Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 339, NWS Philadelphia/Mount Holly

September 8, 2023Hunterdon County, New Jersey; Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 8, 2023, 5:14 PM EDT for Hunterdon County, New Jersey; Bucks County, Montgomery County, Pennsylvania. It was in force for 46 min. 3 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
Sep 8, 2023, 5:14 PM EDT (21:14 UTC)
Expired
Sep 8, 2023, 6:00 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Hunterdon County, NJ, Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 75 km from the middle of the area, began a volume at 21:15 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.

What was reported inside it

TimeReportWhereRemark
Sep 8, 5:20 PM EDTTSTM WND DMG1 Nw New Britain, PASeveral reports of trees down on wires in central Bucks County. Impacted roads include PARK AV, FERRY RD, NEW GALENA RD, RAILROAD AV, BARRY RD, SUNSET AV, POINT PLEASANT PK, and BYRUM RD. Time estimated from radar.
Sep 8, 5:51 PM EDTTSTM WND DMGDoylestown, PAEmergency management reports trees and wires down across Doylestown. Time estimated by radar.
Sep 8, 6:02 PM EDTTSTM WND DMGBuckingham Twp, PAEmergency management reports trees and wires down across Buckingham Twp. Time estimated by radar.

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
Sep 8, 3:11 PM EDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.2 hours before the alert went out and 202 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 2023-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2469 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 2023-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 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
2469 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
566 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.7
Supercell composite
4.0

Open this sounding in Storm Lab

The text

As transmitted.

444 
WUUS51 KPHI 082114
SVRPHI
NJC019-PAC017-091-082200-
/O.NEW.KPHI.SV.W.0339.230908T2114Z-230908T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
514 PM EDT Fri Sep 8 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Hunterdon County in northwestern New Jersey...
  Central Montgomery County in southeastern Pennsylvania...
  Central Bucks County in southeastern Pennsylvania...

* Until 600 PM EDT.

* At 514 PM EDT, a severe thunderstorm was located over Chalfont, or
  19 miles north of Philadelphia, moving northeast 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...
  Lansdale, Perkasie, Doylestown, Byram, Souderton, Bedminster,
  Chalfont, Tinicum, Hatfield, New Hope, Dublin, Frenchtown, Milford,
  Stockton, Fricks, Revere, Lumberville, Ottsville, Sergeantsville
  and Pipersville.

This includes Northeast Extension between mile markers 31 and 32.
 
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 this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

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

&&

LAT...LON 4017 7522 4027 7537 4059 7510 4040 7483
TIME...MOT...LOC 2114Z 224DEG 11KT 4029 7522 

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

$$

Staarmann
2 follow-up statements
521 
WWUS51 KPHI 082135
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
535 PM EDT Fri Sep 8 2023

NJC019-PAC017-091-082200-
/O.CON.KPHI.SV.W.0339.000000T0000Z-230908T2200Z/
Hunterdon NJ-Montgomery PA-Bucks PA-
535 PM EDT Fri Sep 8 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTHWESTERN HUNTERDON...NORTHEASTERN MONTGOMERY AND CENTRAL
BUCKS COUNTIES...

At 535 PM EDT, a severe thunderstorm was located over Doylestown, or
22 miles west of Trenton, moving northeast at 15 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...
Lansdale, Perkasie, Doylestown, Byram, Souderton, Bedminster,
Chalfont, Tinicum, Hatfield, New Hope, Dublin, Frenchtown, Milford,
Stockton, Fricks, Revere, Lumberville, Ottsville, Sergeantsville and
Pipersville.

This includes Northeast Extension between mile markers 31 and 32.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Frequent cloud to ground lightning is occurring with this storm. 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.

