Alert archive / Delaware / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 223, NWS Philadelphia/Mount Holly

August 1, 2011New Castle County, Delaware; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 1, 2011, 4:46 PM EDT for New Castle County, Delaware; Cecil County, Maryland. It was in force for 48 min. 2 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 1, 2011, 4:46 PM EDT (20:46 UTC)
Expired: Aug 1, 2011, 5:34 PM EDT
In force: 48 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties New Castle County, DE, Cecil County, MD

What was reported inside it

Time	Report	Where	Remark
Aug 1, 5:05 PM EDT	TSTM WND DMG	North East, MD	TREES REPORTED DOWN IN NORTH EAST.
Aug 1, 5:13 PM EDT	TSTM WND DMG	Elk Neck, MD	FEW TREES DOWN ALONG ROAD IN ELK NECK.

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.8 hours before the alert went out and 20 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 307 J/kg
Mixed-layer CIN: -150 J/kg
Mixed-layer LCL: 1512 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: -192 m²/s²
0-3 km storm-relative helicity: -166 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -1.5

Open this sounding in Storm Lab

The text

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

511 
WUUS51 KPHI 012046
SVRPHI
DEC003-MDC015-012145-
/O.NEW.KPHI.SV.W.0223.110801T2046Z-110801T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
446 PM EDT MON AUG 1 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CECIL COUNTY IN NORTHEAST MARYLAND...
  THIS INCLUDES THE CITY OF ELKTON...
  SOUTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITY OF MIDDLETOWN...

* UNTIL 545 PM EDT

* AT 443 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
  WOODLAWN...OR 13 MILES WEST OF ELKTON...AND MOVING SOUTHEAST AT 20
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BAY VIEW AROUND 455 PM EDT...
  CHARLESTOWN AND NORTH EAST AROUND 500 PM EDT...
  HOLLYWOOD BEACH AROUND 515 PM EDT...
  BRANTWOOD AND CAYOTS AROUND 525 PM EDT...
  BOHEMIAS MILLS AROUND 535 PM EDT...
  MOUNT PLEASANT...MIDDLETOWN AND SAINT GEORGES AROUND 540 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...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 3971 7607 3957 7555 3954 7555 3948 7558
      3930 7573 3933 7577 3938 7577 3938 7585
      3937 7584 3948 7601 3953 7599 3955 7603
      3954 7607 3962 7616
TIME...MOT...LOC 2046Z 295DEG 19KT 3961 7605

$$

TFG

1 follow-up statement

866 
WWUS51 KPHI 012134
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
534 PM EDT MON AUG 1 2011

DEC003-MDC015-012144-
/O.CAN.KPHI.SV.W.0223.000000T0000Z-110801T2145Z/
CECIL MD-NEW CASTLE DE-
534 PM EDT MON AUG 1 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN NEW CASTLE AND CECIL
COUNTIES IS CANCELLED...

THE STORM HAS WEAKENED BELOW SEVERE LIMITS.

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 3971 7607 3957 7555 3954 7555 3948 7558
      3930 7573 3933 7577 3938 7577 3938 7585
      3937 7584 3948 7601 3953 7599 3955 7603
      3954 7607 3962 7616
TIME...MOT...LOC 2134Z 295DEG 19KT 3950 7575

$$

TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 3:15 PM EDT	Special Weather Statement	PHI	Sussex	45 min
Aug 1, 3:38 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	37 min
Aug 1, 3:59 PM EDT	Flash Flood Warning	PHI	Sussex	4 hr
Aug 1, 6:20 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	46 min
Aug 1, 7:31 PM EDT	Special Weather Statement	PHI	Kent, New Castle, Sussex	119 min
Aug 1, 4:07 PM EDT	Special Weather Statement	PHI	Cecil	53 min
Aug 1, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	78 min
Aug 1, 6:12 PM EDT	Areal Flood Advisory	PHI	Kent, Queen Anne's	2 hr
Aug 1, 6:41 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	18 min
Aug 1, 7:46 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's	38 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2011 Severe Thunderstorm Warnings in Maryland, 2011 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.