More than 94 million expected to drive or fly [UPDATE] WASHINGTON, Dec. 21 (UPI) -- An unfolding storm has begun to threaten Christmas travel across the middle of the United States, Accuweather.com reported Saturday. More than 94 million were expected to drive or fly during the weekend. Accuweather said a heavy coast of ice has fallen in portions of central Oklahoma to central Missouri, and will spread will spread the Northeast during this weekend. The report said thunderstorms were increasing from eastern Texas to the lower Mississippi Valley, and might produce tornadoes Saturday afternoon and evening. Heavier snow was set to develop later farther north and west of the ice over portions of Kansas, northeastward up into northern Michigan and across central Ontario, the report said. The U.S. midsection may see its last pre-Christmas Saturday of the year washed out by a large and vigorous storm system, weather forecasters said.