The severe weather outlook for Saturday is shown above. A Level 4 out of 5 severe weather risk has been added and now expanded for Saturday in the areas in red, which is very unusual this far in advance. The rest of the state will have a Level 3 risk on Saturday. Storm Prediction Center

Alabamians are urged to remain vigilant as a dynamic storm system is set to unleash two rounds of severe thunderstorms across the state from

Storm Chaser Heath Lollar said he and his crew will be on the ground in central Alabama Saturday feeding information to weather services when the anticipated storm hits.

A severe weather outbreak is expected on Saturday in Alabama, according to the National Weather Service. NOAA’s Storm Prediction Center has added -- and now expanded as of Thursday afternoon -- a rarely-used Level 4 out of 5 risk for parts of a large part of Alabama for Saturday.

Severe weather can, and does, happen any time in Alabama, but the period of March through May is considered to be when chances are greatest for severe weather. The weekend has a complicated forecast, with the cold front hooking up with two low pressure systems. Here's what to expect.

Much of central Alabama for Saturday has been placed under a level four out of five threat for severe weather, an almost unprecedented listing, on a scale where five is considered to be the highest chances for severe weather. The rating occurs about once a year, said Jason Davis, meteorologist with the National Weather Service office in Birmingham.