Alert archive / New Jersey / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 1, NWS Philadelphia/Mount Holly

February 12, 20174 states

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Feb 12, 2017, 11:10 PM EST for 4 states. It was in force for 50 min. 3 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
Feb 12, 2017, 11:10 PM EST (04:10 UTC)
Expired
Feb 13, 2017, 12:00 AM EST
In force
50 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties New Castle County, DE, Cecil County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Dover AFB radar (KDOX), 80 km from the middle of the area, began a volume at 04:11 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.

What was reported inside it

TimeReportWhereRemark
Feb 12, 11:20 PM ESTTSTM WND DMGFairview, PA3 LARGE TREES SNAPPED OR UPROOTED
Feb 12, 11:30 PM ESTTSTM WND GST 56Morris, NJ
Feb 12, 11:40 PM ESTTSTM WND GST 57Morris, NJ

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 4.2 hours before the alert went out and 180 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 00:00Z on 2017-02-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 44 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 00:00Z on 2017-02-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 119 square meters per square second.1939587897117Sfc1 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
44 J/kg
Mixed-layer CIN
-160 J/kg
Mixed-layer LCL
1215 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
119 m²/s²
0-3 km storm-relative helicity
173 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

The text

As transmitted.

363 
WUUS51 KPHI 130410
SVRPHI
DEC003-MDC015-NJC001-005-007-011-015-025-029-033-PAC017-029-045-091-
101-130500-
/O.NEW.KPHI.SV.W.0001.170213T0410Z-170213T0500Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1110 PM EST SUN FEB 12 2017

The National Weather Service in Mount Holly NJ  has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  Cecil County in northeastern Maryland...
  Ocean County in southern New Jersey...
  Camden County in southern New Jersey...
  Atlantic County in southern New Jersey...
  Cumberland County in southern New Jersey...
  Salem County in southern New Jersey...
  Gloucester County in southern New Jersey...
  Burlington County in southern New Jersey...
  Southwestern Monmouth County in central New Jersey...
  Southern Montgomery County in southeastern Pennsylvania...
  Southeastern Bucks County in southeastern Pennsylvania...
  Chester County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until midnight EST

* At 1108 PM EST, severe thunderstorms were located along a line
  extending from near Plymouth Meeting to near Bel Air North, moving
  east at 60 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Locations impacted include...
  Philadelphia, Toms River, Camden, Wilmington, Vineland, Newark,
  Millville, Bridgeton, Middletown, West Chester, Elkton, Gloucester
  City, Cumberland, Lakewood, Calvert, Bensalem, Jackson, Evesham,
  Mount Laurel and Norristown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3983 7408 3949 7451 3922 7502 3931 7538
      3939 7548 3929 7540 3929 7546 3931 7543
      3936 7551 3929 7568 3930 7576 3938 7578
      3938 7605 3952 7598 3955 7608 3972 7623
      3976 7606 3995 7600 4024 7571 4006 7403
TIME...MOT...LOC 0408Z 281DEG 68KT 4010 7524 3960 7633 

HAIL...<.75IN
WIND...60MPH
 
$$

JRK
2 follow-up statements
496 
WWUS51 KPHI 130438
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1138 PM EST SUN FEB 12 2017

NJC025-PAC017-029-130445-
/O.CAN.KPHI.SV.W.0001.000000T0000Z-170213T0500Z/
Monmouth NJ-Bucks PA-Chester PA-
1138 PM EST SUN FEB 12 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MONMOUTH...
SOUTHEASTERN BUCKS AND CHESTER COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of
the warned area. Therefore the warning has been cancelled.

