Alert archive / Pennsylvania / Flash Flood Warnings in 2014

Flash Flood Warning 47, NWS Philadelphia/Mount Holly

August 1, 20144 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 1, 2014, 6:38 PM EDT for 4 counties in Pennsylvania. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 1, 2014, 6:38 PM EDT (22:38 UTC)
Expired
Aug 1, 2014, 10:30 PM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 121 km from the middle of the area, began a volume at 22:41 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.6 hours before the alert went out and 121 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 2014-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 696 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 2014-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
696 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
781 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
8 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.

040 
WGUS51 KPHI 012238
FFWPHI
PAC011-017-077-091-020230-
/O.NEW.KPHI.FF.W.0047.140801T2238Z-140802T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
638 PM EDT FRI AUG 1 2014

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...
  SOUTHERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  WEST CENTRAL BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 1030 PM EDT

* AT 631 PM EDT...RAIN CONTINUES TO FALL OVER THE AREA AFTER HEAVY 
  THUNDERSTORMS DUMPED TWO TO THREE INCHES OR MORE OVER THE PAST TWO 
  HOURS. THIS RAINFALL IS EXPECTED TO CAUSE FLOODING OF SOME CREEKS 
  AND STREAMS...IN PARTICULAR THE PERKIOMEN CREEK IN UPPER 
  MONTGOMERY COUNTY. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO EMMAUS...
  ANCIENT OAKS...ZIONSVILLE...TOPTON...LYONS...KUTZTOWN AND
  CLAUSSVILLE

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 4056 7586 4068 7565 4043 7530 4027 7549

$$

AMC
1 follow-up statement
625 
WGUS71 KPHI 020039
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
839 PM EDT FRI AUG 1 2014

PAC011-017-077-091-020046-
/O.CAN.KPHI.FF.W.0047.000000T0000Z-140802T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BERKS PA-BUCKS PA-LEHIGH PA-MONTGOMERY PA-
839 PM EDT FRI AUG 1 2014

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHWESTERN
MONTGOMERY...SOUTHERN LEHIGH...WEST CENTRAL BUCKS AND NORTHEASTERN
BERKS COUNTIES...

THE STORMS WHICH PROMPTED THE WARNINGS HAVE NOW DISSIPATED. NO 
FLOODING HAS BEEN REPORTED TO THE NATIONAL WEATHER SERVICE ALTHOUGH 
THE PERKIOMEN CREEK AT EAST GREENVILLE IN UPPER MONTGOMERY COUNTY 
HAS RISEN ABOVE CAUTION STAGE.

LAT...LON 4056 7586 4068 7565 4043 7530 4027 7549

$$

AMC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 2:45 PM EDTSpecial Weather StatementPHIBucks, Chester, Delaware, Montgomery, Philadelphia3 hr
Aug 1, 3:27 PM EDTAreal Flood AdvisoryPHIBucks3 hr
Aug 1, 4:34 PM EDTSpecial Weather StatementPHIBerks, Carbon, Lehigh, Monroe, Northampton56 min
Aug 1, 5:10 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Lehigh, Montgomery110 min
Aug 1, 5:42 PM EDTSpecial Weather StatementPHILehigh93 min

Nearby

Flash Flood Warnings in Pennsylvania, 2014Every flash flood warning in 2014

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.