A strong upper level trough across the southern Great Basin ejected out into the Southern Plains during the day on May 21st. Strong convection developed during peak heating across the region and this convection was aided by moderate to strong instability, excessive deep layer shear and mid level lapse rates.
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 SHV wrote it up.
A strong upper level trough across the southern Great Basin ejected out into the Southern Plains during the day on May 21st. Strong convection developed during peak heating across the region and this convection was aided by moderate to strong instability, excessive deep layer shear and mid level lapse rates. Add a frontal boundary to the mix and severe thunderstorms became widespread, some of which produced large hail and damaging thunderstorm wind gusts.
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 Shreveport, LA wrote its last area forecast discussion before the first event at May 21, 3:27 PM CST, 2 hours 21 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 427 PM CDT TUE MAY 21 2013 .DISCUSSION... TORNADO WATCH CONTINUES IN EFFECT UNTIL 10 PM CDT. A VERY MOIST AND UNSTABLE AIR MASS REMAINED OVER MUCH OF THE FOUR STATE REGION THIS AFTERNOON WITH SCATTERED SHOWERS AND THUNDERSTORMS OVER NORTHEAST TEXAS INTO SOUTHWEST ARKANSAS AND IN SOUTHEAST OKLAHOMA. THESE THUNDERSTORMS WERE ALONG A SURFACE TROUGH OF LOW PRESSURE EXTENDING EAST FROM SURFACE LOW PRESSURE OVER NORTH TEXAS. APPROACHING TO THE WEST IS ANOTHER BAND OF SHOWERS AND THUNDERSTORMS OUT AHEAD OF AN UPPER TROUGH OF LOW PRESSURE DROPPING SOUTHWEST ACROSS THE CENTRAL AND SOUTHERN PLAINS AND INTO THE BIG BEND AREA OF WEST TEXAS. THESE STORMS WERE ALONG A SURFACE BOUNDARY THAT WAS NEARLY STATIONARY FROM NORTHEAST OKLAHOMA INTO NORTHWEST TEXAS AROUND THE SURFACE LOW AND SOUTH ALONG THE COLD FRONT FROM NORTHWEST TEXAS INTO THE DRY LINE INTERSECTION NORTH OF BIG BEND. AS THE UPPER TROUGH OF LOW PRESSURE SWINGS EAST DURING THE LATE AFTERNOON AND OVERNIGHT...ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP EAST OVER THE FOUR STATE REGION. SOME OF THE THUNDERSTORMS WILL BE STRONG TO SEVERE PRODUCING LARGE HAIL...HIGH AND DAMAGING WINDS... DEADLY LIGHTNING...LOCALLY HEAVY RAINFALL...AND ISOLATED TORNADOES. RAINFALL AMOUNTS WILL RANGE FROM NEAR ONE TO TWO INCHES WITH HIGHER AMOUNTS AS STORMS TRAIN OVER SOME OF THE SAME LOCATIONS. BY EARLY WEDNESDAY MORNING NEAR 7 AM CDT THE COLD FRONT WILL EXTEND FROM NEAR A HOT SPRINGS ARKANSAS TO SHREVEPORT LOUISIANA AND LUFKIN TEXAS LINE. THE UPPER TROUGH AXIS WILL BE DROPPING SOUTH INTO THE FOUR STATE REGION WITH STORMS DECREASING FROM NORTHWEST TO SOUTHEAST AS UPPER SUPPORT AND THE FRONTAL SYSTEM CONTINUE OFF TO THE EAST. THE SURFACE BOUNDARY WILL BECOME NEARLY STATIONARY KEEPING RAIN CHANCES IN FOR SOUTHERN SECTIONS. AN UPPER RIDGE AMPLIFIES NORTH ACROSS TEXAS AND INTO THE CENTRAL AND NORTHERN SECTIONS OF THE COUNTRY FOR LATE WEEK KEEPING A NORTHWEST FLOW PATTERN OVER THE FOUR STATE REGION WITH THE UPPER TROUGH DROPPING SOUTH FROM THE GREAT LAKES SOUTH INTO THE SOUTHEAST STATES. WILL KEEP LOW END POPS IN UNDER THE INFLUENCE OF THE UPPER RIDGE FOR THE LATE PART OF THE EXTENDED. /06/ && .AVIATION... FIRST ROUND OF CONVECTION IS RAPIDLY DEVELOPING ALONG THE I-30 CORRIDOR. ADDITIONAL DEVELOPMENT BACK TO THE WSW IS LIKELY THIS AFTERNOON. THIS ACTIVITY IS EXPECTED EVENTUALLY TO CONGEAL INTO A SINGLE COMPLEX AND WILL GENERALLY REMAIN NORTH OF I-20. A SECOND CONVECTIVE COMPLEX HAS DEVELOPED ACROSS ERN OK SWD TOWARDS THE DFW METROPLEX AHEAD OF A COLD FRONT. THE COMPLEX WILL EVENTUALLY AFFECT MOST OF THE TAF SITES AND SHOULD BE CLOSE TO A KLFK-KASL-MAGNOLIA AR LINE AROUND THE START OF THE 00Z TAF PERIOD. EXPECT DETERIORATING