Alert archive / Tennessee / Tornado Watches in 2018
Tornado Watch 14
The Storm Prediction Center issued this tornado watch at Mar 19, 2018, 3:40 PM CDT for 20 counties in Tennessee. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 19, 2018, 3:40 PM CDT (20:40 UTC)
- Expired
- Mar 19, 2018, 8:11 PM CDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 50 kt
Counties Cannon County, TN, Cheatham County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Hickman County, TN, Jackson County, TN, Macon County, TN, Montgomery County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Williamson County, TN, Wilson County, TN
The radar
The Nashville radar (KOHX), 6 km from the middle of the area, began a volume at 20:39 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
- 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
- 10%
- 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
- 50%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 19, 3:43 PM CDT | Severe Thunderstorm Warning | OHX | Robertson | 32 min |
| Mar 19, 5:25 PM CDT | Severe Thunderstorm Warning | OHX | Robertson, Sumner | 21 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
Nashville Metro, TN (KBNA), launched 12:00Z, 8.7 hours before the alert went out and 11 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
- 1252 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 113 m²/s²
- 0-3 km storm-relative helicity
- 231 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
985
WWUS20 KWNS 192038
SEL4
SPC WW 192038
TNZ000-200400-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 14
NWS Storm Prediction Center Norman OK
340 PM CDT Mon Mar 19 2018
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Northern Middle Tennessee
* Effective this Monday afternoon and evening from 340 PM until
1100 PM CDT.
* Primary threats include...
A couple tornadoes possible
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Isolated damaging wind gusts to 60 mph possible
SUMMARY...A few severe storms should develop east through the
evening with a risk for large hail, tornadoes, and damaging winds.
The tornado watch area is approximately along and 40 statute miles
north and south of a line from 35 miles south of Clarksville TN to
70 miles east of Nashville TN. For a complete depiction of the watch
see the associated watch outline update (WOUS64 KWNS WOU4).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 13...
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2 inches. Extreme turbulence and surface wind
gusts to 50 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 25040.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 19, 2:06 PM CDT | Mesoscale Discussion | SPC | Franklin, Giles, Hardin, Lawrence, Lincoln, McNairy and 3 more | 84 min |
| Mar 19, 3:28 PM CDT | Tornado Watch | SPC | Bedford, Coffee, Franklin, Giles, Grundy, Hardin and 8 more | 9 hr |
| Mar 19, 6:22 PM CDT | Mesoscale Discussion | SPC | Cannon, Davidson, DeKalb, Jackson, Macon, Putnam and 8 more | 83 min |
Nearby
Tornado Watches in Tennessee, 2018Every tornado watch in 2018
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.