Outflow from Keystone Dam reached the highest level in 24 years Monday after recent heavy rains drenched the Arkansas River drainage basin northwest of Tulsa. MIKE SIMONS/Tulsa World Just as swollen lakes and rivers in northeast Oklahoma begin to fall, forecasters at the National Weather Service Storm Prediction Center have their eyes set to several consecutive days, beginning Friday, with severe storm potential. The pattern is forecast to begin Friday and persist throughout the weekend. The preliminary outlook, as of Wednesday morning, puts the risk of severe weather, including large hail and tornadoes, west of the northeast Oklahoma region. A brief lull in thunderstorm activity is expected for Sunday before severe weather chances increase again Monday and Tuesday, according to the weather service. The Three Forks, located near Muskogee, is the area where the Arkansas, Neosho and Verdigris rivers merge. The Arkansas River near Muskogee, after the three rivers merge, has exceeded the minor flood stage, 28 feet, multiple times in early May. It peaked over 29 feet on May 9. Provided there is […]