Alert archive / Tennessee / Flash Flood Warnings in 2012

Flash Flood Warning 7, NWS Morristown, TN

April 6, 2012Blount County, Knox County, Tennessee

NWS Morristown, TN issued this flash flood warning at Apr 6, 2012, 12:05 AM EDT for Blount County, Knox County, Tennessee. It was in force for 3 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
Apr 6, 2012, 12:05 AM EDT (04:05 UTC)
Expired
Apr 6, 2012, 3:00 AM EDT
In force
3 hr
Issued by
NWS Morristown, TN
Area
Storm-based polygon
Flood severity
None

Counties Blount County, TN, Knox County, TN

The radar

The Knoxville radar (KMRX), 71 km from the middle of the area, began a volume at 04:08 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, 4.1 hours before the alert went out and 221 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-pSkew-T log-p diagram, Nashville Metro, TN at 00:00Z on 2012-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 00:00Z on 2012-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -46 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
2 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
461 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-46 m²/s²
0-3 km storm-relative helicity
-53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

741 
WGUS54 KMRX 060405
FFWMRX
TNC009-093-060700-
/O.NEW.KMRX.FF.W.0007.120406T0405Z-120406T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MORRISTOWN TN
1205 AM EDT FRI APR 6 2012

THE NATIONAL WEATHER SERVICE IN MORRISTOWN HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BLOUNT COUNTY IN EAST TENNESSEE...
  KNOX COUNTY IN EAST TENNESSEE...
  THIS INCLUDES THE CITY OF KNOXVILLE...

* UNTIL 300 AM EDT

* AT 1155 PM EDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH    
  FLOODING ACROSS KNOX COUNTY...ESPECIALLY ACROSS WESTERN AVE OF
  KNOXVILLE.  NUMEROUS REPORTS OF FLOODED ROADWAYS AND FLOODING OF   
  LOW LYING AREAS HAVE BEEN REPORTED BY KNOX COUNTY LAW              
  ENFORCEMENT.  LIGHT TO MODERATE RAIN WILL CONTINUE ACROSS 
  THE WARNED AREA UNTIL AROUND 2 AM.  

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO POWELL...
  KARNS AND HALLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

&&

LAT...LON 3590 8427 3592 8425 3594 8427 3593 8424
      3595 8424 3595 8422 3597 8422 3600 8419
      3599 8414 3603 8406 3607 8409 3617 8395
      3597 8372 3574 8411

$$

DH
2 follow-up statements
425 
WGUS74 KMRX 060519
FFSMRX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
119 AM EDT FRI APR 6 2012

TNC009-093-060700-
/O.CON.KMRX.FF.W.0007.000000T0000Z-120406T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KNOX TN-BLOUNT TN-
119 AM EDT FRI APR 6 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM EDT FOR
BLOUNT AND KNOX COUNTIES...

AT 112 AM EDT...KNOX COUNTY LOCAL LAW ENFORCEMENT OFFICIALS CONTINUE 
TO REPORT FLOODING ACROSS WESTERN AVE NEAR THE INTERSECTION OF THE 
640 BY-PASS.  ALSO...SEVERAL REPORTS OF PONDING OF LOW LYING AREAS 
AND STREET FLOODING CONTINUES ACROSS KNOX COUNTY.  AN AREA OF LIGHT
TO MODERATE RAIN WITH CONTINUE ACROSS THE WARNED AREA WITH ADDITIONAL
RAINFALL UP TO ONE-HALF INCH POSSIBLE.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO KNOXVILLE

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM RECENT HEAVY RAINFALL WILL CAUSE FLOODING OF 
SMALL CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. DO NOT DRIVE 
YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROADWAY. THE 
WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY. MOVE 
TO HIGHER GROUND.

&&

LAT...LON 3590 8427 3592 8425 3594 8427 3593 8424
      3595 8424 3595 8422 3597 8422 3600 8419
      3599 8414 3603 8406 3607 8409 3617 8395
      3597 8372 3574 8411

$$

DH
171 
WGUS74 KMRX 060653
FFSMRX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
253 AM EDT FRI APR 6 2012

TNC009-093-060702-
/O.EXP.KMRX.FF.W.0007.000000T0000Z-120406T0700Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
KNOX TN-BLOUNT TN-
253 AM EDT FRI APR 6 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 300 AM EDT FOR BLOUNT AND
KNOX 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 ALLOWED TO EXPIRE.

LAT...LON 3590 8427 3592 8425 3594 8427 3593 8424
      3595 8424 3595 8422 3597 8422 3600 8419
      3599 8414 3603 8406 3607 8409 3617 8395
      3597 8372 3574 8411

$$

DH

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 5, 11:14 PM EDTAreal Flood AdvisoryMRXBlount, Knox, Loudon3 hr
Apr 6, 3:21 AM EDTFrost AdvisoryMRXAnderson, Bledsoe, Blount, Campbell, Carter, Claiborne and 19 more31 hr

Nearby

Flash Flood Warnings in Tennessee, 2012Every 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.