Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 185, NWS Philadelphia/Mount Holly

August 9, 20095 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 9, 2009, 4:30 PM EDT for 5 counties in Pennsylvania. It was in force for 90 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: Aug 9, 2009, 4:30 PM EDT (20:30 UTC)
Expired: Aug 9, 2009, 6:00 PM EDT
In force: 90 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Berks County, PA, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 145 km from the middle of the area, began a volume at 20:30 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
Aug 9, 5:05 PM EDT	TSTM WND DMG	5 Ene Fredericksburg, PA	TREES AND WIRES DOWN THROUGHOUT THE COUNTY.

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
Aug 9, 3:18 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 8.5 hours before the alert went out and 243 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 897 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 136 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.

000 
WUUS51 KPHI 092030
SVRPHI
PAC011-025-077-089-095-092200-
/O.NEW.KPHI.SV.W.0185.090809T2030Z-090809T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
430 PM EDT SUN AUG 9 2009

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...
  LEHIGH COUNTY IN EASTERN PENNSYLVANIA...
  THIS INCLUDES THE CITY OF ALLENTOWN...
  WESTERN NORTHAMPTON COUNTY IN EASTERN PENNSYLVANIA...
  CARBON COUNTY IN NORTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF LEHIGHTON...
  WESTERN MONROE COUNTY IN NORTHEAST PENNSYLVANIA...
  THIS INCLUDES THE CITY OF MOUNT POCONO...

* UNTIL 600 PM EDT

* AT 426 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS
  UP TO AROUND 70 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
  EXTENDING FROM 32 MILES NORTHWEST OF WHITE HAVEN TO 41 MILES
  NORTHWEST OF STRAUSSTOWN...OR ALONG A LINE EXTENDING FROM 22 MILES
  WEST OF WILKES-BARRE TO 58 MILES NORTHWEST OF READING...AND MOVING
  SOUTHEAST AT 45 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  WEATHERLY AND NESQUEHONING AROUND 515 PM EDT...
  NEW MAHONING...STRAUSSTOWN AND JIM THORPE AROUND 520 PM EDT...
  WOMELSDORF...LEHIGHTON...HAMBURG AND BERNVILLE AROUND 525 PM EDT...
  BELTZVILLE STATE PARK AROUND 530 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS LINE OF STORMS HAS A HISTORY OF PRODUCING WIDESPREAD WIND 
DAMAGE SINCE ITS INCEPTION IN WESTERN NEW YORK STATE AND INTO 
NORTH CENTRAL PENNSYLVANIA AND SHOULD BE TAKEN VERY SERIOUSLY. 
THIS IS AN EXTREMELY DANGEROUS SITUATION. SEEK SHELTER NOW 
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS AND TREES

IN ADDITION TO DAMAGING WINDS...HEAVY RAIN WILL OCCUR
WITH THESE STORMS AND CAUSE LOW-LYING AND POOR DRAINAGE FLOODING.

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

&&

LAT...LON 4123 7538 4060 7522 4049 7542 4042 7549
      4044 7553 4024 7570 4014 7590 4050 7644
      4054 7618 4060 7605 4059 7603 4064 7600
      4073 7579 4091 7600 4100 7575 4105 7578
      4110 7577 4114 7570 4113 7564 4123 7554
TIME...MOT...LOC 2028Z 314DEG 39KT 4129 7627 4076 7685

$$
 
TFG

3 follow-up statements

000 
WWUS51 KPHI 092058
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
458 PM EDT SUN AUG 9 2009

PAC011-025-077-089-095-092200-
/O.CON.KPHI.SV.W.0185.000000T0000Z-090809T2200Z/
BERKS PA-LEHIGH PA-NORTHAMPTON PA-CARBON PA-MONROE PA-
458 PM EDT SUN AUG 9 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR WESTERN MONROE...CARBON...WESTERN NORTHAMPTON...LEHIGH AND BERKS
COUNTIES...

AT 455 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING
DESTRUCTIVE WINDS TO AROUND 70 MPH.  THESE STORMS WERE LOCATED
ALONG A LINE EXTENDING FROM 11 MILES WEST OF WHITE HAVEN TO 21 MILES
WEST OF STRAUSSTOWN...OR ALONG A LINE EXTENDING FROM 13 MILES
SOUTHWEST OF WILKES-BARRE TO 37 MILES NORTHWEST OF READING...MOVING
SOUTHEAST AT 45 MPH. AS OF THIS MOMENT BERKS COUNTY IS ON TRACK TO
GET THE MOST DESTRUCTIVE PART OF THIS LINE.

SEVERE THUNDERSTORMS WILL BE NEAR...
  TRESCKOW BY 505 PM EDT...
  BEAVER MEADOWS BY 510 PM EDT...
  WEATHERLY...NESQUEHONING AND LANSFORD BY 515 PM EDT...
  NEW MAHONING...SUMMIT HILL...STRAUSSTOWN AND JIM THORPE BY 520 PM
  EDT...
  WOMELSDORF BY 525 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE ACROSS
NORTH CENTRAL PENNSYLVANIA. THIS IS AN EXTREMELY DANGEROUS SITUATION.
SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS AND TREES

IN ADDITION TO DAMAGING WINDS...CONTINUOUS 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.

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

&&

LAT...LON 4123 7538 4060 7522 4049 7542 4042 7549
      4044 7553 4024 7570 4014 7590 4050 7644
      4054 7618 4060 7605 4059 7603 4064 7600
      4073 7579 4091 7600 4100 7575 4105 7578
      4110 7577 4114 7570 4113 7564 4123 7554
TIME...MOT...LOC 2056Z 314DEG 39KT 4108 7598 4055 7657

$$
 
TFG

000 
WWUS51 KPHI 092123
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
523 PM EDT SUN AUG 9 2009

PAC025-089-095-092132-
/O.CAN.KPHI.SV.W.0185.000000T0000Z-090809T2200Z/
NORTHAMPTON PA-CARBON PA-MONROE PA-
523 PM EDT SUN AUG 9 2009

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN MONROE...CARBON AND
WESTERN NORTHAMPTON COUNTIES IS CANCELLED...

