Atmospheric conditions appear to be setting up for a major severe thunderstorm and tornado outbreak tomorrow afternoon and evening across the Ohio and Tennessee Valleys. The states in line with the greatest chance for this severe weather outbreak on Friday include Ohio, Indiana, Kentucky, Tennessee, Alabama and Mississippi, and all neighboring states have a risk as well, but perhaps a slight bit lower. As daytime heating commences on Friday in a warm and humid air mass in this part of the country, a strong cold front will advance slowly to the east at the same time a powerful upper-level jet streak plows into the region. In fact, this unusually strong upper-level jet streak will see winds increase to over 150 knots later tomorrow and tomorrow night, and this will significantly increase upward motion in the atmosphere contributing greatly to overall instability. By early tomorrow night, the severe thunderstorms will likely move from the Ohio and Tennessee Valleys to over the Appalachian Mountains. This same system will then arrive in the Mid-Atlantic States later tomorrow night, but in a weakened state. Nonetheless, we can expect some occasional rain, gusty winds and possible thunderstorms here in the Mid-Atlantic from tomorrow night through Saturday morning as the cold front gradually crosses the region. Colder air will follow the front on Sunday and Monday, but another significant warm up begins here later next week.