Alert archive / Pennsylvania / Flash Flood Warnings in 2015

Flash Flood Warning 15, NWS Philadelphia/Mount Holly

June 26, 2015Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jun 26, 2015, 10:59 PM EDT for Montgomery 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, 10:59 PM EDT (02:59 UTC)
Expired: Jun 27, 2015, 3:00 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 90 km from the middle of the area, began a volume at 03:02 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

Time	Report	Where	Remark
Jun 26, 11:15 PM EDT	FLASH FLOOD	Collegeville, PA	ROADS FLOODED AND SOME WATER INTO HOMES.
Jun 27, 2:00 AM EDT	HEAVY RAIN 2.03	Eagleville, PA
Jun 27, 2:00 AM EDT	HEAVY RAIN 3.81	Collegeville, PA

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, 3.0 hours before the alert went out and 217 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

478 
WGUS51 KPHI 270259
FFWPHI
PAC091-270700-
/O.NEW.KPHI.FF.W.0015.150627T0259Z-150627T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1059 PM EDT FRI JUN 26 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

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

* UNTIL 300 AM EDT

* AT 1057 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...
  NORRISTOWN...PHOENIXVILLE...WEST NORRITON...EAST NORRITON...
  COLLEGEVILLE...ROYERSFORD...TRAPPE...SKIPPACK...TROOPER...
  EAGLEVILLE...EVANSBURG AND AUDUBON.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...CROSSMANS RUN...
SCHUYLKILL RIVER...PERKIOMEN CREEK...TOWAMENCIN CREEK...STONY
CREEK...SKIPPACK CREEK...WEST BRANCH SKIPPACK CREEK AND MINGO CREEK.

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 4024 7537 4014 7532 4011 7546 4013 7546
      4013 7548 4020 7555

$$

GORSE

2 follow-up statements

387 
WGUS71 KPHI 270417
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1217 AM EDT SAT JUN 27 2015

PAC091-270700-
/O.CON.KPHI.FF.W.0015.000000T0000Z-150627T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-
1217 AM EDT SAT JUN 27 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM EDT FOR
CENTRAL MONTGOMERY COUNTY...

AT 1213 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 COLLEGEVILLE AND AUDUBON. COUNTY OFFICIALS ARE REPORTING ROAD 
CLOSURES IN THE COLLEGEVILLE AREA.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
NORRISTOWN...PHOENIXVILLE...WEST NORRITON...EAST NORRITON...
COLLEGEVILLE...ROYERSFORD...TRAPPE...SKIPPACK...TROOPER...
EAGLEVILLE...EVANSBURG AND AUDUBON.

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...CROSSMANS RUN...
SCHUYLKILL RIVER...PERKIOMEN CREEK...TOWAMENCIN CREEK...STONY
CREEK...SKIPPACK CREEK...WEST BRANCH SKIPPACK CREEK AND MINGO CREEK.

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 4024 7537 4014 7532 4011 7546 4013 7546
      4013 7548 4020 7555

$$

GORSE

862 
WGUS71 KPHI 270654
FFSPHI

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

PAC091-270702-
/O.EXP.KPHI.FF.W.0015.000000T0000Z-150627T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-
254 AM EDT SAT JUN 27 2015

...THE FLASH FLOOD WARNING FOR CENTRAL MONTGOMERY COUNTY WILL EXPIRE
AT 300 AM EDT...

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

LAT...LON 4024 7537 4014 7532 4011 7546 4013 7546
      4013 7548 4020 7555

$$

GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 26, 9:42 PM EDT	Areal Flood Advisory	PHI	Montgomery	4 hr
Jun 26, 10:38 PM EDT	Areal Flood Advisory	PHI	Montgomery, Philadelphia	3 hr
Jun 26, 11:13 PM EDT	Flash Flood Warning	PHI	Montgomery, Philadelphia	4 hr
Jun 26, 11:45 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	4 hr
Jun 27, 5:30 PM EDT	Coastal Flood Advisory	PHI	Delaware, Philadelphia	7 hr
Jun 27, 5:35 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	4 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2015 Every 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.