Alert archive / Delaware / Areal Flood Warnings in 2011
Areal Flood Warning 45, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood warning at Aug 19, 2011, 4:00 AM EDT for New Castle County, Delaware; Delaware 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
- Aug 19, 2011, 4:00 AM EDT (08:00 UTC)
- Expired
- Aug 19, 2011, 7:54 AM EDT
- In force
- 4 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Flood severity
- None
Counties New Castle County, DE, Delaware County, PA
The radar
The Philadelphia radar (KDIX), 99 km from the middle of the area, began a volume at 08:01 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
Wallops Is Stn, VA (KWAL), launched 00:00Z, 8.0 hours before the alert went out and 211 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.
- Mixed-layer CAPE
- 27 J/kg
- Mixed-layer CIN
- -177 J/kg
- Mixed-layer LCL
- 1773 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 5 m²/s²
- 0-3 km storm-relative helicity
- 34 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
240
WGUS41 KPHI 190800
FLWPHI
BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
400 AM EDT FRI AUG 19 2011
DEC003-PAC045-191345-
/O.NEW.KPHI.FA.W.0045.110819T0800Z-110819T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DELAWARE PA-NEW CASTLE DE-
400 AM EDT FRI AUG 19 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* FLOOD WARNING FOR URBAN AREAS AND SMALL STREAMS IN...
SOUTHWESTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
NORTHEASTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
* UNTIL 945 AM EDT
* AT 359 AM EDT THE HEAVY OVERNIGHT RAINS HAVE ESSENTIALLY ENDED
LEAVING CONSIDERABLE POOR DRAINAGE FLOODING IN THE URBAN AREAS OF
FAR NORTHERN NEW CASTLE COUNTY ADJACENT THE PENNSYLVANIA DELAWARE
BORDER. REPORTS WERE RECEIVED OF INUNDATED ROADS AND A COUPLE OF
HOMES ISOLATED NEAR TALLEYVILLE CLAYMONT...TO THE NORTH OF
WILMINGTON WHERE THE HEAVIEST RAIN OCCURRED BETWEEN 1 AM AND 230
AM. THERE WERE ALSO REPORTS OF FLOODED BASEMENTS THERE.
* THE BRANDYWINE CREEK HAD STOPPED ITS RAPID RISE NEAR 14.8 FEET...
MORE THAN A FOOT AND HALF BELOW FLOOD STAGE. ABOUT 2.5 INCHES OF
RAIN FELL IN CLAYMONT.
THIS STATEMENT SUPERSEDES THE FLOOD ADVISORY ISSUED EARLIER FOR
NORTHERN DELAWARE.
A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN REPORTED.
ALL INTERESTED PARTIES SHOULD TAKE NECESSARY AVOIDANCE PRECAUTIONS
IMMEDIATELY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
EXCESSIVE RUNOFF FROM HEAVY RAINFALL HAS CAUSED ELEVATED LEVELS ON
SMALL CREEKS AND STREAMS...AND PONDING OF WATER IN URBAN AREAS...
HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER POOR DRAINAGE
AREAS AND LOW LYING SPOTS.
A FLOOD WARNING MEANS FLOODING HAS OCCURRED. MOST FLOOD RELATED
DEATHS OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED
BRIDGES...DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A
FLOWING STREAM...EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER
MOVE UP TO HIGHER GROUND.
&&
LAT...LON 3984 7560 3985 7561 3989 7555 3985 7545
3982 7540 3974 7553 3975 7557 3978 7560
3983 7561 3984 7561
$$
DRAG2 follow-up statements
900
WGUS81 KPHI 190837
FLSPHI
FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
437 AM EDT FRI AUG 19 2011
DEC003-PAC045-191345-
/O.CON.KPHI.FA.W.0045.000000T0000Z-110819T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DELAWARE PA-NEW CASTLE DE-
437 AM EDT FRI AUG 19 2011
...THE FLOOD WARNING REMAINS IN EFFECT UNTIL 945 AM EDT FOR URBAN
AREAS AND SMALL STREAMS IN NORTHEASTERN NEW CASTLE AND SOUTHWESTERN
DELAWARE COUNTIES...
AT 429 AM EDT THE HEAVY OVERNIGHT RAINS /ABOUT 2.5 INCHES IN
CLAYMONT/ HAVE ENDED LEAVING CONSIDERABLE POOR DRAINAGE FLOODING IN
THE URBAN AREAS OF FAR NORTHERN NEW CASTLE COUNTY ADJACENT THE
PENNSYLVANIA DELAWARE BORDER. REPORTS WERE RECEIVED OF INUNDATED
ROADS AND A COUPLE OF HOMES ISOLATED NEAR TALLEYVILLE CLAYMONT...
NORTH OF WILMINGTON WHERE THE HEAVIEST RAIN OCCURRED BETWEEN 1 AM
AND 230 AM. THERE WERE ALSO REPORTS OF FLOODED BASEMENTS THERE.
* THE BRANDYWINE CREEK IN NORTHERN NEWCASTLE COUNTY HAD STOPPED ITS
RAPID RISE NEAR 14.8 FEET...MORE THAN A FOOT AND HALF BELOW FLOOD
STAGE.
* HOWEVER ON THE PENNSYLVANIA SIDE...THERE WAS A REPORT FROM CHESTER
COUNTY THAT THE BRANDYWINE WAS OUT OF ITS BANKS AND CLOSED A ROAD
IN BIRMINGHAM TOWNSHIP...JUST SOUTH OF WEST CHESTER.
THIS STATEMENT SUPERSEDES THE FLOOD ADVISORY ISSUED EARLIER FOR
NORTHERN DELAWARE.
