Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 44, NWS Morristown, TN

October 6, 2021Marion County, Tennessee

NWS Morristown, TN issued this flash flood warning at Oct 6, 2021, 7:20 PM CDT for Marion County, Tennessee. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Oct 6, 2021, 7:20 PM CDT (00:20 UTC)
Expired: Oct 7, 2021, 1:00 AM CDT
In force: 6 hr
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Flood severity: None

County Marion County, TN

The radar

The Northeast Alabama radar (KHTX), 53 km from the middle of the area, began a volume at 00:21 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 00:00Z, 0.3 hours before the alert went out and 142 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: 595 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 871 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 81 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

As transmitted.

921 
WGUS54 KMRX 070020
FFWMRX
TNC115-070600-
/O.NEW.KMRX.FF.W.0044.211007T0020Z-211007T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Morristown TN
720 PM CDT Wed Oct 6 2021

The National Weather Service in Morristown has issued a

* Flash Flood Warning for...
  Marion County in east Tennessee...

* Until 100 AM CDT.

* At 720 PM CDT, local law enforcement reported thunderstorms 
  producing heavy rain across the warned area. Between 2 and 4 
  inches of rain have fallen today. Flash flooding will likely occur 
  this evening or tonight with additional rain that is expected.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Law enforcement reported.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Chattanooga, Jasper, South Pittsburg, Whitwell, Kimball, 
  Monteagle, Powells Crossroads, Orme, Sequatchie Cave, Foster Falls 
  State Park, Martin Springs, Chimneys State Park, Fiery Gizzard 
  State Park, New Hope, Haletown (guild), Griffith Creek, Hicks Gap 
  State Park and Lone Oak.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3527 8549 3526 8544 3520 8539 3514 8539
      3511 8540 3510 8537 3507 8537 3504 8539
      3504 8541 3501 8543 3498 8547 3499 8586
      3521 8586 3522 8587 3524 8585 3524 8582
      3522 8574 3524 8569 3529 8571 3532 8556

FLASH FLOOD...OBSERVED

$$

19

1 follow-up statement

942 
WGUS74 KMRX 070553
FFSMRX

Flash Flood Statement
National Weather Service Morristown TN
1253 AM CDT Thu Oct 7 2021

TNC115-070603-
/O.EXP.KMRX.FF.W.0044.000000T0000Z-211007T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Marion TN-
1253 AM CDT Thu Oct 7 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1 AM CDT EARLY THIS MORNING 
FOR MARION COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 700 AM CDT Thursday for 
portions of southwest North Carolina. portions of east Tennessee.

LAT...LON 3527 8549 3526 8544 3520 8539 3514 8539
      3511 8540 3510 8537 3507 8537 3504 8539
      3504 8541 3501 8543 3498 8547 3499 8586
      3521 8586 3522 8587 3524 8585 3524 8582
      3522 8574 3524 8569 3529 8571 3532 8556

$$

CD

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 6, 8:03 PM CDT	River Flood Warning	MRX	Bledsoe, Marion, Sequatchie	48 hr
Oct 6, 8:04 PM CDT	Special Weather Statement	MRX	Scott	26 min
Oct 6, 8:52 PM CDT	Special Weather Statement	MRX	Scott	38 min
Oct 7, 4:08 PM CDT	Special Weather Statement	MRX	Blount, Knox, Loudon	52 min
Oct 7, 4:59 PM CDT	Special Weather Statement	MRX	Anderson, Knox, Loudon	46 min
Oct 7, 5:08 PM CDT	Areal Flood Advisory	MRX	Blount, Knox, Loudon, Monroe	112 min

Nearby

Flash Flood Warnings in Tennessee, 2021 Every flash flood warning in 2021

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.