FLIGHT CONDITIONS IN THE VICINITY OF ANY CONVECTION. MVFR OR LOWER CONDITIONS WILL BE LIKELY. VERY HEAVY RAINFALL...DAMAGING WINDS...LARGE HAIL...AND ISOLATED TORNADOES WILL BE POSSIBLE THROUGH THE EVENING. THE COLD FRONT MAY SLOW DOWN AND THE SECOND LINE OF CONVECTION MAY BEGIN TO OUTRUN IT. THIS MAY ALLOW FOR SOME SCATTERED REDEVELOPMENT ALONG THE FRONT THROUGH THE OVERNIGHT AND EARLY MORNING HOURS. COLD FRONT SHOULD BEGIN TO ENTER THE WRN FRINGES OF THE AREA AFTER 22/06Z. WINDS SHOULD SHIFT TO THE NW AFTER THE FRONT PASSES. PRECIP SHOULD SHOULD GRADUALLY END FROM NW TO SE DURING THE DAYTIME HOURS OF WEDNESDAY. /09/ && .PRELIMINARY POINT TEMPS/POPS... SHV 69 86 65 91 69 / 80 30 10 10 10 MLU 69 86 63 90 66 / 80 60 10 20 20 DEQ 58 83 57 88 62 / 80 10 10 20 20 TXK 65 86 60 88 65 / 80 10 10 10 10 ELD 65 84 59 89 63 / 80 30 10 20 20 TYR 65 87 65 89 70 / 80 10 10 10 10 GGG 65 86 65 90 69 / 80 20 10 10 10 LFK 69 89 68 91 69 / 80 30 10 10 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && 06/09
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SHREVEPORT LA 1245 PM CDT TUE MAY 21 2013 ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077-TXZ096- 097-108>112-124>126-136>138-149>153-165>167-221100- ANGELINA-BIENVILLE-BOSSIER-BOWIE-CADDO-CALDWELL-CAMP-CASS-CHEROKEE- CLAIBORNE-COLUMBIA-DE SOTO-FRANKLIN-GRANT-GREGG-HARRISON-HEMPSTEAD- HOWARD-JACKSON-LA SALLE-LAFAYETTE-LINCOLN-LITTLE RIVER-MARION- MCCURTAIN-MILLER-MORRIS-NACOGDOCHES-NATCHITOCHES-NEVADA-OUACHITA- PANOLA-RED RIVER LA-RED RIVER TX-RUSK-SABINE LA-SABINE TX- SAN AUGUSTINE-SEVIER-SHELBY-SMITH-TITUS-UNION AR-UNION LA-UPSHUR- WEBSTER-WINN-WOOD- 1245 PM CDT TUE MAY 21 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL AND SOUTHWEST ARKANSAS...NORTH CENTRAL AND NORTHWEST LOUISIANA...SOUTHEAST OKLAHOMA...AND EAST AND NORTHEAST TEXAS. .DAY ONE...THIS AFTERNOON AND TONIGHT... THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS TODAY ACROSS MUCH OF EAST TEXAS...SOUTHEAST OKLAHOMA...SOUTHWEST ARKANSAS...AND NORTHWEST LOUISIANA AND PARTS OF NORTH CENTRAL LOUISIANA. AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL SHIFT EAST ACROSS THE SOUTHERN PLAINS THIS AFTERNOON AND OVERNIGHT...AND INTERACT WITH STRONG INSTABILITY...VARIOUS CONVECTIVE BOUNDARIES LEFT IN PLACE FROM SHOWERS AND THUNDERSTORMS EARLIER MONDAY NIGHT AND EARLY TUESDAY MORNING...AND A MOIST ATMOSPHERE. ONGOING SHOWERS AND THUNDERSTORMS OVER SOUTHEAST OKLAHOMA INTO SOUTHWEST ARKANSAS AND EXTREME NORTHEAST TEXAS WILL EXPAND AND DEVELOP OVER REMAINING PARTS OF THE FOUR STATE REGION. WINDS FEEDING INTO THE AREA WILL BE TURNING WITH HEIGHT PROVIDING WIND SHEAR WHICH WILL HELP WITH UPDRAFT ROTATION...SUCH THAT SOME OF THESE STORMS WILL BECOME SEVERE...CAPABLE OF PRODUCING DAMAGING WINDS...LARGE HAIL... AND ISOLATED TORNADOES. THESE STORMS WILL ALSO PRODUCE LOCALLY HEAVY RAINFALL AT TIMES...GIVEN THE AMOUNT OF MOISTURE PROVIDED BY THE GULF OF MEXICO...THAT CAN PRODUCE FROM ONE TO THREE INCHES OF RAIN ACROSS NORTHEAST TEXAS...SOUTHEAST OKLAHOMA... SOUTHWEST ARKANSAS AND NORTHWEST LOUISIANA. THESE STORMS SHOULD CONSOLIDATE INTO A LARGE THUNDERSTORM COMPLEX TONIGHT AS IT PROPAGATES EAST SOUTHEAST ACROSS SOUTHWEST ARKANSAS AND NORTH LOUISIANA...WHERE STRONG DAMAGING STRAIGHT LINE WINDS WILL BE POSSIBLE. SHOWERS AND THUNDERSTORMS SHOULD WEAKEN LATE TONIGHT AND EARLY WEDNESDAY MORNING NORTH CENTRAL LOUISIANA AS INSTABILITY GRADUALLY DIMINISHES. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY... SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING WEDNESDAY MORNING ACROSS NORTH CENTRAL LOUISIANA AND PORTIONS OF DEEP EAST TEXAS...BUT SHOULD DIMINISH FROM WEST TO EAST BY LATE MORNING WITH THE DEPARTURE OF THE UPPER TROUGH. ISOLATED SHOWERS AND THUNDERSTORMS MAY REDEVELOP WEDNESDAY AFTERNOON MAINLY SOUTH OF INTERSTATE 20 OVER EAST TEXAS AND NORTH LOUISIANA...WHERE A WEAK SURFACE BOUNDARY BECOMES STATIONARY. THESE STORMS SHOULD DIMINISH WEDNESDAY EVENING WITH THE LOSS OF HEATING. .SPOTTER INFORMATION STATEMENT... ACTIVATION OF EMERGENCY MANAGERS...SKYWARN NETWORKS...AND AMATEUR RADIO PERSONNEL...WILL BE REQUIRED THIS AFTERNOON AND TONIGHT. 06
