Alert archive / New Jersey / Tornado Warnings in 2021

Tornado Warning 45, NWS Philadelphia/Mount Holly

September 1, 2021Hunterdon County, Mercer County, Somerset County, New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Sep 1, 2021, 6:20 PM EDT for Hunterdon County, Mercer County, Somerset County, New Jersey; Bucks County, Pennsylvania. It was in force for 40 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
Sep 1, 2021, 6:20 PM EDT (22:20 UTC)
Expired
Sep 1, 2021, 7:00 PM EDT
In force
40 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Hunterdon County, NJ, Mercer County, NJ, Somerset County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 61 km from the middle of the area, began a volume at 22:19 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
Sep 1, 6:30 PM EDTTORNADOUpper Makefield Twp., PAA TORNADO EMBEDDED WITHIN A SQUALL LINE DEVELOPED SEVERAL MILES SOUTHEAST OF THE STORM WHICH PRODUCED A TORNADO IN BUCKINGHAM TOWNSHIP. TORNADIC DAMAGE WAS FIRST OBSERVED IN THE VICINITY OF STONEYBROOK RD AT EAGLE RD, NEAR JERICHO CREEK. THE TORNADO TRACKED NO

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
Sep 1, 12:40 PM EDTTornado WatchSPC9 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.3 hours before the alert went out and 185 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 2021-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 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 2021-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.19395878Sfc1 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
51 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1274 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

243 
WFUS51 KPHI 012220
TORPHI
NJC019-021-035-PAC017-012300-
/O.NEW.KPHI.TO.W.0045.210901T2220Z-210901T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
620 PM EDT Wed Sep 1 2021

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Southeastern Hunterdon County in northwestern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Southwestern Somerset County in northern New Jersey...
  East central Bucks County in southeastern Pennsylvania...

* Until 700 PM EDT.
    
* At 620 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Richboro, or 11 miles west of Trenton, moving
  northeast at 35 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* Locations impacted include...
  Ewing, Flemington, Pennington, New Hope, Newtown, Hopewell,
  Stockton, Richboro, Washington Crossing, Skillman, Lambertville,
  Village Shires, Newtown Grant and Churchville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4019 7497 4025 7505 4031 7503 4037 7500
      4052 7486 4042 7465
TIME...MOT...LOC 2220Z 219DEG 30KT 4025 7499 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

JEO
3 follow-up statements
046 
WWUS51 KPHI 012231
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
631 PM EDT Wed Sep 1 2021

NJC019-021-035-PAC017-012300-
/O.CON.KPHI.TO.W.0045.000000T0000Z-210901T2300Z/
Hunterdon NJ-Mercer NJ-Somerset NJ-Bucks PA-
631 PM EDT Wed Sep 1 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM EDT FOR
SOUTHEASTERN HUNTERDON...NORTHWESTERN MERCER...SOUTHWESTERN SOMERSET
AND EAST CENTRAL BUCKS COUNTIES...
    
At 631 PM EDT, a severe thunderstorm capable of producing a tornado
was located near Washington Crossing, or 10 miles northwest of
Trenton, moving northeast at 35 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Ewing, Flemington, Pennington, New Hope, Hopewell, Stockton,
Washington Crossing, Skillman and Lambertville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4024 7490 4031 7499 4036 7501 4037 7500
      4052 7486 4042 7465
TIME...MOT...LOC 2231Z 219DEG 30KT 4032 7491 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

JEO
437 
WWUS51 KPHI 012248
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
648 PM EDT Wed Sep 1 2021

PAC017-012257-
/O.CAN.KPHI.TO.W.0045.000000T0000Z-210901T2300Z/
Bucks PA-
648 PM EDT Wed Sep 1 2021

...THE TORNADO WARNING FOR EAST CENTRAL BUCKS COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 1000 PM EDT for central,
northern and northwestern New Jersey.

