Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 207, NWS Philadelphia/Mount Holly

August 18, 2024Monroe County, Northampton County, Pennsylvania; Sussex County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 18, 2024, 4:41 PM EDT for Monroe County, Northampton County, Pennsylvania; Sussex County, Warren County, New Jersey. It was in force for 34 min. 2 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 18, 2024, 4:41 PM EDT (20:41 UTC)
Expired
Aug 18, 2024, 5:15 PM EDT
In force
34 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

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

The radar

The Philadelphia radar (KDIX), 132 km from the middle of the area, began a volume at 20:40 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 18, 4:48 PM EDTTSTM WND DMGHardwick Twp, NJA few trees down near Hardwick Township. Time estimated from radar.
Aug 18, 5:05 PM EDTTSTM WND DMG1 Ene Hardwick Twp, NJDowned tree at the intersection of Butler Rd and Sunset Lake Rd.

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 18, 2:02 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.7 hours before the alert went out and 178 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 2024-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 109 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 2024-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 187 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
109 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
582 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
187 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

765 
WUUS51 KPHI 182041
SVRPHI
NJC037-041-PAC089-095-182130-
/O.NEW.KPHI.SV.W.0207.240818T2041Z-240818T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
441 PM EDT Sun Aug 18 2024

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Western Sussex County in northwestern New Jersey...
  Central Warren County in northwestern New Jersey...
  East central Monroe County in northeastern Pennsylvania...
  East central Northampton County in eastern Pennsylvania...

* Until 530 PM EDT.

* At 440 PM EDT, severe thunderstorms were located along a line
  extending from near Bushkill to near Columbia to near Harmony,
  moving northeast at 15 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Blairstown, Belvidere, Harmony, Oxford, Hope, Tatamy,
  Flatbrookville, Brass Castle, Pleasant Valley, Werry Lake,
  Millbrook, Roxburg, Five Points, Columbia, Crandon Lakes, Echo
  Lake, Hainesville, Great Meadows-Vienna, Portland, and Hidden Lake.

This includes Interstate 80 in New Jersey between mile markers 4 and
16.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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

&&

LAT...LON 4131 7477 4099 7484 4072 7503 4072 7527
      4091 7511 4110 7505 4108 7503 4109 7500
      4116 7490 4127 7484
TIME...MOT...LOC 2040Z 245DEG 12KT 4113 7498 4094 7505 4074 7519 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MPS
3 follow-up statements
616 
WWUS51 KPHI 182059
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
459 PM EDT Sun Aug 18 2024

PAC089-182109-
/O.CAN.KPHI.SV.W.0207.000000T0000Z-240818T2130Z/
Monroe PA-
459 PM EDT Sun Aug 18 2024

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

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

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
northwestern New Jersey...and eastern and northeastern Pennsylvania.

LAT...LON 4099 7484 4072 7503 4072 7513 4105 7503
      4110 7497 4109 7499 4116 7490 4122 7486
      4125 7479
TIME...MOT...LOC 2059Z 255DEG 14KT 4112 7495 4094 7499 4074 7506 

$$

NJC037-041-PAC095-182130-
/O.CON.KPHI.SV.W.0207.000000T0000Z-240818T2130Z/
Sussex NJ-Warren NJ-Northampton PA-
459 PM EDT Sun Aug 18 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHWESTERN SUSSEX...CENTRAL WARREN AND EAST CENTRAL NORTHAMPTON
COUNTIES...

At 459 PM EDT, severe thunderstorms were located along a line
extending from Flatbrookville to near Hope to near Pleasant Valley,
moving east at 15 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Blairstown, Belvidere, Oxford, Hope, Flatbrookville, Brass Castle,
Roxburg, Five Points, Crandon Lakes, Pleasant Valley, Millbrook, and
Great Meadows-Vienna.

This includes Interstate 80 in New Jersey between mile markers 6 and
16.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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

&&

LAT...LON 4099 7484 4072 7503 4072 7513 4105 7503
      4110 7497 4109 7499 4116 7490 4122 7486
      4125 7479
TIME...MOT...LOC 2059Z 255DEG 14KT 4112 7495 4094 7499 4074 7506 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MPS
051 
WWUS51 KPHI 182106
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
506 PM EDT Sun Aug 18 2024

PAC095-182116-
/O.CAN.KPHI.SV.W.0207.000000T0000Z-240818T2130Z/
Northampton PA-
506 PM EDT Sun Aug 18 2024

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL NORTHAMPTON
COUNTY IS CANCELLED...

