Upper level low from the Gulf combines with a deepening trough over the northern Plains to result in widespread 3-6 inch rainfall amounts across east TN.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MRX wrote it up.
Upper level low from the Gulf combines with a deepening trough over the northern Plains to result in widespread 3-6 inch rainfall amounts across east TN.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Morristown, TN wrote its last area forecast discussion before the first event at Sep 18, 12:37 AM EST, 43 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
137 AM EDT TUE SEP 18 2012
.AVIATION...MOISTURE LADEN ATMOSPHERE CONTINUES TO BE LIFTED IN THE
PRESENCE OF NORTHERN AND SOUTHERN STREAM SHORTER WAVELENGTH
SYSTEMS. LOOKS LIKE PERIODS OF MODERATE TO HEAVY RAIN ESPECIALLY AT
CHA AND TYS BEFORE DAYBREAK WITH SOME SHADOWING KEEPING FLIGHT
WEATHER A LITTLE BETTER AT TRI. STILL LOOKS LIKE THE WORST FLIGHT
WEATHER WILL OCCUR FROM AROUND NOW THROUGH 12Z AT THE TERMINALS
WITH BEST LIFT GRADUALLY SHIFTING EAST DURING THE DAY. MVFR WITH
OCCASIONAL IFR CONDITIONS WILL PREVAIL DURING THIS PERIOD.
POSSIBILITY OF SLIGHT IMPROVEMENT TO MAINLY MVFR DURING THE DAY AS
A SURFACE COLD FRONT SLIDES SLOWLY EAST TOWARD THE NORTH CAROLINA
BORDER. WOULD EXPECT VFR FLIGHT TO DEVELOP AROUND 18-00Z TUE/WED AS
DOWNWARD MOTION AND DRIER AIR BUILD ACROSS THE GREAT VALLEY.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
CHEROKEE...CLAY.
TN...FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
ANDERSON...BLEDSOE...BLOUNT SMOKY MOUNTAINS...BRADLEY...
CAMPBELL...CLAIBORNE...COCKE SMOKY MOUNTAINS...EAST POLK...
GRAINGER...HAMBLEN...HAMILTON...HANCOCK...HAWKINS...
JEFFERSON...JOHNSON...KNOX...LOUDON...MARION...MCMINN...
MEIGS...MORGAN...NW BLOUNT...NORTH SEVIER...NORTHWEST
CARTER...NORTHWEST COCKE...NORTHWEST GREENE...NORTHWEST
MONROE...RHEA...ROANE...SCOTT TN...SEQUATCHIE...SEVIER
SMOKY MOUNTAINS...SOUTHEAST CARTER...SOUTHEAST GREENE...
SOUTHEAST MONROE...SULLIVAN...UNICOI...UNION...WASHINGTON
TN...WEST POLK.
VA...FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES: LEE...
RUSSELL...SCOTT...WASHINGTON...WISE.
&&HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE MORRISTOWN TN 513 PM EDT MON SEP 17 2012 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-182100- CHEROKEE-CLAY-SCOTT TN-CAMPBELL-CLAIBORNE-HANCOCK-HAWKINS- SULLIVAN-JOHNSON-MORGAN-ANDERSON-UNION-GRAINGER-HAMBLEN- NORTHWEST COCKE-COCKE SMOKY MOUNTAINS-NORTHWEST GREENE- SOUTHEAST GREENE-WASHINGTON TN-UNICOI-NORTHWEST CARTER- SOUTHEAST CARTER-ROANE-LOUDON-KNOX-JEFFERSON-NW BLOUNT- BLOUNT SMOKY MOUNTAINS-NORTH SEVIER-SEVIER SMOKY MOUNTAINS- SEQUATCHIE-BLEDSOE-RHEA-MEIGS-MCMINN-NORTHWEST MONROE- SOUTHEAST MONROE-MARION-HAMILTON-BRADLEY-WEST POLK-EAST POLK-LEE- WISE-SCOTT-RUSSELL-WASHINGTON- 513 PM EDT MON SEP 17 2012 /413 PM CDT MON SEP 17 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST NORTH CAROLINA...EAST TENNESSEE AND SOUTHWEST VIRGINIA. .DAY ONE...TONIGHT... A FLOOD WATCH IS IN EFFECT FOR MUCH OF THE TENNESSEE VALLEY AND CUMBERLAND PLATEAU FROM THIS AFTERNOON THROUGH TUESDAY MORNING. HEAVY RAINFALL IS EXPECTED...WITH 2 TO 4 INCHES EXPECTED ACROSS THE AREA THROUGH TUESDAY MORNING. LOCAL AMOUNTS UP TO 5 INCHES WILL BE POSSIBLE...MAINLY ALONG THE CUMBERLAND PLATEAU. LOCALIZED FLOODING OF SMALL CREEKS AND STREAMS WILL BE POSSIBLE...AS WELL AS URBAN AREAS. IN ADDITION TO THE LOCALLY HEAVY RAINFALL...SOME SCATTERED STRONG TO SEVERE THUNDERSTORMS WILL CREATE AN ISOLATED TORNADO THREAT...PRIMARILY ACROSS THE SOUTHERN HALF OF THE CUMBERLAND PLATEAU...SOUTHEAST TENNESSEE AND SOUTHWEST NORTH CAROLINA AS A LOW-LEVEL JET RAMPS UP ACROSS THIS AREA LATE THIS AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY... HEAVY RAIN WILL CONTINUE THROUGH TUESDAY MORNING...THEN DIMINISH IN THE AFTERNOON. NO HAZARDOUS WEATHER IS EXPECTED THROUGH THE REMAINDER OF THE PERIOD. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON THROUGH TUESDAY MORNING.
The national radar mosaic for the moment the first event began.
2 flood. Local standard time, as filed.
Water was encroaching upon some homes in Chattanooga and Red Bank. Partial Road closures in East Ridge.
Roads flooded and cars stranded in Knoxville.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2012Every state in 2012This day in weather historyWarnings in Tennessee, September 2012
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 408094, 408103.