Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 33, NWS Morristown, TN

August 14, 2021Monroe County, Tennessee

NWS Morristown, TN issued this flash flood warning at Aug 14, 2021, 8:36 PM EDT for Monroe County, Tennessee. It was in force for 3 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: Aug 14, 2021, 8:36 PM EDT (00:36 UTC)
Expired: Aug 14, 2021, 11:45 PM EDT
In force: 3 hr
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Flood severity: None

County Monroe County, TN

The radar

The Knoxville radar (KMRX), 123 km from the middle of the area, began a volume at 00:40 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
Aug 14, 9:14 PM EDT	FLASH FLOOD	Tellico Plains, TN	2 FT OF WATER OVER UNICOI LANE AND VETERANS MEMORIAL DRIVE.

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 00:00Z, 0.6 hours before the alert went out and 220 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: 1476 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 941 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: -3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

998 
WGUS54 KMRX 150036
FFWMRX
TNC123-150345-
/O.NEW.KMRX.FF.W.0033.210815T0036Z-210815T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Morristown TN
836 PM EDT Sat Aug 14 2021

The National Weather Service in Morristown has issued a

* Flash Flood Warning for...
  Southwestern Monroe County in east Tennessee...

* Until 1145 PM EDT.

* At 836 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 inches of rain 
  have fallen. The expected rainfall rate is 1 to 2 inches in 1 
  hour. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Tellico Plains and Mount Vernon.

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 3540 8441 3545 8436 3546 8427 3541 8421
      3533 8420 3526 8424 3530 8437 3534 8440
      3535 8441 3536 8441 3537 8441 3538 8441
      3539 8441

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

JLB

1 follow-up statement

201 
WGUS74 KMRX 150122
FFSMRX

Flash Flood Statement
National Weather Service Morristown TN
922 PM EDT Sat Aug 14 2021

TNC123-150345-
/O.CON.KMRX.FF.W.0033.000000T0000Z-210815T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Monroe TN-
922 PM EDT Sat Aug 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 PM EDT THIS 
EVENING FOR SOUTHWESTERN MONROE COUNTY...

At 922 PM EDT, Doppler radar and 911 dispatch reported thunderstorms 
producing heavy rain and flash flooding within the warned area. 
Between 2.5 and 3.5 inches of rain have fallen. The expected 
rainfall rate is 0.5 to 1 inch in 1 hour. Flash flooding is already 
occurring with roads flooded and closed near Tellico Plains.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and Emergency 911 Dispatch.

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...
  Tellico Plains and Mount Vernon.

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 3540 8441 3545 8436 3546 8427 3541 8421
      3533 8420 3526 8424 3530 8437 3534 8440
      3535 8441 3536 8441 3537 8441 3538 8441
      3539 8441

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

JLB

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 14, 8:13 PM EDT	Severe Thunderstorm Warning	MRX	Knox	32 min
Aug 14, 8:25 PM EDT	Special Weather Statement	MRX	Jefferson	50 min
Aug 14, 8:33 PM EDT	Special Weather Statement	MRX	Blount	42 min
Aug 14, 8:35 PM EDT	Areal Flood Advisory	MRX	Knox	3 hr
Aug 14, 8:42 PM EDT	Severe Thunderstorm Warning	MRX	Knox	33 min
Aug 14, 8:49 PM EDT	Areal Flood Advisory	MRX	McMinn, Monroe, Polk	3 hr
Aug 14, 8:49 PM EDT	Severe Thunderstorm Warning	MRX	Blount	41 min
Aug 14, 8:59 PM EDT	Areal Flood Advisory	MRX	Blount	3 hr
Aug 14, 9:12 PM EDT	Special Weather Statement	MRX	Knox	48 min
Aug 14, 11:24 PM EDT	Areal Flood Advisory	MRX	Anderson, Campbell, Claiborne, Union	3 hr
Aug 15, 3:34 PM EDT	Special Weather Statement	MRX	Knox	26 min
Aug 15, 4:09 PM EDT	Special Weather Statement	MRX	Knox	36 min
Aug 15, 4:27 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Knox, Union	33 min
Aug 15, 4:35 PM EDT	Special Weather Statement	MRX	Meigs, Rhea	25 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.