Alert archive / Pennsylvania / Flash Flood Warnings in 2012

Flash Flood Warning 25, NWS Philadelphia/Mount Holly

August 1, 2012Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Aug 1, 2012, 4:07 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 3 hr. 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: Aug 1, 2012, 4:07 PM EDT (20:07 UTC)
Expired: Aug 1, 2012, 7:03 PM EDT
In force: 3 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), 62 km from the middle of the area, began a volume at 20:10 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
Aug 1, 4:15 PM EDT	FLASH FLOOD	Warwick Twp, PA	ROADWAY FLOODING REPORTED

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.1 hours before the alert went out and 117 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: 897 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 643 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: -2 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.

270 
WGUS51 KPHI 012007
FFWPHI
PAC017-091-020000-
/O.NEW.KPHI.FF.W.0025.120801T2007Z-120802T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
407 PM EDT WED AUG 1 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL BUCKS COUNTY...
  EASTERN MONTGOMERY COUNTY...

* UNTIL 800 PM EDT...

* AT 405 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER CENTRAL BUCKS AND EASTERN
  MONTGOMERY COUNTIES.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO AMBLER...
  BRYN ATHYN...CHALFONT...DOYLESTOWN...FEASTERVILLE...HATBORO...
  HATFIELD...IVYLAND...LANSDALE...NORRISTOWN...PLYMOUTH MEETING...
  RICHBORO...SOUDERTON...WILLOW GROVE...ABINGTON AND FRICKS.

ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO INCHES ARE POSSIBLE IN THE 
WARNED AREA.

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 4012 7498 4013 7502 4012 7504 4010 7537
      4033 7536 4034 7498 4012 7493

$$

MEOLA

1 follow-up statement

093 
WGUS71 KPHI 012303
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
703 PM EDT WED AUG 1 2012

PAC017-091-012314-
/O.CAN.KPHI.FF.W.0025.000000T0000Z-120802T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BUCKS PA-MONTGOMERY PA-
703 PM EDT WED AUG 1 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EASTERN MONTGOMERY
AND SOUTHERN 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 4012 7498 4013 7502 4012 7504 4010 7537
      4033 7536 4034 7498 4012 7493

$$

HAYES

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 8:11 PM EDT	Special Weather Statement	PHI	Berks	64 min
Jul 31, 9:12 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	63 min
Jul 31, 9:51 PM EDT	Coastal Flood Statement	PHI	Delaware, Philadelphia	5 hr
Aug 1, 1:02 AM EDT	Special Weather Statement	PHI	Chester	58 min
Aug 1, 2:03 PM EDT	Special Weather Statement	PHI	Chester	57 min
Aug 1, 2:27 PM EDT	Special Weather Statement	PHI	Bucks	63 min
Aug 1, 2:47 PM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Aug 1, 3:03 PM EDT	Special Weather Statement	PHI	Monroe	57 min
Aug 1, 3:31 PM EDT	Coastal Flood Statement	PHI	Delaware, Philadelphia	11 hr
Aug 1, 3:35 PM EDT	Special Weather Statement	PHI	Philadelphia	55 min
Aug 1, 4:16 PM EDT	Special Weather Statement	PHI	Carbon, Monroe	59 min
Aug 1, 4:51 PM EDT	Areal Flood Advisory	PHI	Monroe	36 min
Aug 1, 4:53 PM EDT	Special Weather Statement	PHI	Philadelphia	67 min
Aug 1, 5:06 PM EDT	Areal Flood Advisory	PHI	Montgomery, Philadelphia	12 min
Aug 1, 5:09 PM EDT	Flash Flood Warning	PHI	Montgomery, Philadelphia	3 hr
Aug 1, 5:22 PM EDT	Flash Flood Warning	PHI	Monroe	106 min
Aug 1, 5:34 PM EDT	Special Weather Statement	PHI	Carbon	56 min
Aug 1, 5:43 PM EDT	Special Weather Statement	PHI	Delaware, Montgomery	62 min
Aug 1, 5:46 PM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	31 min
Aug 1, 5:50 PM EDT	Special Weather Statement	PHI	Montgomery	55 min
Aug 1, 5:53 PM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	100 min
Aug 1, 5:55 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe, Northampton	65 min
Aug 1, 6:08 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	2 hr
Aug 1, 6:16 PM EDT	Areal Flood Advisory	PHI	Philadelphia	46 min
Aug 1, 6:22 PM EDT	Special Weather Statement	PHI	Lehigh	53 min
Aug 1, 6:30 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	64 min
Aug 1, 6:53 PM EDT	Areal Flood Advisory	PHI	Lehigh, Northampton	69 min
Aug 1, 6:59 PM EDT	Special Weather Statement	PHI	Northampton	61 min
Aug 1, 7:32 PM EDT	Special Weather Statement	PHI	Chester	58 min
Aug 1, 7:49 PM EDT	Areal Flood Advisory	PHI	Chester	52 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.