Alert archive / Kansas / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 159
The Storm Prediction Center issued this severe thunderstorm watch at Apr 12, 2012, 8:38 PM CDT for 15 counties in Kansas; 4 counties in Nebraska. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 12, 2012, 8:38 PM CDT (01:38 UTC)
- Expired
- Apr 13, 2012, 1:03 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Cheyenne County, KS, Decatur County, KS, Gove County, KS, Graham County, KS, Greeley County, KS, Lane County, KS, Logan County, KS, Norton County, KS, Rawlins County, KS, Scott County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, Wichita County, KS, Frontier County, NE, Hayes County, NE, Hitchcock County, NE, Red Willow County, NE
The radar
The Goodland radar (KGLD), 65 km from the middle of the area, began a volume at 01:39 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 9:03 PM CDT | Severe Thunderstorm Warning | GLD | Cheyenne, Rawlins | 20 min |
| Apr 12, 9:10 PM CDT | Severe Thunderstorm Warning | GLD | Hitchcock, Red Willow | 50 min |
| Apr 12, 9:40 PM CDT | Severe Thunderstorm Warning | GLD | Hitchcock, Red Willow | 50 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
N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 1.6 hours before the alert went out and 182 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
- 188 J/kg
- Mixed-layer CIN
- -78 J/kg
- Mixed-layer LCL
- 487 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 458 m²/s²
- 0-3 km storm-relative helicity
- 490 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.5
The text
As transmitted, in the capitals the NWS used until 2016.
066
WWUS20 KWNS 130139
SEL9
SPC WW 130139
COZ000-KSZ000-NEZ000-130900-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 159
NWS STORM PREDICTION CENTER NORMAN OK
740 PM MDT THU APR 12 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
EAST-CENTRAL COLORADO
NORTHWEST KANSAS
SOUTHWEST NEBRASKA
EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 740 PM
UNTIL 300 AM MDT.
HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55
STATUTE MILES EAST AND WEST OF A LINE FROM 10 MILES NORTH
NORTHEAST OF MCCOOK NEBRASKA TO 80 MILES SOUTH SOUTHEAST OF
GOODLAND KANSAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).
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 157...WW 158...
DISCUSSION...TSTMS WILL LIKELY PERSIST TONIGHT ALONG COLD FRONT AS
IT PROGRESSES EWD/SEWD...OVERTAKING DRYLINE. 00Z SOUNDINGS INDICATE
THAT MARGINAL BOUNDARY LAYER MOISTURE AND PERSISTENT CLOUD COVER
HAVE LIMITED THE DEGREE OF DESTABILIZATION...AND THE ONSET OF
DIABATIC COOLING IN THE BOUNDARY LAYER WILL RESULT IN ACCUMULATING
CONVECTIVE INHIBITION. WHILE A TORNADO IS POSSIBLE OWING TO THE
PRESENCE OF STRONG LOW-LEVEL SHEAR...THE INCREASING CONVECTIVE
INHIBITION AND LINEAR FORCING ALONG THE COLD FRONT ARE EXPECTED TO
MITIGATE THIS THREAT WITH DAMAGING WINDS AND HAIL BEING THE PRIMARY
HAZARDS.
AVIATION...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 22025.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 7:53 PM CDT | Mesoscale Discussion | SPC | Cheyenne, Decatur, Gove, Lane, Logan, Rawlins and 6 more | 97 min |
| Apr 12, 11:24 PM CDT | Mesoscale Discussion | SPC | Decatur, Gove, Graham, Norton, Phillips, Sheridan and 1 more | 96 min |
| Apr 13, 2:37 PM CDT | Mesoscale Discussion | SPC | Allen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 9 more | 113 min |
| Apr 13, 3:40 PM CDT | Severe Thunderstorm Watch | SPC | Allen, Anderson, Bourbon, Butler, Chase, Chautauqua and 19 more | 6 hr |
| Apr 13, 5:40 PM CDT | Mesoscale Discussion | SPC | Allen, Anderson, Bourbon, Chautauqua, Cherokee, Coffey and 14 more | 65 min |
| Apr 12, 8:57 PM CDT | Mesoscale Discussion | SPC | Blaine, Buffalo, Custer, Dawson, Franklin, Furnas and 7 more | 93 min |
Nearby
Severe Thunderstorm Watches in Kansas, 2012Severe Thunderstorm Watches in Nebraska, 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.