Alert archive / New Jersey / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 21, NWS Philadelphia/Mount Holly

May 15, 20185 counties in New Jersey; 5 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 15, 2018, 5:53 PM EDT for 5 counties in New Jersey; 5 counties in Pennsylvania. It was in force for 52 min. 9 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: May 15, 2018, 5:53 PM EDT (21:53 UTC)
Expired: May 15, 2018, 6:45 PM EDT
In force: 52 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Burlington County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 38 km from the middle of the area, began a volume at 21:55 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
May 15, 5:54 PM EDT	TSTM WND DMG	Plymouth Valley, PA	LARGE TREE DOWN, DAMAGING A RESIDENTIAL PROPERTY, ON MILL CREEK ROAD. TIME ESTIMATED BY RADAR.
May 15, 5:55 PM EDT	TSTM WND DMG	Plymouth Meadows, PA	SEVERAL TREES DOWN ON MALVERN ROAD.
May 15, 5:55 PM EDT	TSTM WND DMG	Plymouth Twp, PA	ROOF MATERIAL COMPLETELY BLOWN OFF A HOME. TIME ESTIMATED FROM RADAR.
May 15, 5:57 PM EDT	TSTM WND DMG	Scudders Falls, NJ	DOWNED TREE ON STATE HIGHWAY 29 NEAR UPPER FERRY ROAD. LANE CLOSURES IN PLACE.
May 15, 6:01 PM EDT	TSTM WND DMG	Abington Twp, PA	DOWNED TREE CLOSED SUSQUEHANNA ROAD BETWEEN VALLEY ROAD AND RYDAL ROAD. TIME APPROXIMATED FROM RADAR.
May 15, 6:04 PM EDT	TSTM WND DMG	Somerville, PA	TREES DOWN ON OGONTZ AVENUE AND 66TH STREET.
May 15, 6:10 PM EDT	TSTM WND DMG	Fox Chase, PA	TREE DOWN ON WIRES, FORCING CLOSURE OF A ROAD. TIME ESTIMATED FROM RADAR.
May 15, 6:17 PM EDT	HAIL 1	Freehold, NJ	HAIL UP TO QUARTER SIZE.
May 15, 6:23 PM EDT	TSTM WND DMG	Tacony, PA	LARGE TREE DOWNED WITH MINOR DAMAGE TO A VEHICLE AND SEVERE DAMAGE TO A PORCH. TIME ESTIMATED FROM RADAR.

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
May 15, 1:46 PM EDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.9 hours before the alert went out and 184 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 909 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 153 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

940 
WUUS51 KPHI 152153
SVRPHI
NJC005-021-023-025-029-PAC017-029-045-091-101-152245-
/O.NEW.KPHI.SV.W.0021.180515T2153Z-180515T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
553 PM EDT TUE MAY 15 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Ocean County in southern New Jersey...
  Mercer County in central New Jersey...
  Northern Burlington County in southern New Jersey...
  Southwestern Middlesex County in northern New Jersey...
  Southern Monmouth County in central New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Southeastern Bucks County in southeastern Pennsylvania...
  East central Chester County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Northern Delaware County in southeastern Pennsylvania...

* Until 645 PM EDT.

* At 552 PM EDT, a severe thunderstorm was located over Bryn Athyn,
  or 10 miles northeast of Philadelphia, moving east at 60 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Philadelphia, Trenton, Lakewood, Bensalem, Howell, Manalapan,
  Ewing, Norristown, Willingboro, Tinton Falls, Phoenixville, West
  Norriton, East Norriton, Lumberton, Princeton, Florence,
  Burlington, Bristol, Mount Holly and Riverside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3995 7482 4000 7504 3998 7507 4007 7571
      4024 7519 4040 7457 4019 7400 4017 7400
TIME...MOT...LOC 2152Z 277DEG 75KT 4014 7505 

HAIL...0.75IN
WIND...60MPH
 
$$

po

1 follow-up statement

709 
WWUS51 KPHI 152232
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
632 PM EDT TUE MAY 15 2018

NJC023-PAC029-045-152238-
/O.CAN.KPHI.SV.W.0021.000000T0000Z-180515T2245Z/
Middlesex NJ-Chester PA-Delaware PA-
632 PM EDT TUE MAY 15 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MIDDLESEX...EAST
CENTRAL CHESTER AND NORTHERN DELAWARE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning have weakened.
Therefore, the warning has been cancelled. Other thunderstorms 
continue south and east of this area however. 

