From the National Weather Service, Norman Forecast Office:
Hazardous weather outlook
Day one…This afternoon and tonight
Thunderstorms… There is a slight risk of severe thunderstorms late this afternoon through tonight across much of Oklahoma and western north Texas.
Location… The slight risk area is east of a Woodward to Altus to Seymour line. The slight risk area includes Oklahoma City…Wichita Falls… Lawton…Stillwater…Enid…Ponca City…Weatherford…Ada… Ardmore…and Durant.
Timing… The main time frame for the strongest severe storms will be between 4 and 10 pm. The risk of severe storms will continue beyond 10 pm this evening…but these storms will likely not be as strong.
Impacts… Very large hail up to the size of tennis balls or baseballs will be the main hazard. Damaging winds up to 70 mph are possible as well. In addition…a couple of tornadoes may occur.
Discussion… A warm front will likely be positioned near the Kansas, Oklahoma border late this afternoon with a dryline intersecting the front in northwest Oklahoma and extending southward across western Oklahoma and western north Texas.
From 4 pm to 10 pm…A strong cap will hamper thunderstorm development but lift near these boundaries and afternoon heating could be sufficient for a few thunderstorms to develop late this afternoon or early evening. The best chance for storm development will be near the intersection of the dryline and warm front in northwest Oklahoma… but initiation further south along the dryline can not be ruled out. The warm moist airmass across the area will become unstable this afternoon. With this unstable airmass and moderate wind shear… any storms that develop will likely become severe. Very large hail will be the primary concern… but strong damaging wind gusts and a tornado or two can not be ruled out.
After 10 pm tonight…Severe storm chances may continue mainly along and east of I-35 as the mid/upper trough approaches. Although the chance for very large hail and tornadoes will likely decrease…some severe storms producing hail up to the size of half dollars and wind gusts to 60 mph will remain possible.
Thunderstorms… A few strong to severe storms may linger through 4 pm thursday east of I-35. Large hail and damaging winds remain the main hazards.