By Jose Serrano (staff@latinospost.com) | First Posted: May 07, 2015 08:37 PM EDT

Oklahoma Gov. Mary Fallin issued an emergency declaration for 12 counties Thursday after tornadoes and severe thunderstorms ravaged the region overnight.

Authorities reported 12 injuries - five people in critical condition - and one death; an unidentified 42-year-old woman who drowned in her underground shelter. A number of south Oklahoma City residents were treated for tornado-related injuries when a motel and trailer park were upended Wednesday night.

Threats of repeated tornadoes near the state capital forced the evacuation of Will Rogers World Airport around 7 p.m. The three-hour-long delay affected two terminals that had already suffered water damage as a result of flash floods.

Officials in Oklahoma City issued first-ever flash flood warnings after seven-plus inches had already fallen. Some of the warnings will remain in effect into the weekend.

As of Thursday morning, The National Weather Service had reports of at least 50 tornadoes ranging throughout the Great Plains. Heavy rain pounded Kansas and Nebraska, pushing rivers and creeks over their banks.

Texas had its own share of flooding problems. Northern parts of the Lone Star State saw as much as three inches per hour of rain. Winds reached 80 mph in the small city of Woodson where rooftops and porches sustained significant damage. Some areas reported baseball-sized hail drop.

Tornado threats will continue into Mother's Day. Three severe thunderstorms will stretch out as far as Colorado working their way east. The hail that smothered northern Colorado Springs and shut down parts of Interstate 25 Thursday will give way to a mix of rain and snow through the weekend.

Des Moines and Dallas-Ft. Worth areas are especially vulnerable to oncoming winds and possible tornadoes. The brunt of the storm will have moved into the Midwest by Sunday afternoon.

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