Alert archive / New Jersey / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 189, NWS Philadelphia/Mount Holly

August 22, 20174 states

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 22, 2017, 10:58 PM EDT for 4 states. It was in force for 62 min. 11 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 22, 2017, 10:58 PM EDT (02:58 UTC)
Expired: Aug 23, 2017, 12:00 AM EDT
In force: 62 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 1.0 in
Wind: 60.0 mph

Counties Kent County, DE, New Castle County, DE, Cecil County, MD, Kent County, MD, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Middlesex County, NJ, Salem County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 02:59 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
Aug 22, 11:00 PM EDT	TSTM WND DMG	Haverford Twp, PA	LARGE TREE BRANCH REPORTED DOWN ON A FENCE IN HAVERFORD TOWNSHIP. TIME ESTIMATED FROM RADAR.
Aug 22, 11:05 PM EDT	TSTM WND DMG	1 Nne Highland Park, PA	LARGE TREE BRANCH REPORTED DOWN AND BLOCKING THE STREET. TIME ESTIMATED FROM RADAR. PUBLIC REPORT RELAYED BY OEM.
Aug 22, 11:05 PM EDT	TSTM WND DMG	Sw Philadelphia, PA	SOME TREES BLOWN DOWN ACROSS PORTIONS OF SOUTHWEST PHILADELPHIA. TIME ESTIMATED FROM RADAR.
Aug 22, 11:06 PM EDT	TSTM WND DMG	Rittenhouse, PA	TREE REPORTED DOWN AND BLOCKING THE INTERSECTION OF LOMBARD STREET AND 17TH STREET. TIME ESTIMATED FROM RADAR. PUBLIC REPORT RELAYED BY OEM.
Aug 22, 11:08 PM EDT	TSTM WND DMG	Wynnefield Heights, PA	LARGE TREE BRANCH REPORTED DOWN AND BLOCKING THE SIDEWALK. TIME ESTIMATED FROM RADAR. PUBLIC REPORT RELAYED BY OEM.
Aug 22, 11:10 PM EDT	TSTM WND DMG	Wilmington, DE	SEVERAL LARGE BRANCHES BLOWN DOWN.
Aug 22, 11:14 PM EDT	TSTM WND DMG	Somerville, PA	LARGE BRANCH REPORTED DOWN AND BLOCKING THE ENTRANCE TO A SCHOOL. TIME ESTIMATED FROM RADAR. PUBLIC REPORT RELAYED BY OEM.
Aug 22, 11:16 PM EDT	TSTM WND DMG	Fern Rock, PA	TREE REPORTED DOWN AND BLOCKING THE STREET. TIME ESTIMATED FROM RADAR. PUBLIC REPORT RELAYED BY OEM.
Aug 22, 11:24 PM EDT	TSTM WND DMG	1 W Tioga Park, PA	TREE REPORTED DOWN AND BLOCKING KEIM STREET. TIME ESTIMATED FROM RADAR. PUBLIC REPORT RELAYED BY OEM.
Aug 22, 11:48 PM EDT	TSTM WND GST 47	Philadelphia Intl Airpo, PA
Aug 22, 11:56 PM EDT	TSTM WND DMG	Overbrook, PA	TREE DOWN ACROSS CITY AVENUE IN LOWER MERION. TIME AND LOCATION ESTIMATED.

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
Aug 22, 4:19 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 3.0 hours before the alert went out and 207 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: 1036 J/kg
Mixed-layer CIN: -68 J/kg
Mixed-layer LCL: 890 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 104 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 4.0

Open this sounding in Storm Lab

The text

As transmitted.

540 
WUUS51 KPHI 230258
SVRPHI
DEC001-003-MDC015-029-NJC005-007-011-015-021-023-033-PAC017-029-045-
091-101-230400-
/O.NEW.KPHI.SV.W.0189.170823T0258Z-170823T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1058 PM EDT TUE AUG 22 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  North central Kent County in central Delaware...
  Northeastern Kent County in northeastern Maryland...
  Southeastern Cecil County in northeastern Maryland...
  Camden County in southern New Jersey...
  Southern Mercer County in central New Jersey...
  Northwestern Cumberland County in southern New Jersey...
  Salem County in southern New Jersey...
  Gloucester County in southern New Jersey...
  Northwestern Burlington County in southern New Jersey...
  Southern Middlesex County in northern New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Southern Bucks County in southeastern Pennsylvania...
  Southeastern Chester County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until midnight EDT

* At 1058 PM EDT, severe thunderstorms were located along a line
  extending from Pipersville to Hollywood Beach, moving east at 40
  mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Minor damage to vehicles is possible. Expect damage to 
           trees and power lines. 

* Locations impacted include...
  Philadelphia, Trenton, Camden, Wilmington, Vineland, Newark,
  Millville, Bridgeton, Middletown, West Chester, Elkton, Gloucester
  City, Cherry Hill, Bensalem, Evesham, Mount Laurel, Ewing,
  Norristown, Chester and Willingboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4033 7531 4027 7442 4018 7461 4009 7456
      3927 7520 3930 7536 3939 7548 3931 7541
      3937 7606
TIME...MOT...LOC 0258Z 269DEG 33KT 4042 7511 3950 7594 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

MWG

1 follow-up statement

408 
WWUS51 KPHI 230316
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1116 PM EDT TUE AUG 22 2017

PAC029-230325-
/O.CAN.KPHI.SV.W.0189.000000T0000Z-170823T0400Z/
Chester PA-
1116 PM EDT TUE AUG 22 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CHESTER COUNTY IS
CANCELLED...

