Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 135, NWS Philadelphia/Mount Holly

June 27, 2002Bucks County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 27, 2002, 7:59 PM EDT for Bucks County, Philadelphia County, Pennsylvania. It was in force for 31 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jun 27, 2002, 7:59 PM EDT (23:59 UTC)
Expired: Jun 27, 2002, 8:30 PM EDT
In force: 31 min
Issued by: NWS Philadelphia/Mount Holly
Area: Whole counties

Counties Bucks County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 65 km from the middle of the area, began a volume at 00:03 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 27, 8:25 PM EDT	Thunderstorm Wind 52 E	Germantown, PA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 27, 2:00 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 12.0 hours before the alert went out and 114 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: 287 J/kg
Mixed-layer CIN: -83 J/kg
Mixed-layer LCL: 1213 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: 76 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 272359
SVRPHI
PAC017-101-280030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
759 PM EDT THU JUN 27 2002

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  PHILADELPHIA COUNTY IN SOUTHEAST PENNSYLVANIA.
  SOUTHEASTERN BUCKS COUNTY IN SOUTHEAST PENNSYLVANIA.

* UNTIL 830 PM EDT.

* AT 757 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  SEVERE THUNDERSTORMS...ALONG A LINE EXTENDING FROM 4 MILES
  NORTHWEST OF LANGHORNE TO 8 MILES WEST OF PHILADELPHIA...MOVING
  EAST AT 45 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  PHILADELPHIA...LANGHORNE AT 805 PM.
  LEVITTOWN AT 810 PM.

HAIL UP TO ONE INCH IN DIAMETER AND WINDS GREATER THAN 55 MILES AN
HOUR ARE EXPECTED FROM THIS STORM. SEEK SHELTER IN A STURDY STRUCTURE
UNTIL THE STORM HAS PASSED.

FOR THE LATEST STORM INFORMATION...PLEASE TUNE TO NOAA WEATHER
RADIO...YOUR LOCAL RADIO OR TELEVISION STATION...OR YOUR CABLE
TELEVISION OUTLET.

$$

LAT...LON 4001 7519 3997 7525 3992 7522 4017 7477
          4022 7488 4002 7514 4006 7519 4005 7524

KRUZDLO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 27, 4:05 PM EDT	Severe Thunderstorm Warning	PHI	Lehigh, Northampton	25 min
Jun 27, 4:33 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Northampton	37 min
Jun 27, 5:36 PM EDT	Severe Thunderstorm Warning	PHI	Berks	39 min
Jun 27, 6:05 PM EDT	Tornado Warning	PHI	Berks	55 min
Jun 27, 6:30 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Northampton	60 min
Jun 27, 6:55 PM EDT	Flash Flood Warning	PHI	Berks	3 hr
Jun 27, 7:13 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Montgomery	47 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2002 Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.