Alert archive / New Jersey / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 19, NWS Philadelphia/Mount Holly

April 9, 20205 counties in Pennsylvania; 6 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 9, 2020, 1:00 PM EDT for 5 counties in Pennsylvania; 6 counties in New Jersey. It was in force for 45 min. 24 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: Apr 9, 2020, 1:00 PM EDT (17:00 UTC)
Expired: Apr 9, 2020, 1:45 PM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 66 km from the middle of the area, began a volume at 17:03 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
Apr 9, 1:00 PM EDT	TSTM WND DMG	1 E Oaks, PA	TREE DOWN ON A HOUSE IN LOWER PROVIDENCE TOWNSHIP.
Apr 9, 1:06 PM EDT	TSTM WND DMG	2 N Byram, NJ	TREE DOWN ON TUMBLE FALLS ROAD IN KINGWOOD TOWNSHIP. TIME ESTIMATED FROM RADAR.
Apr 9, 1:06 PM EDT	TSTM WND GST 56	Doylestown Airport (Kdy, PA	KDYL ASOS MEASURED 49 KT WIND GUST.
Apr 9, 1:07 PM EDT	TSTM WND GST 57	Ambler, PA
Apr 9, 1:10 PM EDT	HAIL 0.25	Buckingham Twp, PA
Apr 9, 1:12 PM EDT	HAIL 0.25	Washington Crossing, PA	TIME ESTIMATED FROM RADAR.
Apr 9, 1:15 PM EDT	TSTM WND DMG	Wrightstown Twp, PA	OUTDOOR SHED SIGNIFICANTLY DAMAGED. TIME ESTIMATED FROM RADAR.
Apr 9, 1:15 PM EDT	TSTM WND GST 47	Wings Field Airport (Kl, PA
Apr 9, 1:15 PM EDT	HAIL 0.7	Horsham, PA	PEA TO DIME SIZE HAIL REPORTED IN HORSHAM.
Apr 9, 1:18 PM EDT	TSTM WND DMG	1 Ese Brownsburg, PA	LARGE TREE UPROOTED. TIME ESTIMATED FROM RADAR.
Apr 9, 1:18 PM EDT	TSTM WND DMG	Richboro, PA	2 LARGE TREES UPROOTED IN RICHBORO. TIME ESTIMATED FROM RADAR.
Apr 9, 1:20 PM EDT	TSTM WND DMG	Woodlyn, PA	TREE INTO A HOUSE IN WOODLYN. TIME ESTIMATED FROM RADAR.
Apr 9, 1:20 PM EDT	HAIL 0.7	Blue Bell, PA	HAIL UP TO DIME SIZE REPORTED IN BULE BELL.
Apr 9, 1:24 PM EDT	TSTM WND DMG	2 E Fox Chase, PA	LARGE TREE SNAPPED IN HALF IN BELLS CORNER. TIME ESTIMATED FROM RADAR.
Apr 9, 1:24 PM EDT	TSTM WND GST 55	Northeast Philadelphia, PA
Apr 9, 1:24 PM EDT	HAIL 0.25	Hopewell, NJ
Apr 9, 1:27 PM EDT	TSTM WND GST 45	Trenton Mercer Airport, NJ	KTTN MEASURED 39 KT WIND GUST.
Apr 9, 1:28 PM EDT	TSTM WND GST 50	Aston Twp., PA
Apr 9, 1:30 PM EDT	TSTM WND DMG	3 Ese Montgomery Twp, NJ	LARGE SPRUCE TREE DOWN ACROSS DRIVEWAY. TIME ESTIMATED FROM RADAR.
Apr 9, 1:35 PM EDT	HAIL 0.25	1 S Feasterville-Trevos, PA
Apr 9, 1:35 PM EDT	HAIL 0.88	2 Wsw Heathcote, NJ	DIME TO NICKEL SIZE HAIL REPORTED IN KINGSTON. TIME ESTIMATED FROM RADAR.
Apr 9, 1:36 PM EDT	TSTM WND DMG	1 Nne Watchung, NJ	PARLIN LANE CLOSED DUE TO DOWN TREES AND WIRES. TIME ESTIMATED FROM RADAR.
Apr 9, 1:42 PM EDT	HAIL 1	Hillsborough Twp, NJ	MOSTLY PEA SIZE WITH A FEW STONES TO QUARTER SIZE. TIME ESTIMATED FROM RADAR.
Apr 9, 1:48 PM EDT	TSTM WND DMG	Lansdale, PA	LARGE TREE BRANCH FELL INTO THE STREET. 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
Apr 9, 12:01 PM EDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 5.0 hours before the alert went out and 164 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: 942 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 241 m²/s²
0-3 km storm-relative helicity: 361 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

