Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 289, NWS Philadelphia/Mount Holly

August 12, 2023Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 12, 2023, 5:31 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 44 min. 5 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 12, 2023, 5:31 PM EDT (21:31 UTC)
Expired
Aug 12, 2023, 6:15 PM EDT
In force
44 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 73 km from the middle of the area, began a volume at 21:32 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 12, 5:32 PM EDTTSTM WND DMG1 Nw Franconia Twp, PATrees down on wires resulting in power outages. Time estimated via radar.
Aug 12, 5:33 PM EDTTSTM WND DMG1 Ssw Franconia Twp, PAPPL reports tree limbs on wires near Harleysville and Franconia. Time estimated from radar.
Aug 12, 5:47 PM EDTHAIL 0.25Hilltown Twp, PAPea size hail in Hilltown. Time estimated via radar.
Aug 12, 6:00 PM EDTHAIL 11 Nw Plumstead Twp, PAPictures sent in of quarter-sized hail near Plumstead Township. Time estimated from radar.
Aug 12, 6:11 PM EDTHAIL 12 Nne Gardenville, PAQuarter size hail reported in Plumsteadville. Picture provided via social media. Time estimated via radar.

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, 9.5 hours before the alert went out and 198 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 2023-08-12Temperature 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 2023-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 square meters per square second.1939Sfc1 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
1539 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

417 
WUUS51 KPHI 122131
SVRPHI
PAC017-091-122215-
/O.NEW.KPHI.SV.W.0289.230812T2131Z-230812T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
531 PM EDT Sat Aug 12 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Montgomery County in southeastern Pennsylvania...
  Central Bucks County in southeastern Pennsylvania...

* Until 615 PM EDT.

* At 531 PM EDT, a severe thunderstorm was located near Souderton, or
  21 miles south of Allentown, moving east at 20 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, Stockton, Green
  Lane, Washington Crossing, Fricks, Pipersville, Gardenville, Spring
  Mount, Richboro and Skippack.

This includes Northeast Extension between mile markers 28 and 38.
 
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.

&&

LAT...LON 4020 7542 4033 7548 4047 7507 4042 7506
      4040 7504 4041 7499 4040 7496 4033 7494
      4030 7487 4025 7485
TIME...MOT...LOC 2131Z 254DEG 17KT 4029 7538 

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

$$

Hoeflich
2 follow-up statements
737 
WWUS51 KPHI 122154
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
554 PM EDT Sat Aug 12 2023

PAC091-122204-
/O.CAN.KPHI.SV.W.0289.000000T0000Z-230812T2215Z/
Montgomery PA-
554 PM EDT Sat Aug 12 2023

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4023 7516 4031 7530 4038 7532 4046 7508
      4042 7506 4040 7504 4041 7499 4040 7496
      4033 7494 4031 7490 4025 7488
TIME...MOT...LOC 2154Z 257DEG 20KT 4032 7520 

$$

PAC017-122215-
/O.CON.KPHI.SV.W.0289.000000T0000Z-230812T2215Z/
Bucks PA-
554 PM EDT Sat Aug 12 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR CENTRAL BUCKS COUNTY...

At 554 PM EDT, a severe thunderstorm was located over Chalfont, or 21
miles north of Philadelphia, moving east at 25 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...
Perkasie, Doylestown, Bedminster, Chalfont, Tinicum, New Hope,
Dublin, Stockton, Fricks, Pipersville, Gardenville, Richboro,
Sellersville, New Britain, Silverdale, Brittany Farms-Highlands and
Newtown Grant.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4023 7516 4031 7530 4038 7532 4046 7508
      4042 7506 4040 7504 4041 7499 4040 7496
      4033 7494 4031 7490 4025 7488
TIME...MOT...LOC 2154Z 257DEG 20KT 4032 7520 

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

$$

Hoeflich
195 
WWUS51 KPHI 122210
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
610 PM EDT Sat Aug 12 2023

PAC017-122220-
/O.EXP.KPHI.SV.W.0289.000000T0000Z-230812T2215Z/
Bucks PA-
610 PM EDT Sat Aug 12 2023

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL BUCKS COUNTY WILL
EXPIRE AT 615 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until midnight 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 4023 7516 4031 7530 4038 7532 4046 7508
      4042 7506 4040 7504 4041 7499 4040 7496
      4033 7494 4031 7490 4025 7488
TIME...MOT...LOC 2210Z 254DEG 17KT 4034 7511 

$$

Hoeflich

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 12:57 PM EDTAreal Flood AdvisoryPHIDelaware, Philadelphia3 hr
Aug 12, 1:38 PM EDTAreal Flood AdvisoryPHIDelaware, Philadelphia3 hr
Aug 12, 3:06 PM EDTSpecial Weather StatementPHIBerks24 min
Aug 12, 3:39 PM EDTSpecial Weather StatementPHIBerks36 min
Aug 12, 3:49 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery41 min
Aug 12, 3:55 PM EDTSpecial Weather StatementPHIChester35 min
Aug 12, 4:06 PM EDTSevere Thunderstorm WarningPHIChester, Delaware39 min
Aug 12, 4:37 PM EDTSevere Thunderstorm WarningPHIChester, Delaware38 min
Aug 12, 4:57 PM EDTSevere Thunderstorm WarningPHICarbon48 min
Aug 12, 5:05 PM EDTAreal Flood AdvisoryPHIChester3 hr
Aug 12, 5:16 PM EDTSpecial Weather StatementPHIDelaware29 min
Aug 12, 6:42 PM EDTSpecial Weather StatementPHIMontgomery33 min
Aug 12, 6:47 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery28 min
Aug 12, 6:58 PM EDTAreal Flood AdvisoryPHIChester3 hr

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.