Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 19, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 15, 2018, 5:22 PM EDT for 5 counties in Pennsylvania; 5 counties in New Jersey. It was in force for 38 min. 13 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, 5:22 PM EDT (21:22 UTC)
Expired: May 15, 2018, 6:00 PM EDT
In force: 38 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.88 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), 40 km from the middle of the area, began a volume at 21:24 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, 5:30 PM EDT	TSTM WND DMG	Plymouth Meeting, PA	LARGE TREE LIMBS DOWN
May 15, 5:34 PM EDT	TSTM WND DMG	1 Wsw Hollow Woods, PA	TREE DOWN ON ROYERSFORD ROAD NEAR SOUDER ROAD. TIME APPROXIMATED BY RADAR.
May 15, 5:37 PM EDT	TSTM WND DMG	1 Wnw Chesterbrook, PA	A COUPLE REPORTS OF DOWNED OR UPROOTED TREES IN VALLEY FORGE AND CHESTERBROOK. TIME APPROXIMATED BASED ON SOCIAL MEDIA POSTINGS AND RADAR.
May 15, 5:40 PM EDT	MARINE TSTM WIND 47	Port Monmouth, NJ
May 15, 5:48 PM EDT	TSTM WND DMG	1 Wnw Rushland, PA	LARGE TREES UPROOTED NEAR SWAMP ROAD AND RUSHLAND ROAD IN JAMISON. TIME ESTIMATED FROM RADAR.
May 15, 5:48 PM EDT	TSTM WND GST 49	Northeast Philadelphia, PA
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.

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, 9.4 hours before the alert went out and 145 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.

169 
WUUS51 KPHI 152122
SVRPHI
NJC005-021-023-025-029-PAC017-029-045-091-101-152200-
/O.NEW.KPHI.SV.W.0019.180515T2122Z-180515T2200Z/

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

The National Weather Service in Mount Holly NJ has issued a

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

* Until 600 PM EDT.

* At 521 PM EDT, severe thunderstorms were located along a line 
  extending from near Keansburg to Valley Forge, moving east at 60 
  mph.

  HAZARD...60 mph wind gusts and nickel size hail. Strong winds 
           precede the heaviest rains and thunder. 

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Philadelphia, Toms River, Trenton, Long Branch, Asbury Park, Sandy
  Hook, Lakewood, Middletown, Old Bridge, Bensalem, Jackson, Howell,
  East Brunswick, South Brunswick, Sayreville, Marlboro, Manalapan,
  Ewing, Norristown and Willingboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

&&

LAT...LON 4029 7397 3985 7407 3998 7501 4000 7504
      3998 7507 4007 7574 4039 7466 4038 7462
      4037 7461 4041 7458 4051 7426 4049 7427
      4044 7420 4046 7418 4045 7413 4041 7398
      4048 7402 4048 7401 4043 7397
TIME...MOT...LOC 2121Z 277DEG 72KT 4047 7416 4009 7549 

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

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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	Berks, Bucks, Chester, Delaware, Lehigh, Montgomery and 1 more	21 hr
May 15, 2:49 PM EDT	Special Weather Statement	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	56 min
May 15, 3:20 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	55 min
May 15, 3:46 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Northampton	74 min
May 15, 4:12 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	33 min
May 15, 4:24 PM EDT	Special Weather Statement	PHI	Berks	51 min
May 15, 4:26 PM EDT	Tornado Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	19 min
May 15, 4:41 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	64 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, 5:31 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Montgomery	3 hr
May 15, 5:35 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
May 15, 5:38 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	67 min
May 15, 5:53 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	52 min
May 15, 6:10 PM EDT	Areal Flood Advisory	PHI	Philadelphia	4 hr
May 15, 6:15 PM EDT	Severe Thunderstorm Warning	PHI	Chester	60 min
May 15, 6:35 PM EDT	Severe Thunderstorm Warning	PHI	Chester	40 min
May 15, 6:58 PM EDT	Areal Flood Advisory	PHI	Chester	4 hr
May 15, 4:49 PM EDT	Special Marine Warning	PHI		86 min
May 15, 6:02 PM EDT	Special Marine Warning	PHI		88 min
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, 6:46 PM EDT	Special Weather Statement	PHI	Atlantic, Cumberland, Ocean, Salem	74 min
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

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2018 Severe Thunderstorm Warnings in New Jersey, 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.