Alert archive / Maryland / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 13, NWS Philadelphia/Mount Holly

May 11, 2013Cecil County, Maryland; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 11, 2013, 5:18 PM EDT for Cecil County, Maryland; New Castle County, Delaware. It was in force for 42 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 11, 2013, 5:18 PM EDT (21:18 UTC)
Expired
May 11, 2013, 6:00 PM EDT
In force
42 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties New Castle County, DE, Cecil County, MD

The radar

The Dover AFB radar (KDOX), 89 km from the middle of the area, began a volume at 21:18 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.3 hours before the alert went out and 161 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 2013-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 2013-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 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
6 J/kg
Mixed-layer CIN
-176 J/kg
Mixed-layer LCL
1218 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
115 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.

064 
WUUS51 KPHI 112118
SVRPHI
DEC003-MDC015-112200-
/O.NEW.KPHI.SV.W.0013.130511T2118Z-130511T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
518 PM EDT SAT MAY 11 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CECIL COUNTY IN NORTHEAST MARYLAND...
  CENTRAL NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  THIS INCLUDES THE CITIES OF...NEWARK...WILMINGTON...

* UNTIL 600 PM EDT

* AT 517 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
  CHARLESTOWN...AND MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  PLEASANT HILL AROUND 525 PM EDT...
  ELKTON AND CHERRY HILL AROUND 530 PM EDT...
  BRANTWOOD AND BARKSDALE AROUND 535 PM EDT...
  GLASGOW AND NEWARK AROUND 540 PM EDT...
  BEAR AND SAINT GEORGES AROUND 545 PM EDT...
  DELAWARE CITY AROUND 550 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...LARGE 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 3977 7546 3972 7548 3971 7551 3962 7560
      3959 7559 3964 7557 3951 7555 3947 7558
      3942 7554 3946 7600 3952 7599 3955 7603
      3954 7607 3955 7608 3967 7609
TIME...MOT...LOC 2118Z 264DEG 32KT 3958 7597

$$

IOVINO
1 follow-up statement
781 
WWUS51 KPHI 112144
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
544 PM EDT SAT MAY 11 2013

DEC003-MDC015-112152-
/O.CAN.KPHI.SV.W.0013.000000T0000Z-130511T2200Z/
NEW CASTLE DE-CECIL MD-
544 PM EDT SAT MAY 11 2013

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

AT 542 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THAT 
THE THUNDERSTORM HAD WEAKENED CONSIDERABLY. AS A RESULT...THE 
WARNING HAS BEEN CANCELLED.


LAT...LON 3977 7546 3972 7548 3971 7551 3962 7560
      3959 7559 3964 7557 3951 7555 3947 7558
      3942 7554 3946 7600 3952 7599 3955 7603
      3954 7607 3955 7608 3967 7609
TIME...MOT...LOC 2142Z 264DEG 32KT 3960 7569

$$

IOVINO

The office that day

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

IssuedProductOfficeCountiesLasted
May 11, 1:39 PM EDTSpecial Weather StatementPHICaroline51 min
May 11, 2:44 PM EDTSpecial Weather StatementPHICaroline, Queen Anne's, Talbot61 min
May 11, 4:27 PM EDTSpecial Weather StatementPHICecil63 min
May 11, 5:10 PM EDTSpecial Weather StatementPHICecil65 min
May 11, 7:49 AM EDTSpecial Weather StatementPHIKent41 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2013Severe Thunderstorm Warnings in Delaware, 2013Every severe thunderstorm warning in 2013

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.