Alert archive / Pennsylvania / Flash Flood Warnings in 2015

Flash Flood Warning 16, NWS Philadelphia/Mount Holly

June 26, 2015Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 26, 2015, 11:13 PM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 4 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
Jun 26, 2015, 11:13 PM EDT (03:13 UTC)
Expired
Jun 27, 2015, 3:15 AM EDT
In force
4 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 79 km from the middle of the area, began a volume at 03:17 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 26, 11:20 PM EDTFLASH FLOODGulph Mills, PAINTERSTATE 76 IN THE GULPH MILLS AREA FLOODED WITH TRAFFIC SLOWED OR STOPPED.
Jun 26, 11:35 PM EDTFLASH FLOODKing Of Prussia, PANUMEROUS ROADS FLOODED.
Jun 27, 12:15 AM EDTFLASH FLOODWest Conshohocken, PABALLIGOMOINGO ROAD CLOSED FROM FRONT STREET TO PORTLAND ROAD DUE TO FLOODING AND A MUD SLIDE.

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, 3.2 hours before the alert went out and 218 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 2015-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 2015-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
7 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1208 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
45 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.

813 
WGUS51 KPHI 270313
FFWPHI
PAC091-101-270715-
/O.NEW.KPHI.FF.W.0016.150627T0313Z-150627T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1113 PM EDT FRI JUN 26 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN PHILADELPHIA COUNTY IN SOUTHEASTERN PENNSYLVANIA...
  SOUTH CENTRAL MONTGOMERY COUNTY IN SOUTHEASTERN PENNSYLVANIA...

* UNTIL 315 AM EDT

* AT 1112 PM EDT...DOPPLER RADAR INDICATED VERY HEAVY RAIN ACROSS 
  THE WARNED AREA ASSOCIATED WITH SLOW MOVING HEAVY SHOWERS. RADAR 
  ESTIMATES INDICATED RAINFALL OF 3 INCHES HAS FALLEN ALREADY IN 
  PORTIONS OF THE WARNED AREA AND ADDITIONAL RAIN IS EXPECTED. THIS 
  AMOUNT OF RAIN IN A SHORT PERIOD OF TIME WILL LEAD TO FLASH 
  FLOODING.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  PHILADELPHIA...NORRISTOWN...WEST NORRITON...EAST NORRITON...
  CONSHOHOCKEN...NARBERTH...PLYMOUTH MEETING...CHESTNUT HILL...BRYN
  MAWR...KING OF PRUSSIA...GERMANTOWN...BRIDGEPORT...WEST
  CONSHOHOCKEN...WYNDMOOR...PENN WYNNE...ARDMORE...FLOURTOWN AND
  AUDUBON.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...GULPH CREEK...
PLYMOUTH CREEK...COBBS CREEK...MILL CREEK...STONY CREEK...ITHAN 
CREEK...CRESHEIM CREEK...TROUT CREEK...AND MILL RUN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

&&

LAT...LON 4014 7532 4007 7515 3998 7527 4004 7534
      4006 7535 4007 7538 4012 7544

$$

GORSE
2 follow-up statements
063 
WGUS71 KPHI 270421
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1221 AM EDT SAT JUN 27 2015

PAC091-101-270715-
/O.CON.KPHI.FF.W.0016.000000T0000Z-150627T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PHILADELPHIA PA-MONTGOMERY PA-
1221 AM EDT SAT JUN 27 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 AM EDT FOR
NORTHWESTERN PHILADELPHIA AND SOUTH CENTRAL MONTGOMERY COUNTIES...

AT 1217 AM EDT...DOPPLER RADAR INDICATED THE NEARLY STATIONARY 
SHOWERS PRODUCING TORRENTIAL RAIN IS WEAKENING SOME. THE RADAR 
ESTIMATES ARE BETWEEN 2 AND 5 INCHES OF RAIN ESPECIALLY BETWEEN 
ABOUT CONSHOHOCKEN TO NARBERTH IN MONTGOMERY COUNTY, WITH LESSER 
AMOUNTS INTO PHILADELPHIA COUNTY. MONTGOMERY COUNTY OFFICIALS ARE 
REPORTING ROAD CLOSURES IN THE CONSHOHOCKEN AREA.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
PHILADELPHIA...NORRISTOWN...WEST NORRITON...EAST NORRITON...
CONSHOHOCKEN...NARBERTH...PLYMOUTH MEETING...CHESTNUT HILL...BRYN
MAWR...KING OF PRUSSIA...GERMANTOWN...BRIDGEPORT...WEST
CONSHOHOCKEN...WYNDMOOR...PENN WYNNE...ARDMORE...FLOURTOWN AND
AUDUBON.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...GULPH CREEK...
PLYMOUTH CREEK...COBBS CREEK...MILL CREEK...STONY CREEK...ITHAN
CREEK...CRESHEIM CREEK...TROUT CREEK...MILL RUN AND SCHUYLKILL RIVER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING.

TURN AROUND...DON'T DROWN WHEN ENCOUNTERING FLOODED ROADS. MOST FLOOD
DEATHS OCCUR IN VEHICLES.

PLEASE REPORT FLOODING TO YOUR LOCAL LAW ENFORCEMENT AGENCY WHEN YOU
CAN DO SO SAFELY.

&&

LAT...LON 4014 7532 4007 7515 3998 7527 4004 7534
      4006 7535 4007 7538 4012 7544

$$

GORSE
181 
WGUS71 KPHI 270708
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
308 AM EDT SAT JUN 27 2015

PAC091-101-270717-
/O.EXP.KPHI.FF.W.0016.000000T0000Z-150627T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PHILADELPHIA PA-MONTGOMERY PA-
308 AM EDT SAT JUN 27 2015

...THE FLASH FLOOD WARNING FOR NORTHWESTERN PHILADELPHIA AND SOUTH
CENTRAL MONTGOMERY COUNTIES WILL EXPIRE AT 315 AM EDT...

FLOOD WATERS ARE RECEDING...AND SHOULD NO LONGER POSE A THREAT TO 
LIFE OR PROPERTY. PLEASE CONTINUE TO HEED ANY ROAD CLOSURES.

LAT...LON 4014 7532 4007 7515 3998 7527 4004 7534
      4006 7535 4007 7538 4012 7544

$$

GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 9:42 PM EDTAreal Flood AdvisoryPHIMontgomery4 hr
Jun 26, 10:38 PM EDTAreal Flood AdvisoryPHIMontgomery, Philadelphia3 hr
Jun 26, 10:59 PM EDTFlash Flood WarningPHIMontgomery4 hr
Jun 26, 11:45 PM EDTFlash Flood WarningPHIChester, Montgomery4 hr
Jun 27, 5:30 PM EDTCoastal Flood AdvisoryPHIDelaware, Philadelphia7 hr
Jun 27, 5:35 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia4 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2015Every flash flood warning in 2015

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.