A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN REPORTED.
ALL INTERESTED PARTIES SHOULD TAKE NECESSARY FLOOD WATER AVOIDANCE
PRECAUTIONS IMMEDIATELY.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.
EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE ELEVATED LEVELS ON
SMALL CREEKS AND STREAMS...AND PONDING OF WATER ON COUNTRY ROADS AND
FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.
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 3984 7560 3985 7561 3989 7555 3985 7545
3982 7540 3974 7553 3975 7557 3978 7560
3983 7561 3984 7561
$$
DRAG852
WGUS81 KPHI 191154
FLSPHI
FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
754 AM EDT FRI AUG 19 2011
DEC003-PAC045-191202-
/O.CAN.KPHI.FA.W.0045.000000T0000Z-110819T1345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DELAWARE PA-NEW CASTLE DE-
754 AM EDT FRI AUG 19 2011
...THE FLOOD WARNING HAS BEEN CANCELLED FOR URBAN AREAS AND SMALL
STREAMS IN NORTHEASTERN NEW CASTLE AND SOUTHWESTERN DELAWARE
COUNTIES...
THE WATER LEVELS ON THE GAGED STREAMS IN THE AREA ARE GENERALLY
FALLING. ANY LINGERING POCKETS OF POOR DRAINAGE FLOODING WILL ALSO
END SHORTLY. THEREFORE, THE FLOOD WARNING HAS BEEN CANCELLED.
LAT...LON 3984 7560 3985 7561 3989 7555 3985 7545
3982 7540 3974 7553 3975 7557 3978 7560
3983 7561 3984 7561
$$
GORSEThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 8:26 PM EDT | Areal Flood Advisory | PHI | New Castle | 112 min |
| Aug 19, 12:50 AM EDT | Special Weather Statement | PHI | New Castle | 40 min |
| Aug 19, 1:14 AM EDT | Areal Flood Advisory | PHI | New Castle | 3 hr |
| Aug 19, 1:44 AM EDT | Special Weather Statement | PHI | New Castle | 61 min |
| Aug 19, 3:06 AM EDT | Areal Flood Advisory | PHI | Kent | 114 min |
| Aug 19, 1:20 PM EDT | Special Weather Statement | PHI | Kent, Sussex | 85 min |
| Aug 19, 1:42 PM EDT | Severe Thunderstorm Warning | PHI | Sussex | 63 min |
| Aug 19, 2:09 PM EDT | Areal Flood Advisory | PHI | Sussex | 92 min |
| Aug 19, 2:33 PM EDT | Areal Flood Advisory | PHI | Kent, New Castle | 7 hr |
| Aug 19, 2:53 PM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 52 min |
| Aug 19, 2:59 PM EDT | Severe Thunderstorm Warning | PHI | Sussex | 61 min |
| Aug 19, 3:13 PM EDT | Special Weather Statement | PHI | Sussex | 92 min |
| Aug 19, 3:53 PM EDT | Areal Flood Advisory | PHI | Kent, Sussex | 5 hr |
| Aug 19, 4:09 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 66 min |
| Aug 19, 4:23 PM EDT | Severe Thunderstorm Warning | PHI | Sussex | 82 min |
| Aug 19, 4:42 PM EDT | Areal Flood Advisory | PHI | New Castle | 4 hr |
| Aug 19, 4:42 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 63 min |
| Aug 19, 6:14 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 65 min |
| Aug 19, 6:34 PM EDT | Areal Flood Advisory | PHI | Sussex | 2 hr |
| Aug 18, 8:08 PM EDT | Special Weather Statement | PHI | Berks | 67 min |
| Aug 18, 8:31 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Montgomery | 59 min |
| Aug 18, 8:48 PM EDT | Special Weather Statement | PHI | Monroe | 57 min |
| Aug 18, 8:48 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 57 min |
| Aug 19, 12:02 AM EDT | Special Weather Statement | PHI | Chester | 58 min |
| Aug 19, 1:31 AM EDT | Special Weather Statement | PHI | Delaware, Philadelphia | 59 min |
| Aug 19, 1:46 PM EDT | Severe Thunderstorm Warning | PHI | Monroe | 59 min |
| Aug 19, 2:35 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 70 min |
| Aug 19, 2:38 PM EDT | Areal Flood Advisory | PHI | Carbon, Monroe | 3 hr |
| Aug 19, 2:57 PM EDT | Flash Flood Warning | PHI | Carbon, Monroe | 3 hr |
| Aug 19, 3:47 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Monroe | 58 min |
| Aug 19, 4:29 PM EDT | Severe Thunderstorm Warning | PHI | Carbon, Lehigh, Monroe, Northampton | 61 min |
| Aug 19, 4:32 PM EDT | Areal Flood Advisory | PHI | Berks, Lehigh, Northampton | 2 hr |
| Aug 19, 4:52 PM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Lehigh, Montgomery, Northampton | 53 min |
| Aug 19, 5:35 PM EDT | Severe Thunderstorm Warning | PHI | Chester | 55 min |
| Aug 19, 5:39 PM EDT | Areal Flood Advisory | PHI | Chester, Delaware | 3 hr |
| Aug 19, 5:42 PM EDT | Severe Thunderstorm Warning | PHI | Chester, Montgomery | 48 min |
| Aug 19, 5:45 PM EDT | Areal Flood Advisory | PHI | Bucks, Montgomery, Philadelphia | 3 hr |
| Aug 19, 5:59 PM EDT | Severe Thunderstorm Warning | PHI | Bucks | 80 min |
Nearby
Areal Flood Warnings in Delaware, 2011Areal Flood Warnings in Pennsylvania, 2011Every 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.