Alert archive / Kansas / Tornado Watches in 2007
Tornado Watch 171
The Storm Prediction Center issued this tornado watch at Apr 23, 2007, 9:41 PM MDT for Kit Carson County, Yuma County, Colorado; 8 counties in Kansas; Dundy County, Hitchcock County, Red Willow County, Nebraska. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 23, 2007, 9:41 PM MDT (03:41 UTC)
- Expired
- Apr 24, 2007, 2:14 AM MDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2.5 in
- Strongest gust expected
- 60 kt
Counties Kit Carson County, CO, Yuma County, CO, Cheyenne County, KS, Decatur County, KS, Graham County, KS, Norton County, KS, Rawlins County, KS, Sheridan County, KS, Sherman County, KS, Thomas County, KS, Dundy County, NE, Hitchcock County, NE, Red Willow County, NE
The radar
The Goodland radar (KGLD), 53 km from the middle of the area, began a volume at 03:42 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
- 50%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 40%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 23, 9:56 PM MDT | Tornado Warning | GLD | Cheyenne | 49 min |
| Apr 23, 9:58 PM MDT | Tornado Warning | GLD | Rawlins | 62 min |
| Apr 23, 10:28 PM MDT | Tornado Warning | GLD | Yuma | 47 min |
| Apr 23, 10:43 PM MDT | Tornado Warning | GLD | Dundy | 26 min |
| Apr 23, 10:51 PM MDT | Tornado Warning | GLD | Decatur, Rawlins | 54 min |
| Apr 23, 11:02 PM MDT | Flash Flood Warning | GLD | Yuma | 3 hr |
| Apr 23, 11:11 PM MDT | Severe Thunderstorm Warning | GLD | Rawlins | 64 min |
| Apr 23, 11:52 PM MDT | Severe Thunderstorm Warning | GLD | Decatur | 53 min |
| Apr 24, 12:15 AM MDT | Severe Thunderstorm Warning | GLD | Hitchcock | 37 min |
| Apr 24, 12:22 AM MDT | Flash Flood Warning | GLD | Rawlins | 53 min |
| Apr 24, 12:39 AM MDT | Flash Flood Warning | GLD | Red Willow | 3 hr |
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, 3.7 hours before the alert went out and 140 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
- 351 J/kg
- Mixed-layer CIN
- -75 J/kg
- Mixed-layer LCL
- 1440 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 187 m²/s²
- 0-3 km storm-relative helicity
- 380 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 4.5
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 240340
SEL1
SPC WW 240340
COZ000-KSZ000-NEZ000-241100-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 171
NWS STORM PREDICTION CENTER NORMAN OK
1040 PM CDT MON APR 23 2007
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
NORTHEAST COLORADO
NORTHWEST KANSAS
SOUTHWEST NEBRASKA
EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 1040 PM
UNTIL 600 AM CDT.
TORNADOES...HAIL TO 2.5 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 45 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 45 MILES NORTHWEST OF
BURLINGTON COLORADO TO 25 MILES NORTH NORTHEAST OF HILL CITY
KANSAS. 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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 168. WATCH NUMBER 168 WILL NOT BE IN EFFECT AFTER
1040 PM CDT. CONTINUE...WW 167...WW 170...
DISCUSSION...SUPERCELLS WILL CONTINUE ACROSS WW FOR MUCH OF THE
NIGHT ALONG AND JUST WEST OF INCREASING SLY LLJ. STORMS SHOULD
REMAIN ROOTED IN AND JUST ABOVE THE BOUNDARY LAYER INVOF SURFACE
WARM FRONT EXPECTED TO REMAIN IN PLACE OVER NWRN KS. LARGE HAIL AND
ISOLATED TORNADOES... ALONG WITH ISOLATED DAMAGING WINDS...WILL
ACCOMPANY THIS ACTIVITY FOR SEVERAL MORE HOURS.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 22025.
...EVANSSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 23, 6:52 PM MDT | Mesoscale Discussion | SPC | Adams, Arapahoe, Bent, Cheyenne, Crowley, Elbert and 10 more | 113 min |
| Apr 24, 12:37 AM MDT | Mesoscale Discussion | SPC | Cheyenne, Kit Carson, Phillips, Yuma | 83 min |
| Apr 24, 1:48 PM MDT | Mesoscale Discussion | SPC | Cheyenne, Kit Carson, Lincoln, Yuma | 117 min |
| Apr 23, 7:54 PM MDT | Mesoscale Discussion | SPC | Barber, Barton, Butler, Cheyenne, Clark, Comanche and 55 more | 2 hr |
| Apr 23, 8:53 PM MDT | Severe Thunderstorm Watch | SPC | Jewell, Mitchell, Osborne, Phillips, Rooks, Smith | 8 hr |
| Apr 24, 4:03 AM MDT | Mesoscale Discussion | SPC | Graham, Jewell, Lincoln, Mitchell, Norton, Osborne and 3 more | 87 min |
| Apr 24, 9:04 AM MDT | Mesoscale Discussion | SPC | Barber, Barton, Clark, Cloud, Comanche, Edwards and 40 more | 116 min |
| Apr 24, 9:48 AM MDT | Tornado Watch | SPC | Barber, Barton, Butler, Chase, Chautauqua, Clay and 41 more | 10 hr |
| Apr 24, 1:03 PM MDT | Mesoscale Discussion | SPC | Allen, Anderson, Atchison, Bourbon, Brown, Cherokee and 26 more | 87 min |
| Apr 24, 2:24 PM MDT | Tornado Watch | SPC | Allen, Anderson, Atchison, Bourbon, Brown, Cherokee and 24 more | 5 hr |
| Apr 24, 2:37 PM MDT | Mesoscale Discussion | SPC | Barber, Barton, Butler, Chase, Chautauqua, Clay and 33 more | 83 min |
| Apr 24, 5:13 PM MDT | Mesoscale Discussion | SPC | Butler, Chase, Chautauqua, Clay, Cloud, Cowley and 17 more | 62 min |
| Apr 24, 12:35 PM MDT | Mesoscale Discussion | SPC | Adams, Buffalo, Butler, Cass, Clay, Custer and 34 more | 55 min |
| Apr 24, 12:48 PM MDT | Severe Thunderstorm Watch | SPC | Adams, Buffalo, Clay, Dawson, Fillmore, Franklin and 21 more | 5 hr |
Nearby
Tornado Watches in Kansas, 2007Tornado Watches in Nebraska, 2007Tornado Watches in Colorado, 2007Every tornado watch in 2007
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.