Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 26, NWS Philadelphia/Mount Holly

May 24, 1999Philadelphia County, Pennsylvania; Camden County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 24, 1999, 3:40 PM EDT for Philadelphia County, Pennsylvania; Camden County, New Jersey. It was in force for 30 min. 2 reports 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: May 24, 1999, 3:40 PM EDT (19:40 UTC)
Expired: May 24, 1999, 4:10 PM EDT
In force: 30 min
Issued by: NWS Philadelphia/Mount Holly
Area: Whole counties

Counties Camden County, NJ, Philadelphia County, PA

What was reported inside it

Time	Report	Where	Remark
May 24, 3:50 PM EDT	Thunderstorm Wind 50	Countywide, PA
May 24, 3:56 PM EDT	Thunderstorm Wind 50	Brooklawn, NJ

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
May 24, 1:00 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.7 hours before the alert went out and 102 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: 61 J/kg
Mixed-layer CIN: -100 J/kg
Mixed-layer LCL: 1309 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 173 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.

999 
WUUS1 KPHL 241941 RRA
SVRPHL
NJC007-PAC101-242010-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
340 PM EDT MON MAY 24 1999

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN PHILADELPHIA COUNTY IN PENNSYLVANIA.
  NORTHWESTERN CAMDEN COUNTY IN NEW JERSEY.

* UNTIL 410 PM EDT.

* AT 336 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR AND
  SPOTTER REPORTS INDICATED A SEVERE THUNDERSTORM 9 MILES SOUTHWEST
  OF PHILADELPHIA INTL AIRPORT... MOVING EASTNORTHEAST AT 40 MPH.

* THE SEVERE THUNDERSTORM IS EXPECTED TO BE NEAR...
  PHILADELPHIA INTL AIRPORT AT 345 PM EDT.
  BROOKLAWN AT 355 PM EDT.
  GLOUCESTER CITY AT 355 PM EDT.
  CAMDEN AT 400 PM EDT.
  HADDONFIELD AT 400 PM EDT.
  CHERRY HILL AT 405 PM EDT.

THIS STORM PRODUCED A WIND GUST OF OVER 60 MPH AT 327 PM IN
WILMINGTON DELAWARE.

THIS IS A DANGEROUS STORM. MOVE INSIDE A STRONG BUILDING AND DO
NOT STAND NEAR WINDOWS. FOR YOUR PROTECTION MOVE TO AN INTERIOR
ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS.

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

.END
JRP/AMC


&

The office that day

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

Issued	Product	Office	Counties	Lasted
May 24, 10:08 AM EDT	Severe Thunderstorm Warning	PHI	Bucks	32 min
May 24, 12:25 PM EDT	Flash Flood Warning	PHI	Bucks, Philadelphia	3 hr
May 24, 3:11 PM EDT	Severe Thunderstorm Warning	PHI	Chester	29 min
May 24, 3:26 PM EDT	Severe Thunderstorm Warning	PHI	Delaware	34 min
May 24, 4:26 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	34 min
May 24, 9:20 AM EDT	Severe Thunderstorm Warning	PHI	Gloucester, Salem	35 min
May 24, 9:39 AM EDT	Severe Thunderstorm Warning	PHI	Camden	31 min
May 24, 9:52 AM EDT	Severe Thunderstorm Warning	PHI	Burlington	33 min
May 24, 10:26 AM EDT	Severe Thunderstorm Warning	PHI	Mercer	34 min
May 24, 10:37 AM EDT	Severe Thunderstorm Warning	PHI	Somerset	48 min
May 24, 4:51 PM EDT	Severe Thunderstorm Warning	PHI	Camden, Gloucester	39 min
May 24, 4:51 PM EDT	Severe Thunderstorm Warning	PHI	Cumberland	39 min
May 24, 5:09 PM EDT	Severe Thunderstorm Warning	PHI	Burlington	51 min
May 24, 5:42 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	33 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 1999 Severe Thunderstorm Warnings in New Jersey, 1999 Every severe thunderstorm warning in 1999

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.