Alert archive / New Jersey / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 189, NWS Philadelphia/Mount Holly

August 9, 2009Kent County, New Castle County, Delaware; 4 counties in Maryland; 5 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 9, 2009, 6:48 PM EDT for Kent County, New Castle County, Delaware; 4 counties in Maryland; 5 counties in New Jersey. It was in force for 72 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 9, 2009, 6:48 PM EDT (22:48 UTC)
Expired
Aug 9, 2009, 8:00 PM EDT
In force
72 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Kent County, DE, New Castle County, DE, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Atlantic County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ

The radar

The Dover AFB radar (KDOX), 47 km from the middle of the area, began a volume at 22:49 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.

What was reported inside it

TimeReportWhereRemark
Aug 9, 7:15 PM EDTTSTM WND DMGHartly, DEWIRES DOWN.
Aug 9, 7:24 PM EDTTSTM WND GST 59Millville, NJA 51 KNOT GUST AT KMIV ASOS.
Aug 9, 7:27 PM EDTTSTM WND GST 52Dover Base Housing, DE52 MPH GUST AT DOVER AIR FORCE BASE, WIRES DOWN IN NORTH DOVER.
Aug 9, 7:30 PM EDTTSTM WND DMG1 E Victory Lakes, NJWIRES KNOCKED DOWN. HOUSE ALSO STRUCK BY LIGHTNING BUT NO DAMAGE.
Aug 9, 7:40 PM EDTTSTM WND DMGHarrington, DEWIRES DOWN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 9, 3:18 PM EDTSevere Thunderstorm WatchSPC5 hr
Aug 9, 5:33 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 10.8 hours before the alert went out and 143 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 2009-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 721 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 2009-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
721 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
814 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 092248
SVRPHI
DEC001-003-MDC011-015-029-035-NJC001-007-011-015-033-100000-
/O.NEW.KPHI.SV.W.0189.090809T2248Z-090810T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
648 PM EDT SUN AUG 9 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  KENT COUNTY IN CENTRAL DELAWARE...
  THIS INCLUDES THE CITY OF DOVER...
  NORTHERN CAROLINE COUNTY IN EASTERN MARYLAND...
  SOUTHEASTERN CECIL COUNTY IN NORTHEAST MARYLAND...
  KENT COUNTY IN NORTHEAST MARYLAND...
  QUEEN ANNES COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF CENTERVILLE...
  SOUTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITY OF MIDDLETOWN...
  WESTERN ATLANTIC COUNTY IN SOUTHERN NEW JERSEY...
  SOUTHEASTERN CAMDEN COUNTY IN SOUTHERN NEW JERSEY...
  CUMBERLAND COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITIES OF...VINELAND...MILLVILLE...
  SOUTHEASTERN GLOUCESTER COUNTY IN SOUTHERN NEW JERSEY...
  SALEM COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 800 PM EDT

* AT 645 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM 17 MILES NORTH OF BETTERTON TO CAYOTS TO MOUNT PLEASANT TO
  PORT PENN TO 7 MILES NORTH OF ALLOWAY TO 17 MILES NORTHWEST OF
  CLAYTON...OR ALONG A LINE EXTENDING FROM 20 MILES WEST OF ELKTON TO
  6 MILES SOUTHWEST OF ELKTON TO 8 MILES NORTH OF MIDDLETOWN TO 11
  MILES SOUTH OF WILMINGTON TO 9 MILES SOUTHEAST OF WILMINGTON TO 7
  MILES SOUTHWEST OF CAMDEN...AND MOVING SOUTHEAST AT 35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  BOHEMIAS MILLS AND ALLOWAY AROUND 655 PM EDT...
  WARWICK AND MIDDLETOWN AROUND 700 PM EDT...
  CECILTON AROUND 705 PM EDT...
  SASSAFRAS...SHILOH...SEABROOK FARMS AND OLIVET AROUND 710 PM EDT...
  BETTERTON AROUND 715 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS. WIND
GUSTS ESTIMATED TO 65 MPH WAS JUST REPORTED IN NEWARK DELAWARE.
SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS AND TREES

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

&&

LAT...LON 3905 7631 3900 7618 3916 7628 3945 7600
      3958 7556 3946 7558 3932 7543 3958 7553
      3976 7487 3955 7453 3918 7502 3917 7514
      3935 7539 3901 7531 3884 7560 3886 7593
      3895 7609 3887 7611 3894 7624 3888 7637
TIME...MOT...LOC 2246Z 328DEG 32KT 3959 7618 3953 7589
          3955 7567 3957 7558 3966 7537 3988 7522

$$
 
TFG
1 follow-up statement
000 
WWUS51 KPHI 092342
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
742 PM EDT SUN AUG 9 2009

DEC003-MDC015-029-035-NJC033-092350-
/O.CAN.KPHI.SV.W.0189.000000T0000Z-090810T0000Z/
CECIL MD-KENT MD-SALEM NJ-QUEEN ANNES MD-NEW CASTLE DE-
742 PM EDT SUN AUG 9 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN NEW CASTLE...QUEEN
ANNES...SALEM...KENT AND SOUTHEASTERN CECIL COUNTIES IS CANCELLED...

