Alert archive / Pennsylvania / Flash Flood Warnings in 2002

Flash Flood Warning 32, NWS Philadelphia/Mount Holly

November 17, 2002Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Nov 17, 2002, 9:26 AM EST for Montgomery County, Pennsylvania. It was in force for 109 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
Nov 17, 2002, 9:26 AM EST (14:26 UTC)
Expired
Nov 17, 2002, 11:15 AM EST
In force
109 min
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 14:28 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, 2.4 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 2002-11-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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 2002-11-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 246 square meters per square second.1939587897117136Sfc1 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
1 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
452 m above ground
0-6 km bulk shear
91 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
521 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 171426
FFWPHI
PAC091-171615-

BULLETIN - EAS ACTIVATION REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
922 AM EST SUN NOV 17 2002

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLOOD WARNING FOR...
  CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 1115 AM EST.

* HEAVY RAIN OVERNIGHT HAS PUSHED THE EAST BRANCH OF THE PERKIOMEN 
  CREEK OVER FLOOD STAGE IN SCHWENKSVILLE. MINOR FLOODING IS EXPECTED
  TO CONTINUE THE REST OF THIS MORNING NEAR THE CREEK. MORE RAIN IS
  EXPECTED TODAY...BUT IS NOT EXPECTED TO EXACERBATE OR CAUSE 
  ADDITIONAL FLOODING PROBLEMS.  

A FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. MOST 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 4034 7539 4018 7526 4021 7540 4039 7555

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 17, 1:10 AM ESTFlash Flood WarningPHIChester6 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2002Every flash flood warning in 2002

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.