Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 48, NWS Philadelphia/Mount Holly

September 5, 2011Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this flash flood warning at Sep 5, 2011, 11:25 PM EDT for Berks 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: Sep 5, 2011, 11:25 PM EDT (03:25 UTC)
Expired: Sep 6, 2011, 3:30 AM EDT
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 146 km from the middle of the area, began a volume at 03:28 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 3.4 hours before the alert went out and 202 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: 451 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 562 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 104 m²/s²
0-3 km storm-relative helicity: 142 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

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

712 
WGUS51 KPHI 060325
FFWPHI
PAC011-060730-
/O.NEW.KPHI.FF.W.0048.110906T0325Z-110906T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1125 PM EDT MON SEP 5 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BERKS COUNTY...

* UNTIL 330 AM EDT...

* AT 1122 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR 
  INDICATED AN AREA OF VERY HEAVY RAIN MOVING INTO BERKS COUNTY.
  THE COUNTY RECEIVED HEAVY RAIN MONDAY EVENING...AND THE ADDITIONAL
  HEAVY RAIN WILL RESULT IN FLASH FLOODING...AS WELL AS FLOODING
  OF SMALL RIVERS AND STREAMS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO READING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 4050 7621 4060 7605 4059 7603 4066 7587
      4045 7554 4034 7563 4017 7583 4017 7591
      4033 7618 4036 7621 4036 7623 4041 7632

$$

HAYES

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 5, 8:19 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	116 min
Sep 5, 9:32 PM EDT	Areal Flood Warning	PHI	Montgomery	9 hr
Sep 5, 10:18 PM EDT	Flash Flood Warning	PHI	Lehigh, Northampton	4 hr
Sep 5, 10:53 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	3 hr
Sep 5, 11:04 PM EDT	Areal Flood Advisory	PHI	Bucks	6 hr
Sep 6, 12:22 AM EDT	Areal Flood Advisory	PHI	Delaware, Philadelphia	3 hr
Sep 6, 1:42 AM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	3 hr
Sep 6, 2:09 AM EDT	Areal Flood Advisory	PHI	Lehigh, Northampton	3 hr
Sep 6, 3:40 AM EDT	Areal Flood Warning	PHI	Berks	3 hr
Sep 6, 5:43 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	3 hr
Sep 6, 5:49 PM EDT	Areal Flood Warning	PHI	Philadelphia	20 hr
Sep 6, 6:10 PM EDT	Areal Flood Warning	PHI	Bucks, Monroe, Northampton	71 hr
Sep 6, 6:32 PM EDT	Areal Flood Warning	PHI	Montgomery	26 hr
Sep 6, 6:38 PM EDT	Areal Flood Warning	PHI	Montgomery, Philadelphia	23 hr
Sep 6, 6:44 PM EDT	Areal Flood Warning	PHI	Chester, Delaware	15 hr
Sep 6, 6:48 PM EDT	Areal Flood Warning	PHI	Bucks	31 hr
Sep 6, 7:03 PM EDT	River Flood Warning	PHI	Chester	16 hr
Sep 6, 7:41 PM EDT	River Flood Warning	PHI	Delaware	5 hr
Sep 6, 7:52 PM EDT	River Flood Warning	PHI	Bucks	52 hr

Nearby

Flash Flood Warnings in Pennsylvania, 2011 Every flash flood warning in 2011

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.