Alert archive / New Jersey / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 12, NWS Philadelphia/Mount Holly

April 15, 2019Bucks County, Chester County, Montgomery County, Pennsylvania; 4 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 15, 2019, 3:27 AM EDT for Bucks County, Chester County, Montgomery County, Pennsylvania; 4 counties in New Jersey. It was in force for 32 min. 1 report 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 15, 2019, 3:27 AM EDT (07:27 UTC)
Expired: Apr 15, 2019, 3:59 AM EDT
In force: 32 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Somerset County, NJ, Bucks County, PA, Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 68 km from the middle of the area, began a volume at 07:28 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 15, 3:35 AM EDT	TSTM WND DMG	1 Wsw Mcpherson, NJ	TREES BLOWN DOWN IN CLINTON TOWNSHIP. 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 15, 1:05 AM EDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 7.5 hours before the alert went out and 189 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: 7 J/kg
Mixed-layer CIN: -95 J/kg
Mixed-layer LCL: 437 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 236 m²/s²
0-3 km storm-relative helicity: 268 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

402 
WUUS51 KPHI 150727
SVRPHI
NJC019-021-027-035-PAC017-029-091-150815-
/O.NEW.KPHI.SV.W.0012.190415T0727Z-190415T0815Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
327 AM EDT MON APR 15 2019

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...
  Northwestern Mercer County in central New Jersey...
  Northwestern Somerset County in northern New Jersey...
  Central Montgomery County in southeastern Pennsylvania...
  Central Bucks County in southeastern Pennsylvania...
  East central Chester County in southeastern Pennsylvania...

* Until 415 AM EDT.

* At 327 AM EDT, severe thunderstorms were located along a line
  extending from Tinicum to Paoli, moving northeast 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...
  Morristown, Bridgewater, Norristown, Lansdale, West Norriton, East
  Norriton, Perkasie, Doylestown, Byram, Hatboro, Souderton,
  Bedminster, Ambler, Flemington, Chalfont, Tinicum, Hatfield,
  Peapack And Gladstone, New Hope and Dublin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

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.

&&

A tornado watch remains in effect until 700 AM EDT for central,
northern and northwestern New Jersey...and southeastern Pennsylvania.

LAT...LON 4025 7491 3998 7556 4052 7518 4080 7445
TIME...MOT...LOC 0727Z 235DEG 39KT 4044 7511 4003 7548 

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

SFJ

2 follow-up statements

439 
WWUS51 KPHI 150745
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
345 AM EDT MON APR 15 2019

PAC029-150754-
/O.CAN.KPHI.SV.W.0012.000000T0000Z-190415T0815Z/
Chester PA-
345 AM EDT MON APR 15 2019

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CHESTER COUNTY IS
CANCELLED...

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

A tornado watch remains in effect until 700 AM EDT for central,
northern and northwestern New Jersey...and southeastern Pennsylvania.

LAT...LON 4012 7522 4062 7492 4080 7445 4025 7491
TIME...MOT...LOC 0744Z 236DEG 56KT 4060 7478 4020 7515 

$$

NJC019-021-027-035-PAC017-091-150815-
/O.CON.KPHI.SV.W.0012.000000T0000Z-190415T0815Z/
Morris NJ-Hunterdon NJ-Mercer NJ-Somerset NJ-Montgomery PA-Bucks PA-
345 AM EDT MON APR 15 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 AM EDT
FOR SOUTHERN MORRIS...SOUTHEASTERN HUNTERDON...NORTHWESTERN MERCER...
NORTHWESTERN SOMERSET...EAST CENTRAL MONTGOMERY AND CENTRAL BUCKS
COUNTIES...

At 344 AM EDT, severe thunderstorms were located along a line
extending from White House Station to near Hatboro, moving northeast
at 65 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...
Morristown, Bridgewater, Hatboro, Flemington, Peapack And Gladstone,
New Hope, Lebanon, Ivyland, Far Hills, Stockton, Lumberville,
Richboro, Sergeantsville, Cloverhill, White House Station, Basking
Ridge, Sand Brook, Willow Grove, Horsham and Bernardsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

A tornado watch remains in effect until 700 AM EDT for central,
northern and northwestern New Jersey...and southeastern Pennsylvania.

