Alert archive / New Jersey / Tornado Warnings in 2021

Tornado Warning 20, NWS Philadelphia/Mount Holly

July 29, 2021Hunterdon County, New Jersey; Bucks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Jul 29, 2021, 5:08 PM EDT for Hunterdon County, New Jersey; Bucks County, Pennsylvania. It was in force for 37 min. 4 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
Jul 29, 2021, 5:08 PM EDT (21:08 UTC)
Expired
Jul 29, 2021, 5:45 PM EDT
In force
37 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Hunterdon County, NJ, Bucks County, PA

The radar

The Philadelphia radar (KDIX), 90 km from the middle of the area, began a volume at 21:11 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
Jul 29, 5:11 PM EDTTSTM WND DMGQuakertown, PASEVERAL TREES DOWN, ALSO HAVE REPORTS FROM BUCKINGHAM AND UPPER MAKEFIELD. TIME ESTIMATED FROM RADAR.
Jul 29, 5:15 PM EDTTSTM WND GST 531 E Milford Square, PAQUAKERTOWN.
Jul 29, 5:15 PM EDTTSTM WND GST 531 Ese Milford Square, PAQUAKERTOWN AIRPORT AWOS MEASURED GUST.
Jul 29, 5:30 PM EDTTSTM WND DMGOttsville, PADEBRIS BLOCKING FRETZ VALLEY ROAD, GEIGEL HILL ROAD AND CREAMERY ROAD.

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
Jul 29, 2:23 PM EDTTornado WatchSPC8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.1 hours before the alert went out and 205 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 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 54 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 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 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
54 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
823 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

517 
WFUS51 KPHI 292108
TORPHI
NJC019-PAC017-292145-
/O.NEW.KPHI.TO.W.0020.210729T2108Z-210729T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Mount Holly NJ
508 PM EDT Thu Jul 29 2021

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Southwestern Hunterdon County in northwestern New Jersey...
  Northwestern Bucks County in southeastern Pennsylvania...

* Until 545 PM EDT.
    
* At 508 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Quakertown, or 12 miles southeast of Allentown,
  moving east at 35 mph.

  HAZARD...Tornado and quarter size hail.

  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...
  Quakertown, Byram, Bedminster, Tinicum, Ferndale, Frenchtown,
  Milford, Revere, Ottsville, Pipersville, Erwinna, Richlandtown and
  Trumbauersville.

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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4039 7540 4049 7541 4059 7502 4042 7497
TIME...MOT...LOC 2108Z 255DEG 29KT 4045 7535 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Fitzsimmons
1 follow-up statement
308 
WWUS51 KPHI 292124
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
524 PM EDT Thu Jul 29 2021

NJC019-PAC017-292145-
/O.CON.KPHI.TO.W.0020.000000T0000Z-210729T2145Z/
Hunterdon NJ-Bucks PA-
524 PM EDT Thu Jul 29 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 545 PM EDT FOR
SOUTHWESTERN HUNTERDON AND NORTH CENTRAL BUCKS COUNTIES...
    
At 523 PM EDT, a severe thunderstorm capable of producing a tornado
was located near Bedminster, or 16 miles southeast of Allentown,
moving east at 25 mph.

HAZARD...Tornado and quarter size hail.

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...
Byram, Bedminster, Tinicum, Ferndale, Frenchtown, Milford, Pleasant
Valley, Pipersville, Erwinna, Revere and Ottsville.

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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4040 7529 4052 7531 4059 7502 4042 7497
TIME...MOT...LOC 2123Z 263DEG 21KT 4045 7524 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Fitzsimmons

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 3:33 AM EDTSmall Craft AdvisoryPHI20 hr
Jul 29, 1:33 PM EDTSpecial Marine WarningPHI42 min
Jul 29, 2:53 PM EDTSpecial Marine WarningPHI100 min
Jul 29, 4:26 PM EDTSpecial Weather StatementPHIMorris34 min
Jul 29, 4:30 PM EDTSevere Thunderstorm WarningPHIHunterdon, Warren45 min
Jul 29, 4:57 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Sussex, Warren3 hr
Jul 29, 5:01 PM EDTSpecial Weather StatementPHIMorris29 min
Jul 29, 5:03 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Sussex, Warren42 min
Jul 29, 5:27 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Morris, Somerset3 hr
Jul 29, 5:32 PM EDTFlash Flood WarningPHIWarren2 hr
Jul 29, 5:32 PM EDTTornado WarningPHIHunterdon28 min
Jul 29, 5:51 PM EDTTornado Warning Tornado observedConsiderable damage threatPHIHunterdon, Mercer24 min
Jul 29, 5:58 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Somerset3 hr
Jul 29, 6:06 PM EDTTornado Warning Considerable damage threatPHIBurlington, Hunterdon, Mercer, Middlesex, Monmouth39 min
Jul 29, 6:44 PM EDTTornado WarningPHIMercer, Monmouth, Ocean46 min
Jul 29, 6:45 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer45 min
Jul 29, 6:56 PM EDTFlash Flood WarningPHIMercer, Middlesex, Monmouth, Ocean, Somerset4 hr
Jul 29, 7:07 PM EDTTornado WarningPHIBurlington23 min
Jul 29, 7:12 PM EDTFlash Flood WarningPHIBurlington4 hr
Jul 29, 7:18 PM EDTTornado WarningPHIMercer, Middlesex, Monmouth, Ocean27 min
Jul 29, 7:25 PM EDTSevere Thunderstorm WarningPHIBurlington, Monmouth, Ocean50 min
Jul 29, 7:28 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean47 min
Jul 29, 7:52 PM EDTSpecial Marine WarningPHI113 min
Jul 29, 3:48 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Northampton42 min
Jul 29, 4:03 PM EDTTornado WarningPHIBerks, Lehigh, Northampton27 min
Jul 29, 4:27 PM EDTTornado WarningPHILehigh, Northampton16 min
Jul 29, 4:46 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh, Northampton3 hr
Jul 29, 4:56 PM EDTTornado WarningPHIBucks, Lehigh, Northampton34 min
Jul 29, 6:21 PM EDTSpecial Weather StatementPHIBucks24 min

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.