An upper level short wave trough with surface cold front moved across the Southern Appalachians during the late evening and early morning hours with sufficient shear but weakening instability to produce isolated severe convection across the Tennessee Valley in Southeast Tennessee.
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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.
An upper level short wave trough with surface cold front moved across the Southern Appalachians during the late evening and early morning hours with sufficient shear but weakening instability to produce isolated severe convection across the Tennessee Valley in Southeast Tennessee.
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 Mar 23, 2:20 PM EST, 1 hour 55 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 320 PM EDT FRI MAR 23 2012 .SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...CURRENT SURFACE ANALYSIS SHOWS AN AREA OF LOW PRESSURE OVER THE MID MS RIVER VALLEY...WITH ITS ASSOCIATED OCCLUDED FRONTAL BOUNDARY EXTENDING SOUTHWARD ACROSS WEST TN AND ALONG THE MS/AL BORDER. A DEEP SOUTHERLY WIND FLOW WAS OCCURRING OVER THE TN RIVER VALLEY AHEAD OF THIS FRONTAL BOUNDARY...WITH AREA RADARS INDICATING MOSTLY SCATTERED CONVECTIVE ACTIVITY OVER THE FORECAST AREA. THE SCATTERED NATURE OF THIS PRECIP APPEARS TO BE DUE MAINLY TO THE COMBINATION OF A CONVECTIVE COMPLEX OVER THE GULF COAST REGION (WHICH IS CUTTING OFF MUCH OF THE MOISTURE FROM THE SOUTH)...AND TO DOWNSLOPING EFFECTS OF THE SOUTHERLY 850 MB WIND FLOW INTO THE GREAT TN VALLEY. AS A RESULT...WILL PLAN TO MENTION SCATTERED CONVECTION ACROSS MOST OF THE FORECAST AREA FOR TONIGHT...WITH CONVECTION AGAIN BECOMING LIKELY BY SATURDAY AFTERNOON AS A DEEP UPPER-LEVEL LOW OVER THE MID MS RIVER VALLEY SLOWLY DRIFTS OVER THE FORECAST AREA. WITH THE FREEZING LEVEL LOWERING WITH THE PASSAGE OF THE UPPER LOW...IT APPEARS THAT SOME SEVERE TSTORMS WITH LARGE HAIL WILL BE POSSIBLE SATURDAY AFTERNOON AND EVENING. AS FOR TEMPS...GFS AND NAM GUIDANCE NUMBERS ARE IN GENERAL AGREEMENT WITH MINS THROUGH SUNDAY NIGHT AND LOOK REASONABLE. HOWEVER...SOME DISCREPANCIES ARE SEEN WITH THE MAXES DUE TO THE DIFFERENCES CLOUD COVER AND PRECIP COVERAGE. FOR NOW...WILL GENERALLY COMPROMISE BETWEEN THE TWO SETS OF GUIDANCE. .LONG TERM (MONDAY THROUGH FRIDAY)...HIGH PRESSURE IN CONTROL EARLY IN THE EXTENDED FOR QUIET WEATHER MONDAY THROUGH WEDNESDAY. MODELS DIFFER BY THE END OF THE PERIOD AND CONFIDENCE LOW ON DETAILS. OVERALL...NEXT SYSTEM BRINGS IN A COLD FRONT WEDNESDAY NIGHT OR THURSDAY AND THEN ANOTHER SYSTEM POSSIBLY BEGINNING TO REACH INTO THE AREA FOR FRIDAY. WILL KEEP HIGHEST POPS WEDNESDAY NIGHT...WHICH CURRENT LOOKS THE BEST TIMING FOR THE INITIAL FRONTAL BOUNDARY. AS FOR TEMPERATURES...GUIDANCE NUMBERS LOOK GOOD AND STAYED CLOSE. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 54 71 51 73 51 / 40 60 30 10 10 KNOXVILLE AIRPORT, TN 54 70 51 71 51 / 50 60 40 30 20 OAK RIDGE, TN 53 70 51 71 51 / 40 60 40 20 10 TRI CITIES AIRPORT, TN 52 70 49 68 49 / 60 70 50 40 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && DMG/MJB
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MORRISTOWN TN 316 AM EDT FRI MAR 23 2012 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-240730- 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- 316 AM EDT FRI MAR 23 2012 /216 AM CDT FRI MAR 23 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST NORTH CAROLINA...EAST TENNESSEE AND SOUTHWEST VIRGINIA. .DAY ONE...TODAY AND TONIGHT... SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE SOUTHERN APPALACHIAN REGION TODAY AND TONIGHT AHEAD OF A COLD FRONT. SOME THUNDERSTORMS MAY BECOME STRONG...BRINGING THE POSSIBILITY OF SMALL HAIL...GUSTY WINDS...AND LOCALLY HEAVY RAINFALL. CONDITIONS DO NOT APPEAR FAVORABLE FOR WIDESPREAD SEVERE STORMS TODAY...ALTHOUGH AN ISOLATED STORM MAY APPROACH SEVERE LIMITS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY... A CHANCE OF THUNDERSTORMS IS EXPECTED TO CONTINUE INTO SATURDAY AS AN UPPER LEVEL LOW PRESSURE SYSTEM BRINGS COLDER TEMPERATURES ALOFT...WHICH MAY ALLOW SOME STORMS TO PRODUCE HAIL. NO HAZARDOUS WEATHER IS EXPECTED ON SUNDAY THROUGH WEDNESDAY...AS DRY WEATHER RETURNS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED TODAY AND SATURDAY.
The Knoxville radar (KMRX), 42 km away, was scanning. The volume nearest the first event began at 21:15 UTC.
3 hail, 1 thunderstorm wind. Local standard time, as filed.
A few trees were reported down approximately one mile east of Bacchus.
Quarter size hail was reported approximately one half mile east of Whitwell.
Quarter size hail was reported five miles southeast of Dayton.
Quarter size hail was reported approximately 15 miles southeast of Ten Mile.
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, March 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: 373566, 373568, 373571, 373572.