Alert archive / New Jersey / Flash Flood Warnings in 2009

Flash Flood Warning 48, NWS Philadelphia/Mount Holly

August 22, 2009Somerset County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 22, 2009, 3:36 AM EDT for Somerset County, New Jersey. It was in force for 4 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
Aug 22, 2009, 3:36 AM EDT (07:36 UTC)
Expired
Aug 22, 2009, 7:30 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 62 km from the middle of the area, began a volume at 07:39 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 00:00Z, 7.6 hours before the alert went out and 150 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 00:00Z on 2009-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1483 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 00:00Z on 2009-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 99 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
1483 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
764 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
99 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.7
Supercell composite
6.3

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 220736
FFWPHI
NJC035-221130-
/O.NEW.KPHI.FF.W.0048.090822T0736Z-090822T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN SOMERSET COUNTY IN NORTHERN NEW JERSEY...

* UNTIL 730 AM EDT

* AT 326 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  THAT 2 TO 3 INCHES OF RAIN HAVE FALLEN ACROSS THE PIKE RUN         
  WATERSHED OVER THE LAST FEW HOURS. IN RESPONSE, THE RIVER GAGE IN  
  BELLE MEAD ON PIKE RUN IS SHOWING RAPID RISES AND IS EXPECTED TO   
  EXCEED FLOOD STAGE. FLASH FLOODING IS IMMINENT.

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.

&&

LAT...LON 4046 7449 4040 7462 4042 7470 4048 7473
      4050 7464 4058 7458 4056 7452 4054 7453
      4051 7448

$$

KRUZDLO

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, 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, 6:02 PM EDTFlash Flood WarningPHIMercer4 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.