An outflow boundary from a complex of thunderstorms building across the Mid South interacted with moderate to strongly unstable air across Eastern Tennessee mainly north of interstate 40. The slow moving storms produced mainly wind damage with some hail as well as some flash flooding.
Every event with a place to put it. Tap one for its entry below.
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 outflow boundary from a complex of thunderstorms building across the Mid South interacted with moderate to strongly unstable air across Eastern Tennessee mainly north of interstate 40. The slow moving storms produced mainly wind damage with some hail as well as some flash flooding.
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 May 21, 1:56 PM EST, 1 hour 34 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 256 PM EDT TUE MAY 21 2013 .SHORT TERM (TONIGHT AND WEDNESDAY)...ONGOING CONVECTION ACROSS MIDDLE TN WILL MOVE INTO THE MRX CWA LATE THIS AFTERNOON/EVENING. BEHIND THIS LINE...A FEW SHOWERS/THUNDERSTORMS MAY LINGER ACROSS THE AREA INTO THE OVERNIGHT HOURS...BUT MOST LOCATIONS SHOULD STAY DRY. ANOTHER BAND OF CONVECTION WILL DEVELOP ALONG AN APPROACHING COLD FRONT AND MOVE THROUGH ON WEDNESDAY. THIS WILL SPREAD A LARGE BAND OF THUNDERSTORMS INTO THE AREA AS EARLY AS LATE WEDNESDAY AFTERNOON. WITH THE WARM...MOIST AND WEAK TO MODERATELY UNSTABLE AIR MASS IN PLACE...SOME OF THESE STORMS MAY BECOME STRONG...POSSIBLY SEVERE. .LONG TERM (WEDNESDAY NIGHT THROUGH TUESDAY)...BEST RAIN CHANCES WILL BE WEDNESDAY NIGHT INTO THURSDAY AHEAD OF THE COLD FRONT. MOS POPS TRENDING LIKELY NOW FOR WEDNESDAY NIGHT WITH PREVIOUS GRIDS LOOKING ON TRACK. SHORTWAVE DROPPING SE ACROSS THE OHIO RIVER VALLEY INTO THE CENTRAL APPALACHIANS ON FRIDAY PLUS DAYTIME HEATING...SO WILL CONTINUE THE SLIGHT CHANCE POPS FOR MAINLY SW VA/NE TN AREAS EARLY FRIDAY. SURFACE AND UPPER RIDGE SHOULD PROVIDE DRY WEATHER FOR SATURDAY INTO SUNDAY...ALTHOUGH WARM FRONT AND NW FLOW ALOFT DEVELOPING ON SUNDAY WILL NEED TO BE WATCHED. KEPT SUNDAY DRY LEADING INTO SLIGHT CHANCE POPS BY SUNDAY NIGHT INTO MONDAY. INTRODUCED TUESDAY WITH DIURNAL CONVECTION OVER FAVORED AREAS OF SW VA AND NE TN...ALTHO JUST SLIGHT CHANCE POPS AT THIS TIME. FOR TEMPS...BOTH 21/00Z AND 21/12Z GFSX MOS TEMPS ARE TRENDING COOLER BEHIND THE COLD FRONTAL PASSAGE LATE THURSDAY. NUDGED TEMPS DOWN A BIT FROM PREVIOUS GRIDS...ESPECIALLY MINS UNTIL SOME SOUTHERLY LOW LEVEL FLOW RETURNS BY MONDAY NIGHT. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 66 84 63 81 57 / 20 60 50 30 20 KNOXVILLE AIRPORT, TN 65 84 62 80 56 / 30 60 50 40 30 OAK RIDGE, TN 65 84 62 81 56 / 30 60 50 40 30 TRI CITIES AIRPORT, TN 61 83 61 79 55 / 40 50 50 50 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && MJB/TG
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MORRISTOWN TN 250 PM EDT TUE MAY 21 2013 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-221900- 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- 250 PM EDT TUE MAY 21 2013 /150 PM CDT TUE MAY 21 2013/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST NORTH CAROLINA...EAST TENNESSEE AND SOUTHWEST VIRGINIA. .DAY ONE...THIS AFTERNOON AND TONIGHT... SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE REMAINDER OF THE AFTERNOON ACROSS THE CUMBERLAND PLATEAU...WHILE ISOLATED THUNDERSTORMS MAY DEVELOP ELSEWHERE. THE STORMS ON THE PLATEAU WILL BE MOVING EAST OR NORTHEAST AT AROUND 25 MPH...AND MAY REACH STRONG TO SEVERE LEVELS THROUGH THIS EVENING. THE MAIN CONCERNS ARE DAMAGING DOWNBURST WINDS UP TO 60 MPH AND LARGE HAIL. ALSO...FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL CAN BE EXPECTED. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY... ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE ON WEDNESDAY AND THURSDAY...AS A SLOW MOVING COLD FRONT NEARS THE REGION. NO HAZARDOUS WEATHER IS ANTICIPATED FOR THE REMAINDER OF THE PERIOD. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING...AND LATER THIS WEEK ON WEDNESDAY OR THURSDAY. TG
The Knoxville radar (KMRX), 120 km away, was scanning. The volume nearest the first event began at 20:30 UTC.
13 thunderstorm wind, 5 flash flood, 2 hail. Local standard time, as filed.
A few trees were reported down in the Big South Fork National River and Recreation Area.
A few trees were reported down in Robbins.
Trees and power lines were downed in Happy Valley.
Several trees were reported down across the county.
Several trees were downed across the county with a concentration near Dandridge.
A few trees were reported down across the county.
Two trees were reported down in Maryville.
Twelve trees were reported down in the county.
A few trees were reported down near East Dumplin Valley Road.
Flash flooding around intersection of Earnest McMahon Rd and Pullen Road.
Several trees were reported down across the county.
Several trees were reported down across the county.
Quarter size hail was reported in Bluff City.
Cars stranded on Black Oak Ridge Road near southwest end of Douglas Lake.
Quarter size hail was reported in Bluff City.
Several trees were reported down across the county.
Many trees were reported down across the county.
Roads washed out by flash flooding.
Ritter Town Road and Browns Branch Road impacted by water and debris. Some homes with water in basements. A few evacuations occurred. Car stranded in water.
Widespread flash flooding over the northern portion of the county from Erwin northward. Numerous road closures. Water intrusion into a dozen homes and several businesses. Roads undercut. Two evacuations.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2013Every state in 2013This day in weather historyWarnings in Tennessee, May 2013
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: 446355, 446356, 446357, 446358, 446359, 446360, 446361, 446362, 446363, 455222, 446364, 446365, 446366, 455225, 446367, 446368, 446369, 455228, 455236, 455239.