LAT...LON 3952 7446 3922 7502 3931 7537 3939 7548
      3929 7540 3936 7551 3929 7568 3930 7576
      3938 7578 3938 7605 3943 7600 3953 7599
      4009 7528 4006 7501 3985 7407
TIME...MOT...LOC 0435Z 290DEG 59KT 3995 7500 3956 7534 3941 7579 

$$

DEC003-MDC015-NJC001-005-007-011-015-029-033-PAC045-091-101-130500-
/O.CON.KPHI.SV.W.0001.000000T0000Z-170213T0500Z/
New Castle DE-Cecil MD-Atlantic NJ-Cumberland NJ-Salem NJ-Ocean NJ-
Camden NJ-Gloucester NJ-Burlington NJ-Montgomery PA-Philadelphia PA-
Delaware PA-
1138 PM EST SUN FEB 12 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL MIDNIGHT EST
FOR NEW CASTLE...SOUTHEASTERN CECIL...ATLANTIC...CUMBERLAND...
SALEM...CENTRAL OCEAN...CAMDEN...GLOUCESTER...BURLINGTON...
SOUTHEASTERN MONTGOMERY...PHILADELPHIA AND DELAWARE COUNTIES...

At 1135 PM EST, severe thunderstorms were located along a line
extending from Cherry Hill Mall to Alloway to Warwick, moving east at
70 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. This line has also had a history of 
         producing wind damage and gusts near 60 mph across southern 
         Pennsylvania, central Maryland and northern Virginia. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Philadelphia, Camden, Wilmington, Vineland, Newark, Millville,
Bridgeton, Middletown, Elkton, Gloucester City, Cumberland, Cherry
Hill, Evesham, Mount Laurel, Chester, Willingboro, Deptford,
Voorhees, Medford and West Deptford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3952 7446 3922 7502 3931 7537 3939 7548
      3929 7540 3936 7551 3929 7568 3930 7576
      3938 7578 3938 7605 3943 7600 3953 7599
      4009 7528 4006 7501 3985 7407
TIME...MOT...LOC 0435Z 290DEG 59KT 3995 7500 3956 7534 3941 7579 

HAIL...<.75IN
WIND...60MPH
 
$$

JRK
101 
WWUS51 KPHI 130459
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1159 PM EST SUN FEB 12 2017

DEC003-MDC015-NJC001-005-007-011-015-029-033-PAC045-091-101-130507-
/O.EXP.KPHI.SV.W.0001.000000T0000Z-170213T0500Z/
New Castle DE-Cecil MD-Atlantic NJ-Cumberland NJ-Salem NJ-Ocean NJ-
Camden NJ-Gloucester NJ-Burlington NJ-Montgomery PA-Philadelphia PA-
Delaware PA-
1159 PM EST SUN FEB 12 2017

...THE SEVERE THUNDERSTORM WARNING FOR NEW CASTLE...SOUTHEASTERN
CECIL...ATLANTIC...CUMBERLAND...SALEM...CENTRAL OCEAN...CAMDEN...
GLOUCESTER...BURLINGTON...SOUTHEASTERN MONTGOMERY...PHILADELPHIA AND
DELAWARE COUNTIES WILL EXPIRE AT MIDNIGHT EST...
    
The storms which prompted the warning have moved out of the 
Philadelphia area. Therefore the warning will be allowed to expire.

Remember, a Severe Thunderstorm Warning still remains in effect for 
portions of southern New Jersey until 1245 AM. 

LAT...LON 3952 7446 3922 7502 3931 7537 3939 7548
      3929 7540 3936 7551 3929 7568 3930 7576
      3938 7578 3938 7605 3943 7600 3953 7599
      4009 7528 4006 7501 3985 7407
TIME...MOT...LOC 0457Z 281DEG 68KT 3988 7453 3949 7487 3934 7532 

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 12, 10:20 PM ESTSpecial Weather StatementPHIBerks, Lehigh, Montgomery70 min
Feb 13, 1:25 AM ESTSpecial Weather StatementPHIMonroe50 min
Feb 12, 11:33 PM ESTSpecial Marine WarningPHI87 min
Feb 12, 11:53 PM ESTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more52 min
Feb 13, 12:02 AM ESTSpecial Marine WarningPHI88 min
Feb 13, 12:29 PM ESTGale WarningPHI9 hr
Feb 12, 11:14 PM ESTSevere Thunderstorm WarningPHIKent46 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2017Severe Thunderstorm Warnings in Pennsylvania, 2017Severe Thunderstorm Warnings in Delaware, 2017Every severe thunderstorm warning in 2017

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.