LAT...LON 4032 7483 4039 7493 4051 7483 4042 7465
TIME...MOT...LOC 2247Z 219DEG 30KT 4043 7479 

$$

NJC019-021-035-012300-
/O.CON.KPHI.TO.W.0045.000000T0000Z-210901T2300Z/
Hunterdon NJ-Mercer NJ-Somerset NJ-
648 PM EDT Wed Sep 1 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM EDT FOR
SOUTHEASTERN HUNTERDON...NORTHWESTERN MERCER AND SOUTHWESTERN
SOMERSET COUNTIES...
    
At 647 PM EDT, a severe thunderstorm capable of producing a tornado
was located near Hopewell, or 13 miles southwest of Somerville,
moving northeast at 35 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Hopewell and Skillman. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4032 7483 4039 7493 4051 7483 4042 7465
TIME...MOT...LOC 2247Z 219DEG 30KT 4043 7479 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

JEO
725 
WWUS51 KPHI 012255
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
655 PM EDT Wed Sep 1 2021

NJC019-021-035-012305-
/O.EXP.KPHI.TO.W.0045.000000T0000Z-210901T2300Z/
Hunterdon NJ-Mercer NJ-Somerset NJ-
655 PM EDT Wed Sep 1 2021

...THE TORNADO WARNING FOR SOUTHEASTERN HUNTERDON...NORTHWESTERN
MERCER AND SOUTHWESTERN SOMERSET COUNTIES WILL EXPIRE AT 700 PM
EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 1000 PM EDT for central,
northern and northwestern New Jersey.

