Alert archive / Maryland / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 18, NWS Philadelphia/Mount Holly

May 7, 2009Cecil County, Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 7, 2009, 1:13 PM EDT for Cecil County, Kent County, Queen Anne's County, Maryland. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 7, 2009, 1:13 PM EDT (17:13 UTC)
Expired
May 7, 2009, 1:56 PM EDT
In force
43 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Cecil County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 78 km from the middle of the area, began a volume at 17:13 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, 5.2 hours before the alert went out and 15 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, Phillips Aaf/Abe, MD at 12:00Z on 2009-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 38 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, Phillips Aaf/Abe, MD at 12:00Z on 2009-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
38 J/kg
Mixed-layer CIN
-66 J/kg
Mixed-layer LCL
642 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
106 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.

000 
WUUS51 KPHI 071713
SVRPHI
MDC015-029-035-071815-
/O.NEW.KPHI.SV.W.0018.090507T1713Z-090507T1815Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
113 PM EDT THU MAY 7 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN CECIL COUNTY IN NORTHEAST MARYLAND...
  KENT COUNTY IN NORTHEAST MARYLAND...
  NORTHEASTERN QUEEN ANNES COUNTY IN NORTHEAST MARYLAND...

* UNTIL 215 PM EDT

* AT 112 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  ROCK HALL...OR 14 MILES NORTHWEST OF CENTERVILLE...AND MOVING
  NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  LANGFORD BY 125 PM EDT...
  CHESTERTOWN AND NEWTOWN BY 130 PM EDT...
  MORGNEC BY 140 PM EDT...
  KENNEDYVILLE BY 145 PM EDT...
  CECILTON AND MASSEY BY 200 PM EDT...
  SASSAFRAS BY 205 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 3934 7618 3934 7615 3938 7610 3937 7606
      3938 7600 3938 7599 3938 7603 3940 7605
      3944 7601 3957 7579 3920 7577 3909 7624
      3916 7628
TIME...MOT...LOC 1713Z 236DEG 28KT 3917 7626

$$

TFG
2 follow-up statements
000 
WWUS51 KPHI 071741
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
141 PM EDT THU MAY 7 2009

MDC015-029-035-071815-
/O.CON.KPHI.SV.W.0018.000000T0000Z-090507T1815Z/
CECIL MD-KENT MD-QUEEN ANNES MD-
141 PM EDT THU MAY 7 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM EDT
FOR NORTHEASTERN QUEEN ANNES...KENT AND SOUTHEASTERN CECIL
COUNTIES...

AT 139 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR CECILTON...OR 8 MILES SOUTHWEST OF MIDDLETOWN...MOVING 
NORTHEAST AT 30 MPH. A SECOND SEVERE THUNDERSTORM IS JUST NORTH
OF CHESTERTOWN AND WILL AFFECT SOUTHERN KENT AND POSSIBLY NORTHERN
QUEEN ANNES COUNTY.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  6 MILES SOUTHEAST OF CAYOTS BY 145 PM EDT...
  7 MILES SOUTHEAST OF CHESAPEAKE CITY AND 9 MILES SOUTHEAST OF
  BRANTWOOD BY 155 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 3911 7617 3919 7622 3934 7618 3934 7615
      3938 7610 3937 7606 3938 7600 3938 7603
      3940 7605 3944 7601 3957 7579 3920 7577
TIME...MOT...LOC 1739Z 238DEG 27KT 3939 7585

$$
 
TFG
000 
WWUS51 KPHI 071756
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
156 PM EDT THU MAY 7 2009

MDC015-029-035-071807-
/O.CAN.KPHI.SV.W.0018.000000T0000Z-090507T1815Z/
CECIL MD-KENT MD-QUEEN ANNES MD-
156 PM EDT THU MAY 7 2009

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN QUEEN ANNES...
KENT AND SOUTHEASTERN CECIL COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM IS NOW IN DELAWARE.

LAT...LON 3911 7617 3919 7622 3934 7618 3934 7615
      3938 7610 3937 7606 3938 7600 3938 7603
      3940 7605 3944 7601 3957 7579 3920 7577
TIME...MOT...LOC 1757Z 238DEG 27KT 3939 7584

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 7, 1:32 AM EDTAreal Flood AdvisoryPHICecil3 hr
May 7, 1:22 PM EDTAreal Flood AdvisoryPHICecil, Kent4 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.