Alert archive / Pennsylvania / Tornado Warnings in 2021

Tornado Warning 18, NWS Philadelphia/Mount Holly

July 29, 2021Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Jul 29, 2021, 4:27 PM EDT for Lehigh County, Northampton County, Pennsylvania. It was in force for 16 min. 8 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, 4:27 PM EDT (20:27 UTC)
Expired: Jul 29, 2021, 4:43 PM EDT
In force: 16 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 129 km from the middle of the area, began a volume at 20:26 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

Time	Report	Where	Remark
Jul 29, 4:27 PM EDT	TSTM WND DMG	Slatington, PA	TREE DOWN AND UPROOTED. TIME ESTIMATED BY RADAR.
Jul 29, 4:27 PM EDT	TORNADO	1 Nnw Slatington, PA	A TORNADO TOUCHED DOWN ON THE GROUNDS OF NORTHERN LEHIGH HIGH SCHOOL IN SLATINGTON. SEVERAL TREES WERE SNAPPED OR UPROOTED AT THE HIGH SCHOOL, WITH MOST OF THE SNAPPING OCCURRING HIGH UP IN THE TREES. A WOODEN DUGOUT ON THE SCHOOL`S BASEBALL FIELD LOST ITS ROO
Jul 29, 4:28 PM EDT	TSTM WND DMG	1 Nnw Slatington, PA	CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 1 NNW SLATINGTON TO 428 PM. DOWNED TREE ON POWER LINES ON SHADOW OAKS LANE. POSSIBLE TORNADO.
Jul 29, 4:28 PM EDT	TSTM WND DMG	1 Nnw Slatington, PA	NUMEROUS TREES AND WIRES DOWN AT AND AROUND NORTHERN LEHIGH HIGH SCHOOL AND ON CENTER STREET IN SLATINGTON. POSSIBLE TORNADO.
Jul 29, 4:28 PM EDT	TSTM WND DMG	1 Nw Walnutport, PA	PLANES DAMAGED AT SLATINGTON AIRPORT.
Jul 29, 4:31 PM EDT	TSTM WND DMG	1 Nnw Walnutport, PA	MULTIPLE DOWNED >3 INCH TREE LIMBS. POSSIBLE TORNADO. TIME ESTIMATED FROM RADAR.
Jul 29, 4:31 PM EDT	TSTM WND DMG	1 Nw Berlinsville, PA	MULTIPLE TREES DOWN ON TIMBERLINE RD. POSSIBLE TORNADO. TIME ESTIMATED FROM RADAR.
Jul 29, 4:31 PM EDT	TSTM WND DMG	1 Wnw Berlinsville, PA	MULTIPLE TREES DOWN ON LEHIGH DR. POSSIBLE TORNADO. TIMES ESTIMATED FROM 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.

Issued	Product	Office	Lasted
Jul 29, 2:23 PM EDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.5 hours before the alert went out and 225 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

214 
WFUS51 KPHI 292027
TORPHI
PAC077-095-292100-
/O.NEW.KPHI.TO.W.0018.210729T2027Z-210729T2100Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Tornado Warning for...
  North central Lehigh County in eastern Pennsylvania...
  West central Northampton County in eastern Pennsylvania...

* Until 500 PM EDT.
    
* At 426 PM EDT, a severe thunderstorm capable of producing a tornado
  was located over Slatington, or 7 miles southeast of Lehighton,
  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...
  Northampton, Nazareth, Slatington, Bath, Walnutport, Berlinsville,
  Danielsville, Neffs, Emerald, Beersville and Chapman.

This includes Northeast Extension between mile markers 65 and 70.
 
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 4069 7566 4077 7567 4083 7534 4070 7531
TIME...MOT...LOC 2026Z 260DEG 23KT 4075 7562 

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

$$

Fitzsimmons

1 follow-up statement

068 
WWUS51 KPHI 292043
SVSPHI

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

PAC077-095-292053-
/O.CAN.KPHI.TO.W.0018.000000T0000Z-210729T2100Z/
Lehigh PA-Northampton PA-
443 PM EDT Thu Jul 29 2021

...THE TORNADO WARNING FOR NORTH CENTRAL LEHIGH AND WEST CENTRAL
NORTHAMPTON COUNTIES IS CANCELLED...
    
The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and a
Severe Thunderstorm Warning remains in effect for the area.

A Tornado Watch remains in effect until 900 PM EDT for eastern
Pennsylvania.



LAT...LON 4069 7566 4077 7567 4083 7534 4070 7531
TIME...MOT...LOC 2040Z 260DEG 23KT 4077 7548 

$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 3:48 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Northampton	42 min
Jul 29, 4:03 PM EDT	Tornado Warning	PHI	Berks, Lehigh, Northampton	27 min
Jul 29, 4:30 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Carbon, Lehigh, Monroe, Northampton	45 min
Jul 29, 4:46 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh, Northampton	3 hr
Jul 29, 4:56 PM EDT	Tornado Warning	PHI	Bucks, Lehigh, Northampton	34 min
Jul 29, 4:57 PM EDT	Areal Flood Advisory	PHI	Bucks, Monroe, Northampton	3 hr
Jul 29, 5:03 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Monroe, Northampton	42 min
Jul 29, 5:08 PM EDT	Tornado Warning	PHI	Bucks	37 min
Jul 29, 5:27 PM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jul 29, 5:32 PM EDT	Flash Flood Warning	PHI	Northampton	2 hr
Jul 29, 5:32 PM EDT	Tornado Warning	PHI	Bucks	28 min
Jul 29, 5:51 PM EDT	Tornado Warning Tornado observedConsiderable damage threat	PHI	Bucks	24 min
Jul 29, 5:58 PM EDT	Flash Flood Warning	PHI	Bucks	3 hr
Jul 29, 6:06 PM EDT	Tornado Warning Considerable damage threat	PHI	Bucks	39 min
Jul 29, 6:21 PM EDT	Special Weather Statement	PHI	Bucks	24 min
Jul 29, 6:45 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	45 min
Jul 29, 7:07 PM EDT	Tornado Warning	PHI	Bucks, Philadelphia	23 min
Jul 29, 7:12 PM EDT	Flash Flood Warning	PHI	Bucks, Philadelphia	4 hr
Jul 29, 7:25 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	50 min

Nearby

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