LAT...LON 4032 7483 4039 7493 4051 7483 4042 7465
TIME...MOT...LOC 2255Z 219DEG 30KT 4047 7474 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 3:23 AM EDTGale WarningPHI32 hr
Sep 1, 3:23 AM EDTSmall Craft AdvisoryPHI41 hr
Sep 1, 4:34 AM EDTRip Current StatementPHIAtlantic, Cape May, Monmouth, Ocean39 hr
Sep 1, 7:58 AM EDTSevere Thunderstorm WarningPHIBurlington, Ocean47 min
Sep 1, 8:39 AM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean39 min
Sep 1, 9:11 AM EDTSpecial Marine WarningPHI64 min
Sep 1, 11:24 AM EDTAreal Flood AdvisoryPHISussex, Warren3 hr
Sep 1, 4:04 PM EDTAreal Flood WarningPHIWarren24 hr
Sep 1, 4:12 PM EDTFlash Flood WarningPHIHunterdon, Warren7 hr
Sep 1, 4:27 PM EDTRiver Flood WarningPHIMorris, Somerset6 days
Sep 1, 4:27 PM EDTRiver Flood WarningPHIEssex, Morris, Passaic8 days
Sep 1, 4:27 PM EDTRiver Flood WarningPHIEssex, Morris, Passaic6 days
Sep 1, 4:27 PM EDTRiver Flood WarningPHIEssex, Passaic21 days
Sep 1, 4:33 PM EDTRiver Flood WarningPHIMorris, Passaic46 hr
Sep 1, 4:40 PM EDTRiver Flood WarningPHIHunterdon, Somerset36 hr
Sep 1, 4:40 PM EDTRiver Flood WarningPHISomerset22 hr
Sep 1, 4:40 PM EDTRiver Flood WarningPHIMiddlesex, Somerset42 hr
Sep 1, 4:40 PM EDTRiver Flood WarningPHIMiddlesex, Somerset48 hr
Sep 1, 4:41 PM EDTRiver Flood WarningPHISomerset61 hr
Sep 1, 5:13 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer47 min
Sep 1, 5:26 PM EDTFlash Flood WarningPHIBurlington, Camden, Gloucester, Salem9 hr
Sep 1, 5:33 PM EDTSpecial Marine WarningPHI27 min
Sep 1, 5:34 PM EDTTornado WarningPHIMercer26 min
Sep 1, 5:35 PM EDTTornado WarningPHICumberland, Salem25 min
Sep 1, 5:42 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Morris, Somerset, Warren10 hr
Sep 1, 5:57 PM EDTTornado WarningPHIGloucester, Salem33 min
Sep 1, 5:57 PM EDTTornado WarningPHIHunterdon, Mercer, Somerset33 min
Sep 1, 6:05 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Middlesex, Morris, Somerset10 hr
Sep 1, 6:08 PM EDTFlash Flood WarningPHIHunterdon, Morris, Somerset, Sussex, Warren6 hr
Sep 1, 6:14 PM EDTSpecial Marine WarningPHI61 min
Sep 1, 6:22 PM EDTTornado Warning Tornado observedPHIBurlington, Camden, Gloucester23 min
Sep 1, 6:42 PM EDTTornado WarningPHIBurlington, Camden33 min
Sep 1, 6:59 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset61 min
Sep 1, 7:04 PM EDTTornado Warning EmergencyTornado observedCatastrophic damage threatPHIBurlington, Mercer26 min
Sep 1, 7:22 PM EDTTornado WarningPHIHunterdon, Mercer11 min
Sep 1, 7:28 PM EDTTornado WarningPHIMercer, Middlesex, Morris, Somerset47 min
Sep 1, 7:31 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatPHIHunterdon, Mercer, Somerset4 hr
Sep 1, 7:44 PM EDTSpecial Marine WarningPHI61 min
Sep 1, 6:19 AM EDTAreal Flood AdvisoryPHIChester, Delaware116 min
Sep 1, 6:49 AM EDTFlash Flood WarningPHIChester, Delaware, Philadelphia86 min
Sep 1, 12:07 PM EDTFlash Flood WarningPHICarbon, Monroe4 hr
Sep 1, 1:29 PM EDTFlash Flood WarningPHIBerks, Lehigh6 hr
Sep 1, 2:53 PM EDTFlash Flood WarningPHIBerks, Chester, Delaware, Montgomery9 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIMontgomery36 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIChester, Montgomery, Philadelphia43 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIMontgomery, Philadelphia41 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIPhiladelphia39 hr
Sep 1, 3:55 PM EDTRiver Flood WarningPHIBerks24 hr
Sep 1, 4:02 PM EDTRiver Flood WarningPHIMonroe24 hr
Sep 1, 4:10 PM EDTRiver Flood WarningPHIMonroe19 hr
Sep 1, 4:12 PM EDTRiver Flood WarningPHILehigh, Northampton25 hr
Sep 1, 4:12 PM EDTRiver Flood WarningPHILehigh, Northampton24 hr
Sep 1, 4:12 PM EDTRiver Flood WarningPHICarbon15 hr
Sep 1, 4:13 PM EDTTornado WarningPHIChester32 min
Sep 1, 4:20 PM EDTRiver Flood WarningPHIMontgomery22 hr
Sep 1, 4:21 PM EDTRiver Flood WarningPHIBucks29 hr
Sep 1, 4:42 PM EDTFlash Flood Warning EmergencyConsiderable damage threatPHIChester, Delaware, Montgomery6 hr
Sep 1, 5:07 PM EDTRiver Flood WarningPHIChester17 hr
Sep 1, 5:15 PM EDTTornado WarningPHIDelaware, Montgomery, Philadelphia30 min
Sep 1, 6:38 PM EDTRiver Flood WarningPHIChester, Delaware26 hr
Sep 1, 7:05 PM EDTFlash Flood Warning EmergencyCatastrophic damage threatPHIBucks8 hr
Sep 1, 7:23 PM EDTAreal Flood WarningPHIBerks, Lehigh14 hr
Sep 1, 7:53 PM EDTRiver Flood WarningPHIDelaware13 hr

Nearby

Tornado Warnings in New Jersey, 2021Tornado Warnings in Pennsylvania, 2021Every tornado warning in 2021Tornadoes 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.