Alert archive / Tennessee / Tornado Watches in 2011
Tornado Watch 22
The Storm Prediction Center issued this tornado watch at Feb 27, 2011, 4:31 PM CST for 17 counties in Kentucky; 19 counties in Tennessee. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 27, 2011, 4:31 PM CST (22:31 UTC)
- Expired
- Feb 27, 2011, 7:02 PM CST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 36 counties
Adair County, KY, Allen County, KY, Barren County, KY, Butler County, KY, Casey County, KY, Clinton County, KY, Cumberland County, KY, Edmonson County, KY, Green County, KY, Hart County, KY, Logan County, KY, Metcalfe County, KY, Monroe County, KY, Russell County, KY, Simpson County, KY, Taylor County, KY, Warren County, KY, Cheatham County, TN, Clay County, TN, Davidson County, TN, Dickson County, TN, Fentress County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Macon County, TN, Montgomery County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Wilson County, TN
The radar
The Nashville radar (KOHX), 58 km from the middle of the area, began a volume at 22:32 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 12:00Z, 10.5 hours before the alert went out and 71 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
- 4 J/kg
- Mixed-layer CIN
- -168 J/kg
- Mixed-layer LCL
- 940 m above ground
- 0-6 km bulk shear
- 60 kt
- 0-1 km storm-relative helicity
- 218 m²/s²
- 0-3 km storm-relative helicity
- 273 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
415
WWUS20 KWNS 272231
SEL2
SPC WW 272231
KYZ000-TNZ000-280400-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 22
NWS STORM PREDICTION CENTER NORMAN OK
435 PM CST SUN FEB 27 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
CENTRAL KENTUCKY
NORTHERN MIDDLE TENNESSEE
EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 435 PM UNTIL
1000 PM CST.
TORNADOES...HAIL TO 2 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 25 MILES SOUTHWEST OF FORT
CAMPBELL KENTUCKY TO 85 MILES EAST OF BOWLING GREEN KENTUCKY.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).
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 20...WW 21...
DISCUSSION...AN ISOLATED SUPERCELL HAS FORMED WEST OF
NASHVILLE...AND IS LIKELY TO PERSIST FOR A FEW HOURS ACROSS NORTHERN
MIDDLE TN AND SOUTH-CENTRAL KY. OTHER STORMS MAY INTENSIFY OVER
THIS REGION CHARACTERIZED BY STRONG LOW LEVEL WARM ADVECTION.
FAVORABLE LOW AND DEEP LAYER VERTICAL SHEAR PROFILES WILL PROMOTE
THE RISK OF TORNADOES...ALONG WITH LARGE HAIL AND DAMAGING WINDS.
AVIATION...TORNADOES AND 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
450. MEAN STORM MOTION VECTOR 24035.
...HARTSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 27, 12:44 PM CST | Mesoscale Discussion | SPC | Fulton, Hickman | 91 min |
| Feb 27, 4:57 PM CST | Mesoscale Discussion | SPC | Ballard, Carlisle, Crittenden, Livingston, McCracken | 2 hr |
Nearby
Tornado Watches in Tennessee, 2011Tornado Watches in Kentucky, 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.