[5] Entering 2013, the Oceanic Niño Index (ONI) for the three-month period lasting from November 2012 to January 2013 based on sea surface temperature (SST) anomalies was -0.3, denoting cooler than normal SSTs in areas of the Pacific.

[7] In late-January, an unusually strong upper-level trough combined with atmospheric instability produced a widespread tornado outbreak over the Southern United States.

Both March and April had near-record low activity, which was attributed to cold air persisting over much of the continental U.S., preventing any significant severe weather from occurring (and allowing for late-season winter storms).

As an intense upper-level trough moved across the interior United States, an extremely warm air mass spread eastward ahead of the storm, resulting in slight atmospheric instability in the Tennessee and Ohio River valleys.

[9] With increased instability in the region, a quasi-linear convective system (QLCS) formed and moved across the area ahead of the cold front, producing numerous tornadoes and wind-related damage.

The high-end EF3 killed one person in Adairsville, ending a record 220‑day streak without a tornado-related fatality in the United States, with the last death occurring due to an EF2 tornado associated with Tropical Storm Debby in Florida in June 2012.

The SPC issued a slight risk zone for areas of Texas, Arkansas, and Louisiana by 1300 UTC on February 18, mentioning the possibility of organized storm activity including bow echoes and supercells.

[24][28]As a powerful trough moved into the Rocky Mountains, return flow from the Gulf of Mexico provided ample moisture for the development of severe thunderstorms.

[60] On the afternoon of May 20, a large, violent tornado touched down west of Newcastle, Oklahoma and impacted the town of Moore, causing severe damage to residential areas as well as Plaza Towers and Briarwood Elementary schools.

For the first time since April 14, 2012, a high risk of severe weather was issued for parts of the Midwest for June 12, with widespread damaging winds being the main threat.

[83] Widespread damaging winds and some tornado activity continued the next day across Kansas, Indiana, the Ohio Valley, and the Northeastern United States, with none stronger than EF1 in intensity.

[84]A low pressure system produced several tornadoes across northeastern Nebraska, western Iowa, and extreme southeastern South Dakota.

[93] Another EF4 tornado tracked across parts of Washington County, Illinois, where it completely destroyed a farm house, killing two people inside, and caused damage to several structures in New Minden.

In addition to the tornado, the parent supercell thunderstorm produced extensive straight-line wind damage from multiple microbursts, which occurred in the rough terrain surrounding Châtillon-sur-Seine.

As the storm moved over Étrochey, the tornado reached F3 strength and destroyed a stone barn, debarked and defoliated trees, broke concrete electrical poles, and tossed a heavy gate several hundred meters.

The first tornado of the event began as a waterspout before coming ashore in Sanremo, sweeping away gazebos, downing many trees, and scattering beach furniture in all directions.

Later that day, the most significant tornado of the outbreak touched down to the northeast of Milan, striking Grezzago and Trezzo sull'Adda, and producing major damage in an industrial area.

Both Prime minister Sheikh Hasina and opposition leader Khaleda Zia visited the impacted areas to meet the affected people and distribute relief.

[119]Due to atmospheric instability associated with Severe Tropical Storm Toraji as it made landfall in Japan in early September, a number of F0 and F1 tornadoes occurred.

The first tornado struck the coastal town of Bargara, east of the city of Bundaberg, at 1 pm on January 26, injuring 17 people and damaging 150 properties.

[140]During the afternoon an evening of March 21, severe supercell thunderstorms spawned a small but damaging outbreak of seven tornadoes in northeastern Victoria, a couple of which were strong to violent.

Continuing along an east-southeasterly path, the large stovepipe tornado intensified as it passed near Cobram, where trees were denuded and partially debarked, and vehicles and pieces of farm machinery were thrown and mangled.

The tornado displayed a multiple-vortex structure in this area and numerous large trees sustained severe debarking, while a small hut was swept clean from its foundation, and some ground scouring was observed.

Past the caravan park, the tornado continued toward Bundalong and weakened slightly, though remained strong as a well-built brick home sustained total roof and exterior wall loss.

Maintaining its strength, the tornado then impacted the Bundalong area and significantly damaged multiple homes, some of which also sustained roof and exterior wall loss.

The final tornado of the day was an EF1 that struck the downtown area of Rutherglen, where windows were broken, awnings were ripped off, and one business sustained total collapse of a masonry exterior wall.

Several roofs were torn off homes in residential areas, and the whole town was left without electricity due to power line damage, however there were no major injuries reported.

[149] The city of Taquarituba, in the state of São Paulo, was partially destroyed by a significant tornado which damaged approximately 200 houses; 2 people died and 64 were injured.

A tornado struck the western Victorian town of Ararat at 7:30 pm local time, causing significant damage to residential and commercial structures.

[160] The damage assessment conducted by the Bureau of Meteorology was unable to completely map tornado paths because, access was limited by the terrain and time was a factor.