Alert archive / New Jersey / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 265, NWS Philadelphia/Mount Holly

August 27, 2020Hunterdon County, Somerset County, Warren County, New Jersey; Bucks County, Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 27, 2020, 8:13 PM EDT for Hunterdon County, Somerset County, Warren County, New Jersey; Bucks County, Lehigh County, Northampton County, Pennsylvania. It was in force for 47 min. 12 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 27, 2020, 8:13 PM EDT (00:13 UTC)
Expired
Aug 27, 2020, 9:00 PM EDT
In force
47 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Hunterdon County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 77 km from the middle of the area, began a volume at 00:17 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 27, 8:20 PM EDTTSTM WND DMG2 Ssw Glendon, PASEVERAL REPORTS OF DOWNED TREES AND POWER LINES IN VICINITY OF TUMBLE CREEK ROAD. TIME ESTIMATED FROM RADAR.
Aug 27, 8:22 PM EDTTSTM WND DMG2 Ene Lower Saucon Twp, PADOWNED TREES AND WIRES NEAR GAFFNEY HILL ROAD. TIME ESTIMATED FROM RADAR.
Aug 27, 8:22 PM EDTTSTM WND DMGRiegelsville, PAMULTIPLE LARGE TREES DOWN IN RIEGELSVILLE SOME BLOCKING ROADS. POWER OUTAGES REPORTED. TIME ESTIMATED FROM RADAR.
Aug 27, 8:27 PM EDTTSTM WND DMG1 Wnw Riegelsville, PADOWNED TREES AND WIRES NEAR SUNNYSIDE ROAD ON THE NORTHAMPTON AND BUCKS COUNTY LINE. TIME ESTIMATED FROM RADAR.
Aug 27, 8:30 PM EDTTSTM WND DMG1 Ene Fountain Hill, PASEVERAL REPORTS OF DOWNED TREES AND WIRES NEAR AND SOUTH AND EAST OF BETHLEHEM TWP. TIME ESTIMATED FROM RADAR.
Aug 27, 8:31 PM EDTTSTM WND DMG3 Wnw Holland Twp, NJDOWNED TREES AND WIRES NEAR PINCHERS POINT ROAD. TIME ESTIMATED FROM RADAR.
Aug 27, 8:36 PM EDTTSTM WND DMG1 Se Fountain Hill, PADOWNED TREES AND WIRES NEAR SOUTH MOUNTAIN PARK. TIME ESTIMATED FROM RADAR.
Aug 27, 8:40 PM EDTTSTM WND DMG2 W Ferndale, PADOWNED TREES AND WIRES NEAR GALLOWS HILL ROAD. TIME ESTIMATED FROM RADAR.
Aug 27, 8:40 PM EDTTSTM WND DMGBetlehem, PASEVERAL TREES DOWN IN THE BETHLEHEM AREA. TIME ESTIMATED FROM RADAR.
Aug 27, 8:42 PM EDTTSTM WND DMG2 Se Bethlehem Twp, PADOWNED TREES AND WIRES NEAR CHARDONNAY DRIVE. TIME ESTIMATED FROM RADAR.
Aug 27, 8:45 PM EDTTSTM WND DMGWilliams Township, PAPHOTOS OF NUMEROUS TREES DOWN THROUGHOUT WILLIAMS TOWNSHIP. SOME MINOR SHINGLE DAMAGE AS WELL. TIME ESTIMATED FROM RADAR.
Aug 27, 8:47 PM EDTTSTM WND DMG2 W Ferndale, PADOWNED TREES AND WIRES NEAR STONY GARDEN ROAD. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.2 hours before the alert went out and 182 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 00:00Z on 2020-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 709 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 00:00Z on 2020-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -140 square meters per square second.19395878Sfc1 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
709 J/kg
Mixed-layer CIN
-113 J/kg
Mixed-layer LCL
777 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
-140 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.6

Open this sounding in Storm Lab

The text

As transmitted.

862 
WUUS51 KPHI 280013
SVRPHI
NJC019-035-041-PAC017-077-095-280100-
/O.NEW.KPHI.SV.W.0265.200828T0013Z-200828T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
813 PM EDT Thu Aug 27 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Hunterdon County in northwestern New Jersey...
  Southwestern Warren County in northwestern New Jersey...
  West central Somerset County in northern New Jersey...
  East central Lehigh County in eastern Pennsylvania...
  North central Bucks County in southeastern Pennsylvania...
  Southeastern Northampton County in eastern Pennsylvania...

* Until 900 PM EDT.

* At 813 PM EDT, a severe thunderstorm was located over Old Orchard,
  or near Easton, moving southeast at 45 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...
  Allentown, Easton, Bethlehem, Forks, Byram, Wilson, Hellertown,
  Nazareth, Flemington, Tinicum, High Bridge, Clinton, Harmony, New
  Hope, Alpha, Glen Gardner, Ferndale, Hampton, Frenchtown and
  Lebanon.

