Alert archive / Pennsylvania / Tornado Watches in 1998

Tornado Watch 487

May 31, 199813 counties in New Jersey; 11 counties in New York; 21 counties in Pennsylvania

The Storm Prediction Center issued this tornado watch at May 31, 1998, 10:00 PM EDT for 13 counties in New Jersey; 11 counties in New York; 21 counties in Pennsylvania. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: May 31, 1998, 10:00 PM EDT (02:00 UTC)
Expired: Jun 1, 1998, 4:00 AM EDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 45 counties

Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Suffolk County, NY, Westchester County, NY, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Dauphin County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Sullivan County, PA, Wyoming County, PA

Warnings issued inside it

21 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
May 31, 10:01 PM EDT	Tornado Warning	PHI	Monroe	34 min
May 31, 10:10 PM EDT	Severe Thunderstorm Warning	OKX	Westchester	60 min
May 31, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	49 min
May 31, 10:31 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	19 min
May 31, 10:37 PM EDT	Flash Flood Warning	OKX	Orange	118 min
May 31, 10:47 PM EDT	Severe Thunderstorm Warning	OKX	Bergen, Passaic	48 min
May 31, 10:47 PM EDT	Severe Thunderstorm Warning	OKX	Westchester	48 min
May 31, 11:01 PM EDT	Severe Thunderstorm Warning	PHI	Warren	34 min
May 31, 11:24 PM EDT	Severe Thunderstorm Warning	PHI	Morris	31 min
May 31, 11:47 PM EDT	Severe Thunderstorm Warning	CTP	Dauphin, York	93 min
Jun 1, 12:09 AM EDT	Severe Thunderstorm Warning	CTP	Lancaster	76 min
Jun 1, 12:17 AM EDT	Severe Thunderstorm Warning	PHI	Berks	48 min
Jun 1, 12:40 AM EDT	Severe Thunderstorm Warning	PHI	Chester	50 min
Jun 1, 12:54 AM EDT	Severe Thunderstorm Warning	PHI	Bucks	31 min
Jun 1, 1:10 AM EDT	Severe Thunderstorm Warning	PHI	Mercer, Middlesex	50 min
Jun 1, 1:15 AM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	35 min
Jun 1, 1:37 AM EDT	Severe Thunderstorm Warning	PHI	Monmouth, Ocean	63 min
Jun 1, 1:37 AM EDT	Severe Thunderstorm Warning	PHI	Middlesex	63 min
Jun 1, 1:44 AM EDT	Severe Thunderstorm Warning	PHI	Mercer	36 min
Jun 1, 2:03 AM EDT	Severe Thunderstorm Warning	OKX	Kings, Queens	47 min
Jun 1, 2:33 AM EDT	Severe Thunderstorm Warning	OKX	Nassau, Suffolk	47 min

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 2.0 hours before the alert went out and 174 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: 151 J/kg
Mixed-layer CIN: -348 J/kg
Mixed-layer LCL: 1224 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 233 m²/s²
0-3 km storm-relative helicity: 319 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.

203 
WWUS9 KMKC 010138
SEL7  
MKC WW 010138
PAZ000-NYZ000-CTZ000-NJZ000-010800-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 487
STORM PREDICTION CENTER NORMAN OK
938 PM EDT SUN MAY 31 1998

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   EASTERN PENNSYLVANIA                       
   SOUTHEASTERN NEW YORK                           
   SOUTHERN CONNECTICUT                        
   NORTHERN AND CENTRAL NEW JERSEY                         

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1000 PM UNTIL
400 AM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 35 MILES NORTH OF HARRISBURG PENNSYLVANIA TO
55 MILES EAST OF ISLIP NEW YORK.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 479...WW 480...WW
481...WW 483...WW 484...WW 485...WW 486...

DISCUSSION...CLUSTER OF SEVERE AND POSSIBLY TORNADIC THUNDERSTORMS
CONTINUES OVER WATCH AREA IN REGION OF MODERATE TO HIGH INSTABILITY
AND STRONG WIND SHEAR.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 27040.


...ROGASH

413,0765 413,0720 400,0720 395,0765

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 31, 8:00 PM EDT	Tornado Watch	SPC		6 hr

Nearby

Tornado Watches in Pennsylvania, 1998 Tornado Watches in New Jersey, 1998 Tornado Watches in New York, 1998 Every tornado watch in 1998

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.