Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 99, NWS Philadelphia/Mount Holly

June 21, 20214 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 21, 2021, 7:02 PM EDT for 4 counties in Pennsylvania. It was in force for 43 min. 14 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: Jun 21, 2021, 7:02 PM EDT (23:02 UTC)
Expired: Jun 21, 2021, 7:45 PM EDT
In force: 43 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

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

The radar

The Philadelphia radar (KDIX), 152 km from the middle of the area, began a volume at 23:05 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
Jun 21, 7:09 PM EDT	TSTM WND DMG	1 W Fleetwood, PA	TREE AND WIRES DOWN. TIME ESTIMATED FROM RADAR.
Jun 21, 7:15 PM EDT	HAIL 0.5	Lansford, PA
Jun 21, 7:19 PM EDT	TSTM WND DMG	3 Nw Lenhartsville, PA	DOWNED TREES AND WIRES NEAR BLUE ROCKS ROAD. TIME ESTIMATED FROM RADAR.
Jun 21, 7:25 PM EDT	TSTM WND DMG	Walnutport, PA	REPORT OF WIRES DOWN. TIME ESTIMATED FROM RADAR.
Jun 21, 7:29 PM EDT	TSTM WND DMG	1 Sw Jim Thorpe, PA	TREE AND WIRES DOWN. TIME ESTIMATED FROM RADAR.
Jun 21, 7:29 PM EDT	TSTM WND DMG	1 Wnw Jim Thorpe, PA	REPORT OF TREE AND WIRES DOWN ON MAIN STREET IN JIM THORPE. TIME ESTIMATED FROM RADAR.
Jun 21, 7:30 PM EDT	TSTM WND DMG	2 N Germansville, PA	REPORT OF TREE AND WIRES DOWN. TIME ESTIMATED FROM RADAR.
Jun 21, 7:30 PM EDT	TSTM WND DMG	4 Sw Christmans, PA	REPORT OF TREE AND WIRES DOWN ON SPARROW LANE.
Jun 21, 7:31 PM EDT	TSTM WND DMG	2 Sw Jim Thorpe, PA	DOWNED TREE IN WIRES NEAR LENTZ TRAIL AND FLAGSTAFF ROAD. TIME ESTIMATED FROM RADAR.
Jun 21, 7:33 PM EDT	TSTM WND DMG	1 Ene Kidder Twp, PA	TREES AND WIRES DOWN IN THE POCONO MOUNTAIN LAKE ESTATES AREA. TIME ESTIMATED FROM RADAR.
Jun 21, 7:40 PM EDT	TSTM WND DMG	1 Ene Palmerton, PA	DOWNED TREES AND WIRES NEAR ALLEY F AND PARK LANE. TIME ESTIMATED FROM RADAR.
Jun 21, 7:45 PM EDT	TSTM WND DMG	1 Wnw Emerald, PA	DOWNED TREES AND WIRES NEAR GRANT STREET. TIME ESTIMATED FROM RADAR.
Jun 21, 7:45 PM EDT	TSTM WND DMG	2 Sw Laurys Station, PA	DOWNED POWER LINES NEAR NEFFS LAURYS ROAD. TIME ESTIMATED FROM RADAR.
Jun 21, 7:50 PM EDT	TSTM WND DMG	1 Ene Palmerton, PA	REPORT OF TREE AND WIRES DOWN. TIME 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
Jun 21, 4:33 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.0 hours before the alert went out and 238 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: 329 J/kg
Mixed-layer CIN: -164 J/kg
Mixed-layer LCL: 801 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

905 
WUUS51 KPHI 212302
SVRPHI
PAC011-025-077-095-212345-
/O.NEW.KPHI.SV.W.0099.210621T2302Z-210621T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
702 PM EDT Mon Jun 21 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northeastern Berks County in eastern Pennsylvania...
  Lehigh County in eastern Pennsylvania...
  Carbon County in northeastern Pennsylvania...
  West central Northampton County in eastern Pennsylvania...

* Until 745 PM EDT.

* At 702 PM EDT, severe thunderstorms were located along a line
  extending from Nesquehoning to near Kutztown, moving northeast at
  30 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Lehighton, Northampton, Palmerton, Kutztown, Jim Thorpe, Hamburg,
  Slatington, Fleetwood, Nesquehoning, Weatherly, Walnutport, Topton,
  Leesport, Shoemakersville, Bernville, Lyons, Lenhartsville, New
  Mahoning, Neffs and Coffeetown.

