Alert archive / Pennsylvania / Flash Flood Warnings in 2012

Flash Flood Warning 7, NWS Philadelphia/Mount Holly

May 27, 2012Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at May 27, 2012, 4:08 AM EDT for Bucks County, Montgomery County, 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: May 27, 2012, 4:08 AM EDT (08:08 UTC)
Expired: May 27, 2012, 8:00 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 98 km from the middle of the area, began a volume at 08:09 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

Brookhaven, NY (KOKX), launched 00:00Z, 8.1 hours before the alert went out and 221 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: 1225 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 871 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 113 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

779 
WGUS51 KPHI 270808
FFWPHI
PAC017-091-271200-
/O.NEW.KPHI.FF.W.0007.120527T0808Z-120527T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
408 AM EDT SUN MAY 27 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL BUCKS COUNTY...
  NORTHWESTERN MONTGOMERY COUNTY...

* UNTIL 800 AM EDT...

* AT 405 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A CLUSTER OF THUNDERSTORMS OVER NORTHWESTERN 
  MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RURAL AREAS
  OF NORTHWESTERN MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES.

ADDITIONAL RAINFALL AMOUNTS OF AN INCH OR SO IS POSSIBLE IN THE 
WARNED AREA. THE ADDITIONAL RAINFALL WILL RESULT IN FLASH FLOODING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4044 7553 4042 7549 4045 7545 4038 7510
      4026 7518 4035 7561

$$

HAYES

4 follow-up statements

343 
WGUS71 KPHI 271004
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
604 AM EDT SUN MAY 27 2012

PAC017-091-271200-
/O.CON.KPHI.FF.W.0007.000000T0000Z-120527T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUCKS PA-MONTGOMERY PA-
604 AM EDT SUN MAY 27 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 AM EDT FOR
NORTHWESTERN MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES...

AT 601 AM EDT...THE HEAVY RAIN HAS EXITED THE WARNED AREA. 
HOWEVER...THUNDERSTORMS WITH HEAVY RAIN ARE EXPECTED TO AFFECT THE 
REGION BEFORE 700 AM. THE ADDITIONAL RAINFALL WILL EXACERBATE 
ONGOING FLOODING. THE PERKIOMEN CREEK AT EAST GREENVILLE WAS ABOUT 
TO GO INTO FLOOD DUE TO THE HEAVY RAIN.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RURAL AREAS 
OF NORTHWESTERN MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES.
PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL
LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE
TOLL FREE AT...1-877-633-6772.

&&

LAT...LON 4044 7553 4042 7549 4045 7545 4038 7510
      4026 7518 4035 7561

$$

HAYES

633 
WGUS71 KPHI 271048
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
648 AM EDT SUN MAY 27 2012

PAC017-091-271200-
/O.CON.KPHI.FF.W.0007.000000T0000Z-120527T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUCKS PA-MONTGOMERY PA-
648 AM EDT SUN MAY 27 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 AM EDT FOR
NORTHWESTERN MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES...

AT 644 AM EDT...THE LAST OF THE HEAVY RAIN WAS EXITING THE WARNED 
AREA. HOWEVER...THE RUNOFF FROM THE HEAVY RAIN CONTINUES TO ENTER 
CREEKS AND STREAMS. THE PERKIOMEN CREEK AT EAST GREENVILLE WAS ABOVE
FLOOD STAGE. OTHER CREEKS AND STREAM IN THE AREA ARE ALSO SHOWING 
SHARP RISES.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RURAL AREAS
OF EXTREME WEST CENTRAL BUCKS AND NORTHWESTERN MONTGOMERY COUNTIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL
LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE
TOLL FREE AT...1-877-633-6772.

&&

LAT...LON 4044 7553 4042 7548 4045 7545 4042 7537
      4031 7539 4035 7561

$$

HAYES

132 
WGUS71 KPHI 271113
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
713 AM EDT SUN MAY 27 2012

PAC017-091-271200-
/O.CON.KPHI.FF.W.0007.000000T0000Z-120527T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUCKS PA-MONTGOMERY PA-
713 AM EDT SUN MAY 27 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 AM EDT FOR
NORTHWESTERN MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES...

