Dallas, TX (USA Today/CBS) -- Tornadoes have been violently spinning in the Dallas-Forth Worth area are collapsing roofs, ripping down power lines and tossing trailers around like toys, authorities say.
Weather service advisories issued Tuesday said storm spotters and radar shows separate "large and extremely dangerous" tornadoes south of Dallas and Fort Worth. The National Weather Service reported that as of 2pm CDT, DFW International Airport was in a direct path of a tornado.
The weather service says "considerable damage" has been reported near Cleburne, south of Fort Worth, and Lancaster, south of Dallas. Local television footage shows overturned and smashed semi-trailers on the ground in the southern portion of Dallas County. Dallas Police spokeswoman Sherri Jeffrey says twisters also have caused damage in the city limits.
A tornado watch - meaning that conditions are ripe for tornadoes to continue to form -was in place for 33 counties in north-central and northeastern Texas until 8 p.m. CDT, the National Weather Service reported.
The Dallas-Fort Worth CBS Affiliate has been showing video of one tornado gaining in size and speed as it churns toward the northeast.
Update at 5:13 p.m. ET: At least five people were hurt in Forney when the tornado ripped through a subdivision, according to emergency responders, the Morning News says. Other news outlets say an undetermined number of people were hurt in and around Dallas.
Update at 5:06 p.m. ET: The Dallas Morning News writes: "Early reports are that there were no kids in Crosby Elementary [in Forney] when the tornado hit, ripping off the roof and throwing cars around in the parking lot."
Update at 5:01 p.m. ET: The Dallas Police Department says Love Field has resumed operations.
Update at 4:56 p.m. ET: Crosby Elementary School in Forney and several homes have been heavily damaged, according to unconfirmed reports.
The twister reportedly just missed the high school.
No reports of casualties yet.
Update at 4:40 p.m. ET: A tornado was reported on the ground in Forney, in Kaufman County, norththeast Texas, a minute ago, NTXLW reports.
Update at 4:38 p.m. ET: Arlington police say no serious injuries have been reported in the city, which has suffered some of the worst damage reported so far, the Morning News reports. Police and firefighters continue to search the hardest hit areas.
Update at 4:35 p.m. ET: Here's the Fort Worth Star-Telegram's report, with photos. American Airlines says it has canceled its DFW Airport operations for the remainder of the day.
Update at 4:33 p.m. ET: Another tornado has been confirmed about three miles west of Cumby, moving northeast 25 mph, WFAA say. Cumby is about 15 miles west of Sulphur Springs.
Update at 4:28 p.m. ET: A new tornado is developing about nine miles southwest of Sulphur Springs and is moving northeast at 25 mph, WFAA-TV reports.
Update at 4:26 p.m. ET: Dallas city officials have released an update on storm damage, the Morning News says:
"Dallas Police south central division reports damage at Strawberry and Tioga, west of Bonnie View, in the 4100 block of Stage Coach. Some trucks were damaged at the Schnieder Truck Company, north of I-20 No significant injuries have been reported. 10 to 20 homes have been damaged in the 4100 block of Stage Coach. Trees have been reported down around Skyline High School; a car was thrown into a fence. Love Field has activated the Terminal Evacuation Plan and all passengers and tenants have been evacuated to the first floor and underground, at the request of the FAA. "
Update at 4:19 p.m. ET: WFAA is reporting that "a new rotation is rapidly developing in the storm in southern Dallas County near Wilmer" and that a tornado "could form at any moment."
Update at 4:17 p.m. ET: A spotter has reported a tornado on the ground four miles north of Lone Oak in Hunt County, the Dallas Morning News says.
Update at 4:07 p.m. ET: The National Weather Service has canceled all tornado warning in the immediate Dallas-Fort Worth area, USA TODAY's Doyle Rice reports. Two tornado warnings are still in effect for counties several miles northeast of Dallas.
Update at 4:03 p.m. ET: A tornado has reportedly touched down at Trinity Mills, west of Plano, local TV stations say.
In Arlington, students have returned to storm shelters as another band of violent weather moves through.
