Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 26, NWS Philadelphia/Mount Holly

May 16, 2009Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 16, 2009, 7:49 PM EDT for Berks County, Pennsylvania. It was in force for 56 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
May 16, 2009, 7:49 PM EDT (23:49 UTC)
Expired
May 16, 2009, 8:45 PM EDT
In force
56 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 161 km from the middle of the area, began a volume at 23:49 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

TimeReportWhereRemark
May 16, 8:30 PM EDTTSTM WND GST 44Leesport, PAA 44 MPH THUNDERSTORM WIND GUST WAS MEASURED IN LEESPORT.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.8 hours before the alert went out and 203 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2009-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 216 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2009-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
216 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
608 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 162349
SVRPHI
PAC011-170045-
/O.NEW.KPHI.SV.W.0026.090516T2349Z-090517T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
749 PM EDT SAT MAY 16 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN BERKS COUNTY IN EASTERN PENNSYLVANIA...

* UNTIL 845 PM EDT

* AT 747 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 17
  MILES WEST OF STRAUSSTOWN...OR 32 MILES NORTH OF LANCASTER...AND
  MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  STRAUSSTOWN BY 815 PM EDT...
  8 MILES NORTH OF BERNVILLE BY 820 PM EDT...
  HAMBURG BY 835 PM EDT...
  LENHARTSVILLE AND 8 MILES NORTHWEST OF KUTZTOWN BY 845 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 4053 7634 4052 7630 4054 7618 4060 7605
      4059 7603 4064 7600 4068 7590 4047 7559
      4032 7617 4036 7621 4036 7624 4047 7640
      4050 7644
TIME...MOT...LOC 2349Z 253DEG 31KT 4048 7648

$$

GORSE
2 follow-up statements
000 
WWUS51 KPHI 170020
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
820 PM EDT SAT MAY 16 2009

PAC011-170045-
/O.CON.KPHI.SV.W.0026.000000T0000Z-090517T0045Z/
BERKS PA-
820 PM EDT SAT MAY 16 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR NORTHERN BERKS COUNTY...

AT 818 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE 
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS 
LOCATED NEAR STRAUSSTOWN...OR 16 MILES NORTHWEST OF READING...MOVING 
EAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  SHOEMAKERSVILLE...CENTERPORT...HAMBURG AND LEESPORT BY 835 PM
  EDT...
  7 MILES NORTH OF TEMPLE AND 9 MILES NORTH OF LAURELDALE BY 840 PM
  EDT...
  LENHARTSVILLE...KUTZTOWN...FLEETWOOD AND 7 MILES NORTHWEST OF LYONS
  BY 845 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 4053 7634 4052 7630 4054 7618 4060 7605
      4059 7603 4064 7600 4068 7590 4047 7559
      4032 7617 4036 7621 4036 7624 4047 7640
      4050 7644
TIME...MOT...LOC 0019Z 259DEG 30KT 4048 7616

$$

GORSE
000 
WWUS51 KPHI 170042
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
842 PM EDT SAT MAY 16 2009

PAC011-170050-
/O.EXP.KPHI.SV.W.0026.000000T0000Z-090517T0045Z/
BERKS PA-
842 PM EDT SAT MAY 16 2009

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN BERKS COUNTY WILL
EXPIRE AT 845 PM EDT...

AT 840 PM, NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
CLUSTER OF THUNDERSTORMS MOVING ACROSS THE NORTHERN HALF OF BERKS 
COUNTY. THE STORMS HAVE BEEN SHOWING A WEAKENING TREND, THEREFORE 
THE WARNING WILL BE ALLOWED TO EXPIRE AT 845 PM. HOWEVER, HEAVY 
RAIN, FREQUENT CLOUD TO GROUND LIGHTNING AND WIND GUSTS TO 40 MPH 
WILL STILL OCCUR.

LAT...LON 4053 7634 4052 7630 4054 7618 4060 7605
      4059 7603 4064 7600 4068 7590 4047 7559
      4032 7617 4036 7621 4036 7624 4047 7640
      4050 7644
TIME...MOT...LOC 0040Z 259DEG 30KT 4051 7593

$$

GORSE

The office that day

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

IssuedProductOfficeCountiesLasted
May 16, 3:41 AM EDTDense Fog AdvisoryPHIDelaware, Philadelphia5 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2009Every 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.