Alert archive / Pennsylvania / Flash Flood Warnings in 2006

Flash Flood Warning 51, NWS Philadelphia/Mount Holly

July 21, 20064 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 21, 2006, 9:32 PM EDT for 4 counties in Pennsylvania. It was in force for 3 hr. 3 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
Jul 21, 2006, 9:32 PM EDT (01:32 UTC)
Expired
Jul 22, 2006, 12:30 AM EDT
In force
3 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 120 km from the middle of the area, began a volume at 01:32 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 21, 10:15 PM EDTFLASH FLOODKutztown, PASAUCONY CREEK OUT OF BANKS. 3.72 INCHES OR RAIN IN 90 MINUTES FROM A SPOTTER IN FLEETWOOD.
Jul 21, 10:30 PM EDTFLASH FLOODDoylestown, PANUMEROUS ROADS FLOODED CENTRAL PART OF COUNTY.
Jul 21, 11:25 PM EDTHEAVY RAIN 0Doylestown, PA2.28 INCHES OF RAIN IN 90 MINUTES.

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 00:00Z, 1.5 hours before the alert went out and 219 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 00:00Z on 2006-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1388 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 00:00Z on 2006-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 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
1388 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
999 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
54 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 220134
FFWPHI
PAC011-017-077-095-220430-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
932 PM EDT FRI JUL 21 2006

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BERKS COUNTY IN EASTERN PENNSYLVANIA
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA
  THIS INCLUDES THE CITY OF ALLENTOWN
  SOUTH CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA
  THIS INCLUDES THE CITY OF BETHLEHEM
  BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 1230 AM EDT

* AT 927 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
  FLASH FLOODING FROM NUMEROUS THUNDERSTORMS OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO OLD
  ORCHARD...NORTHAMPTON...LENHARTSVILLE...KUTZTOWN...HELLERTOWN...
  HAMBURG...EMMAUS AND ANCIENT OAKS

A WEATHER SPOTTER IN CATASAUQUA...NEAR ALLENTOWN...REPORTED 2.8 
INCHES OF RAIN IN LESS THAN ONE HOUR. STREET FLOODING WAS ALSO 
REPORTED.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

LAT...LON 4049 7640 4030 7610 4042 7552 4022 7516
      4026 7491 4074 7531

$$

AMC
1 follow-up statement
000 
WGUS71 KPHI 220317
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1111 PM EDT FRI JUL 21 2006

PAC095-220321-
NORTHAMPTON PA-
1115 PM EDT FRI JUL 21 2006

...THE FLASH FLOOD WARNING FOR NORTHAMPTON COUNTY IS CANCELLED...

LAT...LON 4049 7640 4016 7591 4042 7552 4009 7493
      4017 7474 4067 7555

$$

PAC011-017-077-220430-
BERKS PA-LEHIGH PA-BUCKS PA-
1115 PM EDT FRI JUL 21 2006

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 AM EDT FOR
BUCKS...SOUTHERN LEHIGH AND BERKS COUNTIES...

MORE RAIN IS EXPECTED OVER THE WARNED AREAS DURING THE NEXT HOUR. 

AT 1108 PM EDT...TRAINED WEATHER SPOTTERS REPORTED THAT THE SACONY 
CREEK IN NORTHERN BERKS COUNTY WAS RISING RAPIDLY. NUMEROUS ROADS IN 
THE AREA WERE ALSO REPORTED TO BE FLOODING. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
STRAUSSTOWN...QUAKERTOWN...LENHARTSVILLE...LEESPORT...KUTZTOWN...
HAMBURG...FLEETWOOD...EMMAUS...BERNVILLE...ANCIENT OAKS AND
ALLENTOWN.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

LAT...LON 4049 7640 4016 7591 4042 7552 4009 7493
      4017 7474 4067 7555

$$

AMC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 10:14 PM EDTFlash Flood WarningPHIMontgomery2 hr
Jul 22, 12:11 AM EDTFlash Flood WarningPHIBerks, Bucks, Lehigh4 hr
Jul 22, 3:25 PM EDTFlash Flood WarningPHIMontgomery3 hr
Jul 22, 3:37 PM EDTSevere Thunderstorm WarningPHIDelaware53 min
Jul 22, 3:42 PM EDTSevere Thunderstorm WarningPHIPhiladelphia57 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.