Alert archive / New Jersey / Tornado Warnings in 2021

Tornado Warning 44, 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, 5:57 PM EDT for Hunterdon County, Mercer County, Somerset County, New Jersey; Bucks County, Pennsylvania. It was in force for 33 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
Sep 1, 2021, 5:57 PM EDT (21:57 UTC)
Expired
Sep 1, 2021, 6:30 PM EDT
In force
33 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), 59 km from the middle of the area, began a volume at 22:00 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, 5:59 PM EDTTORNADO1 Wnw Warwick Twp, PATHE STORM WHICH PRODUCED A STRONG TORNADO IN MONTGOMERY COUNTY, PA, CYCLED AND PRODUCED ANOTHER TORNADO IN BUCKS COUNTY, PA. DAMAGE BEGAN NEAR IN THE AREA OF NESHAMINY CREEK BETWEEN VALLEY RD AND PEBBLE HILL RD IN DOYLESTOWN. THE TORNADO TRACKED NORTH-NORTHEAS
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, 10.0 hours before the alert went out and 176 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.

918 
WFUS51 KPHI 012157 RRA
TORPHI
NJC019-021-035-PAC017-012230-
/O.NEW.KPHI.TO.W.0044.210901T2157Z-210901T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
557 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...
  Central Bucks County in southeastern Pennsylvania...

* Until 630 PM EDT.
    
* At 557 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Ivyland, or 16 miles west of Trenton, moving
  northeast at 50 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation. This storm has a history of 
           produicing a tornado.

  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, Princeton, Doylestown, Byram, Flemington, Chalfont,
  Pennington, New Hope, Hopewell, Ivyland, Rocky Hill, Stockton,
  Washington Crossing, Skillman, Lumberville, Sergeantsville,
  Cloverhill, Gardenville, Sand Brook and Richboro.

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 4036 7463 4020 7508 4033 7525 4057 7485
      4037 7461
TIME...MOT...LOC 2157Z 240DEG 44KT 4024 7507 

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

$$

JEO
2 follow-up statements
463 
WWUS51 KPHI 012208
SVSPHI

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

NJC021-012218-
/O.CAN.KPHI.TO.W.0044.000000T0000Z-210901T2230Z/
Mercer NJ-
608 PM EDT Wed Sep 1 2021

...THE TORNADO WARNING FOR NORTHWESTERN MERCER 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...and southeastern Pennsylvania.

LAT...LON 4044 7476 4033 7496 4028 7507 4033 7516
      4040 7510 4045 7506 4057 7485 4046 7472
TIME...MOT...LOC 2208Z 240DEG 44KT 4031 7492 

$$

NJC019-035-PAC017-012230-
/O.CON.KPHI.TO.W.0044.000000T0000Z-210901T2230Z/
Hunterdon NJ-Somerset NJ-Bucks PA-
608 PM EDT Wed Sep 1 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM EDT FOR
SOUTHEASTERN HUNTERDON...SOUTHWESTERN SOMERSET AND CENTRAL BUCKS
COUNTIES...
    
At 608 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Washington Crossing, or 9 miles northwest of
Trenton, moving northeast at 50 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...
Doylestown, Byram, Flemington, New Hope, Stockton, Cloverhill,
Gardenville, Sergeantsville, Lumberville, Sand Brook 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 4044 7476 4033 7496 4028 7507 4033 7516
      4040 7510 4045 7506 4057 7485 4046 7472
TIME...MOT...LOC 2208Z 240DEG 44KT 4031 7492 

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

$$

JEO
991 
WWUS51 KPHI 012212
SVSPHI

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

NJC019-035-PAC017-012230-
/O.CON.KPHI.TO.W.0044.000000T0000Z-210901T2230Z/
Hunterdon NJ-Somerset NJ-Bucks PA-
612 PM EDT Wed Sep 1 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM EDT FOR
SOUTHEASTERN HUNTERDON...SOUTHWESTERN SOMERSET AND CENTRAL BUCKS
COUNTIES...
        
At 612 PM EDT, a confirmed tornado was located near Washington
Crossing, or 9 miles northwest of Trenton, moving northeast at 50
mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

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...
Byram, Flemington, New Hope, Stockton, Cloverhill, Gardenville,
Sergeantsville, Lumberville, Sand Brook and Lambertville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado has been confirmed. 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 4044 7476 4033 7496 4031 7506 4036 7514
      4040 7510 4045 7506 4057 7485 4046 7472
TIME...MOT...LOC 2212Z 240DEG 44KT 4034 7485 

TORNADO...OBSERVED
MAX HAIL SIZE...<.75 IN

$$

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, 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, 6:20 PM EDTTornado WarningPHIHunterdon, Mercer, Somerset40 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.