Alert archive / Pennsylvania / Flash Flood Warnings in 2006

Flash Flood Warning 61, NWS Philadelphia/Mount Holly

July 28, 2006Bucks County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 28, 2006, 12:40 AM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 28, 2006, 12:40 AM EDT (04:40 UTC)
Expired
Jul 28, 2006, 3:45 AM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

Counties Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 60 km from the middle of the area, began a volume at 04:42 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.

What was reported inside it

TimeReportWhereRemark
Jul 28, 1:15 AM EDTFLASH FLOODNorristown, PAROAD AND BASEMENT FLOODING

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 4.7 hours before the alert went out and 208 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, Brookhaven, NY at 00:00Z on 2006-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 874 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, Brookhaven, NY at 00:00Z on 2006-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 square meters per square second.193958Sfc1 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
874 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
789 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
135 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 280441
FFWPHI
PAC017-091-101-280745-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1240 AM EDT FRI JUL 28 2006

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA
  THIS INCLUDES THE CITY OF PHILADELPHIA

* UNTIL 345 AM EDT

* AT 1238 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED FLASH FLOODING WAS IMMINENT FROM SEVERAL THUNDERTORMS
  OVER AND APPROACHING THE WARNED AREA. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WOODSIDE...
  WILLOW GROVE...RICHBORO...PLYMOUTH MEETING...NORRISTOWN...
  NEWTOWN...LEVITTOWN...LANGHORNE...IVYLAND...FEASTERVILLE AND AMBLER

UP TO TWO INCHES OF RAINFALL HAS OCCURRED OVER THE WARNED AREA...AND 
ADDITIONAL RAINFALL AMOUNTS OF AROUND TWO INCHES ARE POSSIBLE IN THE 
WARNED AREA.

LAT...LON 3991 7519 4003 7502 4016 7476 4035 7499
      4010 7539

$$

EBERWINE/MPD
1 follow-up statement
000 
WGUS71 KPHI 280655
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
256 AM EDT FRI JUL 28 2006

PAC017-091-101-280706-
PHILADELPHIA PA-MONTGOMERY PA-BUCKS PA-
256 AM EDT FRI JUL 28 2006

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN BUCKS...SOUTHEASTERN
MONTGOMERY AND PHILADELPHIA COUNTIES IS CANCELLED...

LAT...LON 3991 7519 4003 7502 4016 7476 4035 7499
      4010 7539

$$

MPD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 27, 10:55 PM EDTSevere Thunderstorm WarningPHIChester65 min
Jul 27, 11:32 PM EDTSevere Thunderstorm WarningPHIDelaware, Montgomery88 min
Jul 28, 12:32 AM EDTSevere Thunderstorm WarningPHIPhiladelphia43 min
Jul 28, 12:40 AM EDTSevere Thunderstorm WarningPHIBucks65 min
Jul 28, 2:28 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia62 min
Jul 28, 2:49 PM EDTSevere Thunderstorm WarningPHIPhiladelphia56 min
Jul 28, 3:07 PM EDTSevere Thunderstorm WarningPHIBucks53 min
Jul 28, 4:03 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery57 min

Nearby

Flash Flood Warnings in Pennsylvania, 2006Every flash flood warning in 2006

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.