Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 129, NWS Philadelphia/Mount Holly

June 27, 20234 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 27, 2023, 3:57 PM EDT for 4 counties in Pennsylvania. It was in force for 48 min. 4 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
Jun 27, 2023, 3:57 PM EDT (19:57 UTC)
Expired
Jun 27, 2023, 4:45 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 75 km from the middle of the area, began a volume at 20:00 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
Jun 27, 4:15 PM EDTTSTM WND GST 491 Wsw Ambler, PAKLOM Wings Field.
Jun 27, 4:15 PM EDTTSTM WND GST 491 Wsw Ambler, PAKLOM Wings Field.
Jun 27, 4:38 PM EDTTSTM WND DMGNortheast Philadelphia, PATrees down throughout north and northeast Philadelphia. Time estimated on radar.
Jun 27, 4:38 PM EDTTSTM WND DMGNortheast Philadelphia, PATrees down throughout north and northeast Philadelphia. Time estimated on 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, 8.0 hours before the alert went out and 218 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 2023-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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 2023-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 square meters per square second.19395878Sfc1 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
17 J/kg
Mixed-layer CIN
-243 J/kg
Mixed-layer LCL
793 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
166 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

015 
WUUS51 KPHI 271957
SVRPHI
PAC029-045-091-101-272045-
/O.NEW.KPHI.SV.W.0129.230627T1957Z-230627T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
357 PM EDT Tue Jun 27 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Montgomery County in southeastern Pennsylvania...
  East central Chester County in southeastern Pennsylvania...
  Northern Philadelphia County in southeastern Pennsylvania...
  Northeastern Delaware County in southeastern Pennsylvania...

* Until 445 PM EDT.

* At 357 PM EDT, a severe thunderstorm was located over Norristown,
  or 14 miles northwest 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...
  Philadelphia, Norristown, Lansdale, West Norriton, East Norriton,
  Conshohocken, Hatboro, Ambler, Collegeville, Jenkintown, Narberth,
  Rockledge, Abington, Bryn Athyn, Willow Grove, Germantown,
  Northeast Philadelphia, Bryn Mawr, Trout Lake and Radnor Township.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 325 and 345.
 Northeast Extension between mile markers 21 and 29.
 Interstate 76 in Pennsylvania between mile markers 327 and 338.
 Interstate 476 in Pennsylvania between mile markers 10 and 19.

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 this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4016 7549 4028 7525 4009 7495 4007 7497
      3998 7539
TIME...MOT...LOC 1957Z 248DEG 21KT 4011 7536 

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

$$

MPS
3 follow-up statements
574 
WWUS51 KPHI 272009
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
409 PM EDT Tue Jun 27 2023

PAC029-045-272019-
/O.CAN.KPHI.SV.W.0129.000000T0000Z-230627T2045Z/
Chester PA-Delaware PA-
409 PM EDT Tue Jun 27 2023

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CHESTER AND
NORTHEASTERN DELAWARE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4004 7534 4019 7542 4026 7521 4009 7495
      4007 7497 4006 7500
TIME...MOT...LOC 2009Z 255DEG 18KT 4013 7530 

$$

PAC091-101-272045-
/O.CON.KPHI.SV.W.0129.000000T0000Z-230627T2045Z/
Montgomery PA-Philadelphia PA-
409 PM EDT Tue Jun 27 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR SOUTHEASTERN MONTGOMERY AND NORTHERN PHILADELPHIA COUNTIES...

At 409 PM EDT, a severe thunderstorm was located over Plymouth
Meeting, or 12 miles northwest of Philadelphia, 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...
Philadelphia, Norristown, Lansdale, West Norriton, East Norriton,
Conshohocken, Hatboro, Ambler, Jenkintown, Rockledge, Abington, Bryn
Athyn, Willow Grove, Northeast Philadelphia, Plymouth Meeting,
Chestnut Hill, Andalusia, King Of Prussia, Horsham and Bridgeport.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 329 and 346.
 Northeast Extension between mile markers 21 and 27.
 Interstate 76 in Pennsylvania between mile markers 330 and 335.
 Interstate 476 in Pennsylvania between mile markers 15 and 19.

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 this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4004 7534 4019 7542 4026 7521 4009 7495
      4007 7497 4006 7500
TIME...MOT...LOC 2009Z 255DEG 18KT 4013 7530 

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

$$

MPS
645 
WWUS51 KPHI 272027
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
427 PM EDT Tue Jun 27 2023

PAC091-101-272045-
/O.CON.KPHI.SV.W.0129.000000T0000Z-230627T2045Z/
Montgomery PA-Philadelphia PA-
427 PM EDT Tue Jun 27 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR SOUTHEASTERN MONTGOMERY AND NORTHERN PHILADELPHIA COUNTIES...

At 426 PM EDT, a severe thunderstorm was located over Willow Grove,
or 10 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...
Philadelphia, Hatboro, Ambler, Jenkintown, Rockledge, Abington, Bryn
Athyn, Willow Grove, Andalusia, Northeast Philadelphia, Chestnut
Hill, Horsham, North Wales, Fort Washington, Maple Glen, Glenside,
Flourtown, Spring House, Oreland and Wyndmoor.

This includes Pennsylvania Turnpike between mile markers 336 and 346.
 
