Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 84, NWS Philadelphia/Mount Holly

July 13, 2017Bucks County, Montgomery County, Philadelphia County, Pennsylvania; Burlington County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 13, 2017, 4:50 PM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania; Burlington County, New Jersey. It was in force for 40 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
Jul 13, 2017, 4:50 PM EDT (20:50 UTC)
Expired
Jul 13, 2017, 5:30 PM EDT
In force
40 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Burlington County, NJ, Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 61 km from the middle of the area, began a volume at 20:52 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
Jul 13, 2:57 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.8 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 2017-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 572 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 2017-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 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
572 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1449 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

675 
WUUS51 KPHI 132050 RRA
SVRPHI
NJC005-PAC017-091-101-132130-
/O.NEW.KPHI.SV.W.0084.170713T2050Z-170713T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
450 PM EDT THU JUL 13 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  North central Burlington County in southern New Jersey...
  East central Montgomery County in southeastern Pennsylvania...
  Southeastern Bucks County in southeastern Pennsylvania...
  Northeastern Philadelphia County in southeastern Pennsylvania...

* Until 530 PM EDT

* At 449 PM EDT, a severe thunderstorm was located over Ambler, or 12
  miles northwest of Philadelphia, moving east at 30 mph.

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

  SOURCE...Radar indicated. 

  IMPACT...Minor damage to vehicles is possible. Expect damage to 
           trees and power lines. 

* Locations impacted include...
  Philadelphia, Bensalem, Ewing, Norristown, East Norriton, Florence,
  Burlington, Bristol, Hatboro, Ambler, Jenkintown, Beverly, Yardley,
  Newtown, Tullytown, Abington, Langhorne, Bryn Athyn, Ivyland and
  Feasterville-Trevose.

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 4012 7532 4020 7532 4027 7485 4024 7482
      4005 7478
TIME...MOT...LOC 2049Z 267DEG 27KT 4017 7524 

HAIL...1.00IN
WIND...60MPH
 
$$

MWG
1 follow-up statement
073 
WWUS51 KPHI 132121
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
521 PM EDT THU JUL 13 2017

PAC091-132131-
/O.CAN.KPHI.SV.W.0084.000000T0000Z-170713T2130Z/
Montgomery PA-
521 PM EDT THU JUL 13 2017

...THE SEVERE THUNDERSTORM WARNING FOR EAST 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.

A severe thunderstorm watch remains in effect until 900 PM EDT for
southern and central New Jersey...and southeastern Pennsylvania.

LAT...LON 4008 7502 4009 7503 4012 7504 4014 7502
      4015 7504 4024 7506 4027 7485 4025 7484
      4024 7482 4005 7478
TIME...MOT...LOC 2121Z 277DEG 25KT 4011 7497 

$$

NJC005-PAC017-101-132130-
/O.CON.KPHI.SV.W.0084.000000T0000Z-170713T2130Z/
Burlington NJ-Bucks PA-Philadelphia PA-
521 PM EDT THU JUL 13 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM EDT
FOR NORTH CENTRAL BURLINGTON...SOUTHEASTERN BUCKS AND NORTHEASTERN
PHILADELPHIA COUNTIES...

At 521 PM EDT, a severe thunderstorm was located over Bensalem, or 11
miles northeast of Philadelphia, moving east at 30 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

Locations impacted include...
Philadelphia, Bensalem, Ewing, Florence, Burlington, Bristol,
Beverly, Yardley, Newtown, Tullytown, Langhorne,
Feasterville-Trevose, Florence-Roebling, Northeast Philadelphia,
Feasterville, Woodside, Richboro, Langhorn, Levittown and Penndel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4008 7502 4009 7503 4012 7504 4014 7502
      4015 7504 4024 7506 4027 7485 4025 7484
      4024 7482 4005 7478
TIME...MOT...LOC 2121Z 277DEG 25KT 4011 7497 