667 
WUUS51 KPHI 091700
SVRPHI
NJC019-021-023-027-035-041-PAC017-029-045-091-101-091745-
/O.NEW.KPHI.SV.W.0019.200409T1700Z-200409T1745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
100 PM EDT Thu Apr 9 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southern Morris County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  South central Warren County in northwestern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Somerset County in northern New Jersey...
  Northwestern Middlesex County in northern New Jersey...
  Montgomery County in southeastern Pennsylvania...
  Bucks County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until 145 PM EDT.

* At 100 PM EDT, severe thunderstorms were located along a line
  extending from near Bloomsbury to near Fricks to Marshallton,
  moving east at 45 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, West Chester, Somerville, Bensalem,
  Bridgewater, Ewing, Norristown, Chester, Phoenixville, Lansdale,
  West Norriton, Middlesex, East Norriton, Princeton, Yeadon,
  Westtown, Bound Brook, Manville and Perkasie.

People attending Covid-19 Drive through testing should seek safe
shelter immediately!

This includes the following highways...
 Interstate 287 in New Jersey between mile markers 8 and 27.
 Interstate 295 in New Jersey between mile markers 68 and 76.
 Interstate 78 in New Jersey between mile markers 7 and 43.
 Interstate 95 in Pennsylvania between mile markers 6 and 10.
 Interstate 476 in Pennsylvania between mile markers 0 and 19.
 Pennsylvania Turnpike between exits 320 and 353.
 Northeast Extension between exits A20 and A31.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 76 in Pennsylvania between mile markers 327 and 347.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Mount Holly NJ.

&&

LAT...LON 4060 7445 4059 7445 4032 7464 3985 7530
      3991 7580 4033 7535 4070 7507 4070 7443
      4067 7446 4066 7445 4067 7443 4066 7441
TIME...MOT...LOC 1700Z 268DEG 40KT 4062 7506 4033 7527 3997 7566 

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

MPS

2 follow-up statements

130 
WWUS51 KPHI 091720
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
120 PM EDT Thu Apr 9 2020

NJC041-PAC029-091729-
/O.CAN.KPHI.SV.W.0019.000000T0000Z-200409T1745Z/
Warren NJ-Chester PA-
120 PM EDT Thu Apr 9 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL WARREN AND
NORTHEASTERN CHESTER COUNTIES 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 400 PM EDT for
central, northern and northwestern New Jersey...and southeastern
Pennsylvania.

LAT...LON 3987 7549 4031 7497 4070 7478 4070 7443
      4067 7446 4066 7445 4067 7443 4066 7441
      4060 7445 4059 7445 4032 7464 3985 7530
TIME...MOT...LOC 1719Z 272DEG 50KT 4067 7472 4032 7490 3990 7539 

$$

NJC019-021-023-027-035-PAC017-045-091-101-091745-
/O.CON.KPHI.SV.W.0019.000000T0000Z-200409T1745Z/
Morris NJ-Hunterdon NJ-Mercer NJ-Somerset NJ-Middlesex NJ-
Montgomery PA-Bucks PA-Philadelphia PA-Delaware PA-
120 PM EDT Thu Apr 9 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM EDT
FOR SOUTHERN MORRIS...SOUTHEASTERN HUNTERDON...NORTHWESTERN MERCER...
SOMERSET...NORTHWESTERN MIDDLESEX...SOUTHEASTERN MONTGOMERY...
SOUTHEASTERN BUCKS...PHILADELPHIA AND EASTERN DELAWARE COUNTIES...

