Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 150, NWS Philadelphia/Mount Holly

July 8, 20215 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 8, 2021, 4:45 PM EDT for 5 counties in Pennsylvania. It was in force for 45 min. 5 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 8, 2021, 4:45 PM EDT (20:45 UTC)
Expired: Jul 8, 2021, 5:30 PM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 106 km from the middle of the area, began a volume at 20:46 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 8, 4:55 PM EDT	TSTM WND DMG	Upper Milford Twp, PA	WIRES DOWN IN UPPER MILFORD TWP. TIME ESTIMATED FROM RADAR.
Jul 8, 4:58 PM EDT	HAIL 1	Zionsville, PA	PUBLIC REPORT OF QUARTER SIZED HAIL SOUTH OF ALLENTOWN. TIME ESTIMATED FROM RADAR.
Jul 8, 5:09 PM EDT	TSTM WND DMG	Upper Saucon Twp, PA	NUMEROUS 911 CALLS FOR DOWNED TREES IN UPPER SAUCON. TIME ESTIMATED FROM RADAR.
Jul 8, 5:15 PM EDT	HAIL 0.5	2 N Hellertown, PA	1/2 INCH SIZED HAIL REPORTED NEAR BETHLEHEM AND HELLERTOWN.
Jul 8, 5:21 PM EDT	TSTM WND DMG	1 Se Hellertown, PA	A TREE WAS DOWNED INTO A HOUSE ON CEDAR RD. NO INJURIES BUT THE HOME IS UNINHABITABLE. TIME ESTIMATED FROM RADAR AND EMERGENCY MANAGEMENT REPORTS.

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 8, 2:09 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.8 hours before the alert went out and 210 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: 973 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 751 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

As transmitted.

739 
WUUS51 KPHI 082045
SVRPHI
PAC011-017-077-091-095-082130-
/O.NEW.KPHI.SV.W.0150.210708T2045Z-210708T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
445 PM EDT Thu Jul 8 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  East central Berks County in eastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Southwestern Northampton County in eastern Pennsylvania...

* Until 530 PM EDT.

* At 445 PM EDT, a severe thunderstorm was located over Bally, or 12
  miles southwest of Allentown, moving northeast at 25 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Allentown, Easton, Bethlehem, Emmaus, Northampton, Hellertown, East
  Greenville, Bath, Bally, Bechtelsville, Riegelsville, Steuben,
  Glendon, Pleasant Valley, Zionsville, Ancient Oaks, Lehigh
  University, Geryville, Springtown and Beersville.

This includes the following highways...
 Northeast Extension between mile markers 43 and 59.
 Interstate 78 in Pennsylvania between mile markers 52 and 74.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 4077 7547 4063 7518 4062 7519 4062 7520
      4059 7519 4057 7519 4057 7513 4034 7556
      4043 7573
TIME...MOT...LOC 2045Z 222DEG 23KT 4043 7558 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann

3 follow-up statements

742 
WWUS51 KPHI 082100
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
500 PM EDT Thu Jul 8 2021

PAC011-091-082110-
/O.CAN.KPHI.SV.W.0150.000000T0000Z-210708T2130Z/
Berks PA-Montgomery PA-
500 PM EDT Thu Jul 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL BERKS AND
NORTHWESTERN MONTGOMERY COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

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

LAT...LON 4064 7520 4063 7519 4062 7519 4062 7520
      4057 7518 4057 7514 4040 7545 4049 7559
      4077 7546
TIME...MOT...LOC 2100Z 222DEG 23KT 4050 7550 

$$

PAC017-077-095-082130-
/O.CON.KPHI.SV.W.0150.000000T0000Z-210708T2130Z/
Lehigh PA-Bucks PA-Northampton PA-
500 PM EDT Thu Jul 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHEASTERN LEHIGH...NORTHWESTERN BUCKS AND SOUTHWESTERN
NORTHAMPTON COUNTIES...

