7471

$$

JJM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 22, 1:28 AM EDTFlash Flood WarningPHICamden, Cumberland, Gloucester, Salem4 hr
Aug 22, 1:40 AM EDTAreal Flood AdvisoryPHIBurlington, Hunterdon, Mercer, Middlesex, Monmouth, Morris and 1 more3 hr
Aug 22, 3:36 AM EDTFlash Flood WarningPHISomerset4 hr
Aug 22, 4:26 AM EDTAreal Flood AdvisoryPHIAtlantic, Camden, Cape May, Cumberland, Gloucester, Salem6 hr
Aug 22, 5:42 AM EDTAreal Flood AdvisoryPHICamden, Cumberland, Gloucester, Salem3 hr
Aug 22, 9:01 AM EDTAreal Flood AdvisoryPHIAtlantic, Cape May, Cumberland3 hr
Aug 22, 6:21 PM EDTFlash Flood WarningPHIHunterdon, Warren3 hr
Aug 22, 6:32 PM EDTFlash Flood WarningPHICamden, Gloucester3 hr
Aug 22, 7:32 PM EDTRiver Flood WarningPHIMercer19 hr

Nearby

Flash Flood Warnings in New Jersey, 2009Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.