Alert archive / Pennsylvania / Tornado Warnings in 2021

Tornado Warning 19, NWS Philadelphia/Mount Holly

July 29, 2021Bucks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Jul 29, 2021, 4:56 PM EDT for Bucks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 34 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, 4:56 PM EDT (20:56 UTC)
Expired
Jul 29, 2021, 5:30 PM EDT
In force
34 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 101 km from the middle of the area, began a volume at 20:58 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, 4:57 PM EDTTSTM WND DMG2 Ssw Hellertown, PADOWNED TREES AND POWER LINES ON HAFLER ROAD OFF APPLES CHURCH ROAD IN LOWER SAUCON TOWNSHIP. TIME ESTIMATED FROM RADAR. POSSIBLE TORNADO.
Jul 29, 4:58 PM EDTFUNNEL CLOUD2 Wsw Hellertown, PAPHOTOGRAPH OF A FUNNEL CLOUD ON TWITTER JUST NORTH OF CENTER VALLEY, PA.
Jul 29, 4:58 PM EDTTSTM WND DMG2 S Hellertown, PA3 TO 4 BUILDINGS DAMAGED AT THE INTERSECTION OF LEITHSVILLE RD AND WEAVERS LN. ALSO SOME TREE DAMAGE IN THE AREA. POSSIBLE TORNADO. TIME ESTIMATED FROM RADAR.
Jul 29, 5:00 PM EDTTSTM WND DMG2 S Hellertown, PATHREE BUILDINGS DAMAGED NEAR THE INTERSECTION OF LEITHSVILLE ROAD AND WEAVERS LANE.

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, 8.9 hours before the alert went out and 201 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.

378 
WFUS51 KPHI 292056
TORPHI
PAC017-077-095-292130-
/O.NEW.KPHI.TO.W.0019.210729T2056Z-210729T2130Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  East central Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  South central Northampton County in eastern Pennsylvania...

* Until 530 PM EDT.
    
* At 456 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Hellertown, or near Allentown, moving east at 25
  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...
  Easton, Bethlehem, Wilson, Hellertown, West Easton, Riegelsville,
  Glendon, Springtown, Old Orchard, Freemansburg and Coopersburg.

This includes Interstate 78 in Pennsylvania between mile markers 62
and 76.
 
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.

&&

LAT...LON 4065 7519 4065 7520 4063 7518 4062 7520
      4059 7519 4057 7519 4056 7516 4051 7540
      4056 7544 4070 7521
TIME...MOT...LOC 2056Z 250DEG 21KT 4056 7537 

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

$$

Staarmann
3 follow-up statements
510 
WWUS51 KPHI 292104
SVSPHI

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

PAC077-292113-
/O.CAN.KPHI.TO.W.0019.000000T0000Z-210729T2130Z/
Lehigh PA-
504 PM EDT Thu Jul 29 2021

...THE TORNADO WARNING FOR EAST CENTRAL LEHIGH 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 900 PM EDT for northwestern
New Jersey...and eastern and southeastern Pennsylvania.

LAT...LON 4065 7519 4065 7520 4063 7518 4062 7520
      4059 7519 4057 7519 4056 7516 4053 7532
      4059 7535 4070 7521
TIME...MOT...LOC 2103Z 251DEG 22KT 4057 7530 

$$

PAC017-095-292130-
/O.CON.KPHI.TO.W.0019.000000T0000Z-210729T2130Z/
Bucks PA-Northampton PA-
504 PM EDT Thu Jul 29 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM EDT FOR NORTH
CENTRAL BUCKS AND SOUTH CENTRAL NORTHAMPTON COUNTIES...
    
At 503 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Springtown, or 8 miles southwest of Easton, moving
east at 25 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...
Easton, Bethlehem, Wilson, Hellertown, West Easton, Riegelsville,
Glendon, Springtown and Old Orchard.

This includes Interstate 78 in Pennsylvania between mile markers 68
and 76.
 
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.

