Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 1, NWS Philadelphia/Mount Holly

March 29, 2009Berks County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Mar 29, 2009, 4:41 PM EDT for Berks County, Pennsylvania. It was in force for 94 min. 5 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
Mar 29, 2009, 4:41 PM EDT (20:41 UTC)
Expired
Mar 29, 2009, 6:15 PM EDT
In force
94 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Berks County, PA

The radar

The Philadelphia radar (KDIX), 158 km from the middle of the area, began a volume at 20:41 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
Mar 29, 5:10 PM EDTHAIL 0.88West Lawn, PAMARBLE TO PENNY SIZE HAIL REPORTED IN WEST LAWN.
Mar 29, 5:15 PM EDTHAIL 1Reading, PAQUARTER SIZE HAIL REPORTED IN READING
Mar 29, 5:16 PM EDTTSTM WND GST 54Reading, PA54 MPH WIND GUST MEASURED AT THE READING AIRPORT.
Mar 29, 5:25 PM EDTHAIL 1Fleetwood, PANICKEL TO QUARTER SIZE HAIL REPORTED IN FLEETWOOD, SHILLINGTON AND BLANDON.
Mar 29, 5:30 PM EDTTSTM WND DMG7 Ese Laureldale, PADAMAGE WAS REPORTED AT A FARM IN OLEY TOWNSHIP. ROOF, SIDING AND WINDOW DAMAGE REPORTED TO THE FARMHOUSE WITH SIGNIFICANT DAMAGE TO 2 BARNS.

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, 8.7 hours before the alert went out and 204 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 2009-03-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2009-03-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 246 square meters per square second.1939587897117136Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
491 m above ground
0-6 km bulk shear
79 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
225 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 292041
SVRPHI
PAC011-292215-
/O.NEW.KPHI.SV.W.0001.090329T2041Z-090329T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
441 PM EDT SUN MAR 29 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...

* UNTIL 615 PM EDT

* AT 439 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED 15 MILES SOUTHWEST OF WOMELSDORF...OR 10 MILES
  NORTH OF LANCASTER...AND MOVING NORTHEAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WOMELSDORF BY 505 PM EDT...
  WERNERSVILLE BY 510 PM EDT...
  READING BY 525 PM EDT...
  LEESPORT BY 530 PM EDT...
  FLEETWOOD BY 540 PM EDT...
  KUTZTOWN BY 550 PM EDT...

ADDITIONAL THUNDERSTORMS WERE LOCATED OVER THE NORTHWEST PART OF 
BERKS COUNTY AND THESE WERE ALSO MOVING EAST INTO BERKS COUNTY. 
THESE THUNDERSTORMS ARE ALSO CAPABLE OF PRODUCING HAIL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. 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.

&&

LAT...LON 4049 7643 4053 7632 4052 7630 4054 7618
      4056 7615 4058 7609 4060 7605 4059 7603
      4064 7601 4068 7590 4044 7554 4015 7591
      4036 7621 4036 7624
TIME...MOT...LOC 2040Z 231DEG 27KT 4018 7631

$$

RNS

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 29, 4:58 PM EDTTornado WarningPHIBerks62 min
Mar 29, 5:11 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh64 min
Mar 29, 5:27 PM EDTSevere Thunderstorm WarningPHILehigh63 min
Mar 29, 5:55 PM EDTSevere Thunderstorm WarningPHIBucks, Chester, Lehigh, Montgomery, Northampton50 min
Mar 29, 6:11 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia64 min
Mar 29, 7:09 PM EDTSevere Thunderstorm WarningPHIBucks51 min

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.