Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 185, NWS Philadelphia/Mount Holly

August 9, 2012Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 9, 2012, 3:57 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 63 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
Aug 9, 2012, 3:57 PM EDT (19:57 UTC)
Expired
Aug 9, 2012, 5:00 PM EDT
In force
63 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 97 km from the middle of the area, began a volume at 19:58 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 nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.0 hours before the alert went out and 116 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, Phillips Aaf/Abe, MD at 12:00Z on 2012-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1906 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phillips Aaf/Abe, MD at 12:00Z on 2012-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 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
1906 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
754 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

434 
WUUS51 KPHI 091957
SVRPHI
PAC017-091-092100-
/O.NEW.KPHI.SV.W.0185.120809T1957Z-120809T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
357 PM EDT THU AUG 9 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 500 PM EDT

* AT 353 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND   
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM HAS PRODUCED HAIL 
UPWARDS OF THREE QUARTERS OF AN INCH. THIS STORM WAS LOCATED NEAR   
GREEN LANE...OR 20 MILES SOUTH OF ALLENTOWN...AND MOVING NORTHEAST   
AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GREEN LANE AND 7 MILES SOUTHEAST OF EAST GREENVILLE AROUND 415 PM
  EDT...
  7 MILES SOUTHEAST OF GERYVILLE AROUND 425 PM EDT...
  SOUDERTON...6 MILES NORTHWEST OF HATFIELD AND 9 MILES NORTHWEST OF
  LANSDALE AROUND 455 PM EDT...
  PERKASIE...QUAKERTOWN...6 MILES NORTHWEST OF FRICKS AND 7 MILES
  WEST OF DUBLIN AROUND 500 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...LARGE HAIL...AND DEADLY CLOUD TO
GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4021 7537 4034 7541 4030 7553 4040 7557
      4043 7555 4044 7552 4042 7548 4048 7542
      4055 7526 4029 7509
TIME...MOT...LOC 1957Z 244DEG 7KT 4030 7549

$$

HEAVENER
4 follow-up statements
196 
WWUS51 KPHI 092019
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
419 PM EDT THU AUG 9 2012

PAC017-091-092100-
/O.CON.KPHI.SV.W.0185.000000T0000Z-120809T2100Z/
BUCKS PA-MONTGOMERY PA-
419 PM EDT THU AUG 9 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR CENTRAL MONTGOMERY AND CENTRAL BUCKS COUNTIES...

AT 415 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED 6 MILES WEST OF TELFORD...OR 19 MILES SOUTH OF ALLENTOWN...
MOVING NORTHEAST AT 10 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES NORTHWEST OF KULPSVILLE BY 435 PM EDT...
  8 MILES NORTHWEST OF LANSDALE BY 455 PM EDT...
  SELLERSVILLE...TELFORD...PERKASIE AND SOUDERTON BY 500 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4022 7535 4039 7543 4046 7520 4029 7509
TIME...MOT...LOC 2019Z 244DEG 7KT 4032 7544

$$

HEAVENER
050 
WWUS51 KPHI 092034
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
434 PM EDT THU AUG 9 2012

PAC091-092043-
/O.CAN.KPHI.SV.W.0185.000000T0000Z-120809T2100Z/
MONTGOMERY PA-
434 PM EDT THU AUG 9 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY COUNTY IS
CANCELLED...

THE SEVERE STORM IS IN BUCKS COUNTY.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

LAT...LON 4026 7521 4039 7543 4046 7520 4029 7509
TIME...MOT...LOC 2033Z 264DEG 18KT 4032 7521

$$

PAC017-092100-
/O.CON.KPHI.SV.W.0185.000000T0000Z-120809T2100Z/
BUCKS PA-
434 PM EDT THU AUG 9 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM EDT
FOR CENTRAL BUCKS COUNTY...

