Alert archive / Oklahoma / Tornado Watches in 2004
Tornado Watch 98
The Storm Prediction Center issued this tornado watch at Apr 21, 2004, 1:50 PM CDT for 61 counties in Oklahoma. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 21, 2004, 1:50 PM CDT (18:50 UTC)
- Expired
- Apr 21, 2004, 9:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
All 61 counties
Adair County, OK, Alfalfa County, OK, Atoka County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Cherokee County, OK, Cleveland County, OK, Coal County, OK, Comanche County, OK, Creek County, OK, Custer County, OK, Delaware County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Haskell County, OK, Hughes County, OK, Jackson County, OK, Johnston County, OK, Kingfisher County, OK, Kiowa County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, Logan County, OK, Major County, OK, Mayes County, OK, McClain County, OK, McCurtain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Noble County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Pushmataha County, OK, Roger Mills County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Stephens County, OK, Tulsa County, OK, Wagoner County, OK, Washita County, OK, Woods County, OK, Woodward County, OK
The radar
The Norman radar (KTLX), 78 km from the middle of the area, began a volume at 18:53 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
57 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 3:18 PM CDT | Severe Thunderstorm Warning | TSA | Sequoyah | 42 min |
| Apr 21, 3:53 PM CDT | Severe Thunderstorm Warning | TSA | Muskogee | 67 min |
| Apr 21, 3:55 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Oklahoma | 50 min |
| Apr 21, 4:18 PM CDT | Tornado Warning | OUN | Canadian, Oklahoma | 27 min |
| Apr 21, 4:22 PM CDT | Severe Thunderstorm Warning | OUN | Grady, McClain | 38 min |
| Apr 21, 4:29 PM CDT | Severe Thunderstorm Warning | TSA | Sequoyah | 76 min |
| Apr 21, 4:40 PM CDT | Severe Thunderstorm Warning | OUN | Payne | 50 min |
| Apr 21, 4:41 PM CDT | Tornado Warning | TSA | Sequoyah | 64 min |
| Apr 21, 4:46 PM CDT | Tornado Warning | OUN | Oklahoma | 59 min |
| Apr 21, 4:50 PM CDT | Severe Thunderstorm Warning | OUN | Cleveland | 55 min |
| Apr 21, 4:59 PM CDT | Severe Thunderstorm Warning | OUN | McClain | 46 min |
| Apr 21, 5:01 PM CDT | Severe Thunderstorm Warning | TSA | Pawnee | 74 min |
| Apr 21, 5:08 PM CDT | Severe Thunderstorm Warning | TSA | Cherokee | 82 min |
| Apr 21, 5:16 PM CDT | Severe Thunderstorm Warning | OUN | Garvin | 29 min |
| Apr 21, 5:24 PM CDT | Severe Thunderstorm Warning | OUN | Oklahoma | 51 min |
| Apr 21, 5:24 PM CDT | Severe Thunderstorm Warning | TSA | Muskogee | 51 min |
| Apr 21, 5:28 PM CDT | Tornado Warning | TSA | Sequoyah | 62 min |
| Apr 21, 5:29 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Pottawatomie | 61 min |
| Apr 21, 5:44 PM CDT | Severe Thunderstorm Warning | OUN | Garvin | 46 min |
| Apr 21, 5:45 PM CDT | Severe Thunderstorm Warning | OUN | Cleveland | 45 min |
| Apr 21, 5:54 PM CDT | Severe Thunderstorm Warning | OUN | Payne | 36 min |
| Apr 21, 5:55 PM CDT | Severe Thunderstorm Warning | OUN | Harper | 65 min |
| Apr 21, 5:56 PM CDT | Severe Thunderstorm Warning | TSA | Creek | 79 min |
| Apr 21, 6:12 PM CDT | Severe Thunderstorm Warning | OUN | Pontotoc | 63 min |
| Apr 21, 6:12 PM CDT | Severe Thunderstorm Warning | TSA | Pawnee | 63 min |
| Apr 21, 6:16 PM CDT | Severe Thunderstorm Warning | TSA | Wagoner | 59 min |
| Apr 21, 6:19 PM CDT | Severe Thunderstorm Warning | TSA | Tulsa | 56 min |
| Apr 21, 6:21 PM CDT | Tornado Warning | TSA | Creek | 54 min |
| Apr 21, 6:26 PM CDT | Severe Thunderstorm Warning | TSA | Rogers | 64 min |
| Apr 21, 6:30 PM CDT | Severe Thunderstorm Warning | TSA | Sequoyah | 30 min |
| Apr 21, 6:31 PM CDT | Severe Thunderstorm Warning | OUN | Murray | 29 min |
| Apr 21, 6:33 PM CDT | Severe Thunderstorm Warning | OUN | Garvin | 27 min |
| Apr 21, 6:33 PM CDT | Tornado Warning | TSA | Tulsa | 57 min |
| Apr 21, 6:44 PM CDT | Severe Thunderstorm Warning | OUN | Ellis | 61 min |
| Apr 21, 6:55 PM CDT | Severe Thunderstorm Warning | OUN | Murray | 50 min |
| Apr 21, 6:58 PM CDT | Severe Thunderstorm Warning | OUN | Harper | 47 min |
| Apr 21, 7:06 PM CDT | Severe Thunderstorm Warning | OUN | Oklahoma | 24 min |
| Apr 21, 7:09 PM CDT | Severe Thunderstorm Warning | TSA | Cherokee | 81 min |
| Apr 21, 7:13 PM CDT | Severe Thunderstorm Warning | TSA | Creek | 47 min |
