Alert archive / Tennessee / Flash Flood Warnings in 2017

Flash Flood Warning 3, NWS Nashville, TN

April 17, 2017Williamson County, Tennessee

NWS Nashville, TN issued this flash flood warning at Apr 17, 2017, 6:01 PM CDT for Williamson County, Tennessee. It was in force for 89 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 17, 2017, 6:01 PM CDT (23:01 UTC)
Expired: Apr 17, 2017, 7:30 PM CDT
In force: 89 min
Issued by: NWS Nashville, TN
Area: Storm-based polygon
Flood severity: None

County Williamson County, TN

The radar

The Nashville radar (KOHX), 43 km from the middle of the area, began a volume at 23:01 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.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.0 hours before the alert went out and 30 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 110 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 867 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 87 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

341 
WGUS54 KOHX 172301
FFWOHX
TNC187-180030-
/O.NEW.KOHX.FF.W.0003.170417T2301Z-170418T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Nashville TN
601 PM CDT MON APR 17 2017

The National Weather Service in Nashville has issued a

* Flash Flood Warning for...
  Central Williamson County in Middle Tennessee...

* Until 730 PM CDT

* At 600 PM CDT, trained weather spotters reported heavy rain across
  the warned area. Up to two inches of rain have already fallen.
  Flash flooding is likely.

* Some locations that will experience flooding include...
  Franklin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3599 8674 3583 8673 3584 8698 3599 8695

$$

07

The office that day

Everything else NWS Nashville, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 17, 12:38 PM CDT	Special Weather Statement	OHX	Rutherford	37 min
Apr 17, 12:48 PM CDT	Special Weather Statement	OHX	Van Buren	27 min
Apr 17, 1:11 PM CDT	Special Weather Statement	OHX	Dickson	34 min
Apr 17, 1:56 PM CDT	Special Weather Statement	OHX	DeKalb	34 min
Apr 17, 2:21 PM CDT	Special Weather Statement	OHX	DeKalb	24 min
Apr 17, 3:24 PM CDT	Special Weather Statement	OHX	Hickman	36 min
Apr 17, 3:49 PM CDT	Special Weather Statement	OHX	Dickson	26 min
Apr 17, 3:58 PM CDT	Areal Flood Advisory	OHX	Hickman	2 hr
Apr 17, 4:34 PM CDT	Flash Flood Warning	OHX	Dickson, Hickman, Williamson	116 min
Apr 17, 5:27 PM CDT	Special Weather Statement	OHX	Cumberland	18 min
Apr 17, 6:21 PM CDT	Areal Flood Advisory	OHX	Rutherford	54 min
Apr 17, 6:29 PM CDT	Special Weather Statement	OHX	Cannon	31 min

Nearby

Flash Flood Warnings in Tennessee, 2017 Every flash flood warning in 2017

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.