Alert archive / Oklahoma / Severe Thunderstorm Watches in 2002
Severe Thunderstorm Watch 643
The Storm Prediction Center issued this severe thunderstorm watch at Aug 27, 2002, 1:30 AM CDT for 23 counties in Oklahoma; Hemphill County, Texas. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 27, 2002, 1:30 AM CDT (06:30 UTC)
- Expired
- Aug 27, 2002, 6:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 24 counties
Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Garvin County, OK, Grady County, OK, Greer County, OK, Jackson County, OK, Jefferson County, OK, Kingfisher County, OK, Kiowa County, OK, McClain County, OK, Murray County, OK, Roger Mills County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Hemphill County, TX
The radar
The Norman radar (KTLX), 100 km from the middle of the area, began a volume at 06:29 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 |
|---|---|---|---|---|
| Aug 27, 1:32 AM CDT | Severe Thunderstorm Warning | OUN | Blaine, Dewey | 43 min |
| Aug 27, 2:06 AM CDT | Severe Thunderstorm Warning | OUN | Caddo, Canadian, Custer, Kingfisher, Washita | 54 min |
| Aug 27, 2:46 AM CDT | Severe Thunderstorm Warning | OUN | Grady | 59 min |
| Aug 27, 2:49 AM CDT | Severe Thunderstorm Warning | OUN | Cleveland, McClain, Oklahoma | 41 min |
| Aug 27, 2:57 AM CDT | Severe Thunderstorm Warning | OUN | Caddo, Comanche, Kiowa | 63 min |
| Aug 27, 3:19 AM CDT | Severe Thunderstorm Warning | OUN | Jackson, Tillman | 56 min |
| Aug 27, 3:30 AM CDT | Severe Thunderstorm Warning | OUN | Cleveland, Garvin, Grady, McClain, Stephens | 75 min |
| Aug 27, 3:46 AM CDT | Severe Thunderstorm Warning | OUN | Comanche, Cotton | 44 min |
| Aug 27, 4:21 AM CDT | Severe Thunderstorm Warning | OUN | Carter, Jefferson, Murray | 69 min |
| Aug 27, 4:33 AM CDT | Severe Thunderstorm Warning | OUN | Cotton | 57 min |
| Aug 27, 4:54 AM CDT | Severe Thunderstorm Warning | OUN | Garvin | 36 min |
| Aug 27, 5:38 AM CDT | Severe Thunderstorm Warning | OUN | Carter, Jefferson, Love, Murray | 37 min |
The nearest sounding before it
Norman, OK (KOUN), launched 00:00Z, 6.5 hours before the alert went out and 90 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
- 1167 J/kg
- Mixed-layer CIN
- -149 J/kg
- Mixed-layer LCL
- 1993 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- -41 m²/s²
- 0-3 km storm-relative helicity
- 62 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -1.7
The text
As transmitted, in the capitals the NWS used until 2016.
000 WWUS20 KWNS 270631 SEL3 SPC WW 270630 OKZ000-TXZ000-271100- URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 643 STORM PREDICTION CENTER NORMAN OK 130 AM CDT TUE AUG 27 2002 THE STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR PORTIONS OF WESTERN AND CENTRAL OKLAHOMA EASTERN TEXAS PANHANDLE EFFECTIVE THIS TUESDAY MORNING FROM 130 AM UNTIL 600 AM CDT. HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 75 STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH OF CLINTON OKLAHOMA TO 50 MILES WEST SOUTHWEST OF ARDMORE OKLAHOMA. REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES SEVERE THUNDERSTORM WATCH NUMBER 642. WATCH NUMBER 642 WILL NOT BE IN EFFECT AFTER 130 AM CDT. DISCUSSION...ORGANIZED LINE OF THUNDERSTORMS IN WESTERN OKLAHOMA WILL BE MAINTAINED BY VEERING SELY TO NWLY WINDS FROM 850-500 MB DURING THE NEXT FEW HOURS. STRONG COLD POOL SHOULD SUPPORT CONTINUED THREAT FOR DAMAGING WINDS AS LINE MOVES SEWD AT 35-45 MPH. AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 1 INCH EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM MOTION VECTOR 34030. ...IMY 361,0975 340,0963 340,0990 361,1003
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 10:35 PM CDT | Severe Thunderstorm Watch | SPC | Beaver, Beckham, Custer, Dewey, Ellis, Greer and 6 more | 5 hr |
| Aug 27, 3:40 AM CDT | Severe Thunderstorm Watch | SPC | Archer, Baylor, Bosque, Brown, Callahan, Clay and 38 more | 5 hr |
| Aug 27, 6:45 AM CDT | Severe Thunderstorm Watch | SPC | Anderson, Angelina, Bowie, Camp, Cass, Cherokee and 24 more | 4 hr |
| Aug 27, 10:45 AM CDT | Severe Thunderstorm Watch | SPC | Angelina, Chambers, Hardin, Houston, Jasper, Jefferson and 9 more | 5 hr |
Nearby
Severe Thunderstorm Watches in Oklahoma, 2002Severe Thunderstorm Watches in Texas, 2002Every severe thunderstorm 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.