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

A severe thunderstorm watch remains in effect until midnight EDT for
northern Delaware...northeastern Maryland...southern, central and
northern New Jersey...and southeastern Pennsylvania.

LAT...LON 4018 7461 4009 7456 3927 7520 3930 7536
      3939 7548 3939 7549 3931 7541 3934 7576
      3938 7578 3936 7589 3937 7595 3986 7549
      4032 7521 4027 7442
TIME...MOT...LOC 0315Z 267DEG 38KT 4024 7495 3976 7526 3950 7574 

$$

DEC001-003-MDC015-029-NJC005-007-011-015-021-023-033-PAC017-045-091-
101-230400-
/O.CON.KPHI.SV.W.0189.000000T0000Z-170823T0400Z/
New Castle DE-Kent DE-Kent MD-Cecil MD-Camden NJ-Mercer NJ-
Cumberland NJ-Salem NJ-Gloucester NJ-Burlington NJ-Middlesex NJ-
Montgomery PA-Bucks PA-Philadelphia PA-Delaware PA-
1116 PM EDT TUE AUG 22 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL MIDNIGHT EDT
FOR NEW CASTLE...NORTH CENTRAL KENT...NORTHEASTERN KENT...
SOUTHEASTERN CECIL...CAMDEN...SOUTHERN MERCER...NORTHWESTERN
CUMBERLAND...SALEM...GLOUCESTER...NORTHWESTERN BURLINGTON...SOUTHERN
MIDDLESEX...SOUTHEASTERN MONTGOMERY...SOUTHEASTERN BUCKS...
PHILADELPHIA AND DELAWARE COUNTIES...

At 1115 PM EDT, severe thunderstorms were located along a line
extending from Newtown to near Mullica Hill to near Mount Pleasant, 
moving east at 45 mph. A trained weather spotter reported several 
large tree branches in Wilmington as these storms passed.

HAZARD...60 mph wind gusts and nickel size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Expect damage to trees and power lines. 

Locations impacted include...
Philadelphia, Trenton, Camden, Wilmington, Vineland, Millville,
Bridgeton, Middletown, Gloucester City, Cherry Hill, Bensalem,
Evesham, Mount Laurel, Ewing, Norristown, Chester, Willingboro,
Deptford, Voorhees and Medford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4018 7461 4009 7456 3927 7520 3930 7536
      3939 7548 3939 7549 3931 7541 3934 7576
      3938 7578 3936 7589 3937 7595 3986 7549
      4032 7521 4027 7442
TIME...MOT...LOC 0315Z 267DEG 38KT 4024 7495 3976 7526 3950 7574 

TORNADO...POSSIBLE
HAIL...0.88IN
WIND...60MPH
 
$$

CMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 8:12 PM EDT	Severe Thunderstorm Warning	PHI	Sussex, Warren	48 min
Aug 22, 8:15 PM EDT	Tornado Warning	PHI	Warren	30 min
Aug 22, 8:20 PM EDT	Special Weather Statement	PHI	Sussex	40 min
Aug 22, 8:45 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Somerset, Warren	60 min
Aug 22, 8:58 PM EDT	Severe Thunderstorm Warning	PHI	Sussex, Warren	24 min
Aug 22, 9:42 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset, Warren	48 min
Aug 22, 10:07 PM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	53 min
Aug 22, 10:13 PM EDT	Special Marine Warning	PHI		92 min
Aug 22, 10:27 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	48 min
Aug 22, 10:37 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	4 hr
Aug 22, 10:40 PM EDT	Areal Flood Advisory	PHI	Mercer	4 hr
Aug 22, 11:39 PM EDT	Special Marine Warning	PHI		66 min
Aug 22, 11:42 PM EDT	Flash Flood Warning	PHI	Hunterdon, Middlesex, Somerset	4 hr
Aug 22, 11:46 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester, Ocean, Salem	44 min
Aug 23, 12:06 AM EDT	Flash Flood Warning	PHI	Camden, Gloucester	4 hr
Aug 23, 12:29 AM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Ocean	46 min
Aug 23, 12:37 AM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 1 more	4 hr
Aug 23, 1:56 AM EDT	Areal Flood Advisory	PHI	Salem	4 hr
Aug 23, 2:43 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Ocean and 1 more	4 hr
Aug 23, 3:37 AM EDT	Areal Flood Warning	PHI	Hunterdon, Middlesex, Somerset	4 hr
Aug 23, 4:02 AM EDT	Areal Flood Warning	PHI	Camden, Gloucester	4 hr
Aug 22, 9:18 PM EDT	Areal Flood Advisory	PHI	Berks, Montgomery	4 hr
Aug 22, 9:23 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	52 min
Aug 22, 9:40 PM EDT	Tornado Warning	PHI	Berks, Chester, Montgomery	20 min
Aug 22, 11:30 PM EDT	Special Weather Statement	PHI	Cecil	30 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2017 Severe Thunderstorm Warnings in Pennsylvania, 2017 Severe Thunderstorm Warnings in Delaware, 2017 Every 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.