Alert archive / Pennsylvania / Areal Flood Warnings in 2011

Areal Flood Warning 113, NWS Philadelphia/Mount Holly

November 23, 2011Berks County, Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this areal flood warning at Nov 23, 2011, 11:50 AM EST for Berks County, Chester County, Montgomery 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: Nov 23, 2011, 11:50 AM EST (16:50 UTC)
Expired: Nov 23, 2011, 3:22 PM EST
In force: 4 hr
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Flood severity: None

Counties Berks County, PA, Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 110 km from the middle of the area, began a volume at 16:52 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, 4.8 hours before the alert went out and 88 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: 39 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 510 m above ground
0-6 km bulk shear: 76 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 64 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.

160 
WGUS41 KPHI 231650
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1150 AM EST WED NOV 23 2011

PAC011-029-091-232245-
/O.NEW.KPHI.FA.W.0113.111123T1650Z-111123T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-MONTGOMERY PA-BERKS PA-
1150 AM EST WED NOV 23 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLOOD WARNING FOR URBAN AREAS AND SMALL STREAMS IN...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...
  SOUTHEASTERN BERKS COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 545 PM EST

* AT 1145 AM EST...WATER LEVELS REMAIN HIGH ON FRENCH CREEK, 
PERKIOMEN CREEK, MANATAWNY CREEK, AND THE BRANDYWINE. FLOODING IS 
EXPECTED INTO THIS AFTERNOON AS RUNOFF CONTINUES. 

TWO TO TWO AND ONE-HALF INCHES OF RAIN HAVE FALLEN ACROSS THE WARNED 
AREA SINCE LAST NIGHT.

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.

DRIVING INTO FLOOD WATERS COULD PUT YOUR LIFE AT RISK AND COST YOU
THOUSANDS OF DOLLARS IN VEHICLE REPAIRS. FLOOD WATERS MAY BE DEEPER
THAN YOU THINK. TURN AROUND AND FIND AN ALTERNATE ROUTE.

&&

LAT...LON 4037 7582 4033 7538 4021 7518 3978 7586
      4006 7593

$$

KRUZDLO

1 follow-up statement

224 
WGUS81 KPHI 232022
FLSPHI

FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
322 PM EST WED NOV 23 2011

PAC011-029-091-232032-
/O.CAN.KPHI.FA.W.0113.000000T0000Z-111123T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHESTER PA-MONTGOMERY PA-BERKS PA-
322 PM EST WED NOV 23 2011

...THE FLOOD WARNING HAS BEEN CANCELLED FOR URBAN AREAS AND SMALL
STREAMS IN SOUTHEASTERN BERKS...CENTRAL MONTGOMERY AND CHESTER
COUNTIES...

WATER LEVELS CONTINUE TO RECEDE. THE FLOOD WARNING HAS BEEN 
CANCELLED.

LAT...LON 4037 7582 4033 7538 4021 7518 3978 7586
      4006 7593

$$

KRUZDLO

The office that day

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

Issued	Product	Office	Counties	Lasted
Nov 22, 9:32 PM EST	Coastal Flood Advisory	PHI	Delaware, Philadelphia	15 hr
Nov 22, 9:56 PM EST	Areal Flood Warning	PHI	Berks, Chester, Montgomery	6 hr
Nov 23, 12:35 AM EST	Areal Flood Advisory	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 2 more	6 hr
Nov 23, 1:17 AM EST	Areal Flood Advisory	PHI	Carbon, Lehigh, Monroe, Northampton	6 hr
Nov 23, 2:39 AM EST	River Flood Warning	PHI	Bucks	9 hr
Nov 23, 3:08 AM EST	Special Weather Statement	PHI	Bucks, Chester, Delaware, Monroe, Montgomery, Northampton and 1 more	3 hr
Nov 23, 3:39 AM EST	River Flood Warning	PHI	Montgomery	11 hr
Nov 23, 3:44 AM EST	Areal Flood Warning	PHI	Berks, Bucks, Chester, Delaware, Lehigh, Monroe and 3 more	8 hr
Nov 23, 5:13 AM EST	Areal Flood Advisory	PHI	Philadelphia	3 hr
Nov 23, 5:54 AM EST	River Flood Warning	PHI	Chester, Montgomery, Philadelphia	16 hr
Nov 23, 6:34 AM EST	River Flood Warning	PHI	Chester	7 hr
Nov 23, 6:57 AM EST	River Flood Warning	PHI	Chester, Delaware	16 hr
Nov 23, 9:45 AM EST	Special Weather Statement	PHI	Berks	60 min
Nov 23, 10:26 AM EST	River Flood Warning	PHI	Montgomery, Philadelphia	5 hr

Nearby

Areal Flood Warnings in Pennsylvania, 2011 Every areal 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.