Alert archive / New Jersey / Flash Flood Watches in 2013

Flash Flood Watch 8, NWS Philadelphia/Mount Holly

August 9, 20134 counties in Pennsylvania; 5 counties in New Jersey

NWS Philadelphia/Mount Holly issued this flash flood watch at Aug 9, 2013, 8:03 AM EDT for 4 counties in Pennsylvania; 5 counties in New Jersey. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued
Aug 9, 2013, 8:03 AM EDT (12:03 UTC)
Expired
Aug 9, 2013, 6:38 PM EDT
In force
11 hr
Issued by
NWS Philadelphia/Mount Holly
Flood severity
None

Counties Hunterdon County, NJ, Morris County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 112 km from the middle of the area, began a volume at 12:03 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, 0.1 hours before the alert went out and 186 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 2013-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 673 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 2013-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 134 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
673 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
549 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
165 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.2

Open this sounding in Storm Lab

The text

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

915 
WGUS61 KPHI 091203
FFAPHI

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
803 AM EDT FRI AUG 9 2013
 

NJZ001-007>010-PAZ054-055-061-062-100200-
/O.NEW.KPHI.FF.A.0008.130809T1203Z-130810T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-CARBON-MONROE-LEHIGH-
NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...MORRISTOWN...
FLEMINGTON...SOMERVILLE...JIM THORPE...STROUDSBURG...ALLENTOWN...
BETHLEHEM...EASTON
803 AM EDT FRI AUG 9 2013

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NEW JERSEY AND 
  PENNSYLVANIA...INCLUDING THE FOLLOWING AREAS...IN NEW JERSEY...
   HUNTERDON...MORRIS...SOMERSET...SUSSEX AND WARREN. IN 
  PENNSYLVANIA...CARBON...LEHIGH...MONROE AND NORTHAMPTON. 

* THROUGH THIS EVENING

* HEAVY RAIN HAS FALLEN SINCE YESTERDAY AND ESPECIALLY OVERNIGHT.
  ADDITIONAL HEAVY RAIN IS LIKELY TODAY MAKING THIS AREA THE MOST
  VULNERABLE TO FLASH FLOODING INTO THIS EVENING. ADDITIONAL
  AMOUNTS WILL AVERAGE ONE HALF TO ONE INCH, BUT LOCALIZED AMOUNTS
  COULD EXCEED THREE INCHES.
 
* OTHER AREAS IN EASTERN PENNSYLVANIA AND CENTRAL AND SOUTHERN NEW
  JERSEY NOT IN THE CURRENT FLASH FLOOD WATCH HAVE A LESSER
  CHANCE, BUT NOT A ZERO CHANCE OF EXPERIENCING FLASH FLOODING
  LATER TODAY. THERE WILL BE THUNDERSTORMS WITH LOCALIZED VERY
  HEAVY RAIN THAT WILL MOVE THROUGH THE REGION.

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.

&&

$$

GIGI
1 follow-up statement
638 
WGUS61 KPHI 092238
FFAPHI

FLOOD WATCH
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
638 PM EDT FRI AUG 9 2013

NJZ001-007>010-PAZ054-055-061-062-092345-
/O.CAN.KPHI.FF.A.0008.000000T0000Z-130810T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-CARBON-MONROE-LEHIGH-
NORTHAMPTON-
INCLUDING THE CITIES OF...NEWTON...WASHINGTON...MORRISTOWN...
FLEMINGTON...SOMERVILLE...JIM THORPE...STROUDSBURG...ALLENTOWN...
BETHLEHEM...EASTON
638 PM EDT FRI AUG 9 2013

...FLASH FLOOD WATCH IS CANCELLED...

WHILE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL REMAIN
OVER OUR REGION EARLY THIS EVENING, THE THREAT OF FLASH FLOODING
HAS DIMINISHED. AS A RESULT, THE FLASH FLOOD WATCH HAS BEEN
CANCELLED FOR THE PENNSYLVANIA COUNTIES OF CARBON, MONROE,
NORTHAMPTON AND LEHIGH, AND FOR THE NEW JERSEY COUNTIES OF SUSSEX,
WARREN, MORRIS, HUNTERDON AND SOMERSET.

$$

IOVINO

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 6:30 AM EDTAreal Flood AdvisoryPHIMonroe4 hr
Aug 9, 8:39 AM EDTFlash Flood WarningPHIMonroe4 hr
Aug 9, 3:55 AM EDTSmall Craft AdvisoryPHI16 hr
Aug 9, 7:34 AM EDTFlash Flood WarningPHISussex4 hr

Nearby

Flash Flood Watches in New Jersey, 2013Flash Flood Watches in Pennsylvania, 2013Every flash flood watch in 2013

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.