Alert archive / Maryland / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 78, NWS Philadelphia/Mount Holly

July 20, 2013Cecil County, Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 20, 2013, 10:17 PM EDT for Cecil County, Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware. It was in force for 58 min. 1 report 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
Jul 20, 2013, 10:17 PM EDT (02:17 UTC)
Expired
Jul 20, 2013, 11:15 PM EDT
In force
58 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Kent County, DE, New Castle County, DE, Cecil County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 74 km from the middle of the area, began a volume at 02:20 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
Jul 20, 10:22 PM EDTTSTM WND DMGStill Pond, MDTREES DOWN

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.3 hours before the alert went out and 127 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 00:00Z on 2013-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2416 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2013-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.193958Sfc1 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
2416 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
1423 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
76 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.

849 
WUUS51 KPHI 210217
SVRPHI
DEC001-003-MDC015-029-035-210315-
/O.NEW.KPHI.SV.W.0078.130721T0217Z-130721T0315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1017 PM EDT SAT JUL 20 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  SOUTHEASTERN CECIL COUNTY IN NORTHEAST MARYLAND...
  NORTHERN KENT COUNTY IN NORTHEAST MARYLAND...
  NORTHWESTERN KENT COUNTY IN CENTRAL DELAWARE...
  NORTHEASTERN QUEEN ANNE'S COUNTY IN NORTHEAST MARYLAND...

* UNTIL 1115 PM EDT

* AT 1012 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM. THE STORM WAS NEAR NEWTOWN...MOVING EAST AT 25
  MPH. THIS STORM IS CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL...
  AND DAMAGING WINDS IN EXCESS OF 60 MPH. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  KENNEDYVILLE AND MORGNEC AROUND 1025 PM EDT...
  CRUMPTON AROUND 1035 PM EDT...
  CECILTON AROUND 1040 PM EDT...
  MASSEY AND MILLINGTON AROUND 1045 PM EDT...
  SASSAFRAS AROUND 1050 PM EDT...
  DELANEY CORNER AROUND 1055 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE WINDS OF MORE THAN 57 MPH...OR HAIL ONE
INCH OR LARGER.

&&

LAT...LON 3934 7617 3934 7615 3938 7611 3938 7606
      3939 7605 3943 7557 3915 7558 3920 7618
TIME...MOT...LOC 0216Z 270DEG 23KT 3929 7608

$$

FORECASTER: HEAVENER
1 follow-up statement
570 
WWUS51 KPHI 210307
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1107 PM EDT SAT JUL 20 2013

DEC001-003-MDC015-029-035-210317-
/O.EXP.KPHI.SV.W.0078.000000T0000Z-130721T0315Z/
NEW CASTLE DE-CECIL MD-KENT MD-KENT DE-QUEEN ANNE'S MD-
1107 PM EDT SAT JUL 20 2013

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN QUEEN ANNE'S...
NORTHWESTERN KENT...NORTHERN KENT...SOUTHEASTERN CECIL AND
SOUTHWESTERN NEW CASTLE COUNTIES WILL EXPIRE AT 1115 PM EDT...

THE SEVERE THUNDERSTORM WARNING WILL BE ALLOWED TO EXPIRE.

LAT...LON 3934 7617 3934 7615 3938 7611 3938 7606
      3939 7605 3943 7557 3915 7558 3920 7618
TIME...MOT...LOC 0307Z 270DEG 23KT 3929 7566

$$

FORECASTER: HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 8:56 PM EDTSpecial Weather StatementPHICecil64 min
Jul 20, 9:44 PM EDTSpecial Weather StatementPHIKent61 min
Jul 20, 10:55 PM EDTAreal Flood AdvisoryPHICecil, Kent3 hr
Jul 20, 11:25 PM EDTSpecial Weather StatementPHIKent65 min
Jul 21, 3:44 PM EDTSpecial Weather StatementPHICecil2 hr
Jul 21, 4:35 PM EDTSpecial Weather StatementPHIKent, Queen Anne's85 min
Jul 21, 4:36 PM EDTSpecial Weather StatementPHIKent, Queen Anne's84 min
Jul 21, 3:17 PM EDTSpecial Weather StatementPHISussex58 min
Jul 21, 4:25 PM EDTSpecial Weather StatementPHISussex95 min
Jul 21, 4:50 PM EDTFlash Flood WarningPHISussex4 hr
Jul 21, 4:58 PM EDTAreal Flood AdvisoryPHIKent3 hr
Jul 21, 5:45 PM EDTSpecial Weather StatementPHISussex60 min
Jul 21, 6:28 PM EDTAreal Flood AdvisoryPHIKent, Sussex3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.