Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 73, NWS Philadelphia/Mount Holly

July 1, 2017Berks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 1, 2017, 3:41 PM EDT for Berks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 49 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 1, 2017, 3:41 PM EDT (19:41 UTC)
Expired: Jul 1, 2017, 4:30 PM EDT
In force: 49 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

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

The radar

The Philadelphia radar (KDIX), 151 km from the middle of the area, began a volume at 19:41 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 1, 4:30 PM EDT	TSTM WND DMG	Topton, PA	TREE REPORTED DOWN ON RAILROAD TRACKS IN TOPTON.
Jul 1, 4:35 PM EDT	TSTM WND DMG	Mertztown, PA	TREE REPORTED DOWN IN MERTZTOWN.
Jul 1, 4:37 PM EDT	TSTM WND DMG	East Texas, PA	DOWNED TREES AND WIRES ON BROOKSIDE RD BETWEEN EAST TEXAS RD AND LOWER MACUNGIE RD
Jul 1, 4:40 PM EDT	TSTM WND DMG	Haines, PA	PARTIAL ROOF COLLAPSE OF A COMERCIAL BUILDING ON SCHANTZ RD. 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
Jul 1, 1:34 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.7 hours before the alert went out and 214 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: 160 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 564 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 105 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted.

284 
WUUS51 KPHI 011941
SVRPHI
PAC011-077-095-012030-
/O.NEW.KPHI.SV.W.0073.170701T1941Z-170701T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
341 PM EDT SAT JUL 1 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Berks County in eastern Pennsylvania...
  Lehigh County in eastern Pennsylvania...
  Southwestern Northampton County in eastern Pennsylvania...

* Until 430 PM EDT

* At 341 PM EDT, a severe thunderstorm was located over Fairview
  Hgts, or 10 miles northwest of Reading, moving east at 40 mph.

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

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to trees and power lines. 

* Locations impacted include...
  Allentown, Reading, Bethlehem, Emmaus, Wyomissing, Northampton,
  Kutztown, Hamburg, Slatington, Fleetwood, Sinking Spring,
  Laureldale, Womelsdorf, Bath, Wernersville, Newmanstown,
  Walnutport, Topton, Leesport and Shoemakersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4049 7643 4052 7635 4052 7625 4058 7605
      4057 7602 4065 7598 4070 7583 4073 7578
      4077 7539 4051 7538 4023 7602 4036 7621
TIME...MOT...LOC 1941Z 259DEG 34KT 4046 7604 

HAIL...0.88IN
WIND...60MPH
 
$$

SFJ

2 follow-up statements

653 
WWUS51 KPHI 011958
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
358 PM EDT SAT JUL 1 2017

PAC011-077-095-012030-
/O.CON.KPHI.SV.W.0073.000000T0000Z-170701T2030Z/
Berks PA-Lehigh PA-Northampton PA-
358 PM EDT SAT JUL 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR BERKS...LEHIGH AND SOUTHWESTERN NORTHAMPTON COUNTIES...

At 357 PM EDT, a severe thunderstorm was located over
Shoemakersville, or 12 miles north of Reading, moving northeast at 30
mph.

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

SOURCE...Radar indicated. 

IMPACT...Minor damage to vehicles is possible. Expect damage to 
         trees and power lines. 

Locations impacted include...
Allentown, Reading, Bethlehem, Emmaus, Wyomissing, Northampton,
Kutztown, Hamburg, Slatington, Fleetwood, Sinking Spring, Laureldale,
Womelsdorf, Bath, Wernersville, Newmanstown, Walnutport, Topton,
Leesport and Shoemakersville.

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 4049 7643 4052 7635 4052 7625 4058 7605
      4057 7602 4065 7598 4070 7583 4073 7578
      4077 7539 4051 7538 4023 7602 4036 7621
TIME...MOT...LOC 1957Z 244DEG 24KT 4052 7594 

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

SFJ

920 
WWUS51 KPHI 012019
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
419 PM EDT SAT JUL 1 2017

PAC011-077-095-012030-
/O.CON.KPHI.SV.W.0073.000000T0000Z-170701T2030Z/
Berks PA-Lehigh PA-Northampton PA-
419 PM EDT SAT JUL 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR BERKS...LEHIGH AND SOUTHWESTERN NORTHAMPTON COUNTIES...

At 418 PM EDT, a severe thunderstorm was located near Claussville, or
10 miles west of Allentown, moving east at 40 mph.

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

SOURCE...Radar indicated. 

IMPACT...Minor damage to vehicles is possible. Expect damage to 
         trees and power lines. 

Locations impacted include...
Allentown, Reading, Bethlehem, Emmaus, Wyomissing, Northampton,
Kutztown, Hamburg, Slatington, Fleetwood, Sinking Spring, Laureldale,
Womelsdorf, Bath, Wernersville, Newmanstown, Walnutport, Topton,
Leesport and Shoemakersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

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

&&

LAT...LON 4049 7643 4052 7635 4052 7625 4058 7605
      4057 7602 4065 7598 4070 7583 4073 7578
      4077 7539 4051 7538 4023 7602 4036 7621
TIME...MOT...LOC 2018Z 259DEG 34KT 4056 7568 

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

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 8:09 PM EDT	Special Weather Statement	PHI	Montgomery	51 min
Jun 30, 8:32 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery	118 min
Jun 30, 9:17 PM EDT	Special Weather Statement	PHI	Bucks	43 min
Jul 1, 2:38 PM EDT	Special Weather Statement	PHI	Berks	52 min
Jul 1, 3:22 PM EDT	Special Weather Statement	PHI	Berks, Carbon	23 min
Jul 1, 3:24 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	3 hr
Jul 1, 4:05 PM EDT	Special Weather Statement	PHI	Chester	40 min
Jul 1, 4:20 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh	4 hr
Jul 1, 4:24 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	51 min
Jul 1, 5:00 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	4 hr
Jul 1, 5:01 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	44 min
Jul 1, 5:08 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Montgomery, Northampton	52 min
Jul 1, 5:30 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Jul 1, 5:35 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Delaware, Montgomery, Philadelphia	40 min
Jul 1, 5:50 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	40 min
Jul 1, 6:17 PM EDT	Areal Flood Advisory	PHI	Monroe, Northampton	4 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2017 Every severe thunderstorm warning in 2017

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.