Alert archive / Maryland / Tornado Warnings in 2013

Tornado Warning 4, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 13, 2013, 6:32 AM EDT for Cecil County, Maryland; New Castle County, Delaware; Chester County, Pennsylvania. It was in force for 43 min. 4 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
Aug 13, 2013, 6:32 AM EDT (10:32 UTC)
Expired
Aug 13, 2013, 7:15 AM EDT
In force
43 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 97 km from the middle of the area, began a volume at 10:36 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
Aug 13, 6:50 AM EDTTSTM WND DMGElkton, MD20 TO 30 TREES DOWN 600 BLOCK KNOTTINGHAM ROAD
Aug 13, 6:55 AM EDTTSTM WND GST 60Newark, DE
Aug 13, 6:56 AM EDTTSTM WND DMGBear, DETREES DOWN
Aug 13, 6:56 AM EDTTSTM WND DMGNewark, DETREES 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, 10.5 hours before the alert went out and 141 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 2013-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 00:00Z on 2013-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
1 J/kg
Mixed-layer CIN
-66 J/kg
Mixed-layer LCL
1841 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
84 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.

981 
WFUS51 KPHI 131032
TORPHI
DEC003-MDC015-PAC029-131115-
/O.NEW.KPHI.TO.W.0004.130813T1032Z-130813T1115Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
632 AM EDT TUE AUG 13 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  WEST CENTRAL NEW CASTLE COUNTY IN NORTHERN DELAWARE...
  NORTHERN CECIL COUNTY IN NORTHEAST MARYLAND...
  SOUTH CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 715 AM EDT

* AT 630 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THE STORM
  CONTAINING THE POSSIBLE TORNADO WAS NEAR CHARLESTOWN...MOVING EAST
  AT 20 MPH.

* THE TORNADO WILL BE NEAR...
  HOLLYWOOD BEACH AROUND 640 AM EDT...
  NORTH EAST AND ZION AROUND 645 AM EDT...
  BLAKE AROUND 655 AM EDT...
  ELKTON AND CHERRY HILL AROUND 700 AM EDT...
  BARKSDALE AND APPLETON AROUND 705 AM EDT...
  GLASGOW AND NEWARK AROUND 710 AM EDT...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

TAKE COVER INSIDE NOW. DO NOT WAIT TO SEE OR HEAR THE TORNADO. MOVE
TO AN INTERIOR ROOM ON THE LOWEST LEVEL OF A STURDY BUILDING. PUT AS
MANY WALLS BETWEEN YOU AND THE OUTSIDE AS YOU CAN. AVOID WINDOWS.
PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3979 7575 3955 7557 3947 7600 3952 7599
      3955 7603 3954 7607 3956 7610 3957 7610
      3957 7609 3956 7608 3957 7608 3963 7615
TIME...MOT...LOC 1032Z 252DEG 19KT 3957 7601

$$

KLINE
1 follow-up statement
211 
WWUS51 KPHI 131100
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
700 AM EDT TUE AUG 13 2013

MDC015-PAC029-131110-
/O.CAN.KPHI.TO.W.0004.000000T0000Z-130813T1115Z/
CECIL MD-CHESTER PA-
700 AM EDT TUE AUG 13 2013

...THE TORNADO WARNING FOR SOUTH CENTRAL CHESTER AND CECIL COUNTIES
IS CANCELLED...

THE STORM THAT PROMPTED THE TORNADO WARNING HAS MOVED OUT OF THE
AREA...THEREFORE THE TORNADO WARNING HAS BEEN CANCELLED.

LAT...LON 3973 7577 3976 7575 3977 7574 3977 7573
      3955 7557 3958 7577 3968 7579 3972 7579
TIME...MOT...LOC 1100Z 256DEG 32KT 3965 7570

$$

DEC003-131115-
/O.CON.KPHI.TO.W.0004.000000T0000Z-130813T1115Z/
NEW CASTLE DE-
700 AM EDT TUE AUG 13 2013

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 715 AM EDT FOR WEST
CENTRAL NEW CASTLE COUNTY...

AT 659 AM EDT...WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE A
SEVERE THUNDERSTORM WITH STRONG ROTATION THAT MAY BE PRODUCING A
TORNADO. THIS STORM THAT MAY BE PRODUCING A TORNADO WAS LOCATED NEAR
BROOKSIDE...OR NEAR NEWARK...MOVING EAST AT 35 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
DELAWARE CITY...GLASGOW AND BEAR

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING DAMAGING WINDS AND LARGE HAIL.
SEEK SHELTER NOW INSIDE A STURDY STRUCTURE...AND STAY AWAY FROM
WINDOWS.

&&

LAT...LON 3973 7577 3976 7575 3977 7574 3977 7573
      3955 7557 3958 7577 3968 7579 3972 7579
TIME...MOT...LOC 1100Z 256DEG 32KT 3965 7570

$$

FORECASTER:  DRAG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 2:45 AM EDTFlash Flood WatchPHICecil9 hr
Aug 13, 5:54 AM EDTAreal Flood AdvisoryPHICecil7 hr
Aug 13, 6:23 AM EDTSevere Thunderstorm WarningPHICecil67 min
Aug 13, 12:47 PM EDTAreal Flood AdvisoryPHICecil3 hr
Aug 13, 4:55 PM EDTSpecial Weather StatementPHICecil65 min
Aug 13, 6:51 AM EDTAreal Flood AdvisoryPHINew Castle7 hr
Aug 13, 7:05 AM EDTSevere Thunderstorm WarningPHINew Castle40 min
Aug 13, 7:31 AM EDTSpecial Weather StatementPHINew Castle44 min
Aug 13, 7:54 AM EDTFlash Flood WarningPHINew Castle8 hr
Aug 13, 7:57 AM EDTSevere Thunderstorm WarningPHINew Castle48 min
Aug 13, 8:37 AM EDTRiver Flood WarningPHINew Castle4 hr
Aug 13, 11:19 AM EDTSpecial Weather StatementPHIKent56 min
Aug 13, 1:50 PM EDTRiver Flood WarningPHINew Castle119 min
Aug 13, 2:18 PM EDTAreal Flood WarningPHINew Castle9 hr
Aug 13, 5:15 AM EDTAreal Flood AdvisoryPHIBerks, Chester, Montgomery4 hr
Aug 13, 5:47 AM EDTFlash Flood WarningPHIChester4 hr
Aug 13, 6:07 AM EDTAreal Flood AdvisoryPHIBucks, Lehigh, Northampton7 hr
Aug 13, 6:07 AM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia53 min
Aug 13, 6:20 AM EDTAreal Flood AdvisoryPHIBucks, Delaware, Philadelphia4 hr
Aug 13, 6:36 AM EDTFlash Flood WarningPHIChester, Delaware, Montgomery8 hr
Aug 13, 7:14 AM EDTFlash Flood WarningPHIBerks4 hr
Aug 13, 7:42 AM EDTSpecial Weather StatementPHIPhiladelphia48 min
Aug 13, 7:54 AM EDTSpecial Weather StatementPHIDelaware, Philadelphia66 min
Aug 13, 8:07 AM EDTRiver Flood WarningPHIChester9 hr
Aug 13, 8:20 AM EDTFlash Flood WarningPHIBucks8 hr
Aug 13, 9:50 AM EDTFlash Flood WarningPHIChester4 hr
Aug 13, 11:22 AM EDTRiver Flood WarningPHIChester, Delaware16 hr

Nearby

Tornado Warnings in Maryland, 2013Tornado Warnings in Delaware, 2013Tornado Warnings in Pennsylvania, 2013Every tornado warning in 2013Tornadoes 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.