Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 117, NWS Philadelphia/Mount Holly

July 22, 2017Burlington County, Camden County, Gloucester County, New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 22, 2017, 5:50 PM EDT for Burlington County, Camden County, Gloucester County, New Jersey; 4 counties in Pennsylvania. It was in force for 55 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: Jul 22, 2017, 5:50 PM EDT (21:50 UTC)
Expired: Jul 22, 2017, 6:45 PM EDT
In force: 55 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 61 km from the middle of the area, began a volume at 21:52 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
Jul 22, 5:50 PM EDT	TSTM WND DMG	Willistown Twp, PA	TREE AND WIRES DOWN ON DUTTON MILL ROAD.
Jul 22, 5:59 PM EDT	TSTM WND DMG	Lower Providence Twp, PA	LARGE TREE DOWN ON CROSSKEYS ROAD
Jul 22, 6:00 PM EDT	TSTM WND DMG	Norristown, PA	WIRES DOWN AT DEKALB AND FORNANCE STREETS.
Jul 22, 6:00 PM EDT	TSTM WND DMG	Wayne, PA	TREES DOWN.
Jul 22, 6:20 PM EDT	TSTM WND DMG	Philadelphia, PA	TREE DOWN AT RIDGE AVENUE AND HUNTINGDON STREET.
Jul 22, 6:32 PM EDT	TSTM WND DMG	Camden, NJ	TREE LIMBS DOWN.
Jul 22, 6:32 PM EDT	TSTM WND GST 59	Camden, NJ
Jul 22, 6:35 PM EDT	TSTM WND DMG	Collingswood, NJ	TREE LIMB DOWN ON CAR.
Jul 22, 6:35 PM EDT	TSTM WND DMG	Oaklyn, NJ	TREE DOWN.
Jul 22, 6:35 PM EDT	TSTM WND DMG	Woodlynne, NJ	TREE DOWN ON A TRAILER ON MOUNT EPHRAIM AVENUE.
Jul 22, 6:55 PM EDT	HAIL 0.75	Voorhees Twp, NJ

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.8 hours before the alert went out and 215 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: 1678 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: -25 m²/s²
0-3 km storm-relative helicity: 55 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

967 
WUUS51 KPHI 222150
SVRPHI
NJC005-007-015-PAC029-045-091-101-222245-
/O.NEW.KPHI.SV.W.0117.170722T2150Z-170722T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
550 PM EDT SAT JUL 22 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Camden County in southern New Jersey...
  Northern Gloucester County in southern New Jersey...
  Northwestern Burlington County in southern New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until 645 PM EDT

* At 549 PM EDT, severe thunderstorms were located along a line
  extending from Valley Forge to near Westtown, moving east at 35
  mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Philadelphia, Camden, West Chester, Gloucester City, Cherry Hill,
  Evesham, Mount Laurel, Norristown, Chester, Willingboro, Deptford,
  Voorhees, West Deptford, Glassboro, Lindenwold, Phoenixville, West
  Norriton, East Norriton, Bellmawr and Yeadon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to 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.

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

&&

LAT...LON 4017 7551 4009 7496 4006 7498 4005 7497
      4007 7494 4008 7490 4007 7486 3996 7482
      3973 7497 3968 7509 3990 7552 3995 7564
TIME...MOT...LOC 2149Z 288DEG 30KT 4012 7546 3991 7558 

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

JRK

2 follow-up statements

288 
WWUS51 KPHI 222207
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
607 PM EDT SAT JUL 22 2017

PAC029-222217-
/O.CAN.KPHI.SV.W.0117.000000T0000Z-170722T2245Z/
Chester PA-
607 PM EDT SAT JUL 22 2017

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

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

LAT...LON 3976 7495 3993 7548 4005 7540 4007 7536
      4006 7539 4014 7534 4009 7497 4008 7496
      4006 7498 4005 7497 4007 7494 4007 7486
      3996 7482
TIME...MOT...LOC 2207Z 279DEG 29KT 4011 7528 3993 7541 

$$

NJC005-007-015-PAC045-091-101-222245-
/O.CON.KPHI.SV.W.0117.000000T0000Z-170722T2245Z/
Camden NJ-Gloucester NJ-Burlington NJ-Montgomery PA-Philadelphia PA-
Delaware PA-
607 PM EDT SAT JUL 22 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR NORTHWESTERN CAMDEN...NORTH CENTRAL GLOUCESTER...NORTHWESTERN
BURLINGTON...SOUTHEASTERN MONTGOMERY...PHILADELPHIA AND NORTHEASTERN
DELAWARE COUNTIES...

