Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 115, NWS Philadelphia/Mount Holly

June 26, 2023Chester County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 26, 2023, 9:47 PM EDT for Chester County, Montgomery County, Pennsylvania. It was in force for 43 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 26, 2023, 9:47 PM EDT (01:47 UTC)
Expired
Jun 26, 2023, 10:30 PM EDT
In force
43 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Chester County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 83 km from the middle of the area, began a volume at 01:47 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jun 26, 1:11 PM EDTSevere Thunderstorm WatchSPC11 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.8 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, Washington/Dulle, VA at 00:00Z on 2023-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1362 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, Washington/Dulle, VA at 00:00Z on 2023-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
1362 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
1456 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

696 
WUUS51 KPHI 270147
SVRPHI
PAC029-091-270230-
/O.NEW.KPHI.SV.W.0115.230627T0147Z-230627T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
947 PM EDT Mon Jun 26 2023

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1030 PM EDT.

* At 947 PM EDT, a severe thunderstorm was located over West
  Norriton, or 14 miles northeast of West Chester, moving northeast
  at 25 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...
  Norristown, Phoenixville, Lansdale, West Norriton, East Norriton,
  Conshohocken, Hatboro, Souderton, Ambler, Collegeville, Trappe,
  Hatfield, Bryn Athyn, Willow Grove, Valley Forge, Plymouth Meeting,
  King Of Prussia, Paoli, Radnor Township and Horsham.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 321 and 346.
 Northeast Extension between mile markers 21 and 32.
 Interstate 76 in Pennsylvania between mile markers 327 and 334.
 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.

&&

LAT...LON 4031 7531 4016 7505 4004 7534 4006 7536
      4004 7541 4003 7540 4000 7544 4014 7557
TIME...MOT...LOC 0147Z 235DEG 21KT 4012 7543 

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

$$

MPS
3 follow-up statements
101 
WWUS51 KPHI 270157
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
957 PM EDT Mon Jun 26 2023

PAC029-270206-
/O.CAN.KPHI.SV.W.0115.000000T0000Z-230627T0230Z/
Chester PA-
957 PM EDT Mon Jun 26 2023

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

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
southeastern Pennsylvania.

LAT...LON 4025 7541 4030 7533 4031 7531 4016 7505
      4005 7533 4017 7549
TIME...MOT...LOC 0156Z 225DEG 27KT 4017 7535 

$$

PAC091-270230-
/O.CON.KPHI.SV.W.0115.000000T0000Z-230627T0230Z/
Montgomery PA-
957 PM EDT Mon Jun 26 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR CENTRAL MONTGOMERY COUNTY...

At 956 PM EDT, a severe thunderstorm was located over East Norriton,
or 15 miles northwest of Philadelphia, moving northeast at 30 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...
Norristown, Lansdale, West Norriton, East Norriton, Conshohocken,
Hatboro, Souderton, Ambler, Collegeville, Trappe, Hatfield, Bryn
Athyn, Willow Grove, Plymouth Meeting, King Of Prussia, Horsham,
Skippack, Bridgeport, North Wales and West Conshohocken.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 328 and 346.
 Northeast Extension between mile markers 21 and 32.
 Interstate 76 in Pennsylvania between mile markers 329 and 333.
 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.

&&

LAT...LON 4025 7541 4030 7533 4031 7531 4016 7505
      4005 7533 4017 7549
TIME...MOT...LOC 0156Z 225DEG 27KT 4017 7535 

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

$$

MPS
710 
WWUS51 KPHI 270212
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1012 PM EDT Mon Jun 26 2023

PAC091-270230-
/O.CON.KPHI.SV.W.0115.000000T0000Z-230627T0230Z/
Montgomery PA-
1012 PM EDT Mon Jun 26 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR CENTRAL MONTGOMERY COUNTY...

At 1012 PM EDT, a severe thunderstorm was located over East Norriton,
or 14 miles northwest of Philadelphia, moving northeast at 10 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...
Norristown, Lansdale, West Norriton, East Norriton, Conshohocken,
Hatboro, Ambler, Hatfield, Willow Grove, Plymouth Meeting, King Of
Prussia, Horsham, Skippack, Bridgeport, North Wales, West
Conshohocken, Fort Washington, Blue Bell, Maple Glen and Flourtown.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 330 and 343.
 Northeast Extension between mile markers 21 and 30.
 Interstate 76 in Pennsylvania between mile markers 331 and 334.
 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.

&&

LAT...LON 4006 7534 4023 7540 4030 7529 4021 7514
      4014 7510 4005 7532 4005 7533
TIME...MOT...LOC 0212Z 245DEG 9KT 4017 7532 

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

$$

MPS
354 
WWUS51 KPHI 270221
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1021 PM EDT Mon Jun 26 2023

PAC091-270231-
/O.EXP.KPHI.SV.W.0115.000000T0000Z-230627T0230Z/
Montgomery PA-
1021 PM EDT Mon Jun 26 2023

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY COUNTY WILL
EXPIRE AT 1030 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.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
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 4006 7534 4023 7540 4030 7529 4021 7514
      4014 7510 4005 7532 4005 7533
TIME...MOT...LOC 0221Z 235DEG 21KT 4019 7528 

$$

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, 9:51 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, 3:57 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia48 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.