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

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
northwestern New Jersey...and northeastern Pennsylvania.

LAT...LON 4072 7507 4092 7503 4107 7501 4110 7497
      4110 7498 4116 7490 4122 7486 4125 7479
      4099 7484 4072 7503
TIME...MOT...LOC 2106Z 246DEG 13KT 4112 7494 4094 7497 4074 7505 

$$

NJC037-041-182130-
/O.CON.KPHI.SV.W.0207.000000T0000Z-240818T2130Z/
Sussex NJ-Warren NJ-
506 PM EDT Sun Aug 18 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR SOUTHWESTERN SUSSEX AND NORTHEASTERN WARREN COUNTIES...

At 506 PM EDT, severe thunderstorms were located along a line
extending from near Flatbrookville to near Hope to near Pleasant
Valley, moving northeast at 15 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Blairstown, Oxford, Hope, Flatbrookville, Brass Castle, Five Points,
Crandon Lakes, Pleasant Valley, Millbrook, and Great Meadows-Vienna.

This includes Interstate 80 in New Jersey between mile markers 9 and
16.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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

&&

LAT...LON 4072 7507 4092 7503 4107 7501 4110 7497
      4110 7498 4116 7490 4122 7486 4125 7479
      4099 7484 4072 7503
TIME...MOT...LOC 2106Z 246DEG 13KT 4112 7494 4094 7497 4074 7505 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MPS
540 
WWUS51 KPHI 182115
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
515 PM EDT Sun Aug 18 2024

NJC037-041-182125-
/O.CAN.KPHI.SV.W.0207.000000T0000Z-240818T2130Z/
Sussex NJ-Warren NJ-
515 PM EDT Sun Aug 18 2024

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUSSEX AND
NORTHEASTERN WARREN COUNTIES IS CANCELLED...

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

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
northwestern New Jersey...and northeastern Pennsylvania.

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

LAT...LON 4072 7507 4092 7503 4107 7501 4110 7497
      4110 7498 4116 7490 4122 7486 4125 7479
      4099 7484 4072 7503
TIME...MOT...LOC 2111Z 245DEG 12KT 4113 7492 4095 7495 4075 7503 

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 1:35 AM EDTFlash Flood WarningPHIBucks, Delaware, Montgomery, Philadelphia2 hr
Aug 18, 3:09 AM EDTFlash Flood WarningPHIBucks93 min
Aug 18, 3:24 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton19 min
Aug 18, 3:34 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia41 min
Aug 18, 3:48 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe42 min
Aug 18, 4:04 PM EDTSevere Thunderstorm WarningPHIMonroe41 min
Aug 18, 4:25 PM EDTSevere Thunderstorm WarningPHIBucks, Lehigh, Montgomery, Northampton28 min
Aug 18, 4:56 PM EDTFlash Flood WarningPHIMonroe, Northampton6 hr
Aug 18, 5:21 PM EDTSevere Thunderstorm WarningPHIBucks39 min
Aug 18, 5:31 PM EDTFlash Flood WarningPHIBucks, Lehigh, Northampton6 hr
Aug 18, 5:47 PM EDTSevere Thunderstorm WarningPHIBucks58 min
Aug 18, 4:41 AM EDTFlash Flood WarningPHIBurlington, Camden, Mercer2 hr
Aug 18, 2:17 PM EDTSpecial Marine WarningPHI58 min
Aug 18, 2:42 PM EDTSpecial Marine WarningPHI93 min
Aug 18, 3:55 PM EDTSpecial Marine WarningPHI95 min
Aug 18, 5:10 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Warren29 min
Aug 18, 5:38 PM EDTFlash Flood WarningPHISussex, Warren4 hr
Aug 18, 5:47 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex43 min
Aug 18, 5:51 PM EDTSevere Thunderstorm WarningPHIMorris, Somerset24 min
Aug 18, 5:59 PM EDTSevere Thunderstorm WarningPHIMorris, Sussex18 min
Aug 18, 6:01 PM EDTFlash Flood WarningPHIHunterdon, Morris, Somerset, Sussex, Warren6 hr
Aug 18, 6:24 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Morris, Somerset66 min
Aug 18, 6:36 PM EDTFlash Flood WarningPHIMorris, Somerset5 hr

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.