Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 273, NWS Philadelphia/Mount Holly

August 7, 20237 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 7, 2023, 6:53 PM EDT for 7 counties in Pennsylvania. It was in force for 52 min. 7 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 7, 2023, 6:53 PM EDT (22:53 UTC)
Expired
Aug 7, 2023, 7:45 PM EDT
In force
52 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Berks County, PA, Bucks County, PA, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 134 km from the middle of the area, began a volume at 22:52 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 7, 6:55 PM EDTTSTM WND DMG1 Sse Lyons, PATrees and wires down in the Lyons and Rockland Township area.
Aug 7, 7:00 PM EDTTSTM WND DMGBreinigsville, PAVideo shared on social media with trees down in Breinigsville. Time estimated via radar.
Aug 7, 7:12 PM EDTTSTM WND DMGUpper Milford Twp, PAReport of tree down in Upper Milford Twp on social media. Time estimated via radar.
Aug 7, 7:15 PM EDTTSTM WND GST 65Breinigsville, PAWeather station blew over. Trained spotter estimated 60-70 mph gusts.
Aug 7, 7:20 PM EDTTSTM WND DMG1 Wnw Milford Twp, PALarge tree fell on a house with some structural damage. No injuries. Report via social media, with photos.
Aug 7, 7:21 PM EDTTORNADO2 Sse Lehigh Valley Int, PAOn the evening of August 7th, an EF-1 tornado occurred, primarily in the Midway Manor neighborhood of Allentown, Pennsylvania. The tornado began near East Pennsylvania Street between North Ulster Street and North Van Buren Street. At this location, damage to t
Aug 7, 7:51 PM EDTTSTM WND GST 54Lehigh Valley Internati, PAASOS station KABE Lehigh Valley Intl Airport.

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 7, 3:13 PM EDTTornado WatchSPC8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.9 hours before the alert went out and 235 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 2023-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 36 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 2023-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 143 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
36 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
726 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
143 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

076 
WUUS51 KPHI 072253
SVRPHI
PAC011-017-025-077-089-091-095-072345-
/O.NEW.KPHI.SV.W.0273.230807T2253Z-230807T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
653 PM EDT Mon Aug 7 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Eastern Berks County in eastern Pennsylvania...
  Lehigh County in eastern Pennsylvania...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Southeastern Carbon County in northeastern Pennsylvania...
  West central Bucks County in southeastern Pennsylvania...
  Southwestern Monroe County in northeastern Pennsylvania...
  Southwestern Northampton County in eastern Pennsylvania...

* Until 745 PM EDT.

* At 652 PM EDT, severe thunderstorms were located along a line
  extending from near Christmans to near Claussville to near
  Birdsboro, moving northeast at 25 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, Lehighton, Bethlehem, Pottstown, Emmaus, Northampton,
  Nazareth, Palmerton, Birdsboro, Kutztown, Jim Thorpe, Slatington,
  Fleetwood, East Greenville, Wind Gap, Bath, Walnutport, Topton,
  Bally and Bechtelsville.

People at the Musikfest should seek safe shelter immediately!

This includes the following highways...
 Northeast Extension between mile markers 44 and 82.
 Interstate 78 in Pennsylvania between mile markers 37 and 66.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM EDT for eastern,
southeastern and northeastern Pennsylvania.

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

A Tornado Watch remains in effect until 1100 PM EDT for eastern,
southeastern and northeastern Pennsylvania.

&&

LAT...LON 4102 7535 4082 7529 4033 7545 4019 7589
      4057 7590 4069 7586 4074 7576 4078 7583
      4087 7580
TIME...MOT...LOC 2252Z 235DEG 20KT 4092 7567 4060 7572 4023 7583 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

AKL
2 follow-up statements
901 
WWUS51 KPHI 072336
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
736 PM EDT Mon Aug 7 2023

PAC011-017-091-072345-
/O.CAN.KPHI.SV.W.0273.000000T0000Z-230807T2345Z/
Berks PA-Montgomery PA-Bucks PA-
736 PM EDT Mon Aug 7 2023

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN BERKS...NORTHWESTERN
MONTGOMERY AND WEST CENTRAL BUCKS COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 1100 PM EDT for eastern and
northeastern Pennsylvania.

