Alert archive / Pennsylvania / Flash Flood Warnings in 2014

Flash Flood Warning 43, NWS Philadelphia/Mount Holly

July 28, 2014Delaware County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 28, 2014, 12:31 AM EDT for Delaware County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 3 hr. 2 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: Jul 28, 2014, 12:31 AM EDT (04:31 UTC)
Expired: Jul 28, 2014, 3:30 AM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 63 km from the middle of the area, began a volume at 04:32 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
Jul 28, 12:31 AM EDT	FLASH FLOOD	Philadelphia, PA	FRANKFORD CREEK OVER ITS BANKS.
Jul 28, 1:55 AM EDT	FLASH FLOOD	Philadelphia, PA	APARTMENT BUILDING EVACUATED DUE TO HEAVY RAIN COLLAPSING THE ROOF.

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, 4.5 hours before the alert went out and 215 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: 942 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 994 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 146 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 4.2

Open this sounding in Storm Lab

The text

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

412 
WGUS51 KPHI 280431
FFWPHI
PAC045-091-101-280730-
/O.NEW.KPHI.FF.W.0043.140728T0431Z-140728T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1231 AM EDT MON JUL 28 2014

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTH CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF PHILADELPHIA...

* UNTIL 330 AM EDT

* AT 1230 AM EDT...RUNOFF FROM THE RECENT HEAVY RAINFALL WAS CAUSING 
  FLASH FLOODING IN PHILADELPHIA AND IN ADJACENT AREAS OF MONTGOMERY
  COUNTY AND DELAWARE COUNTY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO YEADON...
  EAST LANSDOWNE...DREXEL HILL...BRYN MAWR...BROOMALL...
  WISSINOMING...TROUT LAKE...TACONY...ROXBOROUGH...PHILADELPHIA...
  NORTHEAST PHILADELPHIA...NEWTOWN SQUARE...NARBERTH...MORRIS PARK...
  KENSINGTON...HOLMESBURG...GERMANTOWN...CHESTNUT HILL AND CENTER
  CITY

* DO NOT DRIVE THROUGH FLOOD WATERS.

LAT...LON 4005 7497 3998 7508 3995 7514 3989 7514
      3988 7519 3985 7525 3984 7535 3999 7542
      4010 7520 4007 7519 4008 7517 4005 7511
      4014 7502 4011 7496

$$

IOVINO

1 follow-up statement

220 
WGUS71 KPHI 280638
FFSPHI

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
238 AM EDT MON JUL 28 2014

PAC045-091-101-280647-
/O.CAN.KPHI.FF.W.0043.000000T0000Z-140728T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MONTGOMERY PA-PHILADELPHIA PA-DELAWARE PA-
238 AM EDT MON JUL 28 2014

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EASTERN DELAWARE...
PHILADELPHIA AND SOUTHEASTERN MONTGOMERY COUNTIES...

THE HEAVY RAIN HAS MOVED OUT OF THE AREA AND THE FLASH FLOOD WARNING 
HAS BEEN CANCELLED.


LAT...LON 4005 7497 3998 7508 3995 7514 3989 7514
      3988 7519 3985 7525 3984 7535 3999 7542
      4010 7520 4007 7519 4008 7517 4005 7511
      4014 7502 4011 7496

$$

IOVINO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 8:28 PM EDT	Special Weather Statement	PHI	Berks	62 min
Jul 27, 8:42 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	3 hr
Jul 27, 9:12 PM EDT	Special Weather Statement	PHI	Chester	63 min
Jul 27, 9:21 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester	54 min
Jul 27, 9:43 PM EDT	Flash Flood Warning	PHI	Berks, Chester, Montgomery	4 hr
Jul 27, 10:20 PM EDT	Special Weather Statement	PHI	Chester, Montgomery	55 min
Jul 27, 10:26 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	3 hr
Jul 27, 10:33 PM EDT	Flash Flood Warning	PHI	Chester, Montgomery	4 hr
Jul 27, 10:44 PM EDT	Special Weather Statement	PHI	Chester, Delaware	61 min
Jul 27, 10:47 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	43 min
Jul 27, 11:28 PM EDT	Special Weather Statement	PHI	Delaware, Philadelphia	62 min
Jul 27, 11:32 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	58 min
Jul 28, 12:35 AM EDT	Special Weather Statement	PHI	Bucks, Chester, Delaware, Philadelphia	85 min
Jul 28, 2:58 AM EDT	River Flood Warning	PHI	Chester	8 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2014 Every flash flood warning in 2014

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.