Alert archive / Pennsylvania / Flash Flood Warnings in 2001

Flash Flood Warning 38, NWS Philadelphia/Mount Holly

August 4, 2001Burlington County, New Jersey; Bucks County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 4, 2001, 7:19 PM EDT for Burlington County, New Jersey; Bucks County, Philadelphia County, Pennsylvania. 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 4, 2001, 7:19 PM EDT (23:19 UTC)
Expired
Aug 4, 2001, 10:15 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

Counties Burlington County, NJ, Bucks County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 50 km from the middle of the area, began a volume at 23:21 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, 11.3 hours before the alert went out and 199 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 2001-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 328 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 2001-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
328 J/kg
Mixed-layer CIN
-78 J/kg
Mixed-layer LCL
949 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
-14 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 
WGUS51 KPHI 042325 CCA
FFWPHI
NJC005-PAC017-101-050215-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING...CORRECTED
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
719 PM EDT SAT AUG 4 2001

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EXTREME SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA
  NORTHEASTERN PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA
  NORTHWESTERN BURLINGTON COUNTY IN SOUTHERN NEW JERSEY

* UNTIL 1015 PM EDT.

* AT 716 PM EDT...WEATHER SERVICE RADAR INDICATED SLOW MOVING
  THUNDERSTORMS THAT HAVE DROPPED UP TO THREE INCHES OF RAIN
  WITHIN ONE HOUR IN FAR WESTERN BURLINGTON COUNTY AND ADJACENT
  PARTS OF BUCKS COUNTY. BEVERLY POLICE IN BURLINGTON COUNTY
  REPORTED WIDESPREAD FLOODING. SEVERE FLOODING WAS REPORTED
  ON U.S. ROUTE 13 IN FALLS TOWNSHIP IN BUCKS COUNTY.

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.

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

$$

LAT...LON 4016 7478 4000 7485 3995 7499 4003 7512

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 4:42 PM EDTFlash Flood WarningPHIOcean2 hr
Aug 4, 4:56 PM EDTFlash Flood WarningPHIMonmouth2 hr
Aug 4, 6:42 PM EDTFlash Flood WarningPHIMonmouth2 hr
Aug 4, 6:39 PM EDTSevere Thunderstorm WarningPHIBucks66 min
Aug 4, 7:29 PM EDTSevere Thunderstorm WarningPHIMontgomery61 min

Nearby

Flash Flood Warnings in Pennsylvania, 2001Flash Flood Warnings in New Jersey, 2001Every flash flood warning in 2001

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.