Update at 3:51 p.m. ET: At 2:45 pm CT (3:35 p.m. ET), a new tornado warning was issued by the National Weather Service for areas between Fort Worth and Dallas, USA TODAY's Doyle Rice reports. This includes Arlington, Euless, Cockrell Hill, and Irving, Texas.
Update at 3:41 p.m. ET: AccuWeather reports significant damage at Six Flags Amusement Park in Arlington.
Flights heading to Dallas-Fort Worth International Airport are being delayed almost 3 hours.
Update at 3:32 p.m. ET: The twisters flung cars and trucks from roadways, NBC reports.
"There's lots of 18-wheelers," an NBC 5 reporter said from near Arlington. "I've never seen this before."
"There's tremendous damage here," said another NBC 5 reporter, in Lancaster. He said that daycare center was heavily damage but that the children and adults inside appeared safe.
NBC said at least two tornadoes appeared to have touched down south of Dallas.
The storms dropped hail the size of baseballs and golfballs, according to reporters and eyewitnesses.
Update at 3:14 .m. ET: WFAA-TV reports a possible tornado is approaching the south side of the Dallas-Fort Worth Airport at 25 mph.
Update at 3:09 p.m. ET: The National Weather Service reports at least two separate "large and extremely dangerous" tornadoes south of Dallas and Fort Worth. Dallas Police spokeswoman Sherri Jeffrey said an apparent twister touched down and caused damage within the city's southern limits. Officials had no immediate information about injuries.
Local television footage shows a large, dark funnel cloud moving on the ground not far from a major interstate this afternoon. Crumpled orange tractor trailers are visible in a Dallas County parking lot, as well as flattened trailers along the sides of highways and access roads.
Update at 3:07 p.m. ET: Police scanners reports a tornado is heading toward the community of Garland east of Dallas.
Update at 3:02 p.m. ET: Three tornadoes have touched down in the Dallas-Fort Worth area. One was on the ground near Fort Worth, and the other two south and southeast of Dallas.
Update at 3 p.m. ET: A Dallas police scanner reports a tornado on the ground in southeast Dallas, the Pleasant Grove area of the city.
Update at 2:59 p.m. ET: The Weather Channel reports that after these tornadoes pass through the Dallas / Fort Worth area, a line of severe storms will move through with high winds, hail, downpours, and frequent lightning. There is now a ground stop for all flights to DFW and Love airports.
Update at 2:57 p.m. ET: A police scanner reports that a building has collapsed and people are trapped in Arlington, which is located between Dallas and Fort Worth, according to AccuWeather.
Update at 2:56 p.m. ET: The National Weather Services reports that storm spotters and radar shows separate "large and extremely dangerous" tornadoes both south of Dallas and Fort Worth. The weather service says "considerable damage" has been reported near Cleburne, south of Fort Worth, and Lancaster, south of Dallas.
Update at 2:53 p.m. ET: MSNBC reports that sirens have been going off in the Mesquite area, on the eastern edge of Dallas, and that students at Mesquites schools have been ordered to take shelter.
Update at 2:45 p.m. ET: The National Weather Service says the says the tornado south of Fort Worth caused "considerable damage" near the town of Cleburne.
Update at 2:40 p.m. ET: CNN reports that a tornado emergency has been issued for South Dallas County.
Update at 2:38 p.m. ET: Video of the tornado shows tractor trailers being picked up in the air and overturned by the storm.
Update at 2:35 p.m. ET: Reports say a tornado near Lancaster, Texas, south of Dallas, moving north at 25 miles per hour. "This is a dangerous storm. Roof tops from houses are flying in the air."
Update at 2:27 p.m. ET: Reports say two tornadoes on the ground in the Dallas-Fort area. One was seen south of Dallas heading toward the city. The other was spotted in or near Fort Worth.
Update at 2:23 p.m. ET: A tornado on the ground just south of downtown Dallas.
Update at 2: 22 p.m. ET: Reports say a "Code Black" has been issued at Parkland Hospital, which means keeping all patients away from windows.