Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 249, NWS Philadelphia/Mount Holly

August 24, 20204 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 24, 2020, 1:15 PM EDT for 4 counties in Pennsylvania. It was in force for 21 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 24, 2020, 1:15 PM EDT (17:15 UTC)
Expired
Aug 24, 2020, 1:36 PM EDT
In force
21 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 136 km from the middle of the area, began a volume at 17:15 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.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 5.3 hours before the alert went out and 225 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 2020-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1431 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 2020-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 square meters per square second.193958Sfc1 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
1431 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
807 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

563 
WUUS51 KPHI 241715
SVRPHI
PAC025-077-089-095-241800-
/O.NEW.KPHI.SV.W.0249.200824T1715Z-200824T1800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
115 PM EDT Mon Aug 24 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 200 PM EDT.

* At 115 PM EDT, a severe thunderstorm was located over Beltzville
  State Park, or 7 miles east of Lehighton, moving east at 10 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

* Locations impacted include...
  Northampton, Palmerton, Slatington, Bath, Walnutport, Danielsville,
  Kunkletown, Beltzville State Park, Saylorsburg, Rossland,
  Berlinsville, Beersville, Kresgeville, Bowmanstown, Parryville,
  Chapman, Trachsville and Fiddletown.

This includes Northeast Extension between mile markers 72 and 74, and
near mile marker 77.
 
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 4080 7569 4091 7562 4090 7528 4066 7544
TIME...MOT...LOC 1715Z 292DEG 9KT 4084 7556 

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

SFJ
2 follow-up statements
695 
WWUS51 KPHI 241726
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
126 PM EDT Mon Aug 24 2020

PAC025-077-089-095-241800-
/O.CON.KPHI.SV.W.0249.000000T0000Z-200824T1800Z/
Lehigh PA-Carbon PA-Monroe PA-Northampton PA-
126 PM EDT Mon Aug 24 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR NORTHEASTERN LEHIGH...SOUTHEASTERN CARBON...SOUTH CENTRAL MONROE
AND WEST CENTRAL NORTHAMPTON COUNTIES...

At 126 PM EDT, a severe thunderstorm was located over Danielsville,
or 9 miles east of Lehighton, moving east at 10 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Northampton, Palmerton, Slatington, Bath, Walnutport, Danielsville,
Kunkletown, Saylorsburg, Rossland, Berlinsville, Beersville,
Bowmanstown, Chapman, Trachsville and Fiddletown.

This includes Northeast Extension between mile markers 71 and 72.
 
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 4079 7568 4088 7559 4090 7528 4066 7544
TIME...MOT...LOC 1726Z 292DEG 9KT 4083 7552 

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

SFJ
070 
WWUS51 KPHI 241736
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
136 PM EDT Mon Aug 24 2020

PAC025-077-089-095-241745-
/O.CAN.KPHI.SV.W.0249.000000T0000Z-200824T1800Z/
Lehigh PA-Carbon PA-Monroe PA-Northampton PA-
136 PM EDT Mon Aug 24 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LEHIGH...
SOUTHEASTERN CARBON...SOUTH CENTRAL MONROE AND WEST CENTRAL
NORTHAMPTON COUNTIES IS CANCELLED...
                
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 has been cancelled.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 4079 7568 4088 7559 4090 7528 4066 7544
TIME...MOT...LOC 1730Z 292DEG 9KT 4082 7549 

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 8:20 PM EDTSpecial Weather StatementPHIChester25 min
Aug 23, 8:42 PM EDTSevere Thunderstorm WarningPHIChester, Delaware48 min
Aug 24, 1:48 PM EDTSpecial Weather StatementPHINorthampton27 min
Aug 24, 2:20 PM EDTSpecial Weather StatementPHINorthampton25 min
Aug 24, 4:05 PM EDTAreal Flood AdvisoryPHICarbon, Monroe2 hr
Aug 24, 4:08 PM EDTSpecial Weather StatementPHIMonroe37 min
Aug 24, 4:38 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe, Northampton37 min
Aug 24, 5:01 PM EDTSpecial Weather StatementPHICarbon29 min
Aug 24, 5:11 PM EDTSpecial Weather StatementPHINorthampton34 min
Aug 24, 5:40 PM EDTSpecial Weather StatementPHINorthampton35 min
Aug 24, 6:05 PM EDTSpecial Weather StatementPHIBerks25 min
Aug 24, 6:14 PM EDTSevere Thunderstorm WarningPHIBucks, Northampton19 min

Nearby

Severe 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.