Alert archive / New Jersey / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 377, NWS Philadelphia/Mount Holly

August 21, 20194 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 21, 2019, 4:36 PM EDT for 4 counties in New Jersey. It was in force for 54 min. 3 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
Aug 21, 2019, 4:36 PM EDT (20:36 UTC)
Expired
Aug 21, 2019, 5:30 PM EDT
In force
54 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Hunterdon County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ

The radar

The Philadelphia radar (KDIX), 75 km from the middle of the area, began a volume at 20:38 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

TimeReportWhereRemark
Aug 21, 4:40 PM EDTTSTM WND DMGFar Hills, NJTREE SNAPPED ON MAIN STREET NEAR FAR HILLS IN BEDMINSTER TWP. TIME ESTIMATED FROM RADAR.
Aug 21, 4:55 PM EDTTSTM WND DMGBernards Twp, NJTREES AND WIRES DOWN. TIME ESTIMATED FROM RADAR.
Aug 21, 4:56 PM EDTTSTM WND DMG1 Sse Madison, NJDOWNED POWER LINES NEAR NOE AVENUE AND SHUNPIKE 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.

IssuedProductOfficeLasted
Aug 21, 3:27 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.6 hours before the alert went out and 132 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2019-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2157 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2019-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
2157 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
499 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.7
Supercell composite
3.7

Open this sounding in Storm Lab

The text

As transmitted.

390 
WUUS51 KPHI 212036
SVRPHI
NJC019-023-027-035-212130-
/O.NEW.KPHI.SV.W.0377.190821T2036Z-190821T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
436 PM EDT Wed Aug 21 2019

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Morris County in northern New Jersey...
  Northeastern Hunterdon County in northwestern New Jersey...
  Northern Somerset County in northern New Jersey...
  Northeastern Middlesex County in northern New Jersey...

* Until 530 PM EDT.

* At 436 PM EDT, a severe thunderstorm was located over White House
  Station, or 9 miles northwest of Somerville, moving east at 25 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Perth Amboy, Somerville, Edison, Bridgewater, Carteret, Madison,
  Middlesex, Bound Brook, Manville, Chatham, Peapack And Gladstone,
  Lebanon, Califon, Far Hills, Colonia, Martinsville, Millington,
  White House Station, Society Hill and Basking Ridge.

This includes the following highways...
 Garden State Parkway between mile markers 128 and 134.
 Interstate 287 in New Jersey between mile markers 0 and 31.
 Interstate 78 in New Jersey between mile markers 18 and 42.
 New Jersey Turnpike between exits 11 and 13.

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 4056 7421 4055 7425 4050 7426 4060 7492
      4074 7481 4075 7437 4067 7446 4066 7445
      4066 7441 4065 7440 4060 7446 4061 7431
      4059 7429 4060 7426 4059 7420
TIME...MOT...LOC 2036Z 283DEG 20KT 4064 7476 

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

Gorse
3 follow-up statements
339 
WWUS51 KPHI 212053
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
453 PM EDT Wed Aug 21 2019

NJC019-212103-
/O.CAN.KPHI.SV.W.0377.000000T0000Z-190821T2130Z/
Hunterdon NJ-
453 PM EDT Wed Aug 21 2019

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN HUNTERDON COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until 1000 PM EDT for
northern and northwestern New Jersey.

LAT...LON 4056 7421 4055 7425 4050 7426 4056 7470
      4059 7472 4062 7471 4064 7473 4073 7472
      4075 7437 4068 7445 4066 7445 4065 7440
      4060 7446 4060 7426 4059 7421
TIME...MOT...LOC 2053Z 277DEG 21KT 4064 7460 

$$

NJC023-027-035-212130-
/O.CON.KPHI.SV.W.0377.000000T0000Z-190821T2130Z/
Morris NJ-Somerset NJ-Middlesex NJ-
453 PM EDT Wed Aug 21 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHEASTERN MORRIS...NORTHERN SOMERSET AND NORTHEASTERN
MIDDLESEX COUNTIES...

