Alert archive / Pennsylvania / Flash Flood Warnings in 1996

Flash Flood Warning 81, NWS Philadelphia/Mount Holly

September 8, 1996Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 8, 1996, 6:29 PM EDT for Montgomery 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
Sep 8, 1996, 6:29 PM EDT (22:29 UTC)
Expired
Sep 8, 1996, 8:30 PM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Whole counties

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 86 km from the middle of the area, began a volume at 22:28 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, 10.5 hours before the alert went out and 224 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 1996-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 278 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 1996-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
278 J/kg
Mixed-layer CIN
-112 J/kg
Mixed-layer LCL
1379 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
90 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPHL 082229
FFWPHL
PAC091-090030-
 
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHILADELPHIA/MOUNT HOLLY NJ
629 PM EDT SUN SEP 8 1996
 
THE NATIONAL WEATHER SERVICE IN PHILADELPHIA/MOUNT HOLLY HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  830 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN  PENNSYLVANIA
 
   ...SOUTHERN MONTGOMERY COUNTY
 
A SKYWARN SPOTTER FROM GLENSIDE REPORTED TORRENTIAL DOWNPOURS FROM
THUNDERSTORMS. ADDITIONALLY...RADAR SHOWED RAINFALL EXCEEDING 2 INCHES
IN AN HOUR FROM THUNDERSTORMS.
 
IF YOU ARE IN AN AREA PRONE TO FLOODING...MOVE TO HIGHER GROUND
IMMEDIATELY...BEFORE YOUR ACCESS IS CUT OFF BY RISING FLOOD WATERS.
CONTINUE TO MONITOR NOA:A WEATHER RADIO...AND YOUR LOCAL RADIO AND
TELEVISION STATIONS FOR THE LATEST INFORMATION ON THE FLOOD WARNING.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 8, 6:16 PM EDTSevere Thunderstorm WarningPHIBucks, Delaware, Philadelphia44 min
Sep 8, 6:23 PM EDTFlash Flood WarningPHIBucks, Philadelphia2 hr

Nearby

Flash Flood Warnings in Pennsylvania, 1996Every flash flood warning in 1996

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.