Severe thunderstorms…including the possibility of very large hail and damaging wind gusts… will be possible through the evening hours in portions of western North Texas and southern Oklahoma. Though unlikely… isolated tornadoes will be possible. At 830 PM…a nearly stationary frontal boundary stretched approximately from Atoka to Madill… then southwest into Texas. Thunderstorms had developed ahead of the cold front in north central Texas into southern Oklahoma. Through 930 PM… thunderstorms carrying a threat of heavy rain…frequent lightning…and isolated large hail will affect portions of south central Oklahoma southeast of a line from Waurika to Pauls Valley and Holdenville. Another rapidly developing storm will affect portions of southern Clay County Texas south of Henrietta. Focused lift along the front… combined with large scale lift from an approaching storm system… should continue to yield isolated to scattered severe thunderstorms this evening. Through midnight…temperatures south of the front will mostly be in the upper 60s to lower 70s…while temperatures north of the front will fall into the 50s and lower 60s. A northeast wind at 10 to 15 mph with gusts to 20 mph will affect locations northwest of the front…while in southeast Oklahoma near the frontal zone winds will be light. Locations east and south of Durant may remain south of the front through midnight…but all other locations in western North Texas… western and central Oklahoma should be north of the front this evening.