Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 78, NWS Philadelphia/Mount Holly

August 17, 2018Warren County, New Jersey; Monroe County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 17, 2018, 5:59 PM EDT for Warren County, New Jersey; Monroe County, Northampton County, Pennsylvania. It was in force for 31 min. 9 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
Aug 17, 2018, 5:59 PM EDT (21:59 UTC)
Expired
Aug 17, 2018, 6:30 PM EDT
In force
31 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Warren County, NJ, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 121 km from the middle of the area, began a volume at 21:59 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

TimeReportWhereRemark
Aug 17, 6:00 PM EDTTSTM WND DMGBath, PATWO TREES DOWNED.
Aug 17, 6:00 PM EDTTSTM WND DMGMoore Twp, PASEVERAL REPORTS OF DOWNED TREES AND POWER LINES IN MOORE TWP...ALLEN TWP...AND CHAPMAN. TIME ESTIMATED FROM RADAR.
Aug 17, 6:00 PM EDTTSTM WND GST 62Bath, PA
Aug 17, 6:03 PM EDTTSTM WND DMGBushkill Twp, PAMULTIPLE REPORTS OF TREES AND WIRES DOWN IN BUSHKILL TOWNSHIP
Aug 17, 6:03 PM EDTTSTM WND DMGRoss Common, PATREES DOWNED IN WIRES. TIME ESTIMATED FROM RADAR.
Aug 17, 6:11 PM EDTTSTM WND DMG1 Ese Ross Common, PADOWNED UTILITY ON BROADWAY STREET BETWEEN THE MONROE COUNTY LINE AND ROUTE 33 NORTH. ALL LANES CLOSED. TIME ESTIMATED FROM RADAR.
Aug 17, 6:18 PM EDTTSTM WND DMG1 Wnw Harmony, NJSEVERAL REPORTS OF TREE DAMAGE NEAR AND NORTHWEST OF HARMONY NEAR THE DELAWARE RIVER. TIME ESTIMATED FROM RADAR.
Aug 17, 6:30 PM EDTTSTM WND DMGUpper Mount Bethel Twp, PASEVERAL TREES DOWN IN UPPER MOUNT BETHEL TWP AND EAST BANGOR. TIME ESTIMATED FROM RADAR.
Aug 17, 6:34 PM EDTTSTM WND DMGBelvidere, NJREPORTS OF A FEW TREES AND LARGE BRANCHES DOWN IN BELVIDERE. 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.

IssuedProductOfficeLasted
Aug 17, 3:44 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.0 hours before the alert went out and 211 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-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2018-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 321 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Brookhaven, NY at 12:00Z on 2018-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
321 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
1245 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

233 
WUUS51 KPHI 172159
SVRPHI
NJC041-PAC089-095-172230-
/O.NEW.KPHI.SV.W.0078.180817T2159Z-180817T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
559 PM EDT FRI AUG 17 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  West central Warren County in northwestern New Jersey...
  South central Monroe County in northeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 630 PM EDT.

* At 558 PM EDT, a severe thunderstorm was located over Bath, or 9
  miles northwest of Easton, moving northeast at 40 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...
  Bethlehem, Northampton, East Stroudsburg, Nazareth, Bangor, Pen
  Argyl, Wind Gap, Bath, Belvidere, Oxford, Belfast, Tatamy, East
  Bangor, Steuben, Stormville, Rossland, Saylorsburg, Roxburg,
  Beersville and Stroudsburg.

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.

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

&&

LAT...LON 4081 7501 4064 7540 4067 7543 4067 7546
      4072 7552 4074 7553 4073 7554 4075 7557
      4102 7521
TIME...MOT...LOC 2158Z 233DEG 34KT 4076 7538 

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

CMS
2 follow-up statements
831 
WWUS51 KPHI 172212
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
612 PM EDT FRI AUG 17 2018

NJC041-PAC089-095-172230-
/O.CON.KPHI.SV.W.0078.000000T0000Z-180817T2230Z/
Warren NJ-Monroe PA-Northampton PA-
612 PM EDT FRI AUG 17 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR WEST CENTRAL WARREN...SOUTH CENTRAL MONROE AND NORTHEASTERN
NORTHAMPTON COUNTIES...