This includes the following highways...
 Interstate 78 in Pennsylvania between mile markers 63 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 22.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 4061 7468 4034 7491 4034 7494 4032 7492
      4031 7493 4061 7549 4079 7521
TIME...MOT...LOC 0013Z 293DEG 40KT 4065 7529 

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

JEO
2 follow-up statements
625 
WWUS51 KPHI 280032
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
832 PM EDT Thu Aug 27 2020

NJC019-035-041-PAC017-077-095-280100-
/O.CON.KPHI.SV.W.0265.000000T0000Z-200828T0100Z/
Hunterdon NJ-Warren NJ-Somerset NJ-Lehigh PA-Bucks PA-Northampton PA-
832 PM EDT Thu Aug 27 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM EDT
FOR HUNTERDON...SOUTHWESTERN WARREN...WEST CENTRAL SOMERSET...EAST
CENTRAL LEHIGH...NORTH CENTRAL BUCKS AND SOUTHEASTERN NORTHAMPTON
COUNTIES...

At 831 PM EDT, a severe thunderstorm was located over Milford, or 12 
miles southeast of Easton, moving southeast at 45 mph. Another 
cluster of severe thunderstorms is now entering the warned area near 
and north of Allentown. A 57 mph wind gust was just reported at 
Lehigh Valley International Airport.

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...
Allentown, Easton, Bethlehem, Forks, Byram, Wilson, Hellertown,
Nazareth, Flemington, Tinicum, High Bridge, Clinton, Harmony, New
Hope, Alpha, Glen Gardner, Ferndale, Hampton, Frenchtown and Lebanon.

This includes the following highways...
 Interstate 78 in Pennsylvania between mile markers 63 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 22.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 4061 7468 4034 7491 4034 7494 4032 7492
      4031 7493 4061 7549 4079 7521
TIME...MOT...LOC 0031Z 293DEG 40KT 4057 7504 

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

JEO
858 
WWUS51 KPHI 280054
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
854 PM EDT Thu Aug 27 2020

NJC019-035-041-PAC017-077-095-280104-
/O.EXP.KPHI.SV.W.0265.000000T0000Z-200828T0100Z/
Hunterdon NJ-Warren NJ-Somerset NJ-Lehigh PA-Bucks PA-Northampton PA-
854 PM EDT Thu Aug 27 2020

...THE SEVERE THUNDERSTORM WARNING FOR HUNTERDON...SOUTHWESTERN
WARREN...WEST CENTRAL SOMERSET...EAST CENTRAL LEHIGH...NORTH CENTRAL
BUCKS AND SOUTHEASTERN NORTHAMPTON COUNTIES WILL EXPIRE AT 900 PM
EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

LAT...LON 4061 7468 4034 7491 4034 7494 4032 7492
      4031 7493 4061 7549 4079 7521
TIME...MOT...LOC 0054Z 293DEG 40KT 4040 7538 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 8:24 PM EDTSpecial Weather StatementPHIMiddlesex, Somerset51 min
Aug 27, 8:29 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset46 min
Aug 27, 8:55 PM EDTSpecial Marine WarningPHI95 min
Aug 27, 9:13 PM EDTSpecial Weather StatementPHIHunterdon, Mercer, Middlesex, Monmouth, Somerset47 min
Aug 27, 9:28 PM EDTSevere Thunderstorm WarningPHIMercer, Middlesex, Monmouth, Ocean, Somerset47 min
Aug 28, 3:05 PM EDTSpecial Marine WarningPHI85 min
Aug 28, 3:41 PM EDTSpecial Weather StatementPHISalem34 min
Aug 28, 3:52 PM EDTSevere Thunderstorm WarningPHICumberland, Gloucester, Salem53 min
Aug 28, 3:53 PM EDTSpecial Marine WarningPHI67 min
Aug 28, 4:07 PM EDTSpecial Marine WarningPHI53 min
Aug 28, 4:17 PM EDTSevere Thunderstorm WarningPHICape May43 min
Aug 28, 4:29 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Mercer61 min
Aug 28, 4:39 PM EDTSevere Thunderstorm WarningPHICamden, Cumberland, Gloucester, Salem66 min
Aug 28, 4:49 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean56 min
Aug 28, 4:55 PM EDTSpecial Marine WarningPHI95 min
Aug 28, 5:13 PM EDTSpecial Marine WarningPHI92 min
Aug 28, 5:28 PM EDTSevere Thunderstorm WarningPHIAtlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and 2 more47 min
Aug 28, 5:37 PM EDTSpecial Marine WarningPHI83 min
Aug 28, 5:51 PM EDTSpecial Marine WarningPHI84 min
Aug 28, 6:53 PM EDTSpecial Marine WarningPHI64 min
Aug 28, 7:55 PM EDTSpecial Marine WarningPHI65 min
Aug 27, 8:26 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery26 min
Aug 28, 3:22 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Chester, Lehigh, Montgomery53 min
Aug 28, 3:33 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Lehigh, Montgomery101 min
Aug 28, 3:36 PM EDTSevere Thunderstorm WarningPHIBerks, Chester54 min
Aug 28, 3:56 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia49 min
Aug 28, 4:01 PM EDTSevere Thunderstorm WarningPHIChester, Delaware44 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2020Severe Thunderstorm Warnings in Pennsylvania, 2020Every severe thunderstorm warning in 2020

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.