A mesoscale convective vortex moved into the Mid-South during the afternoon hours on May 20, 2015. This feature combined with a stalled frontal boundary to produce scattered thunderstorms across West Tennessee and North Mississippi.
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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 MEG wrote it up.
A mesoscale convective vortex moved into the Mid-South during the afternoon hours on May 20, 2015. This feature combined with a stalled frontal boundary to produce scattered thunderstorms across West Tennessee and North Mississippi. A couple of weak tornadoes occurred in West Tennessee and isolated large hail was reported in North Mississippi.
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 Memphis, TN wrote its last area forecast discussion before the first event at May 20, 11:35 AM CST, 2 hours 55 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1235 PM CDT WED MAY 20 2015 .UPDATE... UPDATED FOR THE 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 707 AM CDT WED MAY 20 2015/ DISCUSSION... MAIN FORECAST CHALLENGE TODAY REVOLVES AROUND THUNDERSTORM POTENTIAL...A FEW OF WHICH MAY BECOME STRONG TO SEVERE AS A SURFACE LOW/REMNANT MCV MOVE EAST-NORTHEAST THROUGH THE MID-SOUTH. CURRENTLY...A DIFFUSE FRONTAL BOUNDARY WAS NEARLY STALLED ACROSS CENTRAL MISSISSIPPI...TAILING BACK THROUGH SOUTHERN ARKANSAS. A LOW PRESSURE SYSTEM ASSOCIATED WITH A QUICKLY PROGRESSING SOUTHERN STREAM IMPULSE WAS LOCATED ACROSS EASTERN OKLAHOMA. A LARGE COMPLEX OF SHOWERS AND THUNDERSTORMS WAS ONGOING ALONG THE RED RIVER EAST THROUGH SOUTHEAST OKLAHOMA AND WESTERN ARKANSAS. THIS COMPLEX WILL ULTIMATELY DETERMINE THE MAGNITUDE OF THE SEVERE THREAT LATER TODAY. CURRENT THINKING IS THAT THE STALLED FRONTAL BOUNDARY WILL MOVE QUICKLY NORTH AS THE LOW PRESSURE SYSTEM PROGRESSES EAST NORTHEAST. ONGOING CONVECTION WILL LIKELY AUGMENT ITS TRACK AS AN MCV MAY BE IN THE PROCESS OF DEVELOPING. ON ITS CURRENT TRACK...AREAS JUST NORTH OF I40 AND SOUTH STAND THE BEST CHANCE TO DESTABILIZE THROUGH THE MORNING AND EARLY AFTERNOON AS MID TO UPPER 60S DEWPOINTS ADVECT BACK INTO THE REGION. WHILE WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED...IT APPEARS THAT AT LEAST A SMALL PARAMETER SPACE MAY DEVELOP THAT COULD SUPPORT ISOLATED SEVERE WEATHER. LOW LEVEL HODOGRAPH CURVATURE IS MOST PRONOUNCED NEAR THE LOW CENTER/REMNANT MCV AND WOULD BE MOST SUPPORTIVE OF SEVERE THUNDERSTORMS...BUT WHETHER OR NOT THE AREAS ALONG THE TRACK OF THE LOW CAN DESTABILIZE REMAINS TO BE SEEN. LOW LEVEL WINDS BECOME PROGRESSIVELY MORE VEERED SOUTH OF THE LOW PRESSURE. UNIDIRECTIONAL DEEP LAYER SHEAR PROFILES ARE NOTED ACROSS MUCH OF THE DEEP SOUTH...THEREFORE...IF SUFFICIENT INSTABILITY DEVELOPS...A WIND/HAIL THREAT MAY DEVELOP AS WELL. BEST TIMING FOR STRONG/SEVERE POTENTIAL WOULD BE FROM ROUGHLY NOON TO 5PM. TRENDS WILL BE MONITORED THROUGH THE EARLY MORNING HOURS. TONIGHT...THE FRONTAL BOUNDARY WILL SLOWLY SINK SOUTH WITH SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE THROUGH THE OVERNIGHT ACROSS NORTH MISSISSIPPI. BY THURSDAY...MUCH OF THE MID-SOUTH WILL CLEAR ESPECIALLY TOWARD EVENING. VERY COOL LOW TEMPERATURES ARE EXPECTED THURSDAY NIGHT AS A HIGH PRESSURE SYSTEM SETTLES INTO THE MID SOUTH AND NEAR-IDEAL RADIATIONAL COOLING IS REALIZED...AS LONG AS HIGH CLOUDS DO NOT OVERSPREAD THE REGION. LOWS IN THE LOW TO MID 40S ARE POSSIBLE ACROSS MIDDLE TENNESSEE WITH UPPER 40S TO LOW 50S SOUTH. FRIDAY THROUGH THE WEEKEND...THE UPPER LEVEL PATTERN BEGINS TO AMPLIFY ONCE MORE AS YET ANOTHER WESTERN CONUS TROUGH MOVES ONSHORE. THIS WILL BE A PERSISTENT FEATURE WITH SEVERAL