Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 117, NWS Philadelphia/Mount Holly

July 23, 20124 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 23, 2012, 5:09 PM EDT for 4 counties in Pennsylvania. It was in force for 51 min. 3 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: Jul 23, 2012, 5:09 PM EDT (21:09 UTC)
Expired: Jul 23, 2012, 6:00 PM EDT
In force: 51 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Berks County, PA, Chester County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 118 km from the middle of the area, began a volume at 21:11 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

Time	Report	Where	Remark
Jul 23, 5:20 PM EDT	TSTM WND GST 54	Reading Airport, PA
Jul 23, 5:25 PM EDT	HAIL 0.88	Fleetwood, PA
Jul 23, 5:40 PM EDT	TSTM WND DMG	1 S Fleetwood, PA	TREES DOWN

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

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 23, 1:24 PM EDT	Severe Thunderstorm Watch	SPC	10 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.2 hours before the alert went out and 103 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: 1475 J/kg
Mixed-layer CIN: -34 J/kg
Mixed-layer LCL: 637 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 103 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.4

Open this sounding in Storm Lab

The text

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

721 
WUUS51 KPHI 232109
SVRPHI
PAC011-029-077-091-232200-
/O.NEW.KPHI.SV.W.0117.120723T2109Z-120723T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
509 PM EDT MON JUL 23 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BERKS COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF READING...
  SOUTHERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  NORTHERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTHWESTERN MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 600 PM EDT

* AT 502 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
  AREA OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE 
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THE LEADING EDGE OF 
  THESE STORMS WAS LOCATED ALONG A LINE EXTENDING FROM LAURELDALE 
  TO 10 MILES SOUTH OF SINKING SPRING...OR ALONG A LINE EXTENDING 
  FROM 6 MILES NORTH OF READING TO 12 MILES SOUTHWEST OF READING...
  AND MOVING EAST AT 20   MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  FLEETWOOD AROUND 515 PM EDT...
  NEW MORGAN...HONEY BROOK AND BIRDSBORO AROUND 530 PM EDT...
  PARKESBURG AROUND 535 PM EDT...
  ELVERSON AROUND 540 PM EDT...
  BALLY...COATESVILLE...GLENMOORE AND BECHTELSVILLE AROUND 550 PM
  EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

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 1100 PM EDT
MONDAY EVENING FOR NORTHERN NEW JERSEY AND NORTHEASTERN PENNSYLVANIA.

&&

LAT...LON 4064 7591 4065 7540 4062 7537 4058 7540
      4054 7533 4043 7548 4037 7540 3986 7566
      3994 7600 4003 7594 4011 7595 4014 7589
      4028 7611
TIME...MOT...LOC 2107Z 280DEG 17KT 4041 7587 4018 7603

$$

MPD

1 follow-up statement

525 
WWUS51 KPHI 232138
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
538 PM EDT MON JUL 23 2012

PAC011-029-077-091-232200-
/O.CON.KPHI.SV.W.0117.000000T0000Z-120723T2200Z/
BERKS PA-LEHIGH PA-MONTGOMERY PA-CHESTER PA-
538 PM EDT MON JUL 23 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR NORTHERN CHESTER...NORTHWESTERN MONTGOMERY...SOUTHERN LEHIGH AND
EASTERN BERKS COUNTIES...

AT 532 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE AN AREA OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER
SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THE LEADING EDGE OF
THESE STORMS WAS FROM BECHTELSVILLE TO NEW MORGAN...OR ALONG A LINE 
FROM ABOUT 10 MILES EAST OF READING TO ABOUT 10 MILES SOUTH OF 
READING...MOVING EAST AT 20 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  ELVERSON BY 540 PM EDT...
  AMITY GARDENS BY 545 PM EDT...
  SOUTH COATESVILLE...COATESVILLE...GLENMOORE AND STOWE BY 550 PM
  EDT...
  BALLY...MODENA...CEDARVILLE AND STOWE BY 555 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THE STORMS. MOVE INDOORS
IMMEDIATELY! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

WINDS UP TO 55 MPH WERE REPORTED BY AN AUTOMATED WEATHER OBSERVING 
SYSTEM AT READING AIPORT AT 520 PM. 

HAIL OF ONE INCH IN DIAMETER WAS REPORTED AT TEMPLE IN BERKS COUNTY 
AT 520 PM. 

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 1100 PM EDT
MONDAY EVENING FOR NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 4003 7594 4011 7595 4014 7589 4042 7599
      4052 7598 4064 7591 4065 7541 4062 7537
      4058 7540 4054 7533 4043 7548 4037 7540
      3986 7566 3994 7600
TIME...MOT...LOC 2134Z 280DEG 17KT 4039 7572 4016 7587

$$

MPD

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 4:31 PM EDT	Special Weather Statement	PHI	Berks	59 min
Jul 23, 5:56 PM EDT	Special Weather Statement	PHI	Bucks, Chester, Delaware, Lehigh, Montgomery, Philadelphia	64 min
Jul 23, 6:51 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	69 min
Jul 23, 7:39 PM EDT	Flash Flood Warning	PHI	Monroe	2 hr
Jul 23, 7:56 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	59 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.