Alert archive / Pennsylvania / Tornado Warnings in 2021

Tornado Warning 17, NWS Philadelphia/Mount Holly

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

NWS Philadelphia/Mount Holly issued this tornado warning at Jul 29, 2021, 4:03 PM EDT for Berks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 27 min. 6 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, 4:03 PM EDT (20:03 UTC)
Expired
Jul 29, 2021, 4:30 PM EDT
In force
27 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.0 in

Counties Berks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 134 km from the middle of the area, began a volume at 20:07 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, 4:04 PM EDTTORNADO4 N Greenwich Twp, PAA TORNADO TOUCHED DOWN NEAR TURKEY RD IN KEMPTON, ALBANY TWP, BERKS COUNTY, PA, JUST WEST OF THE BORDER WITH LEHIGH COUNTY. ABOUT 15 TREES WERE UPROOTED IN THE AREA OF TURKEY RD WITH A CONVERGENT DAMAGE PATTERN NOTED IN MULTIPLE NEARBY CORN FIELDS. THE PATH CO
Jul 29, 4:05 PM EDTTSTM WND DMG1 Nw Weisenberg Twp, PAUTILITY POLES DOWN.
Jul 29, 4:05 PM EDTTSTM WND DMGNew Tripoli, PADOWNED TREES AND POWER LINES IN THE NEW TRIPOLI AREA. SOME STRUCTURAL DAMAGE TO AN OUTSIDE BARN AS WELL WITH PIECES OF ROOFING OFF. TIME ESTIMATED FROM RADAR.
Jul 29, 4:06 PM EDTTORNADO3 Wnw Weisenberg Twp, PAA TORNADO TOUCHED DOWN BETWEEN KUNKELS MILL RD AND RED RD NEAR THE FAR SOUTHERN TIP OF LYNN TWP IN LEHIGH COUNTY, PENNSYLVANIA, JUST EAST OF THE COUNTY LINE WITH BERKS COUNTY. MOSTLY MINOR CROP AND TREE DAMAGE WAS OBSERVED IN THIS AREA, BUT WITH A CLEAR CONVER
Jul 29, 4:14 PM EDTTSTM WND DMG1 Ese Weisenberg Twp, PATREES AND WIRES DOWN ON 863. ROUTE 863 IS CLOSED DUE TO DEBRIS.
Jul 29, 4:15 PM EDTTSTM WND DMG1 Nw Weisenberg Twp, PATREES AND WIRES DOWN WITH PARTIALLY TORN OFF ROOF OF A BUILDING. POSSIBLE TORNADO DAMAGE. TIME ESTIMATED BY RADAR.

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

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.1 hours before the alert went out and 230 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, Washington/Dulle, VA at 12:00Z on 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 269 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, Washington/Dulle, VA at 12:00Z on 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 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
269 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
893 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

837 
WFUS51 KPHI 292003
TORPHI
PAC011-077-095-292030-
/O.NEW.KPHI.TO.W.0017.210729T2003Z-210729T2030Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  Northeastern Berks County in eastern Pennsylvania...
  Central Lehigh County in eastern Pennsylvania...
  Western Northampton County in eastern Pennsylvania...

* Until 430 PM EDT.
    
* At 403 PM EDT, a severe thunderstorm capable of producing a tornado
  was located near Wanamakers, or 14 miles southeast of Tamaqua,
  moving east at 15 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...
  Allentown, Emmaus, Northampton, Kutztown, Topton, Lenhartsville,
  Neffs, Wanamakers, Coffeetown, New Tripoli, Ancient Oaks,
  Schnecksville, Claussville, Macungie, Alburtis, Hokendauqua and
  Fullerton.

This includes the following highways...
 Northeast Extension between mile markers 50 and 67.
 Interstate 78 in Pennsylvania between mile markers 36 and 58.

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 4051 7591 4065 7591 4076 7552 4050 7548
TIME...MOT...LOC 2003Z 260DEG 14KT 4061 7583 

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

$$

Fitzsimmons
1 follow-up statement
592 
WWUS51 KPHI 292014
SVSPHI

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

PAC011-077-095-292030-
/O.CON.KPHI.TO.W.0017.000000T0000Z-210729T2030Z/
Berks PA-Lehigh PA-Northampton PA-
414 PM EDT Thu Jul 29 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 430 PM EDT FOR
NORTHEASTERN BERKS...CENTRAL LEHIGH AND WESTERN NORTHAMPTON
COUNTIES...
    
At 414 PM EDT, a severe thunderstorm capable of producing a tornado
was located near Claussville, or 13 miles west 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...
Allentown, Emmaus, Northampton, Kutztown, Neffs, Coffeetown, New
Tripoli, Ancient Oaks, Schnecksville, Claussville, Coplay,
Hokendauqua and Fullerton.

This includes the following highways...
 Northeast Extension between mile markers 53 and 67.
 Interstate 78 in Pennsylvania between mile markers 41 and 58.

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 4053 7582 4067 7582 4076 7552 4053 7548
TIME...MOT...LOC 2014Z 257DEG 22KT 4063 7573 

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, 3:48 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Northampton42 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, 4:56 PM EDTTornado WarningPHIBucks, Lehigh, Northampton34 min
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.