At 500 PM EDT, a severe thunderstorm was located over Zionsville, or
near Allentown, moving northeast at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Allentown, Easton, Bethlehem, Emmaus, Northampton, Hellertown, Bath,
Riegelsville, Steuben, Glendon, Pleasant Valley, Zionsville, Lehigh
University, Springtown, Old Orchard, Beersville, Geryville, Ancient
Oaks, Catasauqua and Fountain Hill.

This includes the following highways...
 Northeast Extension between mile markers 43 and 55.
 Interstate 78 in Pennsylvania between mile markers 55 and 74.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 4064 7520 4063 7519 4062 7519 4062 7520
      4057 7518 4057 7514 4040 7545 4049 7559
      4077 7546
TIME...MOT...LOC 2100Z 222DEG 23KT 4050 7550 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann

794 
WWUS51 KPHI 082117
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
517 PM EDT Thu Jul 8 2021

PAC017-077-095-082130-
/O.CON.KPHI.SV.W.0150.000000T0000Z-210708T2130Z/
Lehigh PA-Bucks PA-Northampton PA-
517 PM EDT Thu Jul 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR EAST CENTRAL LEHIGH...NORTHWESTERN BUCKS AND SOUTH CENTRAL
NORTHAMPTON COUNTIES...

At 517 PM EDT, a severe thunderstorm was located over Hellertown, or
near Allentown, moving northeast at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Allentown, Easton, Bethlehem, Hellertown, Riegelsville, Steuben,
Glendon, Springtown, Old Orchard, Lehigh University, Fountain Hill,
Freemansburg and Coopersburg.

This includes Interstate 78 in Pennsylvania between mile markers 61
and 74.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

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

&&

LAT...LON 4051 7538 4058 7548 4073 7537 4064 7520
      4063 7519 4062 7519 4062 7520 4058 7518
TIME...MOT...LOC 2117Z 224DEG 24KT 4058 7537 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann

798 
WWUS51 KPHI 082137
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
537 PM EDT Thu Jul 8 2021

PAC017-077-095-082147-
/O.EXP.KPHI.SV.W.0150.000000T0000Z-210708T2130Z/
Lehigh PA-Bucks PA-Northampton PA-
537 PM EDT Thu Jul 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL LEHIGH...
NORTHWESTERN BUCKS AND SOUTH CENTRAL NORTHAMPTON COUNTIES HAS
EXPIRED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

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

LAT...LON 4051 7538 4058 7548 4073 7537 4064 7520
      4063 7519 4062 7519 4062 7520 4058 7518
TIME...MOT...LOC 2137Z 222DEG 23KT 4067 7527 

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 11:11 PM EDT	Special Weather Statement	PHI	Monroe	49 min
Jul 8, 8:53 AM EDT	Special Weather Statement	PHI	Monroe	52 min
Jul 8, 9:31 AM EDT	Areal Flood Advisory	PHI	Carbon, Monroe	119 min
Jul 8, 9:46 AM EDT	Special Weather Statement	PHI	Monroe	44 min
Jul 8, 1:49 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	41 min
Jul 8, 3:50 PM EDT	Special Weather Statement	PHI	Berks	25 min
Jul 8, 4:06 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Montgomery	39 min
Jul 8, 4:25 PM EDT	Severe Thunderstorm Warning	PHI	Berks	50 min
Jul 8, 4:51 PM EDT	Severe Thunderstorm Warning	PHI	Berks	54 min
Jul 8, 5:11 PM EDT	Special Weather Statement	PHI	Lehigh	34 min
Jul 8, 5:21 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	39 min
Jul 8, 5:29 PM EDT	Special Weather Statement	PHI	Northampton	46 min
Jul 8, 5:52 PM EDT	Special Weather Statement	PHI	Berks	23 min
Jul 8, 6:06 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	39 min
Jul 8, 6:16 PM EDT	Severe Thunderstorm Warning	PHI	Northampton	44 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Every severe thunderstorm warning 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.