A severe thunderstorm watch remains in effect until 1100 PM EDT for
southern, central and northern New Jersey...and southeastern
Pennsylvania.

LAT...LON 4017 7400 3995 7482 4000 7504 3998 7507
      4002 7532 4004 7534 4009 7499 4026 7449
      4025 7446 4031 7432 4019 7400
TIME...MOT...LOC 2228Z 282DEG 35KT 4006 7447 

$$

NJC005-021-025-029-PAC017-091-101-152245-
/O.CON.KPHI.SV.W.0021.000000T0000Z-180515T2245Z/
Ocean NJ-Mercer NJ-Burlington NJ-Monmouth NJ-Montgomery PA-Bucks PA-
Philadelphia PA-
632 PM EDT TUE MAY 15 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR NORTHWESTERN OCEAN...SOUTHEASTERN MERCER...NORTHERN BURLINGTON...
SOUTHERN MONMOUTH...SOUTHEASTERN MONTGOMERY...SOUTHEASTERN BUCKS AND
CENTRAL PHILADELPHIA COUNTIES...

At 628 PM EDT, an area of  severe thunderstorms was located across 
the Interstate 95 corridor and they were moving slowly east at 30 
mph.

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

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Lakewood, Howell, Manalapan, Willingboro, Tinton Falls,
Lumberton, Florence, Burlington, Bristol, Mount Holly, Riverside,
Palmyra, Narberth, Bordentown, Beverly, Tullytown, Allentown,
Farmingdale and Roosevelt.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4017 7400 3995 7482 4000 7504 3998 7507
      4002 7532 4004 7534 4009 7499 4026 7449
      4025 7446 4031 7432 4019 7400
TIME...MOT...LOC 2228Z 282DEG 35KT 4006 7447 

HAIL...0.75IN
WIND...60MPH
 
$$

PO

The office that day

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

Issued	Product	Office	Counties	Lasted
May 15, 3:40 AM EDT	Flash Flood Watch	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 7 more	21 hr
May 15, 2:49 PM EDT	Special Weather Statement	PHI	Sussex, Warren	56 min
May 15, 3:46 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Sussex, Warren	74 min
May 15, 4:24 PM EDT	Special Weather Statement	PHI	Hunterdon, Somerset	51 min
May 15, 4:41 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset, Warren	64 min
May 15, 4:49 PM EDT	Special Marine Warning	PHI		86 min
May 15, 5:22 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	38 min
May 15, 5:31 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	3 hr
May 15, 5:35 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Somerset	4 hr
May 15, 5:38 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Salem	67 min
May 15, 6:02 PM EDT	Special Marine Warning	PHI		88 min
May 15, 6:10 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Monmouth, Ocean, Salem	4 hr
May 15, 6:12 PM EDT	Special Marine Warning	PHI		63 min
May 15, 6:17 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Cumberland, Gloucester, Ocean	43 min
May 15, 6:35 PM EDT	Severe Thunderstorm Warning	PHI	Salem	40 min
May 15, 6:46 PM EDT	Special Weather Statement	PHI	Atlantic, Cumberland, Ocean, Salem	74 min
May 15, 6:58 PM EDT	Areal Flood Advisory	PHI	Salem	4 hr
May 15, 7:14 PM EDT	Special Marine Warning	PHI		91 min
May 15, 7:18 PM EDT	Severe Thunderstorm Warning	PHI	Salem	57 min
May 15, 7:30 PM EDT	Special Marine Warning	PHI		90 min
May 15, 3:20 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	55 min
May 15, 4:12 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	33 min
May 15, 4:26 PM EDT	Tornado Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	19 min
May 15, 5:12 PM EDT	Severe Thunderstorm Warning	PHI	Chester	63 min
May 15, 5:14 PM EDT	Areal Flood Advisory	PHI	Berks, Chester, Montgomery	2 hr
May 15, 6:15 PM EDT	Severe Thunderstorm Warning	PHI	Chester	60 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2018 Severe Thunderstorm Warnings in Pennsylvania, 2018 Every severe thunderstorm warning in 2018

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.