Alert archive / Delaware / Areal Flood Warnings in 2011

Areal Flood Warning 84, NWS Philadelphia/Mount Holly

September 8, 2011Caroline County, Maryland; Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this areal flood warning at Sep 8, 2011, 7:41 PM EDT for Caroline County, Maryland; Kent County, Sussex County, Delaware. It was in force for 14 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 8, 2011, 7:41 PM EDT (23:41 UTC)
Expired
Sep 9, 2011, 9:23 AM EDT
In force
14 hr
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Flood severity
None

Counties Kent County, DE, Sussex County, DE, Caroline County, MD

The radar

The Dover AFB radar (KDOX), 31 km from the middle of the area, began a volume at 23:41 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 12:00Z, 11.7 hours before the alert went out and 91 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-pSkew-T log-p diagram, Wallops Is Stn, VA at 12:00Z on 2011-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1152 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 12:00Z on 2011-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1152 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
672 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

457 
WGUS41 KPHI 082341
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
741 PM EDT THU SEP 8 2011

DEC001-005-MDC011-090530-
/O.NEW.KPHI.FA.W.0084.110908T2341Z-110909T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENT DE-CAROLINE MD-SUSSEX DE-
741 PM EDT THU SEP 8 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* FLOOD WARNING FOR...
  SOUTHERN KENT COUNTY IN CENTRAL DELAWARE...
  SOUTHERN CAROLINE COUNTY IN EASTERN MARYLAND...
  WESTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...

* UNTIL 130 AM EDT   

* AT 737 PM EDT...FLOODING CONTINUES ACROSS A PORTION OF THE WARNED 
  AREA AS A RESULT OF THE VERY HEAVY RAIN THIS AFTERNOON. SMALL 
  STREAM FLOODING IS EXPECTED TO CONTINUE INTO THE EARLY MORNING 
  HOURS...AS THE NANTICOKE RIVER IN BRIDGEVILLE CONTINUES TO RISE.

A FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR HAS BEEN REPORTED.
STREAM RISES WILL BE SLOW AND FLASH FLOODING IS NOT EXPECTED.
HOWEVER...ALL INTERESTED PARTIES SHOULD TAKE NECESSARY PRECAUTIONS
IMMEDIATELY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF 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.

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 3846 7570 3865 7572 3867 7576 3867 7580
      3869 7583 3868 7592 3880 7592 3881 7590
      3883 7592 3892 7591 3894 7541 3845 7538

$$

HAYES
2 follow-up statements
863 
WGUS41 KPHI 090519
FLWPHI

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
119 AM EDT FRI SEP 9 2011

DEC001-005-MDC011-091330-
/O.EXT.KPHI.FA.W.0084.000000T0000Z-110909T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENT DE-CAROLINE MD-SUSSEX DE-
119 AM EDT FRI SEP 9 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS EXTENDED THE

* FLOOD WARNING FOR...
  SOUTHERN KENT COUNTY IN CENTRAL DELAWARE...
  SOUTHERN CAROLINE COUNTY IN EASTERN MARYLAND...
  WESTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...

* AT 115 AM EDT...FLOODING WAS CONTINUING ACROSS A PORTION OF THE    
  WARNED AREA AS A RESULT OF THE VERY HEAVY RAIN THURSDAY AFTERNOON. 
  FLOODING IS EXPECTED TO CONTINUE UNTIL WATER LEVELS ALONG          
  THE NANTICOKE RIVER BEGIN TO FALL LATER TODAY. 


A FLOOD WARNING MEANS THAT FLOODING IS ALREADY OCCURRING. STREAM 
RISES WILL BE SLOW AND FLASH FLOODING IS NOT EXPECTED. HOWEVER...ALL 
INTERESTED PARTIES SHOULD TAKE NECESSARY PRECAUTIONS IMMEDIATELY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF FLOODING. 

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. 

&&

LAT...LON 3846 7570 3865 7572 3867 7576 3867 7580
      3869 7583 3868 7592 3880 7592 3881 7590
      3883 7592 3892 7591 3894 7541 3845 7538

$$

JJM
279 
WGUS81 KPHI 091323
FLSPHI

FLOOD STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
923 AM EDT FRI SEP 9 2011

DEC001-005-MDC011-091327-
/O.CAN.KPHI.FA.W.0084.000000T0000Z-110909T1330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KENT DE-CAROLINE MD-SUSSEX DE-
923 AM EDT FRI SEP 9 2011

...THE FLOOD WARNING HAS BEEN CANCELLED FOR WESTERN SUSSEX...SOUTHERN
CAROLINE AND SOUTHERN KENT COUNTIES...

WATER CONTINUED TO SLOWLY RECEDE ALONG AND ADJACENT TO THE NANTICOKE 
RIVER. ALTHOUGH COUNTY OFFICIALS REPORTED SOME REMNANT MINOR 
FLOODING REMAINED IN PLACE, THE WARNING WHICH ENDS AT 9:30 AM HAS 
BEEN CANCELLED. 


LAT...LON 3846 7570 3865 7572 3867 7576 3867 7580
      3869 7583 3868 7592 3880 7592 3881 7590
      3883 7592 3892 7591 3894 7541 3845 7538

$$

KRUZDLO

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 8, 9:23 AM EDTAreal Flood AdvisoryPHICaroline, Cecil, Kent, Queen Anne's, Talbot4 hr
Sep 8, 1:51 PM EDTAreal Flood AdvisoryPHICaroline, Queen Anne's, Talbot6 hr
Sep 8, 3:53 PM EDTFlash Flood WarningPHICaroline4 hr
Sep 8, 4:27 PM EDTSpecial Weather StatementPHICaroline63 min
Sep 8, 1:29 AM EDTAreal Flood AdvisoryPHIKent, Sussex4 hr
Sep 8, 3:26 AM EDTFlash Flood WarningPHIKent, Sussex5 hr
Sep 8, 3:41 AM EDTRiver Flood WarningPHINew Castle14 hr
Sep 8, 5:30 AM EDTCoastal Flood AdvisoryPHIKent, New Castle17 hr
Sep 8, 9:56 AM EDTSpecial Weather StatementPHIKent64 min

Nearby

Areal Flood Warnings in Delaware, 2011Areal Flood Warnings in Maryland, 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.