AT 432 PM EDT...A SEVERE THUNDERSTORM WAS REPORTED CAPABLE OF
PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED
NEAR FRICKS...OR 22 MILES NORTH OF PHILADELPHIA...MOVING EAST AT 20
MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEW BRITAIN AND 7 MILES SOUTH OF BEDMINSTER BY 440 PM EDT...
  DOYLESTOWN AND ROBESONIA BY 445 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LIKELY 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.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4026 7521 4039 7543 4046 7520 4029 7509
TIME...MOT...LOC 2033Z 264DEG 18KT 4032 7521

$$
 
TFG
296 
WWUS51 KPHI 092050
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
450 PM EDT THU AUG 9 2012

PAC017-092100-
/O.EXP.KPHI.SV.W.0185.000000T0000Z-120809T2100Z/
BUCKS PA-
450 PM EDT THU AUG 9 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL BUCKS COUNTY WILL
EXPIRE AT 500 PM EDT...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

LAT...LON 4026 7521 4039 7543 4046 7520 4029 7509
TIME...MOT...LOC 2050Z 264DEG 18KT 4033 7510

$$

HEAVENER
238 
WWUS51 KPHI 092051
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
451 PM EDT THU AUG 9 2012

PAC017-092101-
/O.EXP.KPHI.SV.W.0185.000000T0000Z-120809T2100Z/
BUCKS PA-
451 PM EDT THU AUG 9 2012

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL BUCKS COUNTY WILL
EXPIRE AT 500 PM EDT...

THE SEVERE THUNDERSTORM IS EAST OF THE AREA.
 
PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

LAT...LON 4026 7521 4039 7543 4046 7520 4029 7509
TIME...MOT...LOC 2051Z 264DEG 18KT 4033 7509

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 1:00 PM EDTSpecial Weather StatementPHILehigh60 min
Aug 9, 1:22 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery68 min
Aug 9, 1:26 PM EDTAreal Flood AdvisoryPHIBucks, Montgomery3 hr
Aug 9, 1:33 PM EDTSpecial Weather StatementPHINorthampton57 min
Aug 9, 1:42 PM EDTSpecial Weather StatementPHIMonroe63 min
Aug 9, 1:45 PM EDTSpecial Weather StatementPHIBerks60 min
Aug 9, 2:13 PM EDTSevere Thunderstorm WarningPHIBerks77 min
Aug 9, 2:20 PM EDTSevere Thunderstorm WarningPHINorthampton70 min
Aug 9, 2:25 PM EDTSevere Thunderstorm WarningPHIBucks65 min
Aug 9, 3:03 PM EDTSpecial Weather StatementPHIMonroe87 min
Aug 9, 3:05 PM EDTSpecial Weather StatementPHIChester, Montgomery85 min
Aug 9, 3:11 PM EDTAreal Flood AdvisoryPHICarbon, Monroe6 hr
Aug 9, 3:20 PM EDTSevere Thunderstorm WarningPHIChester, Montgomery55 min
Aug 9, 3:39 PM EDTSpecial Weather StatementPHIBucks66 min
Aug 9, 3:57 PM EDTAreal Flood AdvisoryPHIChester, Montgomery104 min
Aug 9, 4:18 PM EDTSpecial Weather StatementPHIBucks57 min
Aug 9, 4:33 PM EDTSevere Thunderstorm WarningPHIBucks57 min
Aug 9, 4:57 PM EDTSevere Thunderstorm WarningPHIBucks78 min
Aug 9, 5:06 PM EDTAreal Flood AdvisoryPHIBucks3 hr
Aug 9, 5:26 PM EDTFlash Flood WarningPHIBucks2 hr
Aug 9, 7:01 PM EDTSpecial Weather StatementPHIBerks59 min
Aug 9, 7:10 PM EDTSevere Thunderstorm WarningPHIBerks, Carbon, Lehigh80 min
Aug 9, 7:40 PM EDTSpecial Weather StatementPHICarbon, Monroe95 min
Aug 9, 7:46 PM EDTAreal Flood AdvisoryPHIBerks3 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2012Every severe thunderstorm warning in 2012

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.