Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 91, NWS Philadelphia/Mount Holly

July 15, 2012Lehigh County, Northampton County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 15, 2012, 6:40 PM EDT for Lehigh County, Northampton County, Pennsylvania. It was in force for 65 min. 1 report 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 15, 2012, 6:40 PM EDT (22:40 UTC)
Expired: Jul 15, 2012, 7:45 PM EDT
In force: 65 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 132 km from the middle of the area, began a volume at 22:40 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 15, 7:05 PM EDT	TSTM WND DMG	Heidelberg Twp, PA	TREES AND WIRES DOWN IN HEIDELBERG TWP

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

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.7 hours before the alert went out and 234 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: 88 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 912 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 79 m²/s²
0-3 km storm-relative helicity: 97 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.

136 
WUUS51 KPHI 152240
SVRPHI
PAC077-095-152345-
/O.NEW.KPHI.SV.W.0091.120715T2240Z-120715T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
640 PM EDT SUN JUL 15 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  WEST CENTRAL NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 745 PM EDT

* AT 635 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 10
  MILES NORTHWEST OF WANAMAKERS...OR 14 MILES WEST OF LEHIGHTON...AND
  MOVING EAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  JORDAN VALLEY AND NEW TRIPOLI AROUND 655 PM EDT...
  JORDAN VALLEY AROUND 700 PM EDT...
  EMERALD...SLATINGTON...WALNUTPORT AND NEFFS AROUND 705 PM EDT...
  COFFEETOWN AROUND 710 PM EDT...
  NORTHAMPTON AROUND 715 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.

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS WITH DOWNED 
TREES AND POWER LINES.

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 4051 7547 4052 7563 4068 7589 4073 7579
      4074 7575 4078 7568 4079 7560 4081 7554
      4081 7548
TIME...MOT...LOC 2239Z 280DEG 33KT 4077 7593

$$

AMC

1 follow-up statement

947 
WWUS51 KPHI 152311
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
711 PM EDT SUN JUL 15 2012

PAC077-095-152345-
/O.CON.KPHI.SV.W.0091.000000T0000Z-120715T2345Z/
LEHIGH PA-NORTHAMPTON PA-
711 PM EDT SUN JUL 15 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR WEST CENTRAL NORTHAMPTON AND LEHIGH COUNTIES...

AT 705 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 NEW TRIPOLI...OR 10 MILES SOUTH OF LEHIGHTON...MOVING
EAST AT 40 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  SCHNECKSVILLE...NEFFS...SLATINGTON AND WALNUTPORT BY 715 PM EDT...
  COFFEETOWN BY 720 PM EDT...
  HOKENDAUQUA...NORTH CATASAUQUA...COPLAY AND NORTHAMPTON BY 725 PM
  EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING DAMAGING WINDS WITH NUMEROUS 
DOWNED TREES AND POWER LINES. SEEK SHELTER INSIDE A STURDY BUILDING  
AND STAY 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 4051 7547 4052 7563 4068 7589 4073 7579
      4074 7575 4078 7568 4079 7560 4081 7554
      4081 7548
TIME...MOT...LOC 2310Z 280DEG 33KT 4068 7567

$$

AMC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 12:51 PM EDT	Special Weather Statement	PHI	Lehigh	39 min
Jul 15, 1:31 PM EDT	Special Weather Statement	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	59 min
Jul 15, 2:34 PM EDT	Special Weather Statement	PHI	Bucks	56 min
Jul 15, 2:41 PM EDT	Special Weather Statement	PHI	Carbon	64 min
Jul 15, 2:50 PM EDT	Special Weather Statement	PHI	Carbon	55 min
Jul 15, 3:29 PM EDT	Special Weather Statement	PHI	Bucks	61 min
Jul 15, 3:44 PM EDT	Excessive Heat Warning	PHI	Delaware, Philadelphia	4 days
Jul 15, 5:07 PM EDT	Special Weather Statement	PHI	Carbon, Monroe	53 min
Jul 15, 5:58 PM EDT	Special Weather Statement	PHI	Monroe	62 min
Jul 15, 6:13 PM EDT	Severe Thunderstorm Warning	PHI	Carbon	62 min
Jul 15, 7:04 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Monroe, Northampton	56 min
Jul 15, 7:58 PM EDT	Special Weather Statement	PHI	Berks, Bucks	62 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.