Alert archive / Pennsylvania / Flash Flood Warnings in 2010

Flash Flood Warning 5, NWS Philadelphia/Mount Holly

July 13, 2010Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Jul 13, 2010, 9:41 AM EDT for Montgomery County, Philadelphia County, Pennsylvania. It was in force for 2 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: Jul 13, 2010, 9:41 AM EDT (13:41 UTC)
Expired: Jul 13, 2010, 11:45 AM EDT
In force: 2 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 13:42 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, 1.7 hours before the alert went out and 106 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: 670 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 553 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 80 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

005 
WGUS51 KPHI 131341
FFWPHI
PAC091-101-131545-
/O.NEW.KPHI.FF.W.0005.100713T1341Z-100713T1545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
941 AM EDT TUE JUL 13 2010

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  WEST CENTRAL PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 1145 AM EDT

* AT 940 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THAT OVER TWO INCHES OF RAIN HAD FALLEN IN PARTS OF THE REGION
  THIS MORNING. MINOR FLOODING WILL OCCUR ALONG THE WISSAHICKON
  CREEK. ADDITIONAL HEAVY RAIN IS EXPECTED TODAY...ALONG WITH MORE
  FLOODING OF ROADWAYS...AREAS OF POOR DRAINAGE AND SMALL STREAMS
  AND CREEKS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO CHESTNUT
  HILL...ABINGTON...GERMANTOWN...WILLOW GROVE...ROCKLEDGE...
  JENKINTOWN...HATBORO...BRYN ATHYN AND AMBLER

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.

&&

LAT...LON 4005 7512 4007 7516 4004 7514 3999 7518
      4005 7527 4024 7520 4014 7503

$$

IOVINO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 8:12 PM EDT	Special Weather Statement	PHI	Chester	63 min
Jul 12, 8:40 PM EDT	Special Weather Statement	PHI	Philadelphia	65 min
Jul 12, 9:53 PM EDT	Special Weather Statement	PHI	Bucks, Montgomery	67 min
Jul 12, 10:42 PM EDT	Special Weather Statement	PHI	Berks	63 min
Jul 12, 11:42 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	63 min
Jul 13, 12:52 AM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Jul 13, 1:06 AM EDT	Areal Flood Advisory	PHI	Berks, Chester, Montgomery	3 hr
Jul 13, 4:08 AM EDT	Areal Flood Advisory	PHI	Berks	115 min
Jul 13, 5:58 AM EDT	Special Weather Statement	PHI	Delaware	62 min
Jul 13, 6:07 AM EDT	Areal Flood Advisory	PHI	Chester, Delaware	113 min
Jul 13, 6:20 AM EDT	Flash Flood Warning	PHI	Delaware	115 min
Jul 13, 7:42 AM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Jul 13, 9:17 AM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	118 min
Jul 13, 9:31 AM EDT	Flash Flood Warning	PHI	Philadelphia	8 hr
Jul 13, 10:28 AM EDT	Flash Flood Warning	PHI	Bucks, Montgomery, Philadelphia	3 hr
Jul 13, 10:38 AM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jul 13, 2:48 PM EDT	Flash Flood Watch	PHI	Delaware, Philadelphia	19 hr
Jul 13, 3:08 PM EDT	Excessive Heat Watch	PHI	Delaware, Philadelphia	63 hr
Jul 13, 5:29 PM EDT	Areal Flood Advisory	PHI	Philadelphia	117 min

Nearby

Flash Flood Warnings in Pennsylvania, 2010 Every flash flood warning in 2010

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.