This includes the following highways...
 Northeast Extension between mile markers 57 and 97.
 Interstate 78 in Pennsylvania between mile markers 21 and 54.
 Interstate 80 in Pennsylvania between mile markers 277 and 283.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with these storms. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

&&

LAT...LON 4058 7606 4057 7602 4065 7598 4070 7583
      4074 7576 4091 7599 4101 7573 4105 7577
      4108 7577 4113 7569 4071 7540 4049 7568
      4035 7612 4053 7619
TIME...MOT...LOC 2302Z 224DEG 24KT 4087 7587 4055 7583 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS

2 follow-up statements

867 
WWUS51 KPHI 212320
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
720 PM EDT Mon Jun 21 2021

PAC011-025-077-095-212345-
/O.CON.KPHI.SV.W.0099.000000T0000Z-210621T2345Z/
Berks PA-Lehigh PA-Carbon PA-Northampton PA-
720 PM EDT Mon Jun 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR NORTHEASTERN BERKS...LEHIGH...CARBON AND WEST CENTRAL NORTHAMPTON
COUNTIES...

At 719 PM EDT, severe thunderstorms were located along a line
extending from near Nesquehoning to near Lenhartsville, moving
northeast at 45 mph.

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

SOURCE...Law enforcement. Several reports of trees and wires down 
         have been received from western portions of Berks County.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Lehighton, Northampton, Palmerton, Kutztown, Jim Thorpe, Hamburg,
Slatington, Fleetwood, Nesquehoning, Weatherly, Walnutport, Topton,
Leesport, Shoemakersville, Lyons, Lenhartsville, New Mahoning, Neffs,
Coffeetown and New Tripoli.

This includes the following highways...
 Northeast Extension between mile markers 57 and 97.
 Interstate 78 in Pennsylvania between mile markers 30 and 54.
 Interstate 80 in Pennsylvania between mile markers 277 and 283.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4057 7602 4065 7598 4070 7583 4074 7576
      4091 7599 4101 7573 4105 7577 4108 7577
      4113 7569 4071 7540 4049 7568 4040 7596
TIME...MOT...LOC 2319Z 226DEG 38KT 4087 7588 4055 7584 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS

256 
WWUS51 KPHI 212334
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
734 PM EDT Mon Jun 21 2021

PAC011-025-077-095-212345-
/O.CON.KPHI.SV.W.0099.000000T0000Z-210621T2345Z/
Berks PA-Lehigh PA-Carbon PA-Northampton PA-
734 PM EDT Mon Jun 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR NORTHEASTERN BERKS...CENTRAL LEHIGH...CARBON AND WEST CENTRAL
NORTHAMPTON COUNTIES...

At 733 PM EDT, severe thunderstorms were located along a line
extending from near White Haven to near Topton, moving northeast at
30 mph.

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

SOURCE...Law enforcement.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Lehighton, Northampton, Palmerton, Kutztown, Jim Thorpe, Slatington,
Nesquehoning, Weatherly, Walnutport, Lenhartsville, New Mahoning,
Neffs, Coffeetown, New Tripoli, Berlinsville, Emerald, Claussville,
Danielsville, Wanamakers and Beltzville State Park.

This includes the following highways...
 Northeast Extension between mile markers 57 and 97.
 Interstate 78 in Pennsylvania between mile markers 36 and 53.
 Interstate 80 in Pennsylvania between mile markers 277 and 283.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4073 7542 4071 7541 4053 7563 4050 7592
      4068 7590 4070 7583 4074 7576 4084 7589
      4095 7588 4101 7573 4105 7577 4108 7577
      4113 7569
TIME...MOT...LOC 2333Z 234DEG 28KT 4101 7575 4056 7572 

HAIL...0.75IN
WIND...60MPH
 
$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 9:27 PM EDT	Special Weather Statement	PHI	Schuylkill	33 min
Jun 20, 9:55 PM EDT	Special Weather Statement	PHI	Lebanon	35 min
Jun 20, 10:04 PM EDT	Areal Flood Advisory	PHI	Berks	86 min
Jun 20, 10:27 PM EDT	Special Weather Statement	PHI	Berks	33 min
Jun 21, 4:35 AM EDT	Heat Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	15 hr
Jun 21, 6:08 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh	52 min
Jun 21, 6:21 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	54 min
Jun 21, 7:12 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	48 min
Jun 21, 7:38 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Monroe, Northampton	52 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.