Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 145, NWS Philadelphia/Mount Holly

July 28, 2012Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 28, 2012, 8:19 PM EDT for Bucks County, Montgomery County, Pennsylvania. It was in force for 56 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 28, 2012, 8:19 PM EDT (00:19 UTC)
Expired: Jul 28, 2012, 9:15 PM EDT
In force: 56 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 91 km from the middle of the area, began a volume at 00:23 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.

Issued	Product	Office	Lasted
Jul 28, 1:36 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.3 hours before the alert went out and 224 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 69 J/kg
Mixed-layer CIN: -143 J/kg
Mixed-layer LCL: 656 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 20 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.

575 
WUUS51 KPHI 290019
SVRPHI
PAC017-091-290115-
/O.NEW.KPHI.SV.W.0145.120729T0019Z-120729T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
819 PM EDT SAT JUL 28 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 915 PM EDT

* AT 817 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 WAS LOCATED NEAR
  GREEN LANE...OR 18 MILES SOUTH OF ALLENTOWN...AND MOVING EAST AT 20
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SOUDERTON AROUND 840 PM EDT...
  HATFIELD AROUND 845 PM EDT...
  LANSDALE AROUND 850 PM EDT...
  FRICKS AROUND 855 PM EDT...
  CHALFONT AROUND 900 PM EDT...
  DOYLESTOWN AND ROBESONIA AROUND 910 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SATURDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4022 7559 4024 7561 4036 7560 4036 7501
      4017 7500
TIME...MOT...LOC 0019Z 272DEG 19KT 4032 7548

$$

HAYES

2 follow-up statements

213 
WWUS51 KPHI 290046
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
846 PM EDT SAT JUL 28 2012

PAC017-091-290115-
/O.CON.KPHI.SV.W.0145.000000T0000Z-120729T0115Z/
BUCKS PA-MONTGOMERY PA-
846 PM EDT SAT JUL 28 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM EDT
FOR NORTHERN MONTGOMERY AND CENTRAL BUCKS COUNTIES...

AT 842 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 NEAR SOUDERTON...OR 21 MILES SOUTHEAST OF ALLENTOWN...MOVING
EAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  FRICKS...BRITTANY FARMS-HIGHLANDS AND MONTGOMERYVILLE BY 855 PM
  EDT...
  CHALFONT BY 900 PM EDT...
  NEW BRITAIN BY 905 PM EDT...
  DOYLESTOWN AND ROBESONIA BY 910 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SATURDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4022 7556 4026 7553 4035 7553 4036 7501
      4017 7500
TIME...MOT...LOC 0046Z 272DEG 19KT 4031 7529

$$

HAYES

706 
WWUS51 KPHI 290106
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
906 PM EDT SAT JUL 28 2012

PAC017-091-290116-
/O.EXP.KPHI.SV.W.0145.000000T0000Z-120729T0115Z/
BUCKS PA-MONTGOMERY PA-
906 PM EDT SAT JUL 28 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN MONTGOMERY AND
CENTRAL BUCKS COUNTIES WILL EXPIRE AT 915 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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SATURDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 4022 7556 4026 7553 4035 7553 4036 7501
      4017 7500
TIME...MOT...LOC 0106Z 272DEG 19KT 4031 7515

$$

HAYES

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 8:02 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery	2 hr
Jul 28, 8:05 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	55 min
Jul 28, 8:26 PM EDT	Areal Flood Advisory	PHI	Bucks, Montgomery, Philadelphia	101 min
Jul 28, 8:38 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	67 min
Jul 28, 8:41 PM EDT	Special Weather Statement	PHI	Delaware	64 min
Jul 28, 9:11 PM EDT	Special Weather Statement	PHI	Bucks, Philadelphia	64 min
Jul 29, 3:03 PM EDT	Special Weather Statement	PHI	Berks, Lehigh	57 min
Jul 29, 3:40 PM EDT	Areal Flood Advisory	PHI	Berks, Chester	74 min
Jul 29, 5:32 PM EDT	Special Weather Statement	PHI	Carbon, Lehigh, Northampton	58 min
Jul 29, 6:08 PM EDT	Areal Flood Advisory	PHI	Carbon	86 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2012 Every 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.