Alert archive / Pennsylvania / Flash Flood Warnings in 2001

Flash Flood Warning 11, NWS Philadelphia/Mount Holly

June 16, 2001Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 16, 2001, 6:40 PM EDT for Delaware County, Pennsylvania. It was in force for 2 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
Jun 16, 2001, 6:40 PM EDT (22:40 UTC)
Expired
Jun 16, 2001, 8:45 PM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Delaware County, PA

The radar

The Philadelphia radar (KDIX), 84 km from the middle of the area, began a volume at 22:43 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.7 hours before the alert went out and 203 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, Washington/Dulle, VA at 12:00Z on 2001-06-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 596 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2001-06-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
596 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
518 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
21 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 162240
FFWPHI
PAC045-170045-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
640 PM EDT SAT JUN 16 2001

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 845 PM EDT.

* AT 631 PM EDT...WEATHER SERVICE RADAR INDICATED OVER 3 INCHES OF 
RAIN ALREADY HAVING FALLEN IN PARTS OF THE COUNTY...WITH ADDITIONAL 
SHOWERS AND THUNDERSTORMS EXPECTED OVER THE NEXT HOUR.

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 3995 7527 3986 7527 3986 7536 3981 7542
          3986 7559 4003 7538

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 16, 2:28 PM EDTFlash Flood WarningPHIMontgomery2 hr
Jun 16, 4:30 PM EDTFlash Flood WarningPHIMontgomery90 min
Jun 16, 5:31 PM EDTFlash Flood WarningPHIBucks3 hr
Jun 16, 6:30 PM EDTFlash Flood WarningPHIMontgomery2 hr
Jun 16, 7:12 PM EDTFlash Flood WarningPHIPhiladelphia2 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; radar from the NEXRAD Level II archive.