Alert archive / Maryland / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 19, NWS Philadelphia/Mount Holly

June 13, 2013Cecil County, Kent County, Maryland; New Castle County, Delaware; Chester County, Delaware County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 13, 2013, 8:40 AM EDT for Cecil County, Kent County, Maryland; New Castle County, Delaware; Chester County, Delaware County, Pennsylvania. It was in force for 50 min. 6 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: Jun 13, 2013, 8:40 AM EDT (12:40 UTC)
Expired: Jun 13, 2013, 9:30 AM EDT
In force: 50 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties New Castle County, DE, Cecil County, MD, Kent County, MD, Chester County, PA, Delaware County, PA

The radar

The Dover AFB radar (KDOX), 102 km from the middle of the area, began a volume at 12:40 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

Time	Report	Where	Remark
Jun 13, 8:55 AM EDT	HAIL 0.25	Conowingo, MD
Jun 13, 9:00 AM EDT	TSTM WND DMG	East Marlborough Twp, PA	SEVERAL TREES WERE DOWNED DUE TO STRAIGHT LINE WIND AND BROUGHT POWER LINES DOWN.
Jun 13, 9:20 AM EDT	TSTM WND DMG	Hockessin, DE	SINGLE TREE INTO POWER LINE
Jun 13, 9:22 AM EDT	TSTM WND DMG	Hockessin, DE	NUMEROUS TREES DOWN...BROKEN LIMBS...POWER OUTAGES
Jun 13, 9:32 AM EDT	TSTM WND DMG	Hockessin, DE	SINGLE TREE INTO POWER LINE
Jun 13, 9:40 AM EDT	HAIL 0.25	Conowingo, MD

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.

Issued	Product	Office	Lasted
Jun 13, 7:30 AM EDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 0.7 hours before the alert went out and 33 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: 416 J/kg
Mixed-layer CIN: -188 J/kg
Mixed-layer LCL: 645 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 172 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.0

Open this sounding in Storm Lab

The text

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

168 
WUUS51 KPHI 131240
SVRPHI
DEC003-MDC015-029-PAC029-045-131330-
/O.NEW.KPHI.SV.W.0019.130613T1240Z-130613T1330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
840 AM EDT THU JUN 13 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN DELAWARE COUNTY IN SOUTHEAST PENNSYLVANIA...
  NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  CECIL COUNTY IN NORTHEAST MARYLAND...
  NORTHEASTERN KENT COUNTY IN NORTHEAST MARYLAND...
  CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 930 AM EDT

* AT 836 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS. THESE SEVERE STORMS EXTENDED FROM
  TERRE HILL TO WAKEFIELD TO CARNEY...MOVING EAST AT 60 MPH. THESE
  STORMS ARE CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH. 

* SEVERE THUNDERSTORMS WILL BE NEAR...
  PARKESBURG AND HONEY BROOK AROUND 845 AM EDT...
  OXFORD AND COATESVILLE AROUND 850 AM EDT...
  WEST GROVE AND DOWNINGTOWN AROUND 855 AM EDT...
  LIONVILLE AND KENNETT SQUARE AROUND 900 AM EDT...
  PAOLI AND BETTERTON AROUND 905 AM EDT...
  CHELSEA AND TALLEYVILLE AROUND 910 AM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

VERY HEAVY RAIN WILL ALSO OCCUR WITH THIS LINE OF SEVERE
THUNDERSTORMS...WHICH COULD FLOOD LOW LYING AREAS QUICKLY AND COVER
ROADS WITH WATER. DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE
ROAD.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS
LINE OF SEVERE THUNDERSTORMS. WHEN THUNDER ROARS...MOVE INDOORS!
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 AM EDT
THURSDAY MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW
JERSEY AND SOUTHEASTERN PENNSYLVANIA.

&&

LAT...LON 3973 7614 3979 7605 4003 7594 4011 7595
      4015 7585 4006 7535 3971 7548 3971 7551
      3962 7560 3959 7559 3964 7556 3951 7555
      3930 7563 3933 7618 3943 7601 3952 7599
      3955 7608 3957 7608 3972 7623
TIME...MOT...LOC 1239Z 263DEG 55KT 4020 7597 3978 7614
          3944 7663

$$

FORECASTER: GORSE

1 follow-up statement

197 
WWUS51 KPHI 131308
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
908 AM EDT THU JUN 13 2013

DEC003-MDC015-029-PAC029-045-131330-
/O.CON.KPHI.SV.W.0019.000000T0000Z-130613T1330Z/
DELAWARE PA-NEW CASTLE DE-CECIL MD-KENT MD-CHESTER PA-
908 AM EDT THU JUN 13 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 AM EDT
FOR CHESTER...NORTHEASTERN KENT...CECIL...NEW CASTLE AND WESTERN
DELAWARE COUNTIES...

AT 903 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING ONE INCH
DIAMETER HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS
WERE LOCATED ALONG A LINE EXTENDING FROM LIONVILLE TO CHERRY HILL TO
14 MILES WEST OF BETTERTON...MOVING EAST AT 60 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
TALLEYVILLE AND NEWPORT AROUND 915 AM EDT...
WILMINGTON MANOR AND NEW CASTLE AROUND 920 AM EDT...
DELAWARE CITY AND GALENA AROUND 925 AM EDT...
SASSAFRAS AND PORT PENN AROUND 930 AM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 AM EDT
THURSDAY MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND NEW
JERSEY AND SOUTHEASTERN PENNSYLVANIA.

&&

LAT...LON 3973 7614 3979 7605 4003 7594 4011 7595
      4015 7585 4006 7535 3971 7548 3971 7551
      3962 7560 3959 7559 3964 7556 3951 7555
      3930 7563 3933 7618 3943 7601 3952 7599
      3955 7608 3957 7608 3972 7623
TIME...MOT...LOC 1308Z 263DEG 50KT 4008 7554 3968 7575
          3935 7624

$$

FORECASTER: GORSE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 13, 8:10 AM EDT	Special Weather Statement	PHI	Cecil, Kent	50 min
Jun 13, 9:18 AM EDT	Severe Thunderstorm Warning	PHI	Cecil	57 min
Jun 13, 9:29 AM EDT	Severe Thunderstorm Warning	PHI	Cecil, Kent, Queen Anne's	31 min
Jun 13, 9:39 AM EDT	Special Weather Statement	PHI	Caroline, Queen Anne's	51 min
Jun 13, 9:55 AM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	35 min
Jun 13, 10:24 AM EDT	Special Weather Statement	PHI	Caroline	81 min
Jun 13, 4:37 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	68 min
Jun 13, 5:04 PM EDT	Areal Flood Advisory	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	4 hr
Jun 13, 1:49 AM EDT	Special Weather Statement	PHI	Sussex	41 min
Jun 13, 4:25 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	65 min
Jun 13, 4:51 PM EDT	Special Weather Statement	PHI	Kent	54 min
Jun 13, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Kent	63 min
Jun 13, 5:19 PM EDT	Special Weather Statement	PHI	New Castle	56 min
Jun 13, 5:51 AM EDT	Special Weather Statement	PHI	Bucks, Montgomery	69 min
Jun 13, 7:01 AM EDT	Special Weather Statement	PHI	Berks	119 min
Jun 13, 7:29 AM EDT	Special Weather Statement	PHI	Berks	61 min
Jun 13, 9:47 AM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Montgomery, Northampton, Philadelphia	58 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2013 Severe Thunderstorm Warnings in Pennsylvania, 2013 Severe Thunderstorm Warnings in Delaware, 2013 Every 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.