Alert archive / Tennessee / Flash Flood Watches in 2019

Flash Flood Watch 5, NWS Nashville, TN

December 16, 201925 counties in Tennessee

NWS Nashville, TN issued this flash flood watch at Dec 16, 2019, 7:39 AM CST for 25 counties in Tennessee. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued
Dec 16, 2019, 7:39 AM CST (13:39 UTC)
Expired
Dec 16, 2019, 7:54 PM CST
In force
12 hr
Issued by
NWS Nashville, TN
Flood severity
None
All 25 counties

Cannon County, TN, Cheatham County, TN, Clay County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Jackson County, TN, Macon County, TN, Montgomery County, TN, Overton County, TN, Perry County, TN, Pickett County, TN, Putnam County, TN, Robertson County, TN, Rutherford County, TN, Smith County, TN, Stewart County, TN, Sumner County, TN, Trousdale County, TN, Williamson County, TN, Wilson County, TN

The radar

The Nashville radar (KOHX), 7 km from the middle of the area, began a volume at 13:38 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, 1.7 hours before the alert went out and 14 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-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2019-12-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2019-12-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 201 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
495 m above ground
0-6 km bulk shear
84 kt
0-1 km storm-relative helicity
201 m²/s²
0-3 km storm-relative helicity
266 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Nashville, TN wrote its last area forecast discussion before this flash flood watch went out at Dec 16, 5:42 AM CST, 1 hour 57 minutes earlier.

Area forecast discussion, Dec 16, 5:42 AM CST, 1 hour 57 minutes before
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Hazardous weather outlook, Dec 16, 5:02 AM CST, 2 hours 37 minutes before
Hazardous Weather Outlook
National Weather Service Nashville TN
502 AM CST Mon Dec 16 2019

TNZ005>011-023>034-056>066-075-077>080-093>095-171115-
Stewart-Montgomery-Robertson-Sumner-Macon-Clay-Pickett-Houston-
Humphreys-Dickson-Cheatham-Davidson-Wilson-Trousdale-Smith-
Jackson-Putnam-Overton-Fentress-Perry-Hickman-Lewis-Williamson-
Maury-Marshall-Rutherford-Cannon-De Kalb-White-Cumberland-Bedford-
Coffee-Warren-Grundy-Van Buren-Wayne-Lawrence-Giles-
502 AM CST Mon Dec 16 2019

This Hazardous Weather Outlook is for portions of Middle
Tennessee.

.DAY ONE...Today and Tonight

Widespread rain and a few thunderstorms will affect Middle
Tennessee today and into the evening ahead of a strong cold front.
Some of these storms may be strong to severe, mainly south of
I-40. Damaging wind gusts are the primary threat. There is also
the potential for flooding, especially in areas that experience
multiple heavy showers and storms.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed today.

Rose

In the hours before

Special weather statement, Dec 16, 1:46 AM CST, 5 hours 53 minutes before
Special Weather Statement
National Weather Service Nashville TN
146 AM CST Mon Dec 16 2019

TNZ008>010-029-031-160830-
Trousdale TN-Sumner TN-Clay TN-Jackson TN-Macon TN-
146 AM CST Mon Dec 16 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN JACKSON...CENTRAL
SUMNER...NORTHWESTERN CLAY...MACON AND NORTHERN TROUSDALE COUNTIES
UNTIL 230 AM CST...

At 146 AM CST, Doppler radar was tracking a strong thunderstorm near
Gallatin, moving east at 55 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Gallatin, Lafayette, Hartsville, Hendersonville, Westmoreland, Red
Boiling Springs, Cottontown, Bethpage, Bugtussle, Oak Grove and
Bledsoe Creek State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3662 8575 3647 8570 3634 8657 3652 8662
      3664 8615
TIME...MOT...LOC 0746Z 255DEG 49KT 3646 8650

Rose

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 16, 12:18 AM CSTSpecial Weather StatementOHXRobertson42 min
Dec 16, 12:57 AM CSTSpecial Weather StatementOHXMacon, Robertson, Sumner48 min
Dec 16, 1:04 AM CSTAreal Flood AdvisoryOHXCheatham, Dickson, Houston, Humphreys, Montgomery, Robertson and 1 more6 hr
Dec 16, 1:07 AM CSTSpecial Weather StatementOHXCheatham, Dickson, Houston38 min
Dec 16, 1:46 AM CSTSpecial Weather StatementOHXMacon, Sumner44 min
Dec 16, 1:50 AM CSTAreal Flood AdvisoryOHXCheatham, Davidson, Macon, Robertson, Sumner, Trousdale and 1 more6 hr
Dec 16, 3:14 AM CSTFlash Flood WarningOHXSumner2 hr
Dec 16, 10:29 AM CSTRiver Flood AdvisoryOHXCheatham16 hr
Dec 16, 10:49 AM CSTSpecial Weather StatementOHXHouston26 min
Dec 16, 11:23 AM CSTAreal Flood AdvisoryOHXHouston, Humphreys3 hr
Dec 16, 1:18 PM CSTSpecial Weather StatementOHXCheatham, Robertson27 min
Dec 16, 1:46 PM CSTSpecial Weather StatementOHXSumner29 min
Dec 16, 2:23 PM CSTAreal Flood AdvisoryOHXCheatham, Davidson, Macon, Montgomery, Robertson, Sumner3 hr
Dec 16, 3:40 PM CSTSpecial Weather StatementOHXLawrence35 min
Dec 16, 3:44 PM CSTFlash Flood WarningOHXMacon, Robertson, Sumner3 hr
Dec 16, 4:25 PM CSTSevere Thunderstorm WarningOHXLawrence, Lewis, Perry, Wayne35 min
Dec 16, 4:34 PM CSTSevere Thunderstorm WarningOHXLawrence, Wayne41 min
Dec 16, 5:15 PM CSTSevere Thunderstorm WarningOHXGiles, Lawrence, Marshall, Maury45 min
Dec 16, 5:46 PM CSTSevere Thunderstorm WarningOHXBedford, Marshall26 min

Nearby

Flash Flood Watches in Tennessee, 2019Every flash flood watch in 2019

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.