Alert archive / Pennsylvania / Flash Flood Warnings in 2004

Flash Flood Warning 99, NWS Philadelphia/Mount Holly

September 28, 2004Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 28, 2004, 5:11 PM EDT for Philadelphia County, Pennsylvania. It was in force for 3 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: Sep 28, 2004, 5:11 PM EDT (21:11 UTC)
Expired: Sep 28, 2004, 8:15 PM EDT
In force: 3 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Counties, with a storm outline in the text

County Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 66 km from the middle of the area, began a volume at 21:12 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.2 hours before the alert went out and 98 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: 95 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 631 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 172 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

000 
WGUS51 KPHI 282114
FFWPHI
PAC101-290015-
/X.NEW.KPHI.FF.W.0018.040928T2111Z-040929T0015Z/
/0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
511 PM EDT TUE SEP 28 2004

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA

* UNTIL 815 PM EDT

* AT 508 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  CONTINUING RAIN OVER THE CITY OF PHILADELPHIA. MORE RAIN IS ON THE 
  WAY FROM THE SOUTH. FLOODING OF STREETS SHOULD BE EXPECTED. STREAMS
  SUCH AS THE FRANKFORD CREEK AND THE PENNYPACK CREEK WILL ALSO 
  EXPERIENCE RADID RISES TO BANKFULL OR A FOOT OVER BANKFULL.

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. TURN AROUND, DONT DROWN.

LAT...LON 4008 7504 3987 7525 3990 7526 3993 7524
      3999 7527 4001 7522 4003 7523 4003 7524
      4006 7514 4005 7512 4008 7504

$$

JJM

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 28, 12:48 PM EDT	Flash Flood Warning	PHI	Monroe, Northampton	3 hr
Sep 28, 3:55 PM EDT	Flash Flood Warning	PHI	Chester, Delaware	3 hr
Sep 28, 4:16 PM EDT	Flash Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	3 hr
Sep 28, 4:41 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	79 min
Sep 28, 4:55 PM EDT	Flash Flood Warning	PHI	Carbon, Monroe	4 hr
Sep 28, 6:05 PM EDT	Special Marine Warning	PHI		115 min
Sep 28, 6:47 PM EDT	Flash Flood Warning	PHI	Chester, Delaware	3 hr
Sep 28, 7:11 PM EDT	Flash Flood Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	6 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2004 Every flash flood warning in 2004

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.