AT 706 AM EDT...THE HEAVY RAINS HAVE ENDED AND SO OTHER THAN THE 
PERKIOMEN CREEK WHICH WAS IN FLOOD AS OF 615 AM...THE WORST OF THIS 
FLOOD EPISODE HAS OCCURRED OVER NORTHWESTERN MONTGOMERY AND WEST 
CENTRAL BUCKS COUNTIES.

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.

PLEASE REPORT FLOODING...HAIL OR WIND DAMAGE BY CALLING YOUR LOCAL
LAW ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE
TOLL FREE AT...1-877-633-6772.

&&

LAT...LON 4044 7553 4042 7548 4045 7545 4042 7537
      4031 7539 4035 7561

$$

DRAG

021 
WGUS71 KPHI 271157
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
757 AM EDT SUN MAY 27 2012

PAC017-091-271200-
/O.CON.KPHI.FF.W.0007.000000T0000Z-120527T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUCKS PA-MONTGOMERY PA-
757 AM EDT SUN MAY 27 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 800 AM EDT FOR
NORTHWESTERN MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES...

AT 715 AM EDT...THE PERKIOMEN AT EAST GREENVILLE WAS FALLING 
STEADILY AND THE RAINS HAVE ENDED FOR THE TIME BEING.

THIS WARNING EXPIRES AT 8AM WITH NO FURTHER FOLLOWUP ANTICIPATED 
THIS MORNING.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO RURAL AREAS
OF NORTHWESTERN MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT ANY REMAINING FLOODING...BY CALLING YOUR LOCAL LAW 
ENFORCEMENT OFFICIALS OR BY CALLING THE NATIONAL WEATHER SERVICE 
TOLL FREE AT...1-877-633-6772.

&&

LAT...LON 4044 7553 4042 7548 4045 7545 4042 7537
      4031 7539 4035 7561

$$

DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
May 27, 2:19 AM EDT	Special Weather Statement	PHI	Berks, Carbon, Lehigh, Montgomery, Northampton	56 min
May 27, 2:54 AM EDT	Special Weather Statement	PHI	Bucks	66 min
May 27, 3:10 AM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery	3 hr
May 27, 3:35 AM EDT	Special Weather Statement	PHI	Berks	55 min
May 27, 3:46 AM EDT	Special Weather Statement	PHI	Bucks, Montgomery	59 min
May 27, 4:35 AM EDT	Special Weather Statement	PHI	Berks	55 min
May 27, 4:46 AM EDT	Special Weather Statement	PHI	Philadelphia	59 min
May 27, 4:58 AM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	83 min
May 27, 5:08 AM EDT	Areal Flood Advisory	PHI	Berks	89 min
May 27, 5:18 AM EDT	Special Weather Statement	PHI	Berks	57 min
May 27, 5:47 AM EDT	Special Weather Statement	PHI	Berks	58 min
May 27, 5:57 AM EDT	Flash Flood Warning	PHI	Bucks, Montgomery, Philadelphia	2 hr
May 27, 8:48 AM EDT	Special Weather Statement	PHI	Montgomery	42 min
May 27, 9:26 AM EDT	Special Weather Statement	PHI	Bucks, Lehigh	49 min
May 27, 10:07 AM EDT	Areal Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Philadelphia	3 hr
May 27, 3:01 PM EDT	Excessive Heat Warning	PHI	Delaware, Philadelphia	52 hr
May 27, 4:56 PM EDT	Special Weather Statement	PHI	Berks	49 min
May 27, 5:51 PM EDT	Areal Flood Warning	PHI	Montgomery	95 min
May 27, 7:36 PM EDT	Special Weather Statement	PHI	Monroe	39 min
May 27, 7:45 PM EDT	Special Weather Statement	PHI	Berks	45 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.