Alert archive / Pennsylvania / Tornado Watches in 2002

Tornado Watch 543

July 28, 20026 counties in Ohio; 23 counties in Pennsylvania

The Storm Prediction Center issued this tornado watch at Jul 28, 2002, 2:50 PM EDT for 6 counties in Ohio; 23 counties in Pennsylvania. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 28, 2002, 2:50 PM EDT (18:50 UTC)
Expired: Jul 28, 2002, 8:00 PM EDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 29 counties

Ashtabula County, OH, Geauga County, OH, Lake County, OH, Mahoning County, OH, Portage County, OH, Trumbull County, OH, Armstrong County, PA, Butler County, PA, Cameron County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Crawford County, PA, Elk County, PA, Forest County, PA, Jefferson County, PA, Lawrence County, PA, Lycoming County, PA, McKean County, PA, Mercer County, PA, Montour County, PA, Northumberland County, PA, Potter County, PA, Snyder County, PA, Sullivan County, PA, Union County, PA, Venango County, PA, Warren County, PA

The radar

The Pittsburgh radar (KPBZ), 122 km from the middle of the area, began a volume at 18:49 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 28, 3:41 PM EDT	Severe Thunderstorm Warning	CLE	Crawford	64 min
Jul 28, 4:12 PM EDT	Severe Thunderstorm Warning	PBZ	Venango	63 min
Jul 28, 5:02 PM EDT	Severe Thunderstorm Warning	PBZ	Forest	58 min
Jul 28, 5:13 PM EDT	Severe Thunderstorm Warning	PBZ	Clarion	62 min
Jul 28, 5:30 PM EDT	Severe Thunderstorm Warning	CLE	Crawford	60 min
Jul 28, 6:06 PM EDT	Tornado Warning	CLE	Crawford	24 min
Jul 28, 6:26 PM EDT	Severe Thunderstorm Warning	PBZ	Venango	49 min

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 6.8 hours before the alert went out and 129 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: 1271 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 857 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 119 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 4.2

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 281851
SEL3  
SPC WW 281850
OHZ000-PAZ000-LEZ000-290000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 543
STORM PREDICTION CENTER NORMAN OK
250 PM EDT SUN JUL 28 2002

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

   NORTHEAST OHIO                               
   NORTHWEST AND NORTH CENTRAL PENNSYLVANIA                       

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 250 PM UNTIL 800
PM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 40 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 40 MILES WEST NORTHWEST OF YOUNGSTOWN OHIO TO
25 MILES EAST SOUTHEAST OF WILLIAMSPORT PENNSYLVANIA.

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 542...

DISCUSSION...ISOLATED THUNDERSTORMS HAVE BEGUN TO FORM ALONG SHORE
OF LAKE ERIE NORTHEAST OF CLE.  THESE STORMS ARE EXPECTED TO
INTENSIFY AND TRACK EASTWARD ACROSS NORTHWEST AND NORTH CENTRAL PA
DURING THE NEXT FEW HOURS.  DAMAGING WINDS WILL BE THE MAIN THREAT. 
HOWEVER...STRONG WESTERLY WINDS JUST ABOVE THE SURFACE ARE
RESULTING IN SUFFICIENT LOW LEVEL AND DEEP LAYER VERTICAL SHEAR TO
POSE THREAT OF ISOLATED TORNADOES IN STRONGEST CELLS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 28035.

...HART

420,0812 414,0762 403,0762 405,0812

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 27, 10:30 PM EDT	Tornado Watch	SPC	Fulton, Lucas, Sandusky, Wood	6 hr
Jul 28, 5:30 PM EDT	Severe Thunderstorm Watch	SPC	Bradford, Susquehanna, Wayne	6 hr

Nearby

Tornado Watches in Pennsylvania, 2002 Tornado Watches in Ohio, 2002 Every tornado watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.