Alert archive / Pennsylvania / Flash Flood Warnings in 2012

Flash Flood Warning 51, NWS Philadelphia/Mount Holly

September 4, 2012Bucks County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 4, 2012, 4:00 AM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 84 min. 1 report 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: Sep 4, 2012, 4:00 AM EDT (08:00 UTC)
Expired: Sep 4, 2012, 5:24 AM EDT
In force: 84 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 53 km from the middle of the area, began a volume at 08:01 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
Sep 4, 4:45 AM EDT	FLASH FLOOD	Upper Moreland Twp, PA	FLOODING AROUND BYBERRY ROAD AND PIONEER ROAD.

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 8.0 hours before the alert went out and 201 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1378 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 153 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.

910 
WGUS51 KPHI 040800
FFWPHI
PAC017-091-101-041100-
/O.NEW.KPHI.FF.W.0051.120904T0800Z-120904T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
400 AM EDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN BUCKS COUNTY...
  SOUTHEASTERN MONTGOMERY COUNTY...
  NORTHERN PHILADELPHIA COUNTY...

* UNTIL 700 AM EDT...

* AT 355 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN IN NORTHEAST PHILADELPHIA AND IN LOWER MONTGOMERY
  COUNTY. THE AREA OF RAIN WAS DRIFTING TO THE NORTH AT 15 MPH.
  RAINFALL TOTALS OF ONE TO TWO INCHES OF RAIN ARE POSSIBLE IN A 
  SHORT AMOUNT OF TIME WITH THE POTENTIAL FOR FLASH FLOODING.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. NEVER ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR IN AN
AUTOMOBILE. TURN AROUND DON'T DROWN!

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE TO THE NATIONAL WEATHER
SERVICE BY CALLING TOLL FREE...1-877-633-6772.

&&

LAT...LON 4008 7487 4007 7494 4002 7500 4001 7504
      3998 7508 4011 7530 4029 7514 4012 7483

$$

IOVINO

1 follow-up statement

291 
WGUS71 KPHI 040924
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
524 AM EDT TUE SEP 4 2012

PAC017-091-101-040934-
/O.CAN.KPHI.FF.W.0051.000000T0000Z-120904T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUCKS PA-MONTGOMERY PA-PHILADELPHIA PA-
524 AM EDT TUE SEP 4 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHERN
PHILADELPHIA...SOUTHEASTERN MONTGOMERY AND SOUTHEASTERN BUCKS
COUNTIES...

THE WATERS FROM THE EARLIER HEAVY RAINS ARE RECEDING AND FLOOD WATERS
NO LONGER POSE A THREAT TO LIFE OR PROPERTY. THEREFORE...THE FLASH
FLOOD WARNING HAS BEEN CANCELLED.

LAT...LON 4008 7487 4007 7494 4002 7500 4001 7504
      3998 7508 4011 7530 4029 7514 4012 7483

$$

IOVINO

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 4, 12:13 AM EDT	Areal Flood Advisory	PHI	Chester	111 min
Sep 4, 3:41 AM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	2 hr
Sep 4, 12:08 PM EDT	Areal Flood Warning	PHI	Bucks, Montgomery, Philadelphia	4 hr
Sep 4, 12:15 PM EDT	Areal Flood Warning	PHI	Berks, Chester, Delaware, Montgomery, Philadelphia	106 min
Sep 4, 1:47 PM EDT	Flash Flood Warning	PHI	Bucks, Delaware, Montgomery, Philadelphia	3 hr
Sep 4, 2:22 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 1 more	4 hr
Sep 4, 2:59 PM EDT	Special Weather Statement	PHI	Lehigh, Northampton	61 min
Sep 4, 3:11 PM EDT	River Flood Warning	PHI	Delaware	50 min
Sep 4, 3:32 PM EDT	Areal Flood Advisory	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	4 hr
Sep 4, 3:40 PM EDT	Areal Flood Advisory	PHI	Monroe, Northampton	4 hr
Sep 4, 4:37 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	3 hr
Sep 4, 5:22 PM EDT	Special Weather Statement	PHI	Philadelphia	53 min
Sep 4, 6:10 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Philadelphia	65 min
Sep 4, 6:34 PM EDT	Special Weather Statement	PHI	Lehigh	56 min
Sep 4, 7:01 PM EDT	Areal Flood Warning	PHI	Philadelphia	55 min
Sep 4, 7:06 PM EDT	Areal Flood Advisory	PHI	Bucks, Carbon, Lehigh, Monroe, Northampton	114 min
Sep 4, 7:33 PM EDT	Flash Flood Warning	PHI	Carbon, Monroe, Northampton	6 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2012 Every flash flood warning in 2012

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.