Orographics and a slightly to moderately unstable atmosphere appeared to play a role in severe thunderstorms that formed on the Cumberland Plateau across Southeast Tennessee as well as in the communities of Oak Ridge and Knoxville.
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.
Orographics and a slightly to moderately unstable atmosphere appeared to play a role in severe thunderstorms that formed on the Cumberland Plateau across Southeast Tennessee as well as in the communities of Oak Ridge and Knoxville.
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 18, 7:23 PM CST, 3 hours 49 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MORRISTOWN TN 923 PM EDT SAT MAY 18 2013 .DISCUSSION... VERY MINOR TWEAKS MADE TO THE FORECAST TONIGHT AS EVERYTHING APPEARS TO BE ON TRACK. A WEAKENING AREA OF LOW PRESSURE WILL CONTINUE TO TRACK ACROSS THE FORECAST AREA TONIGHT...BRINGING GOOD OPPORTUNITIES FOR SCATTERED SHOWERS AND PERHAPS AN ISOLATED RUMBLE OF THUNDER THROUGH LATE EVENING. GIVEN THE HIGH LOW-LEVEL MOISTURE CONTENT...A LOCALLY HEAVY BURST OF RAINFALL WILL BE POSSIBLE UNDER THE STRONGEST SHOWERS. SOME LOW-CLOUD DEVELOPMENT IS ALSO EXPECTED LATER TONIGHT...ALONG WITH SOME LOCALIZED POCKETS OF FOG IN THE USUAL FOG-PRONE SHELTERED AREAS. OVERNIGHT LOWS WILL GENERALLY REMAIN IN THE 60S IN MOST VALLEY LOCATIONS OVERNIGHT GIVEN THE DENSE CLOUD COVER/PRECIPITATION. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 65 83 65 88 67 / 60 60 30 20 10 KNOXVILLE MCGHEE TYSON AIRPORT, TN 64 82 64 87 66 / 60 60 40 20 10 OAK RIDGE, TN 65 82 65 87 67 / 60 60 30 20 10 TRI CITIES AIRPORT, TN 59 80 59 85 61 / 70 70 40 30 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && AMP
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE MORRISTOWN TN 1025 AM EDT SAT MAY 18 2013 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-191000- 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- 1025 AM EDT (925 AM CDT) SAT MAY 18 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST TENNESSEE...SOUTHWEST VIRGINIA...AND EXTREME SOUTHWEST NORTH CAROLINA. .DAY ONE...TODAY AND TONIGHT... AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SLOWLY DRIFT EASTWARD ACROSS THE TENNESSEE RIVER VALLEY THIS AFTERNOON AND EVENING...TRIGGERING SCATTERED SHOWERS AND THUNDERSTORMS. A FEW ISOLATED STORMS MAY BECOME STRONG TO SEVERE...BRINGING THE POSSIBILITY OF DAMAGING WINDS...LARGE HAIL...AND LOCALLY HEAVY RAINFALL. IN ADDITION... OCCASIONAL CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE WITH THE STRONGER STORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY... ISOLATED STRONG TO SEVERE STORMS WILL AGAIN BE POSSIBLE ON SUNDAY... AND THEN LATER IN THE WEEK ON WEDNESDAY AND THURSDAY AS A SLOW MOVING COLD FRONT NEARS THE REGION. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED DUE TO THE ISOLATED NATURE OF THE EXPECTED SEVERE THREAT. DMG
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MORRISTOWN TN 1137 PM EDT SAT MAY 18 2013 TNZ082-083-190400- BLEDSOE TN-RHEA TN- 1137 PM EDT SAT MAY 18 2013 ...SIGNIFICANT WEATHER ADVISORY FOR BLEDSOE AND RHEA COUNTIES UNTIL MIDNIGHT EDT/1100 PM CDT/... AT 1034 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 6 MILES NORTHWEST OF DAYTON...MOVING SOUTHEAST AT 20 MPH. SMALL HAIL AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS STORM. LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...DAYTON... EVENSVILLE...GRAYSVILLE AND OLD WASHINGTON. LOCALLY HEAVY RAINS...IN EXCESS OF ONE INCH PER HOUR...MAY OCCUR WITH THESE THUNDERSTORMS. MOTORISTS SHOULD BE ALERT FOR PONDING OF WATER ON ROADWAYS...AND POSSIBLE MINOR FLOODING OF LOW LYING AREAS. DO NOT DRIVE THROUGH WATERS OF UNKNOWN DEPTH. TURN AROUND! DON'T DROWN! 17
The Northeast Alabama radar (KHTX), 113 km away, was scanning. The volume nearest the first event began at 05:10 UTC.
5 thunderstorm wind, 4 flash flood, 4 hail, 1 heavy rain. Local standard time, as filed.
Law Enforcement reported a mud slide and roadway flooding just east of Pikeville.
County Road 302 closed due to flooding.
Several trees were reported down across the county.
Several trees were reported down with damage to a few campers.
Extensive flooding over the northern half of the county.
A wind gust of almost 70 mph was measured on the west side of Oak Ridge.
Quarter size hail was reported seven miles southwest of Knoxville.
Half dollar size hail was reported at the Bearden community in Knoxville.
Several trees were reported down on roadways in various parts of the county.
Quarter size hail was reported along Kingston Pike near Gallaher View Road in West Knoxville.
Several trees were reported down and half dollar size hail occurred in Oak Ridge.
Several roads closed or impassable across the county.
Significant flooding of a church and a local corner market on Dayton Mountain Hwy. Debris from church rushed downstream. TV media covered.
Several trees were reported down in Jasper.
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: 455162, 455165, 446340, 446341, 455197, 446343, 446344, 446346, 446347, 446348, 446349, 455199, 455250, 446350.