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 this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4005 7522 4022 7528 4025 7519 4009 7495
      4007 7497 4006 7499 4006 7507
TIME...MOT...LOC 2026Z 254DEG 23KT 4015 7516 

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

$$

MPS
187 
WWUS51 KPHI 272038
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
438 PM EDT Tue Jun 27 2023

PAC091-101-272047-
/O.EXP.KPHI.SV.W.0129.000000T0000Z-230627T2045Z/
Montgomery PA-Philadelphia PA-
438 PM EDT Tue Jun 27 2023

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONTGOMERY AND
NORTHERN PHILADELPHIA COUNTIES WILL EXPIRE AT 445 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

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

Remember, a Severe Thunderstorm Warning still remains in effect 
until 515 PM EDT.

LAT...LON 4005 7522 4022 7528 4025 7519 4009 7495
      4007 7497 4006 7499 4006 7507
TIME...MOT...LOC 2037Z 248DEG 21KT 4017 7509 

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 8:27 PM EDTSpecial Weather StatementPHIChester33 min
Jun 26, 8:33 PM EDTSpecial Weather StatementPHIPhiladelphia27 min
Jun 26, 8:36 PM EDTSpecial Weather StatementPHIBucks24 min
Jun 26, 8:40 PM EDTSevere Thunderstorm WarningPHIChester31 min
Jun 26, 8:42 PM EDTSevere Thunderstorm WarningPHIBucks48 min
Jun 26, 9:18 PM EDTSevere Thunderstorm WarningPHIBerks42 min
Jun 26, 9:30 PM EDTFlash Flood WarningPHIMonroe, Northampton3 hr
Jun 26, 9:47 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery43 min
Jun 26, 9:51 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Philadelphia54 min
Jun 26, 9:58 PM EDTSevere Thunderstorm WarningPHIChester47 min
Jun 26, 10:33 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia42 min
Jun 26, 10:54 PM EDTAreal Flood AdvisoryPHIBerks, Chester, Delaware, Montgomery, Philadelphia3 hr
Jun 26, 11:07 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia53 min
Jun 26, 11:27 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia3 hr
Jun 26, 11:35 PM EDTFlash Flood WarningPHIBucks, Chester, Delaware, Montgomery, Philadelphia6 hr
Jun 27, 12:00 AM EDTAreal Flood WarningPHIBucks, Lehigh, Monroe, Northampton7 hr
Jun 27, 12:51 AM EDTFlash Flood WarningPHIChester, Montgomery4 hr
Jun 27, 1:23 AM EDTSpecial Weather StatementPHIMontgomery37 min
Jun 27, 2:23 AM EDTRiver Flood WarningPHIChester6 hr
Jun 27, 2:29 AM EDTSpecial Weather StatementPHIDelaware31 min
Jun 27, 3:01 AM EDTSpecial Weather StatementPHIDelaware, Montgomery, Philadelphia29 min
Jun 27, 3:02 AM EDTFlood WatchPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more46 min
Jun 27, 3:26 AM EDTRiver Flood WarningPHIDelaware4 hr
Jun 27, 3:48 AM EDTFlood WatchPHIBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more17 hr
Jun 27, 3:54 AM EDTRiver Flood WarningPHIChester, Delaware5 hr
Jun 27, 6:14 AM EDTAreal Flood WarningPHIMontgomery, Philadelphia3 hr
Jun 27, 6:16 AM EDTAreal Flood WarningPHIChester, Delaware3 hr
Jun 27, 10:08 AM EDTRiver Flood WarningPHIChester, Delaware109 min
Jun 27, 12:45 PM EDTSpecial Weather StatementPHIBerks30 min
Jun 27, 2:13 PM EDTSevere Thunderstorm WarningPHIChester47 min
Jun 27, 2:18 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe22 min
Jun 27, 2:21 PM EDTSpecial Weather StatementPHIBerks24 min
Jun 27, 2:42 PM EDTAreal Flood AdvisoryPHIBerks3 hr
Jun 27, 2:57 PM EDTAreal Flood AdvisoryPHIChester3 hr
Jun 27, 3:07 PM EDTSevere Thunderstorm WarningPHIBerks38 min
Jun 27, 3:25 PM EDTSevere Thunderstorm WarningPHIChester19 min
Jun 27, 3:33 PM EDTSpecial Weather StatementPHIDelaware27 min
Jun 27, 4:06 PM EDTSpecial Weather StatementPHINorthampton24 min
Jun 27, 4:24 PM EDTAreal Flood AdvisoryPHINorthampton3 hr
Jun 27, 4:30 PM EDTSevere Thunderstorm WarningPHIMontgomery, Philadelphia32 min
Jun 27, 4:33 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton42 min
Jun 27, 4:39 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery, Philadelphia51 min
Jun 27, 4:58 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery, Philadelphia3 hr
Jun 27, 5:01 PM EDTSevere Thunderstorm WarningPHINorthampton44 min
Jun 27, 5:22 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia38 min
Jun 27, 5:43 PM EDTSpecial Weather StatementPHIMonroe, Northampton32 min
Jun 27, 5:44 PM EDTFlash Flood WarningPHIBucks, Montgomery, Philadelphia5 hr
Jun 27, 5:52 PM EDTAreal Flood AdvisoryPHINorthampton3 hr
Jun 27, 5:57 PM EDTAreal Flood AdvisoryPHIBucks, Delaware, Philadelphia3 hr
Jun 27, 6:15 PM EDTSpecial Weather StatementPHINorthampton45 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.