The system was accompanied by strong winds in the middle and high levels of the atmosphere along with cold upper air temperatures.

With these elements coming together with moisture moving north from the Gulf of Mexico, it resulted in conditions favorable for severe weather.

[6] A moderate risk of severe weather was issued for that day by the Storm Prediction Center as a result across eastern Oklahoma and neighboring parts of Arkansas, Kansas, Missouri and Texas.

[13][14] Of those deaths, five were confirmed to have been from straight-line winds and two were as a result of a weak tornado embedded in an overnight squall line that tracked across the state.

[18] The next day, a moderate risk of severe weather was issued for April 16 for the Carolinas and southern Virginia as the cold front tracked eastward and a mesolow developed across the Appalachians.

As storms began moving into areas of strong atmospheric instability, a PDS Tornado Watch was issued shortly after noon and a high risk, the first of 2011, was issued shortly thereafter at 12:30 pm EDT (1630 UTC) for central and eastern North Carolina and immediate adjacent areas in South Carolina and Virginia.

The Burlington area storm would mature into the first of multiple long-tracked, multi-tornado tornadic supercells, producing additional tornadoes near Roxboro and South Hill, Virginia.

Soon afterwards, two additional tornado emergencies were issued farther south and east, as radar images of the developing supercells indicated very prominent hook echoes.

Of the larger cities in eastern North Carolina, Fayetteville, Jacksonville, and Wilson all endured direct hits from EF2 or EF3 tornadoes.

Diesel backup power was restored after a brief outage and the shutdown and cooling of the plant proceeded as designed with no physical damage to the reactors or release of radiation.

This strong long-tracked EF3 wedge tornado first touched down southeast of Philadelphia, Mississippi, in Neshoba County at 12:53 p.m. CDT (17:53 UTC).

In the area of County Road 450, the tornado downed numerous trees, including many pine, before it pushed a mobile home over and damaged the roof of a house.

Crossing MS 491, the tornado began to intensify, destroying a large portion of two chicken houses and causing extensive tree damage.

[25] The tornado weakened a little but continued to cause extensive tree damage and downed power lines and poles as it moved east-northeast toward De Kalb, Mississippi.

Here, the tornado reached its maximum width at 3⁄4 mile (1.2 km), before weakening and narrowing a little and crossing Mississippi Highway 16 again, just west of Scooba.

A large warehouse building was completely destroyed, three homes sustained roof damage, and a pickup truck was thrown a considerable distance.

East of town, thousands of trees were either snapped or uprooted before the tornado lifted at the Tombigbee River just prior to crossing into Greene County at 2:05 p.m. CDT (19:05 UTC).

[26][27] At 2:53 p.m. EDT (18:53 UTC) on April 16, a moderately large and very intense tornado developed around Sanford, North Carolina, in Lee County.

[29] As the storm continued into southwestern Wake County, a tornado emergency was issued for areas downstream, including the city of Raleigh.

In addition, debris tossed by the tornado was picked up by radar and pieces of destroyed homes were reported to have fallen in the adjacent towns of Apex and Cary.

The tornado continued to track northeast, in the direction of downtown Raleigh; by this time a very sharply defined hook echo was visible on local radar.

Many local thoroughfares and neighborhoods were rendered impassable due to building debris, tree damage, and downed power lines.

Live WRAL camera footage showed [31] a rain-wrapped tornado approach the city from the southwest and cross I-40 at South Saunders Street, accompanied by power flashes and flying debris.

[29][35][36][37] Another intense tornado formed at 3:33 p.m. EDT (19:33 UTC) in the Wayside community in Hoke County, 6 miles (9.7 km) northeast of Raeford.

[38] Several houses were then destroyed between Spring Lake and Linden, as the storm grew into a large wedge tornado reported by motorists along the Interstate 95 corridor in Harnett County.

The storm, consistently generating EF2 damage, then tracked along the interstate through Dunn and just south of Benson, where television footage revealed a broad, multiple-vortex tornado structure.

[38] At around 6:55 p.m. EDT (22:55 UTC) on April 16, a strong tornado touched down one mile south of Askewville, North Carolina.

The tornado destroyed seven mobile homes at Jake's Trailer Park, located off of Askewville Road, injuring two people.

[48] A late-season blizzard with high winds and moderate to heavy snow—up to 16 inches (40 cm)—occurred on the back side of the main low pressure area, particularly across western Kansas and Nebraska and parts of South Dakota.

[49][50] Heavy snow and isolated freezing rain was also reported across parts of the Upper Midwest, particularly in Minnesota and western Wisconsin.