Alert archive / Maryland / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 47, NWS Philadelphia/Mount Holly

May 18, 2011Kent County, Queen Anne's County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 18, 2011, 3:22 PM EDT for Kent County, Queen Anne's County, Talbot County, Maryland. It was in force for 47 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 18, 2011, 3:22 PM EDT (19:22 UTC)
Expired
May 18, 2011, 4:09 PM EDT
In force
47 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 72 km from the middle of the area, began a volume at 19:21 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 watch it was issued in

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

IssuedProductOfficeLasted
May 18, 12:55 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.4 hours before the alert went out and 48 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 2011-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 79 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 2011-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939587897Sfc1 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
79 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
561 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
169 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

416 
WUUS51 KPHI 181922
SVRPHI
MDC029-035-041-182030-
/O.NEW.KPHI.SV.W.0047.110518T1922Z-110518T2030Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
322 PM EDT WED MAY 18 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL TALBOT COUNTY IN EASTERN MARYLAND...
  WESTERN KENT COUNTY IN NORTHEAST MARYLAND...
  WESTERN QUEEN ANNE'S COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF CENTERVILLE...

* UNTIL 430 PM EDT

* AT 317 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR WYE MILLS...OR 9 MILES
  NORTHWEST OF EASTON...AND MOVING NORTH AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WYE MILLS AROUND 330 PM EDT...
  GRASONVILLE AROUND 335 PM EDT...
  OVERTON AROUND 355 PM EDT...
  OLD TOWN AROUND 415 PM EDT...
  ROCK HALL AROUND 420 PM EDT...
  LANGFORD AROUND 425 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

&&

LAT...LON 3903 7633 3905 7629 3901 7629 3898 7621
      3900 7618 3903 7625 3907 7623 3918 7628
      3934 7617 3937 7612 3937 7599 3886 7607
      3885 7622 3893 7621 3894 7624 3890 7624
      3893 7629 3902 7633
TIME...MOT...LOC 1922Z 172DEG 15KT 3891 7615

$$

GORSE
2 follow-up statements
803 
WWUS51 KPHI 181943
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
343 PM EDT WED MAY 18 2011

MDC041-181953-
/O.CAN.KPHI.SV.W.0047.000000T0000Z-110518T2030Z/
TALBOT MD-
343 PM EDT WED MAY 18 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL TALBOT COUNTY IS
CANCELLED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS MOVED OUT OF THE 
AREA, THEREFORE THE WARNING HAS BEEN CANCELLED.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

LAT...LON 3895 7606 3896 7620 3902 7633 3903 7633
      3905 7629 3901 7629 3898 7621 3900 7618
      3903 7625 3907 7623 3918 7628 3934 7617
      3937 7612 3937 7599
TIME...MOT...LOC 1943Z 179DEG 23KT 3907 7615

$$

MDC029-035-182030-
/O.CON.KPHI.SV.W.0047.000000T0000Z-110518T2030Z/
KENT MD-QUEEN ANNE'S MD-
343 PM EDT WED MAY 18 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR WESTERN QUEEN ANNE'S AND WESTERN KENT COUNTIES...

AT 340 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING TO
60 MPH. THIS STORM WAS LOCATED NEAR OVERTON...OR NEAR 
CENTERVILLE...MOVING NORTH AT 25 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  OLD TOWN AND ROCK HALL BY 355 PM EDT...
  LANGFORD BY 400 PM EDT...
  CHESTERTOWN AND KINGSTOWN BY 405 PM EDT...
  NEWTOWN BY 420 PM EDT...
  BETTERTON BY 430 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS SEVERE THUNDERSTORM MAY CONTAIN LITTLE OR NO CLOUD TO GROUND 
LIGHTNING. DO NOT WAIT FOR THUNDER BEFORE TAKING COVER. SEEK SHELTER 
IMMEDIATELY INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

&&

LAT...LON 3895 7606 3896 7620 3902 7633 3903 7633
      3905 7629 3901 7629 3898 7621 3900 7618
      3903 7625 3907 7623 3918 7628 3934 7617
      3937 7612 3937 7599
TIME...MOT...LOC 1943Z 179DEG 23KT 3907 7615

$$

GORSE
347 
WWUS51 KPHI 182009
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
409 PM EDT WED MAY 18 2011

MDC029-035-182018-
/O.CAN.KPHI.SV.W.0047.000000T0000Z-110518T2030Z/
KENT MD-QUEEN ANNE'S MD-
409 PM EDT WED MAY 18 2011

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN QUEEN ANNE'S AND
WESTERN KENT COUNTIES IS CANCELLED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE 
LIMITS, THEREFORE THE WARNING HAS BEEN CANCELLED. HOWEVER, DOWNPOURS
WILL OCCUR WITH THIS STORM ALONG WITH THE POTENTIAL FOR LOCALLY 
GUSTY WINDS UP TO 40 MPH.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

LAT...LON 3895 7606 3896 7620 3902 7633 3903 7633
      3905 7629 3901 7629 3898 7621 3900 7618
      3903 7625 3907 7623 3918 7628 3934 7617
      3937 7612 3937 7599
TIME...MOT...LOC 2008Z 179DEG 23KT 3923 7615

$$

GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
May 18, 2:29 PM EDTSpecial Weather StatementPHITalbot61 min
May 18, 2:39 PM EDTTornado WarningPHIQueen Anne's, Talbot51 min
May 18, 4:01 PM EDTCoastal Flood StatementPHIKent, Queen Anne's, Talbot5 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2011Every severe thunderstorm 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.