THE STRONGEST PART OF THE LINE OF SEVERE THUNDERSTORMS WILL BE
AFFECTING LEHIGH AND ESPECIALLY BERKS COUNTY. THE REST OF THE LINE
HAS WEAKENED.

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

LAT...LON 4054 7618 4060 7605 4059 7603 4064 7600
      4078 7566 4051 7539 4042 7549 4044 7553
      4043 7554 4024 7570 4014 7590 4036 7621
      4050 7644
TIME...MOT...LOC 2122Z 313DEG 42KT 4071 7570 4034 7627

$$

PAC011-077-092200-
/O.CON.KPHI.SV.W.0185.000000T0000Z-090809T2200Z/
BERKS PA-LEHIGH PA-
523 PM EDT SUN AUG 9 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR LEHIGH AND BERKS COUNTIES...

AT 519 PM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM JORDAN VALLEY TO 6 MILES WEST OF
WOMELSDORF...OR ALONG A LINE EXTENDING FROM 7 MILES SOUTH OF
LEHIGHTON TO 20 MILES WEST OF READING...MOVING SOUTHEAST AT 50 MPH.
THE STRONGEST PART OF THIS LINE IS MOVING THROUGH BERKS COUNTY.

SEVERE THUNDERSTORMS WILL BE NEAR...
  SCHNECKSVILLE...COFFEETOWN...CLAUSSVILLE AND WERNERSVILLE BY 530 PM
  EDT...
  WYOMISSING HILLS...WYOMISSING...WHITFIELD AND WEST WYOMISSING BY
  535 PM EDT...
  ALLENTOWN AND ST. LAWRENCE BY 540 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

IN ADDITION TO DAMAGING WINDS...CONTINUOUS 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.

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

&&

LAT...LON 4054 7618 4060 7605 4059 7603 4064 7600
      4078 7566 4051 7539 4042 7549 4044 7553
      4043 7554 4024 7570 4014 7590 4036 7621
      4050 7644
TIME...MOT...LOC 2122Z 313DEG 42KT 4071 7570 4034 7627

$$
 
TFG

000 
WWUS51 KPHI 092135
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
535 PM EDT SUN AUG 9 2009

PAC077-092144-
/O.CAN.KPHI.SV.W.0185.000000T0000Z-090809T2200Z/
LEHIGH PA-
535 PM EDT SUN AUG 9 2009

...THE SEVERE THUNDERSTORM WARNING FOR LEHIGH COUNTY IS CANCELLED...

THE LINE OF THUNDERSTORMS HAS WEAKENED AND IS NO LONGER EXPECTED TO
BE SEVERE.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

LAT...LON 4038 7625 4046 7617 4051 7609 4057 7597
      4061 7578 4056 7570 4047 7559 4044 7558
      4044 7554 4024 7570 4014 7590
TIME...MOT...LOC 2134Z 313DEG 39KT 4054 7572 4024 7614

$$

PAC011-092200-
/O.CON.KPHI.SV.W.0185.000000T0000Z-090809T2200Z/
BERKS PA-
535 PM EDT SUN AUG 9 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR BERKS COUNTY...

AT 532 PM EDT...A LINE OF SEVERE THUNDERSTORMS WAS REPORTED CAPABLE
OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM KUTZTOWN TO 6 MILES SOUTHWEST OF
WERNERSVILLE...OR ALONG A LINE EXTENDING FROM 14 MILES WEST OF
ALLENTOWN TO 13 MILES WEST OF READING...MOVING SOUTHEAST AT 45 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  TOPTON...ST. LAWRENCE...SHILLINGTON AND REIFFTON BY 540 PM EDT...
  LORANE AND FLYING HILLS BY 545 PM EDT...
  NEW MORGAN...BOYERTOWN...BIRDSBORO AND BECHTELSVILLE BY 550 PM
  EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SUNDAY EVENING FOR NORTHERN DELAWARE AND NORTHEAST MARYLAND AND NEW
JERSEY AND EASTERN PENNSYLVANIA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 1100 PM EDT SUNDAY EVENING FOR SOUTHERN
DELAWARE AND NORTHEASTERN MARYLAND.

&&

LAT...LON 4038 7625 4046 7617 4051 7609 4057 7597
      4061 7578 4056 7570 4047 7559 4044 7558
      4044 7554 4024 7570 4014 7590
TIME...MOT...LOC 2134Z 313DEG 39KT 4054 7572 4024 7614

$$
 
TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 9:23 AM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	83 min
Aug 9, 9:33 AM EDT	Areal Flood Warning	PHI	Philadelphia	51 min
Aug 9, 11:57 AM EDT	Flash Flood Watch	PHI	Berks, Carbon, Delaware, Lehigh, Monroe, Northampton and 1 more	11 hr
Aug 9, 1:56 PM EDT	Excessive Heat Warning	PHI	Delaware, Philadelphia	30 hr
Aug 9, 1:56 PM EDT	Heat Advisory	PHI	Berks, Lehigh, Northampton	30 hr
Aug 9, 5:17 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	76 min
Aug 9, 5:53 PM EDT	Severe Thunderstorm Warning	PHI	Chester	82 min
Aug 9, 6:03 PM EDT	Areal Flood Advisory	PHI	Berks, Chester, Delaware, Montgomery, Philadelphia	117 min
Aug 9, 6:10 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	80 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.