VORT MAXES ROTATING INTO THE CENTRAL PLAINS. A LEE CYCLONE WILL DEVELOP BEGINNING FRIDAY AFTERNOON ACROSS THE WEST CENTRAL PLAINS AND THIS WILL SLOWLY PROGRESS EAST WITH TIME. MULTIPLE COMPLEXES OF SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP ACROSS THE SOUTHERN PLAINS AND MOVE EAST DURING THE OVERNIGHT HOURS WITH THE MID-SOUTH RECEIVING THE DECAYING CONVECTION...VERY SIMILAR TO THE PATTERN OVER THIS PAST WEEKEND. THUNDERSTORM CHANCES BEGIN INCREASING ON SATURDAY AFTERNOON AND WILL REMAIN IN THE FORECAST FOR THE FORESEEABLE FUTURE. LONG-TERM... THE AFOREMENTIONED LONGWAVE TROUGH AND ASSOCIATED LOW PRESSURE WILL BE SLOW TO MOVE EAST AND A FRONTAL BOUNDARY WILL MEANDER SOMEWHERE NEAR THE MID-SOUTH PROVIDING WEAK BUT SUFFICIENT FORCING FOR ASCENT IN AN UNCAPPED ENVIRONMENT THROUGH EARLY NEXT WEEK. THE WET PATTERN LOOKS TO CONTINUE AS MULTIPLE COMPLEXES OF SHOWERS AND THUNDERSTORMS WILL MOST LIKELY AFFECT THE REGION...THE TIMING OF WHICH ARE UNKNOWN AT THIS TIME. THE BOTTOM LINE IS THAT THIS PATTERN FAVORS ABOVE NORMAL PRECIPITATION. TVT && .AVIATION... 18Z TAF CYCLE AN AREA OF SHOWERS AND THUNDERSTORMS IS PUSHING THROUGH WEST TENNESSEE AND NORTHEAST MISSISSIPPI AT THIS TIME AND WILL PRODUCE A PERIOD OF MVFR CEILINGS AND VISIBILITIES. OUTSIDE OF THIS AREA OF RAIN...VFR CONDITIONS WILL CONTINUE FOR MUCH OF THE AFTERNOON. CEILINGS WILL LOWER TONIGHT AND OVERNIGHT TO IFR/LIFR LEVELS BEFORE IMPROVING SOME THURSDAY MORNING. WINDS WILL BE MAINLY FROM THE NORTH AT 5 TO 10 KNOTS FOR MUCH OF THE FORECAST PERIOD. ARS && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MEMPHIS TN 500 AM CDT WED MAY 20 2015 ARZ008-009-017-018-026>028-035-036-048-049-058-MOZ113-115- MSZ001>017-020>024-TNZ001>004-019>022-048>055-088>092-211200- ALCORN-BENTON MS-BENTON TN-CALHOUN-CARROLL-CHESTER-CHICKASAW-CLAY- COAHOMA-CRAIGHEAD-CRITTENDEN-CROCKETT-CROSS-DESOTO-DECATUR- DUNKLIN-DYER-FAYETTE-GIBSON-GREENE-HARDEMAN-HARDIN-HAYWOOD- HENDERSON-HENRY-ITAWAMBA-LAFAYETTE-LAKE-LAUDERDALE-LAWRENCE- LEE AR-LEE MS-MADISON-MARSHALL-MCNAIRY-MISSISSIPPI-MONROE-OBION- PANOLA-PEMISCOT-PHILLIPS-POINSETT-PONTOTOC-PRENTISS-QUITMAN- RANDOLPH-SHELBY-ST. FRANCIS-TALLAHATCHIE-TATE-TIPPAH-TIPTON- TISHOMINGO-TUNICA-UNION-WEAKLEY-YALOBUSHA- 500 AM CDT WED MAY 20 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST ARKANSAS... THE MISSOURI BOOTHEEL...NORTH MISSISSIPPI...AND WEST TENNESSEE. .DAY ONE...TODAY AND TONIGHT WHILE WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED TODAY...A FEW STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE. THIS WOULD PARTICULARLY BE THE CASE IF THE ATMOSPHERE IS ABLE TO BECOME MORE UNSTABLE THAN CURRENTLY FORECAST. STRONG WINDS AND LARGE HAIL WOULD BE THE MAIN THREATS WITH THIS ACTIVITY. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.
The Memphis radar (KNQA), 57 km away, was scanning. The volume nearest the first event began at 20:30 UTC.
2 tornado. Local standard time, as filed.
A weak tornado briefly touched down south-southwest of Brownsville along Shaw Chapel Road. No damage was reported.
A weak tornado produced intermittent damage in the Lost Creek and Willow Oaks areas located to the east of Decaturville near the Tennessee River in East-Central Decatur County. Several trees were uprooted and one home had small clusters of shingles peeled away. Several other homes had damage to trim and flashing. Estimated maximum winds were 75 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2015Every state in 2015This day in weather historyThe tornado archive for Tennessee, 2015Warnings in Tennessee, May 2015
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: 581707, 580911.