Alert archive / Oklahoma / Tornado Watches in 2008
Tornado Watch 212
The Storm Prediction Center issued this tornado watch at Apr 21, 2008, 8:56 PM CDT for 17 counties in Oklahoma. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 21, 2008, 8:56 PM CDT (01:56 UTC)
- Expired
- Apr 22, 2008, 2:00 AM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
Counties Carter County, OK, Cleveland County, OK, Coal County, OK, Creek County, OK, Garvin County, OK, Hughes County, OK, Johnston County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Murray County, OK, Okfuskee County, OK, Oklahoma County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK
The radar
The Norman radar (KTLX), 26 km from the middle of the area, began a volume at 01:59 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 50%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 9:11 PM CDT | Severe Thunderstorm Warning | OUN | Cleveland, Lincoln, Pottawatomie, Seminole | 34 min |
| Apr 21, 9:37 PM CDT | Severe Thunderstorm Warning | OUN | Garvin, McClain, Pottawatomie | 20 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
Lamont, OK (KLMN), launched 00:00Z, 1.9 hours before the alert went out and 132 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
- 1716 J/kg
- Mixed-layer CIN
- -20 J/kg
- Mixed-layer LCL
- 1734 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 18 m²/s²
- 0-3 km storm-relative helicity
- 169 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 6.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 7:03 PM CDT | Severe Thunderstorm Watch | SPC | Garfield, Grant, Kay, Noble, Osage, Pawnee and 1 more | 7 hr |
| Apr 21, 7:34 PM CDT | Mesoscale Discussion | SPC | Carter, Cleveland, Creek, Garfield, Garvin, Kingfisher and 9 more | 86 min |
| Apr 21, 10:29 PM CDT | Mesoscale Discussion | SPC | Carter, Cleveland, Coal, Creek, Garvin, Hughes and 11 more | 91 min |
| Apr 21, 10:38 PM CDT | Mesoscale Discussion | SPC | Garfield, Grant, Kay, Noble, Osage, Pawnee and 1 more | 2 hr |
| Apr 22, 7:42 AM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Delaware | 63 min |
| Apr 22, 7:49 AM CDT | Severe Thunderstorm Watch | SPC | Adair, Cherokee, Craig, Delaware, Mayes, Ottawa and 1 more | 6 hr |
| Apr 22, 10:12 AM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Delaware, Haskell, Latimer, LeFlore and 5 more | 93 min |
| Apr 22, 12:16 PM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Delaware, Haskell, LeFlore, Sequoyah | 89 min |
| Apr 22, 2:06 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 31 more | 7 hr |
| Apr 22, 2:33 PM CDT | Severe Thunderstorm Watch | SPC | McCurtain | 6 hr |
| Apr 22, 3:30 PM CDT | Mesoscale Discussion | SPC | Adair, Atoka, Carter, Cherokee, Cleveland, Coal and 24 more | 90 min |
| Apr 22, 6:51 PM CDT | Mesoscale Discussion | SPC | Adair, Carter, Cherokee, Coal, Delaware, Garvin and 17 more | 114 min |
Nearby
Tornado Watches in Oklahoma, 2008Every tornado watch in 2008
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.