Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 108, NWS Philadelphia/Mount Holly

July 20, 20175 counties in Pennsylvania; Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 20, 2017, 6:22 PM EDT for 5 counties in Pennsylvania; Warren County, New Jersey. It was in force for 53 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 20, 2017, 6:22 PM EDT (22:22 UTC)
Expired: Jul 20, 2017, 7:15 PM EDT
In force: 53 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Warren County, NJ, Berks County, PA, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 130 km from the middle of the area, began a volume at 22:22 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 20, 6:32 PM EDT	TSTM WND DMG	Parryville, PA	TREES AND POWERLINES DOWN. TIME ESTIMATED FROM RADAR.
Jul 20, 6:55 PM EDT	TSTM WND DMG	Bath, PA	TREES DOWN
Jul 20, 7:07 PM EDT	TSTM WND DMG	Easton, PA	SEVERAL REPORTS OF TREES AND WIRES DOWN IN EASTON. TIME APPROXIMATED FROM RADAR.
Jul 20, 7:10 PM EDT	TSTM WND DMG	Bethlehem, PA	SEVERAL TREES AND WIRES REPORTED DOWN IN BETHLEHEM AND HELLERTOWN. TIME APPROXIMATED FROM RADAR.
Jul 20, 7:10 PM EDT	TSTM WND DMG	Phillipsburg, NJ	LARGE TREE LIMBS BLOCKING ROAD. 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 20, 5:03 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.4 hours before the alert went out and 226 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: 14 J/kg
Mixed-layer CIN: -148 J/kg
Mixed-layer LCL: 1647 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

605 
WUUS51 KPHI 202222
SVRPHI
NJC041-PAC011-025-077-089-095-202315-
/O.NEW.KPHI.SV.W.0108.170720T2222Z-170720T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
622 PM EDT THU JUL 20 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Warren County in northwestern New Jersey...
  Northern Berks County in eastern Pennsylvania...
  Lehigh County in eastern Pennsylvania...
  Carbon County in northeastern Pennsylvania...
  Southwestern Monroe County in northeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 715 PM EDT

* At 620 PM EDT, severe thunderstorms were located along a line
  extending from Albrightsville to Drifton to near Rock Glen, moving
  southeast at 35 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Severe thunderstorms will be near,
  Meckesville, Albrightsville and Christmans around 625 PM EDT. 
  Weatherly, Jonas, Sun Valley and Penn Forest Reservoir around 630 
  PM EDT. 
  Nesquehoning, Kresgeville and McMichael around 635 PM EDT. 
  Jim Thorpe, Gilbert and Brodheadsville around 640 PM EDT. 
  Lehighton, Rossland and Kunkletown around 645 PM EDT. 
  Saylorsburg and Beltzville State Park around 650 PM EDT. 
  Palmerton, Pen Argyl and Wind Gap around 655 PM EDT. 
  Nazareth, Bangor, Slatington, Walnutport, Belfast, Berlinsville 
  and Emerald around 700 PM EDT. 

Other locations impacted by these severe thunderstorms include
Effort, Hokendauqua, Stockertown, Trachsville, Weissport, Parryville,
Eastlawn Gardens, North Catasauqua, Freemansburg and Merwinsburg.

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 this storm. Move indoors
immediately. Remember...if you can hear thunder...you are close
enough to be struck by lightning.

&&

LAT...LON 4071 7498 4069 7500 4070 7502 4068 7504
      4059 7545 4058 7596 4061 7601 4065 7598
      4070 7583 4074 7576 4083 7590 4091 7599
      4100 7577 4103 7544
TIME...MOT...LOC 2220Z 305DEG 29KT 4101 7559 4097 7591 4098 7622 

HAIL...<.75IN
WIND...60MPH
 
$$

Robertson

2 follow-up statements

296 
WWUS51 KPHI 202248
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
648 PM EDT THU JUL 20 2017

NJC041-PAC011-025-077-089-095-202315-
/O.CON.KPHI.SV.W.0108.000000T0000Z-170720T2315Z/
Warren NJ-Berks PA-Lehigh PA-Carbon PA-Monroe PA-Northampton PA-
648 PM EDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR SOUTHWESTERN WARREN...NORTHERN BERKS...LEHIGH...SOUTHERN
CARBON...SOUTH CENTRAL MONROE AND NORTHAMPTON COUNTIES...

