Alert archive / Oklahoma / Tornado Watches in 2002
Tornado Watch 255
The Storm Prediction Center issued this tornado watch at May 8, 2002, 3:00 PM CDT for 29 counties in Oklahoma; Childress County, Texas. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- May 8, 2002, 3:00 PM CDT (20:00 UTC)
- Expired
- May 8, 2002, 9:00 PM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 30 counties
Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Grady County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Logan County, OK, Major County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Roger Mills County, OK, Stephens County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Childress County, TX
The radar
The Altus AFB radar (KFDR), 120 km from the middle of the area, began a volume at 20:02 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
12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 3:18 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa | 42 min |
| May 8, 4:01 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa | 29 min |
| May 8, 4:31 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa | 44 min |
| May 8, 5:15 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa | 45 min |
| May 8, 6:09 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa, Woods | 36 min |
| May 8, 6:24 PM CDT | Tornado Warning | OUN | Grant | 21 min |
| May 8, 6:47 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa, Grant, Woods | 43 min |
| May 8, 7:26 PM CDT | Tornado Warning | OUN | Kay | 34 min |
| May 8, 7:29 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa, Grant | 46 min |
| May 8, 8:15 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa, Garfield, Grant | 45 min |
| May 8, 8:56 PM CDT | Tornado Warning | OUN | Garfield, Noble | 34 min |
| May 8, 9:00 PM CDT | Severe Thunderstorm Warning | OUN | Grant, Kay | 45 min |
The nearest sounding before it
Fort Sill, OK (KFSI), launched 12:00Z, 8.0 hours before the alert went out and 94 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.
- Mixed-layer CAPE
- 383 J/kg
- Mixed-layer CIN
- -458 J/kg
- Mixed-layer LCL
- 1865 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km storm-relative helicity
- 487 m²/s²
- 0-3 km storm-relative helicity
- 495 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
000 WWUS20 KWNS 081940 SEL5 SPC WW 081934 OKZ000-090200- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 255 STORM PREDICTION CENTER NORMAN OK 234 PM CDT WED MAY 8 2002 THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF WESTERN AND CENTRAL OKLAHOMA EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 300 PM UNTIL 900 PM CDT. TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS ALONG AND 80 STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES SOUTHEAST OF ALTUS OKLAHOMA TO 45 MILES WEST NORTHWEST OF PONCA CITY OKLAHOMA. 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 254... DISCUSSION...SURFACE DRYLINE IS MOVING EWD ACROSS NWRN OK AS INTENSIFYING COLD FRONT MOVES SWD/SEWD ACROSS PARTS OF SRN KS. AIR MASS IS VERY UNSTABLE EAST OF THE DRYLINE WITH SBCAPE OF 4500 J/KG. COMBINATION OF STEEP LAPSE RATES AND BOUNDARY FORCING SHOULD DIMINISH CAPPING INVERSION OVER CENTRAL OK ALLOWING STORMS TO DEVELOP RAPIDLY. INSTABILITY AND DEEP LAYER SHEAR UP TO 45 KT POSE ENVIRONMENT FAVORABLE FOR SUPERCELLS/TORNADOES. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION VECTOR 25040. ...MCCARTHY 365,0962 342,0973 342,1002 365,0991 WWUS20 KWNS 081940 SEL5 SPC WW 081934 OKZ000-090200- URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 255 STORM PREDICTION CENTER NORMAN OK 234 PM CDT WED MAY 8 2002 THE STORM PREDICTION CENTER HAS ISSUED A TORNADO WATCH FOR PORTIONS OF WESTERN AND CENTRAL OKLAHOMA EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 300 PM UNTIL 900 PM CDT. TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE TORNADO WATCH AREA IS ALONG AND 80 STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES SOUTHEAST OF ALTUS OKLAHOMA TO 45 MILES WEST NORTHWEST OF PONCA CITY OKLAHOMA. 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 254... DISCUSSION...SURFACE DRYLINE IS MOVING EWD ACROSS NWRN OK AS INTENSIFYING COLD FRONT MOVES SWD/SEWD ACROSS PARTS OF SRN KS. AIR MASS IS VERY UNSTABLE EAST OF THE DRYLINE WITH SBCAPE OF 4500 J/KG. COMBINATION OF STEEP LAPSE RATES AND BOUNDARY FORCING SHOULD DIMINISH CAPPING INVERSION OVER CENTRAL OK ALLOWING STORMS TO DEVELOP RAPIDLY. INSTABILITY AND DEEP LAYER SHEAR UP TO 45 KT POSE ENVIRONMENT FAVORABLE FOR SUPERCELLS/TORNADOES. AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION VECTOR 25040. ...MCCARTHY 365,0962 342,0973 342,1002 365,0991
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 7, 9:00 PM CDT | Severe Thunderstorm Watch | SPC | Craig, Delaware, Nowata, Ottawa, Rogers, Washington | 5 hr |
| May 7, 10:00 PM CDT | Tornado Watch | SPC | Kay | 4 hr |
| May 8, 4:45 PM CDT | Tornado Watch | SPC | Bosque, Brown, Coleman, Collin, Comanche, Concho and 22 more | 5 hr |
Nearby
Tornado Watches in Oklahoma, 2002Tornado Watches in Texas, 2002Every 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.