Alert archive / Delaware / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 61, NWS Philadelphia/Mount Holly

May 19, 2011Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 19, 2011, 6:12 PM EDT for Kent County, New Castle County, Delaware. It was in force for 18 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 19, 2011, 6:12 PM EDT (22:12 UTC)
Expired
May 19, 2011, 6:30 PM EDT
In force
18 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Kent County, DE, New Castle County, DE

The radar

The Dover AFB radar (KDOX), 58 km from the middle of the area, began a volume at 22:11 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, 10.2 hours before the alert went out and 52 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 2011-05-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 143 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 2011-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
143 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
819 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

559 
WUUS51 KPHI 192212
SVRPHI
DEC001-003-192315-
/O.NEW.KPHI.SV.W.0061.110519T2212Z-110519T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
612 PM EDT THU MAY 19 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL KENT COUNTY IN CENTRAL DELAWARE...
  SOUTHEASTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...

* UNTIL 715 PM EDT

* AT 607 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED 7 MILES NORTHWEST OF WOODLAND BEACH...OR 9 MILES
  EAST OF MIDDLETOWN...AND MOVING NORTHEAST AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  CHAMBERSVILLE AND LEIPSIC

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
THURSDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 3936 7562 3940 7557 3937 7550 3934 7547
      3934 7545 3932 7544 3922 7553
TIME...MOT...LOC 2212Z 215DEG 12KT 3942 7554

$$

PO
1 follow-up statement
887 
WWUS51 KPHI 192230
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
630 PM EDT THU MAY 19 2011

DEC001-003-192240-
/O.CAN.KPHI.SV.W.0061.000000T0000Z-110519T2315Z/
KENT DE-NEW CASTLE DE-
630 PM EDT THU MAY 19 2011

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN NEW CASTLE AND
NORTH CENTRAL KENT COUNTIES IS CANCELLED...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
THURSDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 3936 7562 3940 7557 3937 7550 3934 7547
      3934 7545 3932 7544 3922 7553
TIME...MOT...LOC 2230Z 215DEG 12KT 3947 7550

$$

PO

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 1:00 PM EDTSpecial Weather StatementPHIKent60 min
May 19, 1:37 PM EDTAreal Flood AdvisoryPHIKent, New Castle6 hr
May 19, 1:44 PM EDTSevere Thunderstorm WarningPHIKent, New Castle46 min
May 19, 2:19 PM EDTSpecial Weather StatementPHINew Castle56 min
May 19, 3:01 PM EDTAreal Flood AdvisoryPHINew Castle3 hr
May 19, 3:52 PM EDTCoastal Flood StatementPHIKent, New Castle, Sussex8 hr
May 19, 5:11 PM EDTSevere Thunderstorm WarningPHIKent34 min
May 19, 5:13 PM EDTSevere Thunderstorm WarningPHINew Castle62 min
May 19, 5:16 PM EDTSevere Thunderstorm WarningPHIKent29 min
May 19, 5:23 PM EDTSevere Thunderstorm WarningPHIKent, New Castle53 min
May 19, 5:46 PM EDTSevere Thunderstorm WarningPHIKent30 min
May 19, 6:53 PM EDTSpecial Weather StatementPHISussex67 min

Nearby

Severe 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.