From May 2 to 8, 1999, a large tornado outbreak took place across much of the Central and parts of the Eastern United States, as well as southern Canada.

On May 2, a strong area of low pressure moved out of the Rocky Mountains and into the High Plains, producing scattered severe weather and ten tornadoes in Nebraska.

Wind profiles across the region strongly favored tornadic activity, with the Storm Prediction Center stating, "it became more obvious something major was looming" by the afternoon hours.

Following the extensive outbreak, activity became increasingly scattered from May 5 to 8, with 26 tornadoes touching down across the Eastern United States and Quebec.

[8] The outbreak was caused by a vigorous upper-level trough that moved into the Central and Southern Plains states on the morning of May 3.

That morning, low stratus clouds overspread much of Oklahoma, with clear skies along and west of a dry line located from Gage to Childress, Texas.

[9] The Storm Prediction Center (SPC) in Norman, Oklahoma, a division of the National Weather Service, initially issued a slight risk of severe thunderstorms early that morning stretching from the Kansas-Nebraska border to parts of southern Texas, with an intended threat of large hail, damaging winds and tornadoes.

[11] By 3:00 p.m. CDT, it had become evident that a widespread severe weather event was imminent; the Storm Prediction Center upgraded locations within the moderate risk area to a high risk of severe weather around 4:00 p.m. CDT as wind shear profiles, combined with volatile atmospheric conditions, had made conditions highly conducive for a significant tornadic event across most of Oklahoma, southern Kansas and north Texas, including the likelihood of violent, damaging tornadoes.

Large supercell thunderstorms developed, and in the late afternoon through the mid-evening hours of that Monday, tornadoes began to break out across the state.

The storm quickly developed supercell characteristics and began exhibiting potentially tornadic rotation, resulting in the National Weather Service issuing the first tornado warning of the event for Comanche, Caddo, and Grady counties approximately 35 minutes later at 4:50 p.m. CDT.

The storm then turned more northerly, striking parts of Del City and Tinker Air Force Base near Sooner Road as an F4.

[17] Late in the evening on May 3 at 9:25 p.m. CDT, a destructive tornado touched down 3 miles (4.8 km) southwest of Cimarron City in Logan County, Oklahoma, eventually hitting the town of Mulhall, located north of Guthrie.

Scattered damage of high-end F0 to low-end F1 intensity occurred to some homes and businesses on the southeast side of Davenport, though a house located just south of town lost more than half of its roof.

As the tornado continued to track northeast, parallel with Interstate 44 and State Highway 66, Stroud took a direct hit as the storm intensified to F2 strength; the trucking terminal of the Sygma food distribution warehouse on the west side of town was destroyed with some girders and siding from the warehouse thrown northwest across State Highway 66, and the Stroud Municipal Hospital suffered significant roof damage, which resulted in significant water damage within the building.

[23] Stroud's recovery was later complicated by the September 11, 2001, terrorist attacks, although the town has since recovered as a result of higher oil and gas prices.

Stroud is also now a downloading facility location for oil produced in the northern United States into the Cushing pipeline network.

A deadly F4 tornado that tracked 24 miles (39 km) across south-central Kansas killed six people in Haysville and Wichita during the late evening of May 3.

[26] On May 3–4, the day after the initial outbreak event, President Bill Clinton signed a federal disaster declaration for eleven Oklahoma counties.

In a press statement by the Federal Emergency Management Agency (FEMA), then-director James Lee Witt stated that "The President is deeply concerned about the tragic loss of life and destruction caused by these devastating storms.