At 453 PM EDT, a severe thunderstorm was located near Far Hills, or
near Somerville, moving east at 25 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Perth Amboy, Somerville, Edison, Bridgewater, Carteret, Madison,
Middlesex, Bound Brook, Manville, Chatham, Peapack And Gladstone, Far
Hills, Colonia, Martinsville, Millington, Society Hill, Basking
Ridge, Woodbridge, South Plainfield and North Plainfield.

This includes the following highways...
 Garden State Parkway between mile markers 128 and 134.
 Interstate 287 in New Jersey between mile markers 0 and 30.
 Interstate 78 in New Jersey between mile markers 27 and 41.
 New Jersey Turnpike between exits 11 and 13.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm. Move
indoors immediately. Lightning is one of nature's leading killers.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.

&&

LAT...LON 4056 7421 4055 7425 4050 7426 4056 7470
      4059 7472 4062 7471 4064 7473 4073 7472
      4075 7437 4068 7445 4066 7445 4065 7440
      4060 7446 4060 7426 4059 7421
TIME...MOT...LOC 2053Z 277DEG 21KT 4064 7460 

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

Gorse
143 
WWUS51 KPHI 212103
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
503 PM EDT Wed Aug 21 2019

NJC023-027-035-212130-
/O.CON.KPHI.SV.W.0377.000000T0000Z-190821T2130Z/
Morris NJ-Somerset NJ-Middlesex NJ-
503 PM EDT Wed Aug 21 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHEASTERN MORRIS...NORTHEASTERN SOMERSET AND NORTHEASTERN
MIDDLESEX COUNTIES...

At 503 PM EDT, a severe thunderstorm was located over Martinsville,
or near Somerville, moving east at 25 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...
Perth Amboy, Somerville, Edison, Bridgewater, Carteret, Madison,
Middlesex, Bound Brook, Chatham, Peapack And Gladstone, Far Hills,
Colonia, Martinsville, Millington, Basking Ridge, Society Hill,
Woodbridge, South Plainfield, North Plainfield and Metuchen.

This includes the following highways...
 Garden State Parkway between mile markers 128 and 134.
 Interstate 287 in New Jersey between mile markers 0 and 8, and
between mile markers 14 and 31.
 Interstate 78 in New Jersey between mile markers 31 and 41.
 New Jersey Turnpike between exits 11 and 13.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm. Move
indoors immediately. Lightning is one of nature's leading killers.
Remember, if you can hear thunder, you are close enough to be struck
by lightning.

&&

LAT...LON 4056 7421 4055 7425 4050 7426 4059 7467
      4074 7463 4075 7437 4068 7445 4066 7445
      4065 7440 4060 7446 4060 7426 4059 7421
TIME...MOT...LOC 2103Z 283DEG 20KT 4063 7453 

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

Gorse
259 
WWUS51 KPHI 212121
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
521 PM EDT Wed Aug 21 2019

NJC023-027-035-212131-
/O.EXP.KPHI.SV.W.0377.000000T0000Z-190821T2130Z/
Morris NJ-Somerset NJ-Middlesex NJ-
521 PM EDT Wed Aug 21 2019

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MORRIS...
NORTHEASTERN SOMERSET AND NORTHEASTERN MIDDLESEX COUNTIES WILL EXPIRE
AT 530 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire. 

A severe thunderstorm watch remains in effect until 1000 PM EDT for
northern New Jersey.

LAT...LON 4056 7421 4055 7425 4050 7426 4059 7467
      4074 7463 4075 7437 4068 7445 4066 7445
      4065 7440 4060 7446 4060 7426 4059 7421
TIME...MOT...LOC 2121Z 283DEG 20KT 4061 7442 

$$

Gorse

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 3:30 AM EDTSmall Craft AdvisoryPHI23 hr
Aug 21, 4:24 AM EDTSpecial Marine WarningPHI96 min
Aug 21, 5:32 AM EDTSpecial Marine WarningPHI58 min
Aug 21, 4:15 PM EDTSpecial Weather StatementPHIHunterdon30 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2019Every 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.