Alert archive / New Jersey / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 314, NWS Philadelphia/Mount Holly

October 16, 20215 counties in New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Oct 16, 2021, 4:02 PM EDT for 5 counties in New Jersey; Bucks County, Pennsylvania. It was in force for 43 min. 2 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
Oct 16, 2021, 4:02 PM EDT (20:02 UTC)
Expired
Oct 16, 2021, 4:45 PM EDT
In force
43 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, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 76 km from the middle of the area, began a volume at 20:06 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
Oct 16, 4:24 PM EDTTSTM WND DMGHopewell, NJTREE BLOWN OVER ON PRINCETON RD. TIME ESTIMATED FROM RADAR AND THE SPOTTERS REPORT.
Oct 16, 4:34 PM EDTTSTM WND DMGBound Brook, NJA FEW SMALL TREES WERE SNAPPED IN BOUND BROOK. TIME ESTIMATED FROM RADAR.

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, 8.0 hours before the alert went out and 158 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 2021-10-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-10-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 140 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1068 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
140 m²/s²
0-3 km storm-relative helicity
174 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

486 
WUUS51 KPHI 162002
SVRPHI
NJC019-021-023-027-035-PAC017-162045-
/O.NEW.KPHI.SV.W.0314.211016T2002Z-211016T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
402 PM EDT Sat Oct 16 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Hunterdon County in northwestern New Jersey...
  South central Morris County in northern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Somerset County in northern New Jersey...
  Northwestern Middlesex County in northern New Jersey...
  East central Bucks County in southeastern Pennsylvania...

* Until 445 PM EDT.

* At 402 PM EDT, severe thunderstorms were located along a line
  extending from near Clinton to near New Hope, moving northeast at
  50 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Somerville, Somerset, Bridgewater, South Brunswick, Middlesex,
  Bound Brook, Manville, Mendham, Flemington, Clinton, Pennington,
  Peapack And Gladstone, New Hope, Hopewell, Lebanon, Far Hills,
  Rocky Hill, Stockton, Millstone and Skillman.

This includes the following highways...
 Interstate 78 in New Jersey between mile markers 16 and 38.
 Interstate 287 in New Jersey between mile markers 10 and 33.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 4084 7450 4040 7449 4027 7503 4060 7500
TIME...MOT...LOC 2002Z 231DEG 41KT 4059 7494 4032 7497 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JEO
2 follow-up statements
221 
WWUS51 KPHI 162019
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
419 PM EDT Sat Oct 16 2021

PAC017-162029-
/O.CAN.KPHI.SV.W.0314.000000T0000Z-211016T2045Z/
Bucks PA-
419 PM EDT Sat Oct 16 2021

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

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

LAT...LON 4084 7450 4040 7449 4031 7488 4063 7494
TIME...MOT...LOC 2019Z 231DEG 41KT 4071 7475 4044 7478 

$$

NJC019-021-023-027-035-162045-
/O.CON.KPHI.SV.W.0314.000000T0000Z-211016T2045Z/
Hunterdon NJ-Morris NJ-Mercer NJ-Somerset NJ-Middlesex NJ-
419 PM EDT Sat Oct 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR EASTERN HUNTERDON...SOUTH CENTRAL MORRIS...NORTHWESTERN MERCER...
SOMERSET AND NORTHWESTERN MIDDLESEX COUNTIES...

At 419 PM EDT, severe thunderstorms were located along a line
extending from near Peapack And Gladstone to near Cloverhill, moving
northeast at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Somerville, Somerset, Bridgewater, South Brunswick, Middlesex, Bound
Brook, Manville, Mendham, Flemington, Clinton, Pennington, Peapack
And Gladstone, Hopewell, Lebanon, Far Hills, Rocky Hill, Millstone,
Skillman, Flagtown and Kingston.

This includes the following highways...
 Interstate 78 in New Jersey between mile markers 16 and 38.
 Interstate 287 in New Jersey between mile markers 10 and 33.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 4084 7450 4040 7449 4031 7488 4063 7494
TIME...MOT...LOC 2019Z 231DEG 41KT 4071 7475 4044 7478 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JEO
191 
WWUS51 KPHI 162038
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
438 PM EDT Sat Oct 16 2021

NJC019-021-023-027-035-162047-
/O.EXP.KPHI.SV.W.0314.000000T0000Z-211016T2045Z/
Hunterdon NJ-Morris NJ-Mercer NJ-Somerset NJ-Middlesex NJ-
438 PM EDT Sat Oct 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN HUNTERDON...SOUTH
CENTRAL MORRIS...NORTHWESTERN MERCER...SOMERSET AND NORTHWESTERN
MIDDLESEX COUNTIES WILL EXPIRE AT 445 PM EDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 4084 7450 4040 7449 4031 7488 4063 7494
TIME...MOT...LOC 2037Z 231DEG 41KT 4071 7475 4044 7478 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 16, 10:35 AM EDTCoastal Flood StatementPHIOcean2 hr
Oct 16, 3:22 PM EDTSpecial Marine WarningPHI113 min
Oct 16, 3:31 PM EDTSevere Thunderstorm WarningPHISalem18 min
Oct 16, 3:41 PM EDTSpecial Weather StatementPHIHunterdon, Sussex, Warren49 min
Oct 16, 4:18 PM EDTSpecial Weather StatementPHIAtlantic, Burlington, Camden, Cumberland, Gloucester, Mercer and 1 more57 min
Oct 16, 5:10 PM EDTSpecial Marine WarningPHI95 min
Oct 16, 5:29 PM EDTSpecial Marine WarningPHI91 min
Oct 16, 6:09 PM EDTSpecial Marine WarningPHI66 min
Oct 16, 6:52 PM EDTCoastal Flood StatementPHIOcean4 hr
Oct 16, 1:39 PM EDTSpecial Weather StatementPHIBerks51 min
Oct 16, 2:32 PM EDTSpecial Weather StatementPHIBerks, Lehigh58 min
Oct 16, 2:44 PM EDTSpecial Weather StatementPHIChester61 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2021Severe Thunderstorm Warnings in Pennsylvania, 2021Every severe thunderstorm warning in 2021

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.