Alert archive / Pennsylvania / Flash Flood Warnings in 2008

Flash Flood Warning 6, NWS Philadelphia/Mount Holly

June 4, 2008Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 4, 2008, 6:50 PM EDT for Bucks County, Montgomery 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
Jun 4, 2008, 6:50 PM EDT (22:50 UTC)
Expired
Jun 4, 2008, 9:37 PM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 80 km from the middle of the area, began a volume at 22:50 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
Jun 4, 7:30 PM EDTFLASH FLOODHorsham, PAFIRE DEPT RESCUING PEOPLE FORM A CAR ON HORSHAM RD.

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.8 hours before the alert went out and 115 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, Phillips Aaf/Abe, MD at 12:00Z on 2008-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 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, Phillips Aaf/Abe, MD at 12:00Z on 2008-06-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 157 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
27 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
622 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
157 m²/s²
0-3 km storm-relative helicity
221 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 042255
FFWPHI
PAC017-091-050245-
/O.NEW.KPHI.FF.W.0006.080604T2250Z-080605T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
650 PM EDT WED JUN 4 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WESTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 1045 PM EDT

* AT 645 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED BETWEEN
  1.50 AND 2.00 INCHES OF RAIN HAD FALLEN OVER PORTIONS OF WESTERN   
  BUCKS COUNTY AND CENTRAL MONTGOMERY COUNTY. ADDITIONAL RAIN IS ON  
  THE WAY. FLOODING OF POOR DRAINAGE AREAS CAN BE                    
  EXPECTED...ESPECIALLY NEAR HORSHAM...IVYLAND...RICHBORO...
  WARRINGTON AND WILLOW GROVE.

LAT...LON 4034 7544 4037 7497 4013 7493 4019 7547
TIME...MOT...LOC 2250Z 296DEG 14KT 4022 7532

$$

JJM
1 follow-up statement
000 
WGUS71 KPHI 050137
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
935 PM EDT WED JUN 4 2008

PAC017-091-050145-
/O.CAN.KPHI.FF.W.0006.000000T0000Z-080605T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-BUCKS PA-
935 PM EDT WED JUN 4 2008

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR WESTERN BUCKS AND
CENTRAL MONTGOMERY COUNTIES...

DOPPLER RADAR INDICATES THE HEAVY RAIN HAS MOVED OUT OF THE AREA FOR 
THE TIME BEING. THE IMMEDIATE THREAT FOR FLOODING HAS ABATED, AND SO
THE FLASH FLOOD WARNING HAS BEEN CANCELLED.


LAT...LON 4034 7544 4037 7497 4013 7493 4019 7547
TIME...MOT...LOC 0135Z 296DEG 14KT 3994 7457

$$

JJM

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 4, 2:00 AM EDTAreal Flood WarningPHIBucks, Philadelphia3 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2008Every flash flood warning in 2008

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.