Alert archive / New Jersey / Flash Flood Watches in 2009

Flash Flood Watch 3, NWS Philadelphia/Mount Holly

June 18, 20094 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood watch at Jun 18, 2009, 4:55 AM EDT for 4 counties in New Jersey. It took effect at Jun 18, 2009, 8:00 AM EDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Jun 18, 2009, 4:55 AM EDT (08:55 UTC)
In effect from
Jun 18, 2009, 8:00 AM EDT
Expired
Jun 18, 2009, 3:58 PM EDT
In force
8 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties Middlesex County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ

The radar

The Philadelphia radar (KDIX), 90 km from the middle of the area, began a volume at 08:57 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

Albany, NY (KALY), launched 00:00Z, 8.9 hours before the alert went out and 224 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, Albany, NY at 00:00Z on 2009-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Albany, NY at 00:00Z on 2009-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1668 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
WGUS61 KPHI 180855
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
455 AM EDT THU JUN 18 2009

NJZ001-008-010-012-190000-
/O.NEW.KPHI.FF.A.0003.090618T1200Z-090619T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-MORRIS-SOMERSET-MIDDLESEX-
INCLUDING THE CITIES OF...NEWTON...MORRISTOWN...SOMERVILLE...
NEW BRUNSWICK
455 AM EDT THU JUN 18 2009

...FLASH FLOOD WATCH IN EFFECT FROM 8 AM EDT THIS MORNING THROUGH
THIS EVENING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

FLASH FLOOD WATCH FOR A PORTION OF NORTHERN NEW JERSEY...
INCLUDING THE FOLLOWING COUNTIES...MIDDLESEX...MORRIS...SOMERSET
AND SUSSEX.

FROM 8 AM EDT THIS MORNING THROUGH THIS EVENING SHOWERS AND
THUNDERSTORMS WILL OCCUR. HEAVY RAIN IS POSSIBLE AT TIMES WITH
RAINFALL AMOUNTS EXPECTED TO AVERAGE AROUND 1 1/2 INCHES. THIS
WILL CAUSE A SIGNIFICANT RISE TO STREAM LEVELS AND FLOODING IS
POSSIBLE. PARTICULARLY SUSCEPTABLE WILL BE THE RARITAN AND
PASSAIC RIVER BASINS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$

RPW
2 follow-up statements
000 
WGUS61 KPHI 181521
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1121 AM EDT THU JUN 18 2009

NJZ001-008-010-012-190000-
/O.CON.KPHI.FF.A.0003.000000T0000Z-090619T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-MORRIS-SOMERSET-MIDDLESEX-
INCLUDING THE CITIES OF...NEWTON...MORRISTOWN...SOMERVILLE...
NEW BRUNSWICK
1121 AM EDT THU JUN 18 2009

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

THE FLASH FLOOD WATCH CONTINUES FOR

* A PORTION OF NORTHERN NEW JERSEY...INCLUDING THE FOLLOWING
  AREAS...MIDDLESEX...MORRIS...SOMERSET AND SUSSEX.

* UNTIL 8 PM EDT THIS EVENING

* UP TO AN INCH OF RAIN FELL OVER THE WATCH AREA LATE LAST NIGHT
  AND EARLY THIS MORNING. RAIN HAD BECOME LIGHTER LATE THIS
  MORNING...AND COVERAGE HAD BECOME MORE SCATTERED IN NATURE.
  HOWEVER...CONTINUED SHOWER ACTIVITY IS EXPECTED TODAY. THAT
  ACTIVITY MAY BECOME MORE WIDESPREAD IN NATURE AND THUNDERSTORMS
  ALSO MAY DEVELOP. THE ATMOSPHERE IS VERY MOIST AND THAT MAY LEAD
  TO ADDITIONAL HEAVY DOWNPOURS...AND SO THE THREAT OF FLASH
  FLOODING HAS NOT YET ENDED. SMALLER STREAMS AND CREEKS AND POOR
  DRAINAGE AREAS WOULD BE MOST SUSCEPTIBLE TO FLASH FLOODING.
  LARGER RIVER BASINS LIKELY ARE NOT THREATENED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

&&

$$

RPW/MPD
000 
WGUS61 KPHI 181958
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
358 PM EDT THU JUN 18 2009

...THE THREAT OF FLASH FLOODING HAS DIMINISHED...

NJZ001-008-010-012-182100-
/O.CAN.KPHI.FF.A.0003.000000T0000Z-090619T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-MORRIS-SOMERSET-MIDDLESEX-
INCLUDING THE CITIES OF...NEWTON...MORRISTOWN...SOMERVILLE...
NEW BRUNSWICK
358 PM EDT THU JUN 18 2009

...FLASH FLOOD WATCH IS CANCELLED...

ALTHOUGH SCATTERED SHOWERS WILL REMAIN POSSIBLE INTO THE EVENING
HOURS, THE THREAT OF HEAVY RAIN AND FLASH FLOODING HAS
DIMINISHED. WITH THIS IN MIND, THE FLASH FLOOD WATCH HAS BEEN
CANCELLED. 

$$

KRUZDLO

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 18, 11:40 AM EDTAreal Flood AdvisoryPHIMonmouth3 hr
Jun 18, 2:53 PM EDTCoastal Flood AdvisoryPHIBurlington, Camden, Gloucester, Salem9 hr

Nearby

Flash Flood Watches in New Jersey, 2009Every flash flood watch 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.