At 607 PM EDT, severe thunderstorms were located along a line
extending from Plymouth Meeting to Lima, moving east at 35 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Philadelphia, Camden, Gloucester City, Cherry Hill, Evesham, Mount
Laurel, Norristown, Willingboro, Deptford, Voorhees, Lindenwold, West
Norriton, East Norriton, Bellmawr, Yeadon, Woodbury, Burlington,
Riverside, Conshohocken and Berlin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to 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.

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

&&

LAT...LON 3976 7495 3993 7548 4005 7540 4007 7536
      4006 7539 4014 7534 4009 7497 4008 7496
      4006 7498 4005 7497 4007 7494 4007 7486
      3996 7482
TIME...MOT...LOC 2207Z 279DEG 29KT 4011 7528 3993 7541 

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

JRK

140 
WWUS51 KPHI 222228
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
628 PM EDT SAT JUL 22 2017

PAC045-222237-
/O.CAN.KPHI.SV.W.0117.000000T0000Z-170722T2245Z/
Delaware PA-
628 PM EDT SAT JUL 22 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DELAWARE COUNTY
IS CANCELLED...

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

LAT...LON 3978 7494 3987 7523 3998 7522 4002 7519
      4003 7515 4011 7514 4009 7497 4006 7498
      4005 7497 4007 7494 4007 7486 3996 7482
TIME...MOT...LOC 2227Z 284DEG 27KT 4009 7507 3990 7518 

$$

NJC005-007-015-PAC091-101-222245-
/O.CON.KPHI.SV.W.0117.000000T0000Z-170722T2245Z/
Camden NJ-Gloucester NJ-Burlington NJ-Montgomery PA-Philadelphia PA-
628 PM EDT SAT JUL 22 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR NORTHWESTERN CAMDEN...NORTH CENTRAL GLOUCESTER...NORTHWESTERN
BURLINGTON...EASTERN MONTGOMERY AND PHILADELPHIA COUNTIES...

At 627 PM EDT, severe thunderstorms were located along a line
extending from Rockledge to South Philadelphia, moving east at 30
mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Philadelphia, Camden, Gloucester City, Cherry Hill, Evesham, Mount
Laurel, Willingboro, Voorhees, Lindenwold, Bellmawr, Woodbury,
Burlington, Riverside, Berlin, Palmyra, Jenkintown, Magnolia,
Westville, National Park and Beverly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to 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.

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

&&

LAT...LON 3978 7494 3987 7523 3998 7522 4002 7519
      4003 7515 4011 7514 4009 7497 4006 7498
      4005 7497 4007 7494 4007 7486 3996 7482
TIME...MOT...LOC 2227Z 284DEG 27KT 4009 7507 3990 7518 

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

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 2:33 AM EDT	Special Weather Statement	PHI	Cape May	27 min
Jul 22, 2:36 AM EDT	Special Marine Warning	PHI		54 min
Jul 22, 2:57 AM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland	2 hr
Jul 22, 3:55 AM EDT	Special Marine Warning	PHI		65 min
Jul 22, 10:45 AM EDT	Coastal Flood Advisory	PHI	Atlantic, Burlington, Cape May, Cumberland, Middlesex, Monmouth and 1 more	13 hr
Jul 22, 3:08 PM EDT	Special Marine Warning	PHI		97 min
Jul 22, 3:43 PM EDT	Special Marine Warning	PHI		92 min
Jul 22, 3:50 PM EDT	Special Weather Statement	PHI	Ocean	55 min
Jul 22, 4:05 PM EDT	Areal Flood Advisory	PHI	Burlington, Ocean	115 min
Jul 22, 4:56 PM EDT	Special Weather Statement	PHI	Ocean	34 min
Jul 22, 6:00 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer	3 hr
Jul 22, 6:38 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Monmouth, Ocean	52 min
Jul 22, 7:10 PM EDT	Areal Flood Advisory	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Ocean and 1 more	4 hr
Jul 22, 7:22 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Ocean	34 min
Jul 22, 7:31 PM EDT	Special Marine Warning	PHI		119 min
Jul 22, 3:58 PM EDT	Special Weather Statement	PHI	Berks	62 min
Jul 22, 4:11 PM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Jul 22, 4:57 PM EDT	Areal Flood Advisory	PHI	Chester, Montgomery	4 hr
Jul 22, 5:03 PM EDT	Special Weather Statement	PHI	Bucks, Chester, Montgomery	42 min
Jul 22, 5:18 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Delaware, Montgomery, Philadelphia	42 min
Jul 22, 6:46 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Carbon, Lehigh, Monroe, Northampton	4 hr

Nearby

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