Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 41, NWS Morristown, TN

September 19, 2021Hamilton County, Tennessee

NWS Morristown, TN issued this flash flood warning at Sep 19, 2021, 7:14 PM EDT for Hamilton County, Tennessee. It was in force for 4 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 19, 2021, 7:14 PM EDT (23:14 UTC)
Expired: Sep 19, 2021, 11:15 PM EDT
In force: 4 hr
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Flood severity: None

County Hamilton County, TN

The radar

The Northeast Alabama radar (KHTX), 80 km from the middle of the area, began a volume at 23:17 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 was reported inside it

Time	Report	Where	Remark
Sep 19, 8:10 PM EDT	FLASH FLOOD	3 Wnw East Brainerd, TN	ROAD CLOSURE DUE TO WATER OVER GUNBARREL ROAD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.2 hours before the alert went out and 174 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: 92 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 895 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

111 
WGUS54 KMRX 192314
FFWMRX
TNC065-200315-
/O.NEW.KMRX.FF.W.0041.210919T2314Z-210920T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Morristown TN
714 PM EDT Sun Sep 19 2021

The National Weather Service in Morristown has issued a

* Flash Flood Warning for...
  South Central Hamilton County in east Tennessee...

* Until 1115 PM EDT.

* At 714 PM EDT, emergency management reported thunderstorms 
  producing heavy rain across the warned area. Between 1 and 2 
  inches of rain have fallen. Additional rainfall amounts of 0.5 to 
  1 inch are possible in the warned area. Flash flooding is ongoing 
  or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Emergency dispatch 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, Soddy-Daisy, Walden, Lakesite, Ridgeside, Harrison, 
  Red Bank, Middle Valley, Falling Water, East Ridge, Ooltewah and 
  North Chickamauga Creek Gorge.

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.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3523 8529 3523 8516 3499 8511 3499 8513
      3499 8517 3499 8519 3499 8521 3499 8524
      3499 8526 3498 8526 3499 8527 3498 8529

FLASH FLOOD...OBSERVED

$$

BW

2 follow-up statements

199 
WGUS74 KMRX 192320
FFSMRX

Flash Flood Statement
National Weather Service Morristown TN
720 PM EDT Sun Sep 19 2021

TNC065-200315-
/O.CON.KMRX.FF.W.0041.000000T0000Z-210920T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hamilton TN-
720 PM EDT Sun Sep 19 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1115 PM EDT THIS 
EVENING FOR SOUTH CENTRAL HAMILTON COUNTY...

At 720 PM EDT, emergency dispatch reported thunderstorms producing 
heavy rain across the warned area. Between 1 and 2 inches of rain 
have fallen. Additional rainfall amounts of 0.5 to 1 inch are 
possible in the warned area. Flash flooding is ongoing or expected 
to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Emergency dispatch 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, Soddy-Daisy, Walden, Lakesite, Ridgeside, Harrison, 
  Red Bank, Middle Valley, Falling Water, East Ridge, Ooltewah and 
  North Chickamauga Creek Gorge.

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.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3523 8529 3523 8516 3499 8511 3499 8513
      3499 8517 3499 8519 3499 8521 3499 8524
      3499 8526 3498 8526 3499 8527 3498 8529

FLASH FLOOD...OBSERVED

$$

029 
WGUS74 KMRX 200319
FFSMRX

Flash Flood Statement
National Weather Service Morristown TN
1119 PM EDT Sun Sep 19 2021

TNC065-200329-
/O.EXP.KMRX.FF.W.0041.000000T0000Z-210920T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hamilton TN-
1119 PM EDT Sun Sep 19 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR SOUTH CENTRAL HAMILTON 
COUNTY...

The Flash Flood Warning has been replaced by a Flood Warning for 
southwestern Hamilton County in effect until 900 AM EDT.

A Flash Flood Watch remains in effect until 800 PM EDT Monday for A 
portion of east Tennessee.

LAT...LON 3523 8529 3523 8516 3499 8511 3499 8513
      3499 8517 3499 8519 3499 8521 3499 8524
      3499 8526 3498 8526 3499 8527 3498 8529

$$

BW

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 19, 3:12 AM EDT	Flash Flood Watch	MRX	Bledsoe, Bradley, Hamilton, Marion, Meigs, Rhea and 1 more	47 hr
Sep 19, 10:19 AM EDT	Areal Flood Advisory	MRX	Hamilton, Marion, Sequatchie	3 hr
Sep 19, 3:36 PM EDT	Special Weather Statement	MRX	Sevier	39 min
Sep 19, 3:59 PM EDT	Special Weather Statement	MRX	Hamblen, Jefferson	46 min
Sep 19, 4:19 PM EDT	Areal Flood Advisory	MRX	Hamilton, Marion, Sequatchie	3 hr
Sep 19, 5:33 PM EDT	Flash Flood Warning	MRX	Hamilton, Marion, Sequatchie	6 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.