Alert archive / Pennsylvania / Flash Flood Warnings in 2003

Flash Flood Warning 36, NWS Philadelphia/Mount Holly

August 11, 2003Northampton County, Pennsylvania; Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 11, 2003, 6:07 PM EDT for Northampton County, Pennsylvania; Warren 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 counties it named.

The facts

Issued
Aug 11, 2003, 6:07 PM EDT (22:07 UTC)
Expired
Aug 11, 2003, 9:00 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Warren County, NJ, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 114 km from the middle of the area, began a volume at 22:06 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.1 hours before the alert went out and 169 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, Phillips Aaf/Abe, MD at 12:00Z on 2003-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 123 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, Phillips Aaf/Abe, MD at 12:00Z on 2003-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
123 J/kg
Mixed-layer CIN
-96 J/kg
Mixed-layer LCL
875 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 112211
FFWPHI
NJC041-PAC095-120100-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
607 PM EDT MON AUG 11 2003

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA
  WESTERN WARREN COUNTY IN NORTHWEST NEW JERSEY

* UNTIL 900 PM EDT.

* AT 600 PM EDT...WEATHER SERVICE RADAR INDICATED AN AREA OF SHOWERS
  AND THUNDERSTORMS PRODUCING VERY HEAVY RAINFALL.  RAINFALL RATES
  AS HIGH AS TWO INCHES AN HOUR ARE OCCURRING. 

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. 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. VEHICLES
CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. MOVE TO HIGHER
GROUND.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO
TRIGGER ROCK AND MUDSLIDES IN STEEP TERRAIN.

FOR THE LATEST STORM INFORMATION...PLEASE TUNE TO NOAA WEATHER 
RADIO...YOUR LOCAL RADIO OR TELEVISION STATION...OR YOUR CABLE 
TELEVISION OUTLET.

$$

LAT...LON 4101 7491 4070 7503 4058 7533 4076 7535
          4092 7512

SZATKOWSKI

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 2:01 AM EDTFlash Flood WarningPHIMontgomery3 hr
Aug 11, 3:16 AM EDTFlash Flood WarningPHIBucks, Lehigh119 min
Aug 10, 9:14 PM EDTFlash Flood WarningPHISussex2 hr
Aug 11, 11:40 AM EDTFlash Flood WarningPHISussex3 hr
Aug 11, 6:25 PM EDTFlash Flood WarningPHIMorris, Sussex3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2003Flash Flood Warnings in New Jersey, 2003Every flash flood warning in 2003

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.