Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 9, NWS Philadelphia/Mount Holly

April 30, 2024Warren County, New Jersey; 5 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 30, 2024, 7:38 PM EDT for Warren County, New Jersey; 5 counties in Pennsylvania. It was in force for 52 min. 18 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
Apr 30, 2024, 7:38 PM EDT (23:38 UTC)
Expired
Apr 30, 2024, 8:30 PM EDT
In force
52 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.5 in
Wind
60.0 mph

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

The radar

The Philadelphia radar (KDIX), 118 km from the middle of the area, began a volume at 23:38 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
Apr 30, 7:39 PM EDTHAIL 0.25Lehigh Twp, PA
Apr 30, 7:45 PM EDTHAIL 1North Whitehall Twp, PAReport from CoCoRaHS station Schnecksville 1.7 ENE.
Apr 30, 7:46 PM EDTHAIL 0.52 W Northampton, PA
Apr 30, 7:49 PM EDTTSTM WND DMGMoore Twp, PAA few trees reported down across Moore Township. Power outages in the area as well. Time estimated from radar.
Apr 30, 7:50 PM EDTHAIL 0.252 Ssw West Catasauqua, PAPea sized hail reported along with brief heavy rain in the Fernwood/Greenawalds section of South Whitehall Township.
Apr 30, 7:50 PM EDTHAIL 11 W Hokendauqua, PAReport from mPING: Quarter (1.00 in.).
Apr 30, 7:52 PM EDTHAIL 1.25Whitehall Twp, PATrained spotter reports max hail size of 1.25 inches fell from 7:52-7:56pm.
Apr 30, 7:53 PM EDTHAIL 0.25Northampton, PA
Apr 30, 7:53 PM EDTHAIL 1Whitehall Twp, PA
Apr 30, 7:55 PM EDTTSTM WND GST 37North Catasauqua, PATime estimated from radar.
Apr 30, 7:55 PM EDTHAIL 1.25North Catasauqua, PAUpdates previous hail report from North Catasauqua. 16 minutes of dime to quarter sized hail in North Catasauqua. Hail briefly grew to half dollar size. Time estimated from radar.
Apr 30, 7:56 PM EDTTSTM WND GST 37Lehigh Valley Internati, PAASOS station KABE Lehigh Valley Intl Airport.
Apr 30, 7:58 PM EDTTSTM WND DMGPlainfield Twp, PAA few trees reported down across Plainfield Township. Some power outages and cell phone reception outages in the area. Time estimated from radar.
Apr 30, 8:00 PM EDTTSTM WND GST 401 Ene Catasauqua, PAEstimated wind gusts in excess of 40 mph at the Lehigh County EMA building.
Apr 30, 8:00 PM EDTHAIL 0.51 Ene Catasauqua, PAEmergency Management reported pea to half inch sized hail at the Lehigh County EMA building. Photos included in report.
Apr 30, 8:05 PM EDTHAIL 0.252 Se Lehigh Valley Inte, PAPea sized hail 2 miles SE of the Lehigh Valley Airport in Bethlehem.
Apr 30, 8:07 PM EDTHAIL 0.752 Se Allentown, PAReport from mPING: Dime (0.75 in.).
Apr 30, 8:10 PM EDTHAIL 0.252 E Bethlehem, PAPea sized hail reported in the Freemansburg section of Bethlehem.

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 12:00Z, 11.6 hours before the alert went out and 209 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 2024-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2024-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
609 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
97 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

210 
WUUS51 KPHI 302338
SVRPHI
NJC041-PAC017-025-077-089-095-010030-
/O.NEW.KPHI.SV.W.0009.240430T2338Z-240501T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
738 PM EDT Tue Apr 30 2024

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Warren County in northwestern New Jersey...
  Lehigh County in eastern Pennsylvania...
  Southeastern Carbon County in northeastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  South central Monroe County in northeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 830 PM EDT.

* At 738 PM EDT, severe thunderstorms were located along a line
  extending from Danielsville to Schnecksville, moving east at 25
  mph.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Wind 
           damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton,
  Quakertown, Wilson, Hellertown, Nazareth, Palmerton, Bangor,
  Slatington, Pen Argyl, Wind Gap, Bath, Belvidere, Harmony, Alpha,
  and Walnutport.

This includes the following highways...
 Northeast Extension between mile markers 48 and 71.
 Interstate 78 in Pennsylvania between mile markers 49 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 2.

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 these storms. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

&&

LAT...LON 4089 7503 4040 7529 4062 7575 4087 7561
TIME...MOT...LOC 2338Z 289DEG 22KT 4080 7554 4067 7561 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Staarmann
3 follow-up statements
237 
WWUS51 KPHI 302348
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
748 PM EDT Tue Apr 30 2024

NJC041-PAC017-025-077-089-095-010030-
/O.CON.KPHI.SV.W.0009.000000T0000Z-240501T0030Z/
Warren NJ-Lehigh PA-Carbon PA-Bucks PA-Monroe PA-Northampton PA-
748 PM EDT Tue Apr 30 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM EDT
FOR SOUTHWESTERN WARREN...LEHIGH...SOUTHEASTERN CARBON...NORTHWESTERN
BUCKS...SOUTH CENTRAL MONROE AND NORTHAMPTON COUNTIES...

