Alert archive / Oklahoma / Tornado Watches in 2012
Tornado Watch 201
The Storm Prediction Center issued this tornado watch at Apr 28, 2012, 10:36 PM CDT for 17 counties in Oklahoma. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2012, 10:36 PM CDT (03:36 UTC)
- Expired
- Apr 29, 2012, 2:00 AM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3 in
- Strongest gust expected
- 60 kt
Counties Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Jefferson County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Oklahoma County, OK, Payne County, OK, Pottawatomie County, OK, Stephens County, OK, Tillman County, OK
The radar
The Norman radar (KTLX), 73 km from the middle of the area, began a volume at 03:37 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
- 30%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 90%
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 |
|---|---|---|---|---|
| Apr 28, 10:44 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Oklahoma | 46 min |
| Apr 28, 10:53 PM CDT | Severe Thunderstorm Warning | OUN | Blaine, Garfield, Kingfisher, Major | 52 min |
| Apr 28, 11:01 PM CDT | Severe Thunderstorm Warning | OUN | Caddo, Canadian, Grady | 44 min |
| Apr 28, 11:25 PM CDT | Severe Thunderstorm Warning | OUN | Logan, Oklahoma | 50 min |
| Apr 28, 11:41 PM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Logan, Oklahoma, Payne | 49 min |
| Apr 28, 11:42 PM CDT | Severe Thunderstorm Warning | OUN | Garfield, Kingfisher, Logan, Noble, Payne | 63 min |
| Apr 28, 11:46 PM CDT | Severe Thunderstorm Warning | OUN | Canadian, Grady | 44 min |
| Apr 29, 12:27 AM CDT | Severe Thunderstorm Warning | OUN | Canadian, Cleveland, Lincoln, Logan, Oklahoma, Pottawatomie | 48 min |
| Apr 29, 12:30 AM CDT | Severe Thunderstorm Warning | OUN | Blaine, Kingfisher | 60 min |
| Apr 29, 12:32 AM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Payne | 58 min |
| Apr 29, 1:26 AM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Payne | 33 min |
| Apr 29, 1:43 AM CDT | Severe Thunderstorm Warning | OUN | Lincoln, Logan, Payne | 62 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, 3.6 hours before the alert went out and 57 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
- 1947 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 989 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 144 m²/s²
- 0-3 km storm-relative helicity
- 232 m²/s²
- Significant tornado parameter
- 2.1
- Supercell composite
- 7.6
The text
As transmitted, in the capitals the NWS used until 2016.
248
WWUS20 KWNS 290338
SEL1
SPC WW 290338
OKZ000-290700-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 201
NWS STORM PREDICTION CENTER NORMAN OK
1035 PM CDT SAT APR 28 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHWEST THROUGH CENTRAL OKLAHOMA
EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1035 PM
UNTIL 200 AM CDT.
TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES SOUTH SOUTHEAST OF
FORT SILL OKLAHOMA TO 35 MILES NORTHWEST OF CHANDLER OKLAHOMA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).
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 200...
DISCUSSION...SUPERCELLS THAT FORMED JUST W OF SW-NE FRONT THROUGH
SW/CNTRL OK EXPECTED TO CONTINUE MOVING ENE THROUGH EARLY SUN. AS
THE STORMS ENCOUNTER WARMER/MORE MOIST AIR E OF BOUNDARY...INCREASE
IN THETA-E MAY SUFFICIENTLY ENHANCE LOW LVL MESO STRENGTH TO POSE A
RISK FOR TORNADOES...IN ADDITION TO ON-GOING RISK FOR LARGE
HAIL/HIGH WIND.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 25025.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 10:54 PM CDT | Mesoscale Discussion | SPC | Caddo, Canadian, Cleveland, Comanche, Cotton, Grady and 4 more | 2 hr |
| Apr 28, 11:52 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Cherokee, Craig, Creek, Delaware, McIntosh and 13 more | 5 hr |
| Apr 29, 1:37 AM CDT | Mesoscale Discussion | SPC | Alfalfa, Beckham, Blaine, Custer, Dewey, Garfield and 8 more | 23 min |
| Apr 29, 1:53 AM CDT | Mesoscale Discussion | SPC | Adair, Cherokee, Craig, Creek, Delaware, Kay and 12 more | 2 hr |
| Apr 29, 3:13 AM CDT | Mesoscale Discussion | SPC | Beckham, Custer, Dewey, Roger Mills | 92 min |
| Apr 29, 2:22 PM CDT | Mesoscale Discussion | SPC | Cimarron | 113 min |
| Apr 29, 5:10 PM CDT | Severe Thunderstorm Watch | SPC | Beaver, Cimarron, Harper, Texas | 8 hr |
| Apr 29, 5:51 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Canadian, Craig, Creek, Garfield, Grant and 17 more | 2 hr |
Nearby
Tornado Watches in Oklahoma, 2012Every tornado watch in 2012
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.