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
559 PM CDT TUE MAY 21 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0545 PM TSTM WND DMG NESBITT 32.59N 94.45W
05/21/2013 HARRISON TX EMERGENCY MNGR
MULTIPLE TREES DOWN ON HWY 154 NEAR NESBITT
&&
EVENT NUMBER SHV1300164
19PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
604 PM CDT TUE MAY 21 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0530 PM TSTM WND DMG LONGVIEW 32.52N 94.76W
05/21/2013 GREGG TX TRAINED SPOTTER
POWER LINES DOWN ON EASTMAN ROAD AND HAWKINS PKWY
&&
EVENT NUMBER SHV1300165
19PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
612 PM CDT TUE MAY 21 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0610 PM TSTM WND DMG TYLER 32.33N 95.30W
05/21/2013 SMITH TX LAW ENFORCEMENT
TREES DOWN THROUGHOUT THE COUNTY
&&
EVENT NUMBER SHV1300166
19PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
642 PM CDT TUE MAY 21 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0630 PM TSTM WND DMG HALLSVILLE 32.50N 94.58W
05/21/2013 HARRISON TX LAW ENFORCEMENT
TREES DOWN IN HALLSVILLE
&&
EVENT NUMBER SHV1300167
19PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
645 PM CDT TUE MAY 21 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM TSTM WND DMG LONGVIEW 32.52N 94.76W
05/21/2013 GREGG TX LAW ENFORCEMENT
MULTIPLE TREES DOWN ACROSS THE COUNTY
&&
EVENT NUMBER SHV1300168
19PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SHREVEPORT LA
648 PM CDT TUE MAY 21 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0615 PM TSTM WND DMG LEWISVILLE 33.36N 93.58W
05/21/2013 LAFAYETTE AR LAW ENFORCEMENT
TREES DOWN IN LEWISVILLE
&&
EVENT NUMBER SHV1300169
19The Shreveport radar (KSHV), 53 km away, was scanning. The volume nearest the first event began at 23:48 UTC.
21 thunderstorm wind. Local standard time, as filed.
Several trees were downed in Plain Dealing, Louisiana.
Trees were downed on Crabapple Drive in south Shreveport.
Trees were downed in Grand Cane, Louisiana.
Trees were downed across the entire parish.
Trees were downed in Taylortown, Louisiana along Hwy. 71.
A utility pole was snapped in half in the Beaver Creek Subdivision.
A tree was on a home in Green Terrace in Southwest Shreveport.
Another tree was reported to be downed near Crabapple in Southern Hills portion of south Shreveport.
Trees were downed in Converse, Louisiana.
Trees were downed in Gibsland, Louisiana.
Several trees were downed throughout the entire parish.
Trees were downed northeast of Campti, Louisiana.
A utility pole was snapped northeast of Zwolle, Louisiana.
Trees were downed throughout the entire parish.
Trees were downed in Athens, Louisiana.
A tree was downed on a home in Dodson, Louisiana. There were no reports of injuries.
Numerous trees were downed throughout the entire parish.
Numerous trees were downed throughout the entire parish.
Trees and powerlines were downed throughout the entire parish.
Trees were downed throughout the entire parish.
A large tree was downed in Pollock, Louisiana.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Louisiana in 2013Every state in 2013This day in weather historyWarnings in Louisiana, 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: 444033, 444036, 444042, 444044, 444045, 444046, 444048, 444269, 444271, 444272, 444273, 444275, 444276, 444277, 444284, 444278, 444279, 444280, 444281, 444282, 444283.