Alert archive / Tennessee / Flash Flood Warnings in 2021

Flash Flood Warning 30, NWS Morristown, TN

July 11, 2021Meigs County, Tennessee

NWS Morristown, TN issued this flash flood warning at Jul 11, 2021, 8:54 PM EDT for Meigs 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: Jul 11, 2021, 8:54 PM EDT (00:54 UTC)
Expired: Jul 12, 2021, 12:00 AM EDT
In force: 3 hr
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Flood severity: None

County Meigs County, TN

The radar

The Northeast Alabama radar (KHTX), 123 km from the middle of the area, began a volume at 00:54 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
Jul 11, 9:30 PM EDT	FLASH FLOOD	4 Nne Big Spring, TN	STANDING WATER ON MANY ROADS ACROSS MEIGS COUNTY.

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, 0.9 hours before the alert went out and 173 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: 853 J/kg
Mixed-layer CIN: -4 J/kg
Mixed-layer LCL: 764 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 107 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

As transmitted.

779 
WGUS54 KMRX 120054
FFWMRX
TNC121-120400-
/O.NEW.KMRX.FF.W.0030.210712T0054Z-210712T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Morristown TN
854 PM EDT Sun Jul 11 2021

The National Weather Service in Morristown has issued a

* Flash Flood Warning for...
  Central Meigs County in east Tennessee...

* Until midnight EDT.

* At 854 PM EDT, local law enforcement reported thunderstorms 
  producing heavy rain across the warned area. Between 1 and 2 
  inches of rain have fallen. Additional rainfall amounts up to 1.5 
  inches are possible in the warned area. Flash flooding is ongoing 
  or expected to begin shortly.

  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...
  Decatur and Big Spring.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3552 8488 3555 8485 3555 8480 3558 8481
      3559 8479 3555 8470 3546 8480 3535 8486
      3536 8488 3533 8488 3529 8493 3530 8494
      3529 8495 3531 8497 3536 8498 3537 8499
      3544 8494 3545 8491 3548 8490 3550 8486

FLASH FLOOD...OBSERVED

$$

19

1 follow-up statement

417 
WGUS74 KMRX 120200
FFSMRX

Flash Flood Statement
National Weather Service Morristown TN
1000 PM EDT Sun Jul 11 2021

TNC121-120400-
/O.CON.KMRX.FF.W.0030.000000T0000Z-210712T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Meigs TN-
1000 PM EDT Sun Jul 11 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL MIDNIGHT EDT TONIGHT 
FOR CENTRAL MEIGS COUNTY...

At 1000 PM EDT, local law enforcement reported flash flooding across 
the warned area. Between 1 and 3 inches of rain have fallen.

HAZARD...Flash flooding caused by heavy rain.

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...
  Decatur and Big Spring.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3552 8488 3555 8485 3555 8480 3558 8481
      3559 8479 3555 8470 3546 8480 3535 8486
      3536 8488 3533 8488 3529 8493 3530 8494
      3529 8495 3531 8497 3536 8498 3537 8499
      3544 8494 3545 8491 3548 8490 3550 8486

FLASH FLOOD...OBSERVED

$$

19

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 11, 8:04 PM EDT	Special Weather Statement	MRX	Scott	41 min
Jul 11, 8:23 PM EDT	Special Weather Statement	MRX	Hamilton	52 min
Jul 11, 8:30 PM EDT	Special Weather Statement	MRX	Anderson	45 min
Jul 11, 8:53 PM EDT	Special Weather Statement	MRX	Anderson	52 min
Jul 11, 8:59 PM EDT	Areal Flood Advisory	MRX	Bradley, Hamilton	3 hr
Jul 11, 9:23 PM EDT	Special Weather Statement	MRX	Loudon	37 min
Jul 12, 6:27 PM EDT	Areal Flood Advisory	MRX	Carter, Sullivan	3 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.