Alert archive / Maryland / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 266, NWS Philadelphia/Mount Holly

August 19, 2011Kent County, Delaware; Caroline County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 19, 2011, 4:09 PM EDT for Kent County, Delaware; Caroline County, Queen Anne's County, Maryland. It was in force for 66 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
Aug 19, 2011, 4:09 PM EDT (20:09 UTC)
Expired
Aug 19, 2011, 5:15 PM EDT
In force
66 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Kent County, DE, Caroline County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 43 km from the middle of the area, began a volume at 20:11 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, 8.2 hours before the alert went out and 49 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 2011-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 146 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 2011-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 359 square meters per square second.1939587897117136Sfc1 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
146 J/kg
Mixed-layer CIN
-154 J/kg
Mixed-layer LCL
1250 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
359 m²/s²
0-3 km storm-relative helicity
370 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.

935 
WUUS51 KPHI 192009
SVRPHI
DEC001-MDC011-035-192115-
/O.NEW.KPHI.SV.W.0266.110819T2009Z-110819T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
409 PM EDT FRI AUG 19 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN KENT COUNTY IN CENTRAL DELAWARE...
  NORTHEASTERN CAROLINE COUNTY IN EASTERN MARYLAND...
  NORTHEASTERN QUEEN ANNE'S COUNTY IN NORTHEAST MARYLAND...

* UNTIL 515 PM EDT

* AT 407 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  SANDTOWN...OR 15 MILES SOUTHWEST OF DOVER...AND MOVING NORTH AT 20
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  6 MILES WEST OF HAZLETTVILLE AROUND 420 PM EDT...
  HARTLY AROUND 435 PM EDT...
  SUDLERSVILLE AROUND 445 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.

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 GREATEST KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...HEAVY RAIN WILL OCCUR
WITH THESE STORMS AND CAUSE LOW-LYING AND POOR DRAINAGE FLOODING.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 3920 7598 3928 7557 3899 7555 3891 7576
TIME...MOT...LOC 2010Z 167DEG 17KT 3905 7574

$$

TFG
1 follow-up statement
377 
WWUS51 KPHI 192105
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
505 PM EDT FRI AUG 19 2011

MDC035-192115-
/O.CAN.KPHI.SV.W.0266.000000T0000Z-110819T2115Z/
QUEEN ANNE'S MD-
505 PM EDT FRI AUG 19 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN QUEEN ANNE'S
COUNTY IS CANCELLED...

THE STORM IS SOUTH OF THE COUNTY.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR NORTHERN DELAWARE AND NEW JERSEY AND EASTERN
PENNSYLVANIA.

LAT...LON 3906 7586 3918 7556 3899 7555 3891 7576
TIME...MOT...LOC 2105Z 215DEG 21KT 3901 7580

$$

DEC001-MDC011-192115-
/O.CON.KPHI.SV.W.0266.000000T0000Z-110819T2115Z/
KENT DE-CAROLINE MD-
505 PM EDT FRI AUG 19 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM EDT
FOR NORTHEASTERN CAROLINE AND CENTRAL KENT COUNTIES...

AT 502 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR GREENSBORO...OR 14 MILES EAST OF CENTERVILLE...MOVING
NORTHEAST AT 25 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  GOLDSBORO BY 510 PM EDT...
  HENDERSON...SANDTOWN AND 7 MILES SOUTHWEST OF HAZLETTVILLE BY 515
  PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT FRIDAY
EVENING FOR NORTHERN DELAWARE AND NEW JERSEY AND EASTERN
PENNSYLVANIA.

&&

LAT...LON 3906 7586 3918 7556 3899 7555 3891 7576
TIME...MOT...LOC 2105Z 215DEG 21KT 3901 7580

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 8:26 PM EDTAreal Flood AdvisoryPHINew Castle112 min
Aug 19, 12:50 AM EDTSpecial Weather StatementPHINew Castle40 min
Aug 19, 1:14 AM EDTAreal Flood AdvisoryPHINew Castle3 hr
Aug 19, 1:44 AM EDTSpecial Weather StatementPHINew Castle61 min
Aug 19, 3:06 AM EDTAreal Flood AdvisoryPHIKent114 min
Aug 19, 4:00 AM EDTAreal Flood WarningPHINew Castle4 hr
Aug 19, 1:20 PM EDTSpecial Weather StatementPHIKent, Sussex85 min
Aug 19, 1:42 PM EDTSevere Thunderstorm WarningPHISussex63 min
Aug 19, 2:09 PM EDTAreal Flood AdvisoryPHISussex92 min
Aug 19, 2:33 PM EDTAreal Flood AdvisoryPHIKent, New Castle7 hr
Aug 19, 2:53 PM EDTSevere Thunderstorm WarningPHIKent, New Castle52 min
Aug 19, 2:59 PM EDTSevere Thunderstorm WarningPHISussex61 min
Aug 19, 3:13 PM EDTSpecial Weather StatementPHISussex92 min
Aug 19, 3:53 PM EDTAreal Flood AdvisoryPHIKent, Sussex5 hr
Aug 19, 4:23 PM EDTSevere Thunderstorm WarningPHISussex82 min
Aug 19, 4:42 PM EDTAreal Flood AdvisoryPHINew Castle4 hr
Aug 19, 4:42 PM EDTSevere Thunderstorm WarningPHIKent, Sussex63 min
Aug 19, 6:14 PM EDTSevere Thunderstorm WarningPHINew Castle65 min
Aug 19, 6:34 PM EDTAreal Flood AdvisoryPHISussex2 hr
Aug 18, 8:35 PM EDTSpecial Weather StatementPHIQueen Anne's55 min
Aug 19, 12:02 AM EDTSpecial Weather StatementPHICecil58 min
Aug 19, 1:00 AM EDTSpecial Weather StatementPHICecil45 min
Aug 19, 4:53 PM EDTAreal Flood AdvisoryPHICaroline, Cecil, Kent, Queen Anne's5 hr
Aug 19, 5:35 PM EDTSevere Thunderstorm WarningPHICecil55 min
Aug 19, 5:39 PM EDTAreal Flood AdvisoryPHICecil3 hr
Aug 19, 6:18 PM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's, Talbot3 hr
Aug 19, 6:21 PM EDTSevere Thunderstorm WarningPHICecil, Kent, Queen Anne's69 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2011Severe Thunderstorm Warnings in Delaware, 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.