Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 2, NWS Philadelphia/Mount Holly

April 20, 2015Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 20, 2015, 9:03 PM EDT for Berks County, Pennsylvania. It was in force for 42 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: Apr 20, 2015, 9:03 PM EDT (01:03 UTC)
Expired: Apr 20, 2015, 9:45 PM EDT
In force: 42 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Berks County, PA

The radar

The State College radar (KCCX), 153 km from the middle of the area, began a volume at 01:04 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
Apr 20, 3:08 PM EDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 1.1 hours before the alert went out and 197 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: 460 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 1835 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 176 m²/s²
0-3 km storm-relative helicity: 177 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

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

607 
WUUS51 KPHI 210103
SVRPHI
PAC011-210145-
/O.NEW.KPHI.SV.W.0002.150421T0103Z-150421T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
903 PM EDT MON APR 20 2015

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WEST CENTRAL BERKS COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 945 PM EDT

* AT 903 PM EDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
  OF 60 MPH. THIS STORM WAS LOCATED OVER HARPER TAVERN...OR 7 MILES
  NORTHWEST OF ANNVILLE...AND MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  STRAUSSTOWN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE AREA. ALTHOUGH A TORNADO IS
NOT IMMEDIATELY LIKELY...IF ONE IS SPOTTED...ACT QUICKLY AND MOVE TO
A PLACE OF SAFETY IN A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE
HAIL AND DAMAGING WINDS. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY. LIGHTNING IS ONE OF NATURES LEADING KILLERS. REMEMBER...
IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY
LIGHTNING.

&&

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT FOR EASTERN
PENNSYLVANIA.

LAT...LON 4052 7634 4052 7625 4055 7614 4051 7607
      4042 7630 4042 7632 4049 7643
TIME...MOT...LOC 0103Z 241DEG 25KT 4042 7658 

$$

HEAVENER

2 follow-up statements

975 
WWUS51 KPHI 210135
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
935 PM EDT MON APR 20 2015

PAC011-210145-
/O.CON.KPHI.SV.W.0002.000000T0000Z-150421T0145Z/
BERKS PA-
935 PM EDT MON APR 20 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM EDT
FOR WEST CENTRAL BERKS COUNTY...

AT 934 PM EDT...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 PINE GROVE...OR 10 MILES NORTH OF
MYERSTOWN. THIS STORM WAS NEARLY STATIONARY.

THIS SEVERE THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF WEST
CENTRAL BERKS COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. ALTHOUGH A
TORNADO IS NOT IMMEDIATELY LIKELY...IF ONE IS SPOTTED...ACT QUICKLY
AND MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE...SUCH AS A
BASEMENT OR SMALL INTERIOR ROOM.

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE
HAIL AND DAMAGING WINDS. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING AND AWAY FROM WINDOWS.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM.  MOVE INDOORS
IMMEDIATELY. LIGHTNING IS ONE OF NATURES LEADING KILLERS. REMEMBER...
IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY
LIGHTNING.

&&

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT FOR EASTERN
PENNSYLVANIA.

LAT...LON 4052 7634 4052 7625 4050 7625 4048 7635
      4050 7640
TIME...MOT...LOC 0134Z 241DEG 25KT 4052 7634 

$$

HEAVENER

702 
WWUS51 KPHI 210143
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
943 PM EDT MON APR 20 2015

PAC011-210152-
/O.EXP.KPHI.SV.W.0002.000000T0000Z-150421T0145Z/
BERKS PA-
943 PM EDT MON APR 20 2015

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL BERKS COUNTY WILL
EXPIRE AT 945 PM EDT...
    
THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING HAS WEAKENED.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.

LAT...LON 4052 7634 4052 7625 4050 7625 4048 7635
      4050 7640
TIME...MOT...LOC 0140Z 241DEG 25KT 4052 7634 

$$

HEAVENER

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 8:47 PM EDT	Special Weather Statement	PHI	Lebanon	58 min
Apr 20, 8:56 PM EDT	Special Weather Statement	PHI	Lehigh	34 min
Apr 20, 10:11 PM EDT	Special Weather Statement	PHI	Schuylkill	64 min
Apr 20, 10:24 PM EDT	Special Weather Statement	PHI	Delaware, Philadelphia	81 min
Apr 20, 11:02 PM EDT	Special Weather Statement	PHI	Carbon, Lehigh, Monroe, Northampton	58 min
Apr 21, 1:45 AM EDT	Areal Flood Advisory	PHI	Bucks, Delaware, Montgomery, Philadelphia	3 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2015 Every severe thunderstorm warning in 2015

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.