Alert archive / Oklahoma / Tornado Watches in 2004
Tornado Watch 101
The Storm Prediction Center issued this tornado watch at Apr 21, 2004, 8:35 PM CDT for 12 counties in Oklahoma. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 21, 2004, 8:35 PM CDT (01:35 UTC)
- Expired
- Apr 22, 2004, 2:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
Counties Atoka County, OK, Bryan County, OK, Choctaw County, OK, Coal County, OK, Haskell County, OK, Hughes County, OK, Latimer County, OK, LeFlore County, OK, McCurtain County, OK, Pittsburg County, OK, Pushmataha County, OK, Seminole County, OK
The radar
The Western Arkansas radar (KSRX), 157 km from the middle of the area, began a volume at 01:35 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
14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 8:56 PM CDT | Severe Thunderstorm Warning | OUN | Bryan | 49 min |
| Apr 21, 8:59 PM CDT | Severe Thunderstorm Warning | OUN | Seminole | 46 min |
| Apr 21, 9:15 PM CDT | Severe Thunderstorm Warning | OUN | Hughes | 30 min |
| Apr 21, 9:25 PM CDT | Severe Thunderstorm Warning | TSA | Pittsburg | 65 min |
| Apr 21, 9:41 PM CDT | Severe Thunderstorm Warning | OUN | Bryan | 64 min |
| Apr 21, 10:08 PM CDT | Severe Thunderstorm Warning | TSA | Haskell | 67 min |
| Apr 21, 10:44 PM CDT | Severe Thunderstorm Warning | TSA | LeFlore, Okfuskee | 61 min |
| Apr 21, 11:24 PM CDT | Tornado Warning | TSA | Haskell, Pittsburg | 66 min |
| Apr 22, 12:03 AM CDT | Tornado Warning | TSA | Haskell | 42 min |
| Apr 22, 12:28 AM CDT | Tornado Warning | TSA | LeFlore | 47 min |
| Apr 22, 12:29 AM CDT | Tornado Warning | TSA | Haskell, Muskogee | 76 min |
| Apr 22, 1:16 AM CDT | Flash Flood Warning | TSA | LeFlore | 4 hr |
| Apr 22, 1:23 AM CDT | Severe Thunderstorm Warning | TSA | LeFlore | 67 min |
| Apr 22, 1:34 AM CDT | Severe Thunderstorm Warning | TSA | LeFlore | 56 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 00:00Z, 1.6 hours before the alert went out and 167 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
- 415 J/kg
- Mixed-layer CIN
- -82 J/kg
- Mixed-layer LCL
- 1340 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 120 m²/s²
- 0-3 km storm-relative helicity
- 357 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 11.0
The text
As transmitted, in the capitals the NWS used until 2016.
526
WWUS20 KWNS 220146
SEL1
SPC WW 220135
OKZ000-220700-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 101
NWS STORM PREDICTION CENTER NORMAN OK
835 PM CDT WED APR 21 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHEAST OKLAHOMA
EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 835 PM
UNTIL 200 AM CDT.
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 60 STATUTE MILES EAST AND WEST
OF A LINE FROM 35 MILES NORTH NORTHEAST OF MCALESTER OKLAHOMA TO
45 MILES EAST OF DURANT 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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 98. WATCH NUMBER 98 WILL NOT BE IN EFFECT AFTER 835
PM CDT.
DISCUSSION...SMALL SUPERCELLS CONTINUE TO BE SUSTAINED WITHIN
MODERATELY UNSTABLE WARM SECTOR ACROSS SERN OK. AS SLY LLJ
INTENSIFIES OVERNIGHT... ISOLATED TORNADOES WILL REMAIN POSSIBLE
WITH INCREASING STORM-RELATIVE HELICITY FOR ANOTHER COUPLE OF HOURS.
THREATS OF LARGE HAIL AND DAMAGING WINDS WILL ALSO ACCOMPANY THESE
STORMS.
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 25020.
...EVANS
352,0942 335,0943 335,0964 352,0963SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 7:06 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Beaver, Blaine, Dewey, Ellis, Harper and 3 more | 2 hr |
| Apr 21, 7:51 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Blaine, Choctaw, Cleveland, Creek, Delaware and 18 more | 84 min |
| Apr 21, 8:35 PM CDT | Severe Thunderstorm Watch | SPC | Alfalfa, Blaine, Dewey, Ellis, Garfield, Grant and 9 more | 5 hr |
| Apr 21, 10:10 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Craig, Creek, Delaware, Mayes and 8 more | 95 min |
| Apr 21, 10:26 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Choctaw, Coal, Haskell, Hughes and 7 more | 64 min |
| Apr 21, 10:50 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Cherokee, Craig, Creek, Delaware, Haskell and 14 more | 5 hr |
| Apr 21, 10:56 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Garfield, Grant, Kay, Kingfisher, Logan and 2 more | 94 min |
| Apr 22, 1:43 AM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Haskell, McIntosh, Mayes, Muskogee and 7 more | 92 min |
| Apr 22, 12:32 PM CDT | Mesoscale Discussion | SPC | Adair, Atoka, Cherokee, Coal, Delaware, Haskell and 15 more | 88 min |
| Apr 22, 1:40 PM CDT | Tornado Watch | SPC | Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 33 more | 6 hr |
| Apr 22, 3:26 PM CDT | Mesoscale Discussion | SPC | Adair, Atoka, Cherokee, Coal, Haskell, Hughes and 16 more | 64 min |
| Apr 22, 4:30 PM CDT | Tornado Watch | SPC | Bryan, Love | 6 hr |
| Apr 22, 5:27 PM CDT | Mesoscale Discussion | SPC | Adair, Atoka, Bryan, Choctaw, Coal, Craig and 23 more | 63 min |
| Apr 22, 6:23 PM CDT | Mesoscale Discussion | SPC | Adair, Carter, Garvin, Hughes, LeFlore, McCurtain and 10 more | 67 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.