Alert archive / Pennsylvania / Flash Flood Warnings in 2009

Flash Flood Warning 7, NWS Philadelphia/Mount Holly

June 13, 2009Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 13, 2009, 2:32 PM EDT for Bucks County, Pennsylvania. It was in force for 2 hr. 2 reports 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 13, 2009, 2:32 PM EDT (18:32 UTC)
Expired
Jun 13, 2009, 5:00 PM EDT
In force
2 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

County Bucks County, PA

The radar

The Philadelphia radar (KDIX), 63 km from the middle of the area, began a volume at 18:34 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 13, 3:20 PM EDTFLASH FLOOD3 S Doylestown, PASEVERAL ROADS CLOSED DUE TO FLOODING IN WARMNISTER TWP.
Jun 13, 3:20 PM EDTFLASH FLOODWarminster Heights, PASEVERAL ROADS CLOSED DUE TO FLOODING IN WARMINSTER TWP.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.5 hours before the alert went out and 254 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 2009-06-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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, Washington/Dulle, VA at 12:00Z on 2009-06-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 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
18 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
989 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
38 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 131832
FFWPHI
PAC017-132100-
/O.NEW.KPHI.FF.W.0007.090613T1832Z-090613T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
232 PM EDT SAT JUN 13 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 500 PM EDT

* AT 230 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
VERY HEAVY RAINS FROM SEVERAL THUNDERSTORMS THAT ARE MOVING VERY 
SLOWLY THROUGH THE COUNTY. RAINFALL WAS FALLING AT A RATE OF TWO TO 
TWO AND A HALF INCHES PER HOUR.
 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO GARDENVILLE
  AND DOYLESTOWN

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4041 7509 4039 7501 4028 7488 4019 7478
      4008 7492 4026 7522

$$

EBERWINE
1 follow-up statement
000 
WGUS71 KPHI 131922
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
322 PM EDT SAT JUN 13 2009

PAC017-132100-
/O.CON.KPHI.FF.W.0007.000000T0000Z-090613T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUCKS PA-
322 PM EDT SAT JUN 13 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM EDT FOR
SOUTHEASTERN BUCKS COUNTY...

AT 319 PM EDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED MANY
FLOODED ROADWAYS IN WARMINSTER AND WARRINGTON TOWNSHIPS. THE HEAVIEST
RAIN ESTIMATED TO BE AROUND FOUR INCHES HAS FALLEN OVER THE LITTLE
NESHAMINY BASIN. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
GARDENVILLE AND DOYLESTOWN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

FOLLOW THE INSTRUCTION OF LAW ENFORCEMENT PERSONNEL IN YOUR AREA 
AND NEVER DRIVE AROUND BARRICADES.

&&

LAT...LON 4041 7509 4039 7501 4028 7488 4019 7478
      4008 7492 4026 7522

$$

GIGI

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 13, 2:27 PM EDTAreal Flood AdvisoryPHIChester4 hr
Jun 13, 2:33 PM EDTFlash Flood WarningPHICarbon, Lehigh, Monroe, Northampton112 min
Jun 13, 2:57 PM EDTFlash Flood WarningPHIMontgomery2 hr
Jun 13, 3:17 PM EDTAreal Flood AdvisoryPHIBucks3 hr
Jun 13, 4:07 PM EDTFlash Flood WarningPHIBucks, Montgomery, Philadelphia6 hr
Jun 13, 4:59 PM EDTAreal Flood AdvisoryPHIChester4 hr
Jun 13, 5:16 PM EDTRiver Flood WarningPHIBucks13 hr
Jun 13, 6:06 PM EDTFlash Flood WarningPHIChester2 hr
Jun 13, 6:39 PM EDTSevere Thunderstorm WarningPHIMonroe66 min
Jun 13, 7:29 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe61 min

Nearby

Flash Flood Warnings in Pennsylvania, 2009Every flash flood warning in 2009

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.