Alert archive / Kansas / Tornado Watches in 2011
Tornado Watch 871
The Storm Prediction Center issued this tornado watch at Nov 7, 2011, 5:37 PM CST for 13 counties in Kansas; 6 counties in Oklahoma. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 7, 2011, 5:37 PM CST (23:37 UTC)
- Expired
- Nov 8, 2011, 1:00 AM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
Counties Allen County, KS, Bourbon County, KS, Chautauqua County, KS, Cherokee County, KS, Cowley County, KS, Crawford County, KS, Elk County, KS, Greenwood County, KS, Labette County, KS, Montgomery County, KS, Neosho County, KS, Wilson County, KS, Woodson County, KS, Craig County, OK, Nowata County, OK, Osage County, OK, Ottawa County, OK, Pawnee County, OK, Washington County, OK
The radar
The Tulsa radar (KINX), 131 km from the middle of the area, began a volume at 23:37 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
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 7, 6:11 PM CST | Severe Thunderstorm Warning | TSA | Osage | 49 min |
| Nov 7, 6:12 PM CST | Severe Thunderstorm Warning | ICT | Chautauqua | 44 min |
| Nov 7, 8:42 PM CST | Severe Thunderstorm Warning | TSA | Creek, Osage, Pawnee, Tulsa | 63 min |
| Nov 7, 9:46 PM CST | Severe Thunderstorm Warning | TSA | Nowata, Osage, Rogers, Tulsa, Washington | 59 min |
| Nov 7, 11:37 PM CST | Flash Flood Warning | TSA | Creek, Osage, Tulsa, Washington | 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
Topeka, KS (KTOP), launched 12:00Z, 11.6 hours before the alert went out and 192 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1478 m above ground
- 0-6 km bulk shear
- 62 kt
- 0-1 km storm-relative helicity
- 87 m²/s²
- 0-3 km storm-relative helicity
- 200 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
789
WWUS20 KWNS 072338
SEL1
SPC WW 072338
KSZ000-OKZ000-080700-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 871
NWS STORM PREDICTION CENTER NORMAN OK
540 PM CST MON NOV 7 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHEAST KANSAS
NORTHEAST OKLAHOMA
EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 540 PM
UNTIL 100 AM CST.
TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH OF CHANUTE
KANSAS TO 20 MILES WEST OF TULSA 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 870...
DISCUSSION...NRN END OF N CNTRL OK SQLN WITH EMBEDDED
SUPERCELLS/SMALLER SCALE CIRCULATIONS EXPECTED TO CONTINUE SLOWLY
EWD THROUGH LATE TNGT...WHILE STORMS MOVE MORE RAPIDLY NNE ALONG IT.
LOW LVL LAPSE RATES WILL REMAIN WEAK. BUT STRENGTHENING LOW LVL
WIND FIELD ASSOCIATED BOTH WITH DIURNAL CYCLE AND WITH APPROACH OF
NM UPR VORT SUGGEST POTENTIAL FOR LOCALLY DMGG WIND AND ISOLD
TORNADOES AS BOUNDARY LAYER MOISTURE CONTINUES TO SLOWLY INCREASE
ACROSS REGION.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 23035.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 7, 1:30 PM CST | Mesoscale Discussion | SPC | Barber, Butler, Chautauqua, Cowley, Elk, Greenwood and 6 more | 2 hr |
| Nov 7, 4:58 PM CST | Mesoscale Discussion | SPC | Chautauqua, Elk, Labette, Montgomery, Neosho, Wilson | 92 min |
| Nov 6, 7:00 PM CST | Mesoscale Discussion | SPC | Carter, Garvin, Jefferson, Johnston, Love, Marshall and 2 more | 90 min |
| Nov 7, 7:52 AM CST | Mesoscale Discussion | SPC | Alfalfa, Beckham, Blaine, Canadian, Custer, Dewey and 15 more | 83 min |
| Nov 7, 12:27 PM CST | Mesoscale Discussion | SPC | Beckham, Caddo, Comanche, Cotton, Custer, Greer and 6 more | 93 min |
| Nov 7, 1:11 PM CST | Tornado Watch | SPC | Beckham, Blaine, Caddo, Canadian, Comanche, Cotton and 17 more | 8 hr |
| Nov 7, 5:51 PM CST | Mesoscale Discussion | SPC | Blaine, Caddo, Canadian, Comanche, Custer, Garfield and 10 more | 114 min |
| Nov 7, 5:53 PM CST | Mesoscale Discussion | SPC | Love, Marshall | 67 min |
Nearby
Tornado Watches in Kansas, 2011Tornado Watches in Oklahoma, 2011Every tornado watch in 2011
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.