Alert archive / Pennsylvania / Flash Flood Warnings in 2001

Flash Flood Warning 28, NWS Philadelphia/Mount Holly

June 22, 2001Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 22, 2001, 6:48 PM EDT for Chester County, Pennsylvania. It was in force for 117 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 22, 2001, 6:48 PM EDT (22:48 UTC)
Expired
Jun 22, 2001, 8:45 PM EDT
In force
117 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Chester County, PA

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.8 hours before the alert went out and 64 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 2001-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 578 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 2001-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.1939Sfc1 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
578 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
563 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
78 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 222251
FFWPHI
PAC029-230045-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
648 PM EDT FRI JUN 22 2001

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 845 PM EDT.

* AT 645 PM EDT...WEATHER SERVICE RADAR INDICATED A STRONG AND 
SLOW-MOVING THUNDERSTORM OVER NORTHWESTERN CHESTER COUNTY.  
THIS STORM IS PRODUCING RAINFALL RATES OF UP TO THREE INCHES
AN HOUR...AND WILL PRODUCE LOCALIZED FLASH FLOODING.

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 4020 7567 4004 7561 3996 7599 4013 7599

GSS

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 22, 12:59 PM EDTFlash Flood WarningPHIBerks2 hr
Jun 22, 1:30 PM EDTSevere Thunderstorm WarningPHIBerks30 min
Jun 22, 1:53 PM EDTSevere Thunderstorm WarningPHINorthampton37 min
Jun 22, 2:07 PM EDTSevere Thunderstorm WarningPHILehigh23 min
Jun 22, 2:12 PM EDTSevere Thunderstorm WarningPHIBerks33 min
Jun 22, 2:43 PM EDTSevere Thunderstorm WarningPHINorthampton47 min
Jun 22, 3:00 PM EDTSevere Thunderstorm WarningPHIBerks45 min
Jun 22, 3:21 PM EDTFlash Flood WarningPHIBerks3 hr
Jun 22, 3:54 PM EDTFlash Flood WarningPHILehigh, Northampton3 hr
Jun 22, 6:08 PM EDTFlash Flood WarningPHIBerks2 hr
Jun 22, 6:58 PM EDTFlash Flood WarningPHILehigh2 hr

Nearby

Flash Flood Warnings in Pennsylvania, 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.