LAT...LON 4012 7522 4062 7492 4080 7445 4025 7491
TIME...MOT...LOC 0744Z 236DEG 56KT 4060 7478 4020 7515 

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

SFJ

259 
WWUS51 KPHI 150759
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
359 AM EDT MON APR 15 2019

NJC019-021-027-035-PAC017-091-150809-
/O.CAN.KPHI.SV.W.0012.000000T0000Z-190415T0815Z/
Morris NJ-Hunterdon NJ-Mercer NJ-Somerset NJ-Montgomery PA-Bucks PA-
359 AM EDT MON APR 15 2019

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MORRIS...SOUTHEASTERN
HUNTERDON...NORTHWESTERN MERCER...NORTHWESTERN SOMERSET...EAST
CENTRAL MONTGOMERY AND CENTRAL BUCKS COUNTIES IS CANCELLED...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning has been cancelled.  However heavy rain is
still possible with these thunderstorms.

A tornado watch remains in effect until 700 AM EDT for central,
northern and northwestern New Jersey...and southeastern Pennsylvania.

LAT...LON 4012 7522 4062 7492 4080 7445 4025 7491
TIME...MOT...LOC 0758Z 235DEG 39KT 4069 7461 4029 7498 

$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 14, 9:19 PM EDT	Areal Flood Advisory	PHI	Berks	3 hr
Apr 15, 12:03 AM EDT	Special Weather Statement	PHI	Monroe	27 min
Apr 15, 1:10 AM EDT	Special Weather Statement	PHI	Schuylkill	50 min
Apr 15, 1:26 AM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	4 hr
Apr 15, 1:28 AM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	47 min
Apr 15, 1:43 AM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Apr 15, 1:58 AM EDT	Special Weather Statement	PHI	Berks, Carbon, Monroe	47 min
Apr 15, 2:21 AM EDT	Areal Flood Advisory	PHI	Lehigh, Northampton	4 hr
Apr 15, 2:28 AM EDT	Special Weather Statement	PHI	Chester	32 min
Apr 15, 2:34 AM EDT	Special Weather Statement	PHI	Berks, Chester, Lehigh, Northampton	41 min
Apr 15, 2:46 AM EDT	Severe Thunderstorm Warning	PHI	Delaware	44 min
Apr 15, 3:03 AM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Montgomery, Northampton	20 min
Apr 15, 3:11 AM EDT	Special Weather Statement	PHI	Bucks, Montgomery, Northampton	49 min
Apr 15, 3:19 AM EDT	Tornado Warning	PHI	Delaware, Montgomery, Philadelphia	26 min
Apr 15, 3:19 AM EDT	Wind Advisory	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	18 hr
Apr 15, 3:39 AM EDT	Severe Thunderstorm Warning	PHI	Bucks, Philadelphia	37 min
Apr 15, 3:59 AM EDT	Areal Flood Advisory	PHI	Montgomery	4 hr
Apr 15, 12:31 AM EDT	Marine Dense Fog Advisory	PHI		5 hr
Apr 15, 2:47 AM EDT	Special Marine Warning	PHI		58 min
Apr 15, 3:00 AM EDT	Areal Flood Advisory	PHI	Sussex, Warren	4 hr
Apr 15, 3:07 AM EDT	Severe Thunderstorm Warning	PHI	Camden, Cumberland, Gloucester, Salem	38 min
Apr 15, 3:08 AM EDT	Special Marine Warning	PHI		67 min
Apr 15, 3:41 AM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more	64 min
Apr 15, 3:42 AM EDT	Special Marine Warning	PHI		63 min
Apr 15, 3:57 AM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Morris, Somerset	13 min
Apr 15, 4:16 AM EDT	Special Marine Warning	PHI		59 min
Apr 15, 4:40 AM EDT	Special Marine Warning	PHI		65 min
Apr 15, 4:47 AM EDT	Special Weather Statement	PHI	Atlantic	28 min
Apr 15, 5:07 AM EDT	Special Marine Warning	PHI		53 min
Apr 15, 5:30 AM EDT	Coastal Flood Statement	PHI	Ocean	7 hr
Apr 15, 6:59 AM EDT	Areal Flood Warning	PHI	Hunterdon	4 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2019 Severe Thunderstorm Warnings in Pennsylvania, 2019 Every severe thunderstorm warning in 2019

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.