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

&&

LAT...LON 4027 7537 4059 7510 4040 7483 4020 7527
TIME...MOT...LOC 2135Z 224DEG 11KT 4034 7516 

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

$$

Staarmann
446 
WWUS51 KPHI 082151 RRA
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
551 PM EDT Fri Sep 8 2023

NJC019-PAC017-091-082201-
/O.EXP.KPHI.SV.W.0339.000000T0000Z-230908T2200Z/
Hunterdon NJ-Montgomery PA-Bucks PA-
551 PM EDT Fri Sep 8 2023

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN HUNTERDON...
NORTHEASTERN MONTGOMERY AND CENTRAL BUCKS COUNTIES WILL EXPIRE AT 600
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 small 
hail, gusty winds, and heavy rain are still possible with this 
thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
northwestern New Jersey...and southeastern 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 4027 7537 4059 7510 4040 7483 4020 7527
TIME...MOT...LOC 2151Z 224DEG 11KT 4037 7512 

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 9:46 PM EDTSpecial Weather StatementPHISussex29 min
Sep 8, 6:02 AM EDTSpecial Marine WarningPHI40 min
Sep 8, 1:36 PM EDTSpecial Weather StatementPHIBurlington24 min
Sep 8, 1:37 PM EDTSpecial Weather StatementPHIMonmouth23 min
Sep 8, 1:46 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean44 min
Sep 8, 1:50 PM EDTSpecial Marine WarningPHI115 min
Sep 8, 1:54 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean51 min
Sep 8, 2:27 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Monmouth48 min
Sep 8, 2:30 PM EDTSevere Thunderstorm WarningPHIBurlington, Middlesex, Monmouth, Ocean45 min
Sep 8, 2:33 PM EDTAreal Flood AdvisoryPHIBurlington, Monmouth, Ocean3 hr
Sep 8, 2:44 PM EDTSpecial Marine WarningPHI18 min
Sep 8, 2:45 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean45 min
Sep 8, 2:53 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Somerset52 min
Sep 8, 3:17 PM EDTSpecial Marine WarningPHI58 min
Sep 8, 3:27 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Monmouth, Ocean63 min
Sep 8, 3:29 PM EDTFlash Flood WarningPHIBurlington, Ocean4 hr
Sep 8, 3:31 PM EDTSevere Thunderstorm WarningPHICumberland, Salem44 min
Sep 8, 3:36 PM EDTSevere Thunderstorm WarningPHIMorris30 min
Sep 8, 3:43 PM EDTSpecial Weather StatementPHIMiddlesex32 min
Sep 8, 3:58 PM EDTSpecial Weather StatementPHISomerset32 min
Sep 8, 4:24 PM EDTSevere Thunderstorm WarningPHIHunterdon51 min
Sep 8, 4:27 PM EDTSevere Thunderstorm WarningPHIBurlington, Ocean51 min
Sep 8, 4:30 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Monmouth, Ocean60 min
Sep 8, 4:50 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Sussex, Warren40 min
Sep 8, 5:12 PM EDTAreal Flood AdvisoryPHIHunterdon3 hr
Sep 8, 5:21 PM EDTFlash Flood WarningPHIHunterdon4 hr
Sep 8, 5:34 PM EDTSevere Thunderstorm WarningPHIWarren41 min
Sep 8, 5:49 PM EDTSevere Thunderstorm WarningPHISussex41 min
Sep 8, 6:11 PM EDTSpecial Weather StatementPHIWarren34 min
Sep 8, 6:34 PM EDTAreal Flood AdvisoryPHISussex, Warren3 hr
Sep 7, 8:08 PM EDTSpecial Weather StatementPHIChester, Lehigh37 min
Sep 7, 8:42 PM EDTSpecial Weather StatementPHIBucks33 min
Sep 7, 9:19 PM EDTSpecial Weather StatementPHIBerks26 min
Sep 7, 9:37 PM EDTSevere Thunderstorm WarningPHIBerks18 min
Sep 7, 10:07 PM EDTSpecial Weather StatementPHIBerks38 min
Sep 7, 10:38 PM EDTAreal Flood AdvisoryPHIBerks76 min
Sep 7, 10:44 PM EDTSpecial Weather StatementPHIBerks, Lehigh61 min
Sep 8, 5:16 PM EDTAreal Flood AdvisoryPHIChester, Montgomery3 hr
Sep 8, 5:29 PM EDTSpecial Weather StatementPHIMontgomery31 min
Sep 8, 6:00 PM EDTSpecial Weather StatementPHIBucks30 min
Sep 8, 6:16 PM EDTSpecial Weather StatementPHINorthampton29 min
Sep 8, 6:24 PM EDTSpecial Weather StatementPHIMonroe36 min
Sep 8, 6:29 PM EDTSpecial Weather StatementPHIBucks31 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2023Severe Thunderstorm Warnings in New Jersey, 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.