| Apr 21, 7:14 PM CDT | Severe Thunderstorm Warning | OUN | Pontotoc | 46 min |
| Apr 21, 7:17 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa | 43 min |
| Apr 21, 7:22 PM CDT | Severe Thunderstorm Warning | OUN | Johnston | 38 min |
| Apr 21, 7:25 PM CDT | Severe Thunderstorm Warning | OUN | Pottawatomie | 50 min |
| Apr 21, 7:27 PM CDT | Severe Thunderstorm Warning | TSA | Tulsa | 63 min |
| Apr 21, 7:30 PM CDT | Tornado Warning | OUN | Ellis | 30 min |
| Apr 21, 7:33 PM CDT | Severe Thunderstorm Warning | OUN | Woodward | 42 min |
| Apr 21, 7:45 PM CDT | Severe Thunderstorm Warning | OUN | Woods | 45 min |
| Apr 21, 7:58 PM CDT | Severe Thunderstorm Warning | OUN | Hughes, Pontotoc | 47 min |
| Apr 21, 7:59 PM CDT | Severe Thunderstorm Warning | OUN | Alfalfa | 31 min |
| Apr 21, 8:01 PM CDT | Severe Thunderstorm Warning | OUN | Coal, Johnston | 44 min |
| Apr 21, 8:10 PM CDT | Severe Thunderstorm Warning | OUN | Grant | 65 min |
| Apr 21, 8:14 PM CDT | Severe Thunderstorm Warning | OUN | Woodward | 46 min |
| Apr 21, 8:18 PM CDT | Severe Thunderstorm Warning | OUN | Bryan, Marshall, Pottawatomie, Seminole | 42 min |
| Apr 21, 8:23 PM CDT | Flash Flood Warning | TSA | Cherokee | 4 hr |
| Apr 21, 8:28 PM CDT | Severe Thunderstorm Warning | OUN | Woods | 47 min |
| Apr 21, 8:48 PM CDT | Severe Thunderstorm Warning | OUN | Dewey | 42 min |
| Apr 21, 8:59 PM CDT | Severe Thunderstorm Warning | OUN | Seminole | 46 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Norman, OK (KOUN), launched 12:00Z, 6.8 hours before the alert went out and 82 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
- 123 J/kg
- Mixed-layer CIN
- -217 J/kg
- Mixed-layer LCL
- 1714 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- -51 m²/s²
- 0-3 km storm-relative helicity
- 57 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.1
The text
As transmitted, in the capitals the NWS used until 2016.
470
WWUS20 KWNS 211923
SEL8
SPC WW 211850
OKZ000-220200-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 98
NWS STORM PREDICTION CENTER NORMAN OK
150 PM CDT WED APR 21 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
MOST OF OKLAHOMA
EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 150 PM UNTIL
900 PM CDT.
...THIS IS A PARTICULARLY DANGEROUS SITUATION...
DESTRUCTIVE TORNADOES...LARGE HAIL TO 4 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS ALONG AND 85 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 30 MILES SOUTH SOUTHWEST OF GAGE OKLAHOMA TO
35 MILES NORTH OF PAGE 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.
DISCUSSION...EXPLOSIVE THUNDERSTORM DEVELOPMENT IS EXPECTED IN THE
NEXT COUPLE OF HOURS ACROSS MUCH OF OK. VERY STEEP LAPSE
RATES...MODERATE TO STRONG INSTABILITY...AND FAVORABLE VERTICAL
SHEAR PROFILES WILL PROMOTE THE DEVELOPMENT OF SUPERCELLS CAPABLE OF
VERY LARGE HAIL AND ...POSSIBLY...DAMAGING TORNADOES.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 27020.
...HART
370,0995 362,0943 335,0943 343,0995SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 7:22 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Craig, Creek, Delaware, Kay and 12 more | 23 min |
| Apr 20, 7:50 PM CDT | Tornado Watch | SPC | Adair, Cherokee, Cleveland, Craig, Creek, Delaware and 13 more | 5 hr |
| Apr 20, 8:57 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Cleveland, Craig, Creek, Delaware and 13 more | 2 hr |
| Apr 20, 10:39 PM CDT | Mesoscale Discussion | SPC | Haskell, Hughes, Latimer, LeFlore, McIntosh, Muskogee and 6 more | 3 hr |
| Apr 20, 10:57 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Cleveland, Craig, Creek, Delaware and 13 more | 93 min |
| Apr 21, 12:58 PM CDT | Mesoscale Discussion | SPC | Atoka, Beckham, Blaine, Bryan, Caddo, Canadian and 34 more | 2 hr |
| Apr 21, 1:56 PM CDT | Mesoscale Discussion | SPC | Beaver, Cimarron, Texas | 94 min |
| Apr 21, 3:00 PM CDT | Severe Thunderstorm Watch | SPC | Beaver, Cimarron, Texas | 6 hr |
| Apr 21, 4:39 PM CDT | Mesoscale Discussion | SPC | Adair, Alfalfa, Atoka, Beckham, Blaine, Caddo and 47 more | 66 min |
| Apr 21, 5:09 PM CDT | Mesoscale Discussion | SPC | Beaver, Cimarron, Texas | 66 min |
| Apr 21, 6:02 PM CDT | Mesoscale Discussion | SPC | Adair, Alfalfa, Atoka, Blaine, Canadian, Cherokee and 43 more | 88 min |
Nearby
Tornado Watches in Oklahoma, 2004Every tornado watch in 2004
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.