HAIL...<.75IN
WIND...60MPH
 
$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 3:25 PM EDTAreal Flood AdvisoryPHIBerks, Carbon, Lehigh, Monroe, Northampton4 hr
Jul 13, 3:30 PM EDTSpecial Weather StatementPHILehigh, Northampton45 min
Jul 13, 4:06 PM EDTAreal Flood AdvisoryPHIBucks, Lehigh, Monroe, Northampton114 min
Jul 13, 4:06 PM EDTSpecial Weather StatementPHINorthampton39 min
Jul 13, 4:08 PM EDTSpecial Weather StatementPHISchuylkill37 min
Jul 13, 4:09 PM EDTSpecial Weather StatementPHIMontgomery36 min
Jul 13, 4:15 PM EDTSevere Thunderstorm WarningPHIBerks60 min
Jul 13, 4:34 PM EDTSpecial Weather StatementPHIChester41 min
Jul 13, 4:36 PM EDTSpecial Weather StatementPHILehigh24 min
Jul 13, 4:42 PM EDTSpecial Weather StatementPHIMontgomery, Philadelphia48 min
Jul 13, 4:50 PM EDTAreal Flood AdvisoryPHIBerks, Bucks, Chester, Montgomery115 min
Jul 13, 5:07 PM EDTAreal Flood AdvisoryPHIBucks, Delaware, Montgomery, Philadelphia7 hr
Jul 13, 5:08 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery35 min
Jul 13, 5:08 PM EDTTornado WarningPHIBerks22 min
Jul 13, 5:21 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia54 min
Jul 13, 5:25 PM EDTFlash Flood WarningPHIBerks, Lehigh3 hr
Jul 13, 5:26 PM EDTTornado WarningPHIBerks, Chester, Montgomery28 min
Jul 13, 5:30 PM EDTSpecial Weather StatementPHIDelaware, Philadelphia45 min
Jul 13, 5:31 PM EDTFlash Flood WarningPHIBucks3 hr
Jul 13, 5:36 PM EDTSpecial Weather StatementPHIMontgomery39 min
Jul 13, 5:44 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery46 min
Jul 13, 5:56 PM EDTSpecial Weather StatementPHIBerks34 min
Jul 13, 6:28 PM EDTSpecial Weather StatementPHIBucks47 min
Jul 13, 6:34 PM EDTSpecial Weather StatementPHIDelaware, Montgomery, Philadelphia41 min
Jul 13, 7:03 PM EDTAreal Flood AdvisoryPHIChester, Montgomery117 min
Jul 13, 7:12 PM EDTSpecial Weather StatementPHIPhiladelphia48 min
Jul 13, 7:26 PM EDTSpecial Weather StatementPHIBerks, Montgomery64 min
Jul 12, 8:22 PM EDTSpecial Weather StatementPHIMorris53 min
Jul 12, 9:17 PM EDTSpecial Weather StatementPHIMorris28 min
Jul 13, 3:25 PM EDTSpecial Weather StatementPHISussex50 min
Jul 13, 3:28 PM EDTSpecial Weather StatementPHIMiddlesex47 min
Jul 13, 3:58 PM EDTAreal Flood AdvisoryPHISussex4 hr
Jul 13, 4:40 PM EDTSpecial Weather StatementPHIHunterdon, Middlesex, Somerset50 min
Jul 13, 4:50 PM EDTSevere Thunderstorm WarningPHIHunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset55 min
Jul 13, 4:58 PM EDTSpecial Marine WarningPHI62 min
Jul 13, 5:14 PM EDTSpecial Weather StatementPHIMercer46 min
Jul 13, 5:33 PM EDTSpecial Marine WarningPHI87 min
Jul 13, 5:39 PM EDTSpecial Weather StatementPHIMercer36 min
Jul 13, 6:07 PM EDTSpecial Weather StatementPHIAtlantic23 min
Jul 13, 6:07 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean25 min
Jul 13, 6:09 PM EDTSpecial Marine WarningPHI66 min
Jul 13, 6:20 PM EDTSpecial Weather StatementPHIBurlington40 min
Jul 13, 6:44 PM EDTSevere Thunderstorm WarningPHIBurlington, Monmouth, Ocean45 min
Jul 13, 6:55 PM EDTSpecial Marine WarningPHI95 min
Jul 13, 7:00 PM EDTSpecial Marine WarningPHI90 min
Jul 13, 7:55 PM EDTSpecial Weather StatementPHIOcean35 min
Jul 13, 7:58 PM EDTSpecial Weather StatementPHICumberland32 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2017Severe Thunderstorm Warnings in New Jersey, 2017Every severe thunderstorm warning in 2017

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.