At 610 PM EDT, a severe thunderstorm was located over Wind Gap, or 10
miles north of Easton, moving northeast at 40 mph.

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

SOURCE...Trained weather spotters. Wind gusts to 62 mph were 
         reported in Bath around 6 pm as this storm passed, with 
         trees reported down as well.

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

Locations impacted include...
Bethlehem, East Stroudsburg, Nazareth, Bangor, Pen Argyl, Wind Gap,
Bath, Belvidere, Oxford, Belfast, Tatamy, East Bangor, Steuben,
Stormville, Saylorsburg, Rossland, Roxburg, Stroudsburg, Roseto and
Stockertown.

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.

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

&&

LAT...LON 4081 7501 4066 7536 4084 7544 4102 7521
TIME...MOT...LOC 2210Z 233DEG 34KT 4083 7525 

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

CMS
545 
WWUS51 KPHI 172226
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
626 PM EDT FRI AUG 17 2018

NJC041-PAC089-095-172235-
/O.EXP.KPHI.SV.W.0078.000000T0000Z-180817T2230Z/
Warren NJ-Monroe PA-Northampton PA-
626 PM EDT FRI AUG 17 2018

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL WARREN...SOUTH
CENTRAL MONROE AND NORTHEASTERN NORTHAMPTON COUNTIES WILL EXPIRE AT
630 PM EDT...
        
A new severe thunderstorm warning has been issued for far northeast 
Monroe, northern Warren, and southeastern Monroe Counties until 7 pm.

A severe thunderstorm watch remains in effect until 1100 PM EDT for
northwestern New Jersey...and eastern and northeastern Pennsylvania.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
in Mount Holly NJ.

LAT...LON 4081 7501 4066 7536 4084 7544 4102 7521
TIME...MOT...LOC 2225Z 233DEG 34KT 4090 7512 

$$

CMS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 3:37 PM EDTSpecial Weather StatementPHIHunterdon38 min
Aug 17, 3:42 PM EDTSpecial Weather StatementPHIWarren48 min
Aug 17, 5:46 PM EDTSpecial Weather StatementPHIMorris14 min
Aug 17, 6:02 PM EDTSpecial Weather StatementPHIMorris13 min
Aug 17, 6:22 PM EDTSevere Thunderstorm WarningPHISussex, Warren38 min
Aug 17, 6:59 PM EDTSpecial Weather StatementPHISussex31 min
Aug 17, 7:28 PM EDTSpecial Weather StatementPHISussex17 min
Aug 17, 7:42 PM EDTSpecial Weather StatementPHIHunterdon, Warren33 min
Aug 17, 2:21 PM EDTSpecial Weather StatementPHILehigh24 min
Aug 17, 4:29 PM EDTSpecial Weather StatementPHIBerks46 min
Aug 17, 5:07 PM EDTSpecial Weather StatementPHIBerks, Lehigh53 min
Aug 17, 5:12 PM EDTSpecial Weather StatementPHIBerks33 min
Aug 17, 5:36 PM EDTSpecial Weather StatementPHILehigh, Northampton39 min
Aug 17, 6:00 PM EDTSpecial Weather StatementPHICarbon30 min
Aug 17, 6:18 PM EDTSpecial Weather StatementPHIBerks27 min
Aug 17, 6:19 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe41 min
Aug 17, 6:23 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh52 min
Aug 17, 6:40 PM EDTFlash Flood WarningPHIBerks2 hr
Aug 17, 7:09 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more51 min
Aug 17, 7:15 PM EDTSpecial Weather StatementPHIPike15 min
Aug 17, 7:34 PM EDTSpecial Weather StatementPHICarbon26 min
Aug 17, 7:39 PM EDTSpecial Weather StatementPHIMonroe51 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2018Severe Thunderstorm Warnings in New Jersey, 2018Every severe thunderstorm warning in 2018

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.