Alert archive / Tennessee / Flash Flood Warnings in 2012

Flash Flood Warning 6, NWS Morristown, TN

April 5, 2012Morgan County, Roane County, Tennessee

NWS Morristown, TN issued this flash flood warning at Apr 5, 2012, 4:21 PM EDT for Morgan County, Roane County, Tennessee. It was in force for 56 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 5, 2012, 4:21 PM EDT (20:21 UTC)
Expired: Apr 5, 2012, 5:17 PM EDT
In force: 56 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Flood severity: None

Counties Morgan County, TN, Roane County, TN

The radar

The Knoxville radar (KMRX), 98 km from the middle of the area, began a volume at 20:23 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, 8.4 hours before the alert went out and 190 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: 670 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 805 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: 57 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

918 
WGUS54 KMRX 052021
FFWMRX
TNC129-145-052315-
/O.NEW.KMRX.FF.W.0006.120405T2021Z-120405T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MORRISTOWN TN
421 PM EDT THU APR 5 2012

THE NATIONAL WEATHER SERVICE IN MORRISTOWN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  MORGAN COUNTY IN EAST TENNESSEE...
  ROANE COUNTY IN EAST TENNESSEE...

* UNTIL 715 PM EDT

* AT 412 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.  RADAR 
INDICATES 1 TO 3 INCHES OF RAIN HAS FALLEN ACROSS THE WARNED AREA.  
AN ADDITIONAL 1 TO 2 INCHES OF RAINFALL IS POSSIBLE AS THUNDERSTORMS 
MOVE MOVE ACROSS THE AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PETROS

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 3598 8470 3618 8451 3615 8444 3614 8445
      3613 8443 3610 8441 3609 8437 3605 8435
      3587 8452

$$

MJB

1 follow-up statement

084 
WGUS74 KMRX 052117
FFSMRX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
517 PM EDT THU APR 5 2012

TNC129-145-052127-
/O.CAN.KMRX.FF.W.0006.000000T0000Z-120405T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ROANE TN-MORGAN TN-
517 PM EDT THU APR 5 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR MORGAN AND ROANE
COUNTIES...

THE HEAVY RAINFALL THAT PROMPTED THE WARNING HAS ENDED ACROSS THE
WARNED AREA...AND THE FLOOD THREAT HAS DIMINISHED. THEREFORE...THE
WARNING HAS BEEN CANCELLED.

LAT...LON 3598 8470 3618 8451 3615 8444 3614 8445
      3613 8443 3610 8441 3609 8437 3605 8435
      3587 8452

$$

DGS

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 5, 12:51 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Campbell	39 min
Apr 5, 1:40 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Claiborne, Union	50 min
Apr 5, 2:09 PM EDT	Severe Thunderstorm Warning	MRX	Cocke	21 min
Apr 5, 3:00 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Jefferson, Sevier	30 min
Apr 5, 3:22 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Hamblen, Hawkins	38 min
Apr 5, 3:52 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Jefferson, Sevier	23 min
Apr 5, 3:55 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Greene, Hawkins	50 min
Apr 5, 4:30 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Unicoi, Washington	45 min
Apr 5, 4:39 PM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Sequatchie	51 min
Apr 5, 5:15 PM EDT	Severe Thunderstorm Warning	MRX	Carter, Johnson, Unicoi, Washington	14 min
Apr 5, 5:34 PM EDT	Areal Flood Advisory	MRX	Washington	56 min
Apr 5, 5:44 PM EDT	Areal Flood Advisory	MRX	Bledsoe, Hamilton, Sequatchie	2 hr
Apr 5, 6:58 PM EDT	Severe Thunderstorm Warning	MRX	Hamilton	47 min
Apr 5, 7:03 PM EDT	Areal Flood Advisory	MRX	Rhea, Roane	3 hr
Apr 5, 7:30 PM EDT	Areal Flood Advisory	MRX	Carter, Greene, Unicoi, Washington	2 hr
Apr 5, 7:32 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Blount, Knox, Loudon	28 min
Apr 5, 7:52 PM EDT	Areal Flood Advisory	MRX	Blount, Knox, Loudon	3 hr

Nearby

Flash Flood Warnings in Tennessee, 2012 Every flash flood warning in 2012

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.