At 119 PM EDT, severe thunderstorms were located along a line
extending from near White House Station to near Washington Crossing
to Nether Providence Township, 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, Somerville, Bensalem, Bridgewater, Ewing,
Chester, Middlesex, Princeton, Yeadon, Bound Brook, Manville,
Hatboro, Folcroft, Swarthmore, Flemington, Jenkintown, Narberth, East
Lansdowne and Pennington.

This includes the following highways...
 Interstate 287 in New Jersey between mile markers 8 and 27.
 Interstate 295 in New Jersey between mile markers 68 and 76.
 Interstate 78 in New Jersey between mile markers 23 and 43.
 Interstate 95 in Pennsylvania between mile markers 6 and 10.
 Interstate 476 in Pennsylvania between mile markers 0 and 9.
 Pennsylvania Turnpike between exits 340 and 353.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 76 in Pennsylvania between mile markers 335 and 347.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Mount Holly NJ.

&&

LAT...LON 3987 7549 4031 7497 4070 7478 4070 7443
      4067 7446 4066 7445 4067 7443 4066 7441
      4060 7445 4059 7445 4032 7464 3985 7530
TIME...MOT...LOC 1719Z 272DEG 50KT 4067 7472 4032 7490 3990 7539 

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

MPS

244 
WWUS51 KPHI 091737 RRA
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
137 PM EDT Thu Apr 9 2020

NJC019-021-023-027-035-PAC017-045-091-101-091747-
/O.EXP.KPHI.SV.W.0019.000000T0000Z-200409T1745Z/
Morris NJ-Hunterdon NJ-Mercer NJ-Somerset NJ-Middlesex NJ-
Montgomery PA-Bucks PA-Philadelphia PA-Delaware PA-
137 PM EDT Thu Apr 9 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MORRIS...SOUTHEASTERN
HUNTERDON...NORTHWESTERN MERCER...SOMERSET...NORTHWESTERN
MIDDLESEX...SOUTHEASTERN MONTGOMERY...SOUTHEASTERN BUCKS...
PHILADELPHIA AND EASTERN DELAWARE COUNTIES WILL EXPIRE AT 145 PM
EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 400 PM EDT for
central, northern and northwestern New Jersey...and southeastern
Pennsylvania.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 3987 7549 4031 7497 4070 7478 4070 7443
      4067 7446 4066 7445 4067 7443 4066 7441
      4060 7445 4059 7445 4032 7464 3985 7530
TIME...MOT...LOC 1737Z 268DEG 40KT 4068 7445 4033 7463 3991 7512 

$$

MPS

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 9, 12:05 PM EDT	Special Weather Statement	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	40 min
Apr 9, 12:23 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	52 min
Apr 9, 1:12 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Philadelphia	48 min
Apr 9, 1:23 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	52 min
Apr 9, 1:26 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Delaware, Montgomery, Philadelphia	49 min
Apr 9, 1:33 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Delaware, Philadelphia	42 min
Apr 9, 3:32 PM EDT	Wind Advisory	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	27 hr
Apr 9, 9:57 AM EDT	Special Marine Warning	PHI		63 min
Apr 9, 10:56 AM EDT	Special Marine Warning	PHI		29 min
Apr 9, 12:52 PM EDT	Special Weather Statement	PHI	Hunterdon, Morris, Somerset, Sussex, Warren	23 min
Apr 9, 1:14 PM EDT	Special Weather Statement	PHI	Morris	31 min
Apr 9, 1:18 PM EDT	Special Weather Statement	PHI	Cumberland	27 min
Apr 9, 1:30 PM EDT	Special Marine Warning	PHI		60 min
Apr 9, 1:44 PM EDT	Special Marine Warning	PHI		61 min
Apr 9, 2:08 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Monmouth, Ocean	30 min
Apr 9, 2:13 PM EDT	Special Marine Warning	PHI		33 min
Apr 9, 3:13 PM EDT	Coastal Flood Statement	PHI	Ocean	4 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2020 Severe Thunderstorm Warnings in Pennsylvania, 2020 Every severe thunderstorm warning in 2020

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.