&&

LAT...LON 4065 7519 4065 7520 4063 7518 4062 7520
      4059 7519 4057 7519 4056 7516 4053 7532
      4059 7535 4070 7521
TIME...MOT...LOC 2103Z 251DEG 22KT 4057 7530 

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

$$

Staarmann
186 
WWUS51 KPHI 292110
SVSPHI

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

PAC017-095-292130-
/O.CON.KPHI.TO.W.0019.000000T0000Z-210729T2130Z/
Bucks PA-Northampton PA-
510 PM EDT Thu Jul 29 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM EDT FOR NORTH
CENTRAL BUCKS AND SOUTH CENTRAL NORTHAMPTON COUNTIES...
    
At 510 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Riegelsville, or near Easton, moving east at 25 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...
Easton, Wilson, West Easton, Riegelsville, Glendon, Springtown and
Old Orchard.

This includes Interstate 78 in Pennsylvania between mile markers 73
and 76.
 
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.

&&

LAT...LON 4065 7519 4065 7520 4063 7518 4062 7520
      4059 7519 4057 7519 4056 7516 4053 7530
      4065 7527 4070 7521
TIME...MOT...LOC 2110Z 250DEG 22KT 4059 7522 

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

$$

Staarmann
038 
WWUS51 KPHI 292117
SVSPHI

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

PAC095-292126-
/O.CAN.KPHI.TO.W.0019.000000T0000Z-210729T2130Z/
Northampton PA-
517 PM EDT Thu Jul 29 2021

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

A Tornado Watch remains in effect until 900 PM EDT for northwestern
New Jersey...and eastern and southeastern Pennsylvania.

LAT...LON 4059 7519 4057 7519 4056 7516 4054 7525
      4059 7523 4061 7521
TIME...MOT...LOC 2116Z 250DEG 21KT 4060 7517 

$$

PAC017-292130-
/O.CON.KPHI.TO.W.0019.000000T0000Z-210729T2130Z/
Bucks PA-
517 PM EDT Thu Jul 29 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM EDT FOR NORTH
CENTRAL BUCKS COUNTY...
    
At 516 PM EDT, a severe thunderstorm capable of producing a tornado
was located over Riegelsville, or near Easton, moving east at 25 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...
Riegelsville.

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.

&&

LAT...LON 4059 7519 4057 7519 4056 7516 4054 7525
      4059 7523 4061 7521
TIME...MOT...LOC 2116Z 250DEG 21KT 4060 7517 

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

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
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, 4:30 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Carbon, Lehigh, Monroe, Northampton45 min
Jul 29, 4:46 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh, Northampton3 hr
Jul 29, 4:57 PM EDTAreal Flood AdvisoryPHIBucks, Monroe, Northampton3 hr
Jul 29, 5:03 PM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Monroe, Northampton42 min
Jul 29, 5:08 PM EDTTornado WarningPHIBucks37 min
Jul 29, 5:27 PM EDTAreal Flood AdvisoryPHIBucks3 hr
Jul 29, 5:32 PM EDTFlash Flood WarningPHINorthampton2 hr
Jul 29, 5:32 PM EDTTornado WarningPHIBucks28 min
Jul 29, 5:51 PM EDTTornado Warning Tornado observedConsiderable damage threatPHIBucks24 min
Jul 29, 5:58 PM EDTFlash Flood WarningPHIBucks3 hr
Jul 29, 6:06 PM EDTTornado Warning Considerable damage threatPHIBucks39 min
Jul 29, 6:21 PM EDTSpecial Weather StatementPHIBucks24 min
Jul 29, 6:45 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia45 min
Jul 29, 7:07 PM EDTTornado WarningPHIBucks, Philadelphia23 min
Jul 29, 7:12 PM EDTFlash Flood WarningPHIBucks, Philadelphia4 hr
Jul 29, 7:25 PM EDTSevere Thunderstorm WarningPHIBucks50 min

Nearby

Tornado 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.