Alert archive / Delaware / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 217, NWS Philadelphia/Mount Holly

September 8, 2012Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 8, 2012, 5:22 PM EDT for Kent County, New Castle County, Delaware. It was in force for 53 min. 5 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
Sep 8, 2012, 5:22 PM EDT (21:22 UTC)
Expired
Sep 8, 2012, 6:15 PM EDT
In force
53 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), 35 km from the middle of the area, began a volume at 21:22 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.

What was reported inside it

TimeReportWhereRemark
Sep 8, 5:25 PM EDTTSTM WND DMGMarydel, DEPORCH AND A SHED DAMAGED IN MARYDEL. ALSO TREES DOWN.
Sep 8, 5:33 PM EDTTSTM WND DMGSmyrna, DETREES DOWN
Sep 8, 5:38 PM EDTTSTM WND DMGFelton, DELARGE TREE LIMBS DOWN IN FELTON.
Sep 8, 5:43 PM EDTTSTM WND DMGDover, DETREES DOWN
Sep 8, 5:50 PM EDTTSTM WND GST 55Dover Afb, DE55 MPH WIND GUST AT DOVER AFB.

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

The watch it was issued in

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

IssuedProductOfficeLasted
Sep 8, 12:15 PM EDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 9.4 hours before the alert went out and 134 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, Wallops Is Stn, VA at 12:00Z on 2012-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 718 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, Wallops Is Stn, VA at 12:00Z on 2012-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939Sfc1 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
718 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
771 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
60 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.

049 
WUUS51 KPHI 082122
SVRPHI
DEC001-003-082215-
/O.NEW.KPHI.SV.W.0217.120908T2122Z-120908T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
522 PM EDT SAT SEP 8 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  KENT COUNTY IN CENTRAL DELAWARE...
  THIS INCLUDES THE CITY OF DOVER...
  SOUTHERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...

* UNTIL 615 PM EDT

* AT 518 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED WEST OF             
  HARTLY...AND MOVING EAST AT 45 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  DOVER...DOVER SPEEDWAY AND RISING SUN AROUND 540 PM EDT...
  8 MILES NORTH OF BOWERS AROUND 550 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS AND CLOUD TO GROUND LIGHTNING. PEOPLE 
OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY INSIDE A STRONG 
BUILDING BUT AWAY FROM WINDOWS.

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 3885 7573 3950 7577 3963 7561 3960 7560
      3954 7555 3946 7558 3926 7539 3907 7539
      3900 7532 3895 7530 3895 7539 3892 7541
      3890 7549 3884 7556 3884 7572
TIME...MOT...LOC 2121Z 260DEG 50KT 3914 7565

$$

JJM
1 follow-up statement
380 
WWUS51 KPHI 082147
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
547 PM EDT SAT SEP 8 2012

DEC003-082157-
/O.CAN.KPHI.SV.W.0217.000000T0000Z-120908T2215Z/
NEW CASTLE DE-
547 PM EDT SAT SEP 8 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN NEW CASTLE COUNTY IS
CANCELLED...

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 3929 7575 3931 7571 3929 7565 3931 7562
      3931 7558 3935 7555 3937 7550 3926 7539
      3907 7539 3900 7532 3895 7530 3895 7539
      3892 7541 3891 7547 3884 7556 3884 7572
TIME...MOT...LOC 2147Z 260DEG 17KT 3922 7552

$$

DEC001-082215-
/O.CON.KPHI.SV.W.0217.000000T0000Z-120908T2215Z/
KENT DE-
547 PM EDT SAT SEP 8 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR KENT COUNTY...

AT 548 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED NEAR
LEIPSIC...OR NEAR DOVER...MOVING EAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  LITTLE CREEK BY 555 PM EDT...
  7 MILES SOUTH OF WOODLAND BEACH BY 600 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.

&&

LAT...LON 3929 7575 3931 7571 3929 7565 3931 7562
      3931 7558 3935 7555 3937 7550 3926 7539
      3907 7539 3900 7532 3895 7530 3895 7539
      3892 7541 3891 7547 3884 7556 3884 7572
TIME...MOT...LOC 2147Z 260DEG 17KT 3922 7552

$$

JJM

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 9:15 PM EDTRip Current StatementPHISussex23 hr
Sep 8, 4:07 PM EDTSpecial Weather StatementPHIKent, New Castle83 min
Sep 8, 6:17 PM EDTSpecial Weather StatementPHISussex58 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2012Every severe thunderstorm warning in 2012

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; radar from the NEXRAD Level II archive.