Alert archive / Kansas / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 541
The Storm Prediction Center issued this severe thunderstorm watch at Jul 30, 2012, 6:53 PM MDT for Cheyenne County, Kit Carson County, Yuma County, Colorado; 6 counties in Kansas; Dundy County, Hitchcock County, Nebraska. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 30, 2012, 6:53 PM MDT (00:53 UTC)
- Expired
- Jul 30, 2012, 10:30 PM MDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Cheyenne County, CO, Kit Carson County, CO, Yuma County, CO, Cheyenne County, KS, Logan County, KS, Rawlins County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, Dundy County, NE, Hitchcock County, NE
The radar
The Goodland radar (KGLD), 40 km from the middle of the area, began a volume at 00:55 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
- 40%
- 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 |
|---|---|---|---|---|
| Jul 30, 7:09 PM MDT | Severe Thunderstorm Warning | GLD | Cheyenne, Kit Carson, Yuma | 66 min |
| Jul 30, 7:34 PM MDT | Severe Thunderstorm Warning | GLD | Cheyenne, Kit Carson, Yuma | 56 min |
| Jul 30, 8:11 PM MDT | Severe Thunderstorm Warning | GLD | Cheyenne, Kit Carson, Yuma | 64 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
Denver, CO (KDNR), launched 00:00Z, 0.9 hours before the alert went out and 115 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
- 144 J/kg
- Mixed-layer CIN
- -163 J/kg
- Mixed-layer LCL
- 1672 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- -3 m²/s²
- 0-3 km storm-relative helicity
- 63 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.4
The text
As transmitted, in the capitals the NWS used until 2016.
490
WWUS20 KWNS 310027
SEL1
SPC WW 310027
COZ000-KSZ000-NEZ000-310600-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 541
NWS STORM PREDICTION CENTER NORMAN OK
630 PM MDT MON JUL 30 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
EASTERN COLORADO
NORTHWEST KANSAS
FAR SOUTHWEST NEBRASKA
EFFECTIVE THIS MONDAY NIGHT FROM 630 PM UNTIL MIDNIGHT MDT.
HAIL TO 1.5 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 65 MILES NORTH OF
GOODLAND KANSAS TO 40 MILES SOUTH OF GOODLAND KANSAS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU1).
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 540...
DISCUSSION...MCS WITH A HISTORY OF DAMAGING WINDS CONTINUES TO
ORGANIZE THIS EVENING OVER THE HIGH PLAINS OF NERN CO WITHIN A STEEP
LAPSE RATE ENVIRONMENT WITH MLCAPE OF 1000-2000 J/KG. GIVEN THE 40
KT MIDLEVEL FLOW OBSERVED BY 00Z DENVER SOUNDING AND ELY LOW-LEVEL
WINDS...KINEMATIC ENVIRONMENT WILL BE SUPPORTIVE OF FORWARD
PROPAGATION OF MCS WITH THE THREAT FOR DAMAGING WINDS SPREADING EWD
ACROSS THE WATCH AREA.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 27030.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 30, 6:24 PM MDT | Mesoscale Discussion | SPC | Cheyenne, Kit Carson, Logan, Phillips, Washington, Yuma | 36 min |
| Jul 31, 2:05 PM MDT | Mesoscale Discussion | SPC | Adams, Arapahoe, Broomfield, Costilla, Crowley, Custer and 13 more | 55 min |
Nearby
Severe Thunderstorm Watches in Kansas, 2012Severe Thunderstorm Watches in Colorado, 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.