THE LINE OF SEVERE THUNDERSTORMS HAS MOVED SOUTH OF THE REGION AND
SEVERE WEATHER IS NO LONGER EXPECTED.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

LAT...LON 3889 7596 3928 7570 3931 7533 3934 7535
      3917 7514 3955 7453 3918 7502 3901 7531
      3884 7560
TIME...MOT...LOC 2340Z 322DEG 33KT 3910 7578 3904 7549
          3906 7527 3908 7518 3917 7497 3939 7482

$$

DEC001-MDC011-NJC001-007-011-015-100000-
/O.CON.KPHI.SV.W.0189.000000T0000Z-090810T0000Z/
KENT DE-CAROLINE MD-CUMBERLAND NJ-CAMDEN NJ-GLOUCESTER NJ-ATLANTIC NJ-
742 PM EDT SUN AUG 9 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR ATLANTIC...SOUTHEASTERN GLOUCESTER...SOUTHEASTERN CAMDEN...
CUMBERLAND...NORTHERN CAROLINE AND KENT COUNTIES...

AT 737 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM TEMPLEVILLE TO WOODSIDE EAST TO 6 MILES NORTH OF BIG
STONE BEACH TO 10 MILES NORTHEAST OF BIG STONE BEACH TO BIVALVE TO
ESTELL MANOR...OR ALONG A LINE EXTENDING FROM 15 MILES WEST OF DOVER
TO 7 MILES SOUTH OF DOVER TO 13 MILES SOUTHEAST OF DOVER TO 17 MILES
EAST OF DOVER TO 14 MILES SOUTH OF MILLVILLE TO 9 MILES SOUTHEAST OF
VINELAND...MOVING SOUTHEAST AT 40 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  HENDERSON...GOLDSBORO...BIG STONE BEACH AND ESTELL MANOR BY 745 PM
  EDT...
  SANDTOWN AND FELTON BY 750 PM EDT...
  HOUSTON...HARRINGTON AND FARMINGTON BY 800 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THESE THUNDERSTORMS HAVE HAD A HISTORY OF PRODUCING DAMAGING WIND
GUSTS. A WIND GUST OF 59 MPH JUST OCCURRED AT MILLVILLE MUNICIPAL 
AIRPORT IN CUMBERLAND COUNTY NEW JERSEY AND A WIND GUST OF 52 MPH
JUST OCCURRED IN DOVER DELAWARE.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

&&

LAT...LON 3889 7596 3928 7570 3931 7533 3934 7535
      3917 7514 3955 7453 3918 7502 3901 7531
      3884 7560
TIME...MOT...LOC 2340Z 322DEG 33KT 3910 7578 3904 7549
          3906 7527 3908 7518 3917 7497 3939 7482

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 11:57 AM EDTFlash Flood WatchPHINew Castle11 hr
Aug 9, 1:56 PM EDTExcessive Heat WarningPHINew Castle30 hr
Aug 9, 1:56 PM EDTHeat AdvisoryPHIKent, Sussex30 hr
Aug 9, 5:53 PM EDTSevere Thunderstorm WarningPHINew Castle82 min
Aug 9, 6:03 PM EDTAreal Flood AdvisoryPHINew Castle117 min
Aug 9, 7:36 PM EDTSevere Thunderstorm WarningPHIKent, Sussex69 min
Aug 9, 9:23 AM EDTAreal Flood AdvisoryPHICamden, Gloucester83 min
Aug 9, 10:33 AM EDTAreal Flood AdvisoryPHIAtlantic, Burlington, Ocean69 min
Aug 9, 6:10 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester, Salem80 min
Aug 9, 6:20 PM EDTSpecial Marine WarningPHI115 min
Aug 9, 7:21 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Cape May, Cumberland, Ocean69 min
Aug 9, 7:33 PM EDTSpecial Marine WarningPHI87 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2009Severe Thunderstorm Warnings in Maryland, 2009Severe Thunderstorm Warnings in Delaware, 2009Every severe thunderstorm warning in 2009

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.