Alert archive / Pennsylvania / Flash Flood Warnings in 2000

Flash Flood Warning 54, NWS Philadelphia/Mount Holly

December 17, 2000Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Dec 17, 2000, 9:33 AM EST 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
Dec 17, 2000, 9:33 AM EST (14:33 UTC)
Expired
Dec 17, 2000, 11:30 AM EST
In force
117 min
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Chester County, PA

The radar

The Philadelphia radar (KDIX), 114 km from the middle of the area, began a volume at 14:36 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, 2.6 hours before the alert went out and 182 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 2000-12-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2000-12-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
483 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
116 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 171435
FFWPHI
PAC029-171630-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
933 AM EST SUN DEC 17 2000

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 1130 AM EST.

* AT 926 AM EST...WEATHER SERVICE RADAR INDICATED A RENEWED AREA OF
HEAVY RAINS HAS MOVED INTO THE WESTERN PORTION OF THE 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.

FLOOD WARNINGS CONTINUE FOR THE BRANDYWINE CREEK.

FOR ADDITIONAL INFORMATION...PLEASE TUNE TO NOAA WEATHER
RADIO...YOUR LOCAL RADIO OR TELE)VISION STATION...OR YOUR CABLE
TELEVISION OUTLET.

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 17, 6:06 AM ESTFlash Flood WarningPHIChester114 min
Dec 17, 6:13 AM ESTSevere Thunderstorm WarningPHIChester32 min
Dec 17, 6:50 AM ESTFlash Flood WarningPHIBucks, Montgomery3 hr
Dec 17, 7:03 AM ESTFlash Flood WarningPHIChester3 hr
Dec 17, 7:29 AM ESTFlash Flood WarningPHIDelaware3 hr
Dec 17, 9:52 AM ESTFlash Flood WarningPHICarbon, Monroe3 hr
Dec 17, 10:00 AM ESTFlash Flood WarningPHIChester3 hr
Dec 17, 10:00 AM ESTFlash Flood WarningPHIDelaware3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2000Every flash flood warning in 2000

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.