Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 76, NWS Philadelphia/Mount Holly

June 15, 20094 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 15, 2009, 4:15 PM EDT for 4 counties in Pennsylvania. It was in force for 60 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: Jun 15, 2009, 4:15 PM EDT (20:15 UTC)
Expired: Jun 15, 2009, 5:15 PM EDT
In force: 60 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Berks County, PA, Bucks County, PA, Lehigh County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 99 km from the middle of the area, began a volume at 20:15 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
Jun 15, 4:35 PM EDT	TSTM WND DMG	Quakertown, PA	TREES DOWN.
Jun 15, 4:35 PM EDT	HAIL 1.75	3 W Quakertown, PA	MILFORD TOWNSHIP.
Jun 15, 5:05 PM EDT	HAIL 0.75	Souderton, PA

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 8.3 hours before the alert went out and 119 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: 196 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 943 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 92 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 152015
SVRPHI
PAC011-017-077-091-152115-
/O.NEW.KPHI.SV.W.0076.090615T2015Z-090615T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
415 PM EDT MON JUN 15 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EXTREME EAST CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...
  SOUTHEASTERN LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  WEST CENTRAL BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA...
  NORTH CENTRAL MONTGOMERY COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 515 PM EDT

* AT 412 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND    
  DAMAGING WINDS UP TO 60 MPH. THIS STORM WAS LOCATED NEAR           
  EMMAUS...OR NEAR ALLENTOWN...AND MOVING SOUTHEAST AT 20 MPH.

THIS STORM HAS A HISTORY OF PRODUCING HAIL TO THE SIZE OF NICKELS.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ZIONSVILLE AROUND 420 PM EDT...
  GERYVILLE AROUND 435 PM EDT...
  QUAKERTOWN AROUND 440 PM EDT...
  PERKASIE AROUND 455 PM EDT...
  SOUDERTON AROUND 505 PM EDT...
  FRICKS AROUND 510 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 LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 4029 7518 4026 7551 4043 7556 4055 7558
      4059 7543
TIME...MOT...LOC 2014Z 332DEG 18KT 4053 7546

$$

GORSE/DEFINO

1 follow-up statement

000 
WWUS51 KPHI 152043
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
443 PM EDT MON JUN 15 2009

PAC011-077-152052-
/O.CAN.KPHI.SV.W.0076.000000T0000Z-090615T2115Z/
BERKS PA-LEHIGH PA-
443 PM EDT MON JUN 15 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LEHIGH AND
EXTREME EAST CENTRAL BERKS COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM IS EXITING THE AREA, THEREFORE THE SEVERE 
THUNDERSTORM WARNING HAS BEEN CANCELLED.

LAT...LON 4041 7554 4042 7549 4049 7540 4029 7518
      4026 7551 4028 7552
TIME...MOT...LOC 2042Z 334DEG 14KT 4040 7542

$$

PAC017-091-152115-
/O.CON.KPHI.SV.W.0076.000000T0000Z-090615T2115Z/
MONTGOMERY PA-BUCKS PA-
443 PM EDT MON JUN 15 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM EDT
FOR WEST CENTRAL BUCKS AND NORTH CENTRAL MONTGOMERY COUNTIES...

AT 439 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE 
HAIL...AND DAMAGING WINDS UP TO 60 MPH.  THIS STORM WAS LOCATED NEAR 
GERYVILLE...OR 13 MILES SOUTH OF ALLENTOWN...MOVING SOUTHEAST AT 15 
MPH.

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  GREEN LANE BY 455 PM EDT...
  SELLERSVILLE AND PERKASIE BY 500 PM EDT...
  SOUDERTON...HARLEYSVILLE...TELFORD AND SILVERDALE BY 510 PM EDT...
  6 MILES WEST OF FRICKS BY 515 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 LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 4041 7554 4042 7549 4049 7540 4029 7518
      4026 7551 4028 7552
TIME...MOT...LOC 2042Z 334DEG 14KT 4040 7542

$$

GORSE/DEFINO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 15, 2:33 PM EDT	Severe Thunderstorm Warning	PHI	Carbon	57 min
Jun 15, 3:16 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Northampton	59 min
Jun 15, 5:13 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	62 min
Jun 15, 5:55 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Montgomery, Philadelphia	65 min
Jun 15, 6:37 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	53 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2009 Every severe thunderstorm warning in 2009

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.