At 648 PM EDT, severe thunderstorms were located along a line
extending from Saylorsburg to Beersville to Mcadoo, moving southeast
at 35 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

These severe storms will be near...
  Northampton, Nazareth, Pen Argyl, Wind Gap, Bath, Saylorsburg, 
  Beersville and Rossland around 655 PM EDT. 
  Bethlehem, Bangor, Belfast and Steuben around 700 PM EDT. 
  Forks, Wilson, West Easton, Tatamy, Old Orchard and Lehigh 
  University around 705 PM EDT. 
  Easton, Lehighton, Harmony, Glendon and Roxburg around 710 PM EDT. 
  Palmerton, Slatington, Alpha, Walnutport, Jordan Valley, Emerald, 
  New Tripoli and Schnecksville around 715 PM EDT. 

Other locations impacted by these severe thunderstorms include
Chapman, Beaver Meadows, Coplay, Fountain Hill, Fullerton,
Hokendauqua, Stockertown, Summit Hill, Bowmanstown and Weissport.

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 this storm. Move indoors
immediately. Remember...if you can hear thunder...you are close
enough to be struck by lightning.

&&

LAT...LON 4071 7498 4069 7500 4070 7502 4068 7504
      4059 7545 4058 7596 4061 7601 4065 7598
      4070 7583 4074 7576 4083 7590 4091 7598
      4094 7591 4087 7554 4095 7532
TIME...MOT...LOC 2248Z 312DEG 32KT 4090 7532 4075 7544 4092 7597 

HAIL...<.75IN
WIND...60MPH
 
$$

Robertson

423 
WWUS51 KPHI 202314
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
714 PM EDT THU JUL 20 2017

NJC041-PAC011-025-077-089-095-202323-
/O.EXP.KPHI.SV.W.0108.000000T0000Z-170720T2315Z/
Warren NJ-Berks PA-Lehigh PA-Carbon PA-Monroe PA-Northampton PA-
714 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WARREN...NORTHERN
BERKS...LEHIGH...SOUTHERN CARBON...SOUTH CENTRAL MONROE AND
NORTHAMPTON COUNTIES WILL EXPIRE AT 715 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore the warning will be allowed to expire.  However gusty winds
and heavy rain are still possible with these thunderstorms.

A severe thunderstorm watch remains in effect until 1000 PM EDT for
northwestern New Jersey...and eastern and northeastern Pennsylvania.

Remember, a Severe Thunderstorm Warning still remains in effect for
for other portions of the area.

LAT...LON 4071 7498 4069 7500 4070 7502 4068 7504
      4059 7545 4058 7596 4061 7601 4065 7598
      4070 7583 4074 7576 4083 7590 4091 7598
      4094 7591 4087 7554 4095 7532
TIME...MOT...LOC 2313Z 305DEG 29KT 4079 7511 4064 7523 4081 7576 

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 3:43 AM EDT	Heat Advisory	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	15 hr
Jul 20, 5:35 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	55 min
Jul 20, 5:37 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	53 min
Jul 20, 6:24 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	66 min
Jul 20, 7:00 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Carbon, Lehigh, Northampton	60 min
Jul 20, 7:52 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	53 min
Jul 20, 7:31 PM EDT	Special Weather Statement	PHI	Morris	29 min
Jul 20, 7:56 PM EDT	Special Weather Statement	PHI	Middlesex, Monmouth, Somerset	49 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2017 Severe Thunderstorm Warnings in New Jersey, 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.