LAT...LON 4102 7535 4082 7529 4062 7536 4057 7558
      4082 7570 4090 7570
TIME...MOT...LOC 2335Z 227DEG 27KT 4099 7544 4079 7544 4061 7552 

$$

PAC025-077-089-095-072345-
/O.CON.KPHI.SV.W.0273.000000T0000Z-230807T2345Z/
Lehigh PA-Carbon PA-Monroe PA-Northampton PA-
736 PM EDT Mon Aug 7 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR NORTHEASTERN LEHIGH...SOUTHEASTERN CARBON...SOUTHWESTERN MONROE
AND SOUTHWESTERN NORTHAMPTON COUNTIES...

At 735 PM EDT, severe thunderstorms were located along a line
extending from Sun Valley to near Beersville to near Allentown,
moving northeast at 30 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, Bethlehem, Northampton, Nazareth, Palmerton, Jim Thorpe,
Slatington, Wind Gap, Bath, Walnutport, Steuben, Brodheadsville,
Kunkletown, Neffs, Gilbert, Coffeetown, Rossland, Berlinsville,
Emerald and Kresgeville.

People at the Musikfest should seek safe shelter immediately!

This includes the following highways...
 Northeast Extension between mile markers 56 and 82.
 Interstate 78 in Pennsylvania between mile markers 53 and 54.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM EDT for eastern and
northeastern Pennsylvania.

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

&&

LAT...LON 4102 7535 4082 7529 4062 7536 4057 7558
      4082 7570 4090 7570
TIME...MOT...LOC 2335Z 227DEG 27KT 4099 7544 4079 7544 4061 7552 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

AKL
153 
WWUS51 KPHI 072347
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
747 PM EDT Mon Aug 7 2023

PAC025-077-089-095-072355-
/O.EXP.KPHI.SV.W.0273.000000T0000Z-230807T2345Z/
Lehigh PA-Carbon PA-Monroe PA-Northampton PA-
747 PM EDT Mon Aug 7 2023

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LEHIGH...
SOUTHEASTERN CARBON...SOUTHWESTERN MONROE AND SOUTHWESTERN
NORTHAMPTON COUNTIES HAS EXPIRED...
    
The storms which prompted the warning have moved out of the initial 
warning area. Therefore, the warning has been allowed to expire. A 
Severe Thunderstorm Warning remains in effect for Monroe and 
Northampton Counties until 815 PM EDT.

A Tornado Watch remains in effect until 1100 PM EDT for eastern and
northeastern Pennsylvania.

Remember, a Severe Thunderstorm Warning still remains in effect for
Monroe and Northampton Counties until 815 PM EDT.

LAT...LON 4102 7535 4082 7529 4062 7536 4057 7558
      4082 7570 4090 7570
TIME...MOT...LOC 2345Z 235DEG 20KT 4102 7539 4082 7539 4064 7547 

$$

AKL

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 7, 5:33 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIBerks, Chester57 min
Aug 7, 5:37 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIDelaware53 min
Aug 7, 5:57 PM EDTAreal Flood AdvisoryPHIChester, Delaware79 min
Aug 7, 6:08 PM EDTTornado WarningPHIChester19 min
Aug 7, 6:21 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIBerks, Bucks, Chester, Delaware, Montgomery, Philadelphia69 min
Aug 7, 6:29 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia63 min
Aug 7, 6:35 PM EDTTornado WarningPHIChester, Delaware, Montgomery, Philadelphia25 min
Aug 7, 6:45 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe45 min
Aug 7, 7:00 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh, Montgomery, Northampton66 min
Aug 7, 7:20 PM EDTSevere Thunderstorm WarningPHIBucks58 min
Aug 7, 7:27 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton48 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2023Every severe thunderstorm warning in 2023

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.