Alert archive / Maryland / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 85, NWS Philadelphia/Mount Holly

June 20, 2009Cecil County, Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware; Cumberland County, Salem County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 20, 2009, 5:01 PM EDT for Cecil County, Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware; Cumberland County, Salem County, New Jersey. It was in force for 59 min. 1 report 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
Jun 20, 2009, 5:01 PM EDT (21:01 UTC)
Expired
Jun 20, 2009, 6:00 PM EDT
In force
59 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 73 km from the middle of the area, began a volume at 21:01 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.

What was reported inside it

TimeReportWhereRemark
Jun 20, 5:03 PM EDTTSTM WND DMG5 Wsw Wilmington, DEPOWER LINE DOWN IN STANTON.

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
Jun 20, 3:05 PM EDTTornado WatchSPC5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.0 hours before the alert went out and 162 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, Washington/Dulle, VA at 12:00Z on 2009-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1441 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, Washington/Dulle, VA at 12:00Z on 2009-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.19395878Sfc1 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
1441 J/kg
Mixed-layer CIN
-83 J/kg
Mixed-layer LCL
978 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
123 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 202101
SVRPHI
DEC001-003-MDC015-029-035-NJC011-033-202200-
/O.NEW.KPHI.SV.W.0085.090620T2101Z-090620T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
501 PM EDT SAT JUN 20 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN KENT COUNTY IN CENTRAL DELAWARE...
  SOUTHEASTERN CECIL COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF ELKTON...
  NORTHEASTERN KENT COUNTY IN NORTHEAST MARYLAND...
  NORTHEASTERN QUEEN ANNES COUNTY IN NORTHEAST MARYLAND...
  NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITIES OF...WILMINGTON...MIDDLETOWN...
  NORTHWESTERN CUMBERLAND COUNTY IN SOUTHERN NEW JERSEY...
  SALEM COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF SALEM...

* UNTIL 600 PM EDT

* AT 500 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING PENNY SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM STANTON TO GLASGOW TO BRANTWOOD
  TO HOLLYWOOD BEACH TO 7 MILES WEST OF HOLLYWOOD BEACH...OR ALONG A
  LINE EXTENDING FROM 8 MILES NORTHWEST OF WILMINGTON TO NEWARK TO
  ELKTON TO 14 MILES SOUTHWEST OF ELKTON...AND MOVING SOUTHEAST AT 35
  MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  NEWPORT AROUND 505 PM EDT...
  WILMINGTON...BOHEMIAS MILLS...MOUNT PLEASANT AND SAINT GEORGES
  AROUND 510 PM EDT...
  CARNEYS POINT...WARWICK...CECILTON AND NEW CASTLE AROUND 515 PM
  EDT...
  SASSAFRAS AROUND 520 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS AND LARGE
DAMAGING HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY
AWAY FROM WINDOWS

&&

LAT...LON 3945 7600 3946 7602 3953 7599 3961 7580
      3982 7556 3952 7504 3932 7533 3939 7545
      3943 7548 3946 7555 3950 7557 3957 7553
      3958 7556 3946 7558 3927 7540 3908 7567
      3941 7604
TIME...MOT...LOC 2101Z 314DEG 32KT 3977 7565 3964 7574
          3959 7576 3956 7580 3953 7586 3948 7602

$$

KRUZDLO

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 20, 3:57 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's, Talbot66 min
Jun 20, 4:06 PM EDTTornado WarningPHIKent, Queen Anne's, Talbot32 min
Jun 20, 4:27 PM EDTSevere Thunderstorm WarningPHICecil53 min
Jun 20, 5:46 PM EDTSevere Thunderstorm WarningPHIKent, Sussex59 min
Jun 20, 6:23 PM EDTSevere Thunderstorm WarningPHISussex27 min
Jun 20, 6:55 PM EDTCoastal Flood AdvisoryPHIKent, New Castle, Sussex5 hr
Jun 20, 4:33 AM EDTSmall Craft AdvisoryPHI3 days
Jun 20, 5:14 PM EDTSpecial Marine WarningPHI61 min
Jun 20, 6:35 PM EDTSpecial Marine WarningPHI40 min
Jun 20, 6:35 PM EDTSevere Thunderstorm WarningPHICape May10 min
Jun 20, 6:38 PM EDTSpecial Marine WarningPHI52 min
Jun 20, 7:29 PM EDTSpecial Marine WarningPHI61 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2009Severe Thunderstorm Warnings in Delaware, 2009Severe Thunderstorm Warnings in New Jersey, 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.