Alert archive / Oklahoma / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 623
The Storm Prediction Center issued this severe thunderstorm watch at Sep 5, 2012, 3:56 PM CDT for 4 counties in Kansas; 13 counties in Oklahoma. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 5, 2012, 3:56 PM CDT (20:56 UTC)
- Expired
- Sep 5, 2012, 11:00 PM CDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 65 kt
Counties Barber County, KS, Clark County, KS, Comanche County, KS, Meade County, KS, Alfalfa County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Harper County, OK, Kingfisher County, OK, Major County, OK, Roger Mills County, OK, Woods County, OK, Woodward County, OK
The radar
The Dodge City radar (KDDC), 125 km from the middle of the area, began a volume at 20:58 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
- 5%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 5, 7:08 PM CDT | Severe Thunderstorm Warning | OUN | Ellis, Roger Mills | 52 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
Dodge City, (KDDC), launched 12:00Z, 8.9 hours before the alert went out and 125 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
- 763 J/kg
- Mixed-layer CIN
- -291 J/kg
- Mixed-layer LCL
- 1814 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 130 m²/s²
- 0-3 km storm-relative helicity
- 67 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.2
The text
As transmitted, in the capitals the NWS used until 2016.
174
WWUS20 KWNS 052057
SEL3
SPC WW 052057
KSZ000-OKZ000-060400-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 623
NWS STORM PREDICTION CENTER NORMAN OK
400 PM CDT WED SEP 5 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
FAR SOUTHERN KANSAS
NORTHERN AND WESTERN OKLAHOMA
EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 400 PM UNTIL
1100 PM CDT.
HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 90
STATUTE MILES EAST AND WEST OF A LINE FROM 60 MILES NORTHWEST OF
ALVA OKLAHOMA TO 55 MILES SOUTH SOUTHEAST OF GAGE OKLAHOMA. FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).
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...CONTINUE...WW 620...WW 621...WW 622...
DISCUSSION...TSTMS NOW FORMING JUST BEHIND WSW-ENE COLD FRONT IN SW
KS EXPECTED TO STRENGTHEN AND MOVE/DEVELOP GENERALLY ESE OVER THE
NEXT FEW HOURS. ADDITIONAL STORMS MAY MOVE INTO WRN OK FROM ERN
PORTIONS OF THE TX PANHANDLE. DEEPLY-MIXED ENVIRONMENT AND ASCENT
WITH WEAK IMPULSE IN SRN EDGE OF THE WLYS OVER CO SHOULD AUGMENT
RISK FOR SVR WIND AND POSSIBLY HAIL AS STORMS ORGANIZE INTO A
CLUSTER.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 29025.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 5, 2:49 PM CDT | Mesoscale Discussion | SPC | Beckham, Custer, Dewey, Ellis, Greer, Harmon and 7 more | 56 min |
| Sep 5, 3:19 PM CDT | Severe Thunderstorm Watch | SPC | Beaver, Texas | 8 hr |
| Sep 5, 6:53 PM CDT | Mesoscale Discussion | SPC | Alfalfa, Beaver, Beckham, Blaine, Caddo, Canadian and 16 more | 67 min |
Nearby
Severe Thunderstorm Watches in Oklahoma, 2012Severe Thunderstorm Watches in Kansas, 2012Every severe thunderstorm 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.