At 747 PM EDT, severe thunderstorms were located along a line 
extending from near Beersville to Coffeetown, moving east at 25 mph. 
Quarter sized hail was recently reported in Slatington.

HAZARD...70 mph wind gusts and ping pong ball size hail.

SOURCE...Public.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings.

Locations impacted include...
Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, Quakertown,
Wilson, Hellertown, Nazareth, Palmerton, Bangor, Slatington, Pen
Argyl, Wind Gap, Bath, Belvidere, Harmony, Alpha, and Walnutport.

This includes the following highways...
 Northeast Extension between mile markers 48 and 69.
 Interstate 78 in Pennsylvania between mile markers 49 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 2.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4089 7503 4040 7529 4062 7575 4087 7556
TIME...MOT...LOC 2347Z 290DEG 22KT 4078 7548 4063 7556 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Staarmann
775 
WWUS51 KPHI 302359
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
759 PM EDT Tue Apr 30 2024

PAC025-010009-
/O.CAN.KPHI.SV.W.0009.000000T0000Z-240501T0030Z/
Carbon PA-
759 PM EDT Tue Apr 30 2024

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CARBON COUNTY IS
CANCELLED...

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

LAT...LON 4089 7503 4040 7529 4059 7569 4081 7550
      4082 7548 4083 7548 4087 7545
TIME...MOT...LOC 2359Z 290DEG 23KT 4076 7535 4066 7543 4059 7551 

$$

NJC041-PAC017-077-089-095-010030-
/O.CON.KPHI.SV.W.0009.000000T0000Z-240501T0030Z/
Warren NJ-Lehigh PA-Bucks PA-Monroe PA-Northampton PA-
759 PM EDT Tue Apr 30 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM EDT
FOR SOUTHWESTERN WARREN...EASTERN LEHIGH...NORTHWESTERN BUCKS...SOUTH
CENTRAL MONROE AND NORTHAMPTON COUNTIES...

At 759 PM EDT, severe thunderstorms were located along a line
extending from near Nazareth to near Steuben to Allentown, moving 
east at 25 mph. Quarter sized hail was recently reported in 
Whitehall Township.

HAZARD...70 mph wind gusts and ping pong ball size hail.

SOURCE...Public.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings.

Locations impacted include...
Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, Quakertown,
Wilson, Hellertown, Nazareth, Bangor, Pen Argyl, Wind Gap, Bath,
Belvidere, Harmony, Alpha, Belfast, West Easton, and Tatamy.

This includes the following highways...
 Northeast Extension between mile markers 48 and 64.
 Interstate 78 in Pennsylvania between mile markers 49 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 2.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4089 7503 4040 7529 4059 7569 4081 7550
      4082 7548 4083 7548 4087 7545
TIME...MOT...LOC 2359Z 290DEG 23KT 4076 7535 4066 7543 4059 7551 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Staarmann
115 
WWUS51 KPHI 010017
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
817 PM EDT Tue Apr 30 2024

PAC089-010026-
/O.CAN.KPHI.SV.W.0009.000000T0000Z-240501T0030Z/
Monroe PA-
817 PM EDT Tue Apr 30 2024

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL MONROE COUNTY IS
CANCELLED...

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

LAT...LON 4089 7503 4040 7529 4057 7565 4069 7549
      4087 7526
TIME...MOT...LOC 0016Z 288DEG 22KT 4079 7506 4063 7531 4051 7545 

$$

NJC041-PAC017-077-095-010030-
/O.CON.KPHI.SV.W.0009.000000T0000Z-240501T0030Z/
Warren NJ-Lehigh PA-Bucks PA-Northampton PA-
817 PM EDT Tue Apr 30 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM EDT
FOR SOUTHWESTERN WARREN...SOUTHEASTERN LEHIGH...NORTHWESTERN BUCKS
AND NORTHAMPTON COUNTIES...

At 816 PM EDT, severe thunderstorms were located along a line
extending from near Roxburg to near Bethlehem to near Emmaus, moving 
east at 25 mph. This storm has a history of producing quarter sized 
to half dollar sized hail in the Lehigh Valley.

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

SOURCE...Public. At 755 PM EDT, half dollar sized hail was reported 
         in Whitehall Township, PA.

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

Locations impacted include...
Allentown, Easton, Bethlehem, Forks, Emmaus, Northampton, Quakertown,
Wilson, Hellertown, Nazareth, Bangor, Pen Argyl, Wind Gap, Bath,
Belvidere, Harmony, Alpha, Belfast, West Easton, and Tatamy.

This includes the following highways...
 Northeast Extension between mile markers 48 and 59.
 Interstate 78 in Pennsylvania between mile markers 50 and 76.
 Interstate 78 in New Jersey between mile markers 0 and 2.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4089 7503 4040 7529 4057 7565 4069 7549
      4087 7526
TIME...MOT...LOC 0016Z 288DEG 22KT 4079 7506 4063 7531 4051 7545 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 30, 5:00 PM EDTSpecial Weather StatementPHICarbon30 min
Apr 30, 5:32 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe30 min
Apr 30, 6:30 PM EDTSpecial Weather StatementPHICarbon, Monroe45 min
Apr 30, 6:52 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton53 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2024Severe Thunderstorm Warnings in New Jersey, 2024Every severe thunderstorm warning in 2024

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.