James Spann: Severe storms likely over north Alabama this evening, tonight

QUIET START: There’s no rain on radar across Alabama at daybreak; temperatures are in the 70s. We rise into the 87- to 91-degree range today with a mix of sun and clouds. Most of the day will be dry; a few showers or storms could try and form along an outflow boundary over the Tennessee Valley this afternoon, but the main round will come after 5 p.m. as a dynamic weather system brings the chance of severe thunderstorms to parts of the Deep South.

The Storm Prediction Center has defined an enhanced risk (level 3 out of 5) of severe thunderstorms as far south as Tuscaloosa, Birmingham and Jacksonville. There is a slight risk (level 2) as far south as Demopolis, Marbury and Lafayette and a marginal risk (level 1) down to Grove Hill, Highland Home and Phenix City.

Here are the key messages for this event:

• All modes of severe weather are possible over north Alabama with this event. The highest risk of tornadoes is in the enhanced risk area, in any discrete cells that form ahead of the main line. A strong tornado (EF-2 or higher) can’t be ruled out.
• As the storms evolve into a line, a couple of brief, isolated tornadoes are still possible.
• As the storms become linear, the main threat will shift to damaging straight-line winds, possibly 70 mph in spots.
• Large hail is also possible with the heavier thunderstorms.
• Storms should slowly weaken late tonight as they move south of I-20; there is no risk of severe storms over the southern third of the state.
• Events like this are common in Alabama in May, which is part of our tornado season (November through May). No need to be worried or anxious; just have a reliable way of hearing warnings (never an outdoor siren), have a good plan and we will get through it together.

REST OF THE WEEK: A few lingering showers are possible Wednesday morning over south Alabama, but the weather will be mostly dry Wednesday through Friday. Highs will be in the low to mid 80s Wednesday and Thursday; a cooler air mass arrives Friday as highs drop into the 70s over the northern half of the state. Most north Alabama communities will drop into the 50s early Friday morning.

MEMORIAL DAY WEEKEND: While south Alabama will be dry Saturday and Sunday, we will mention a chance of showers both days over the northern half of the state — not a washout and not raining everywhere. On Monday, showers and storms become likely statewide ahead of a cold front. For now, it doesn’t look like a severe thunderstorm setup.

Cooler, drier air rolls into the Deep South Tuesday; the weather looks dry for the rest of the week.

ON THIS DATE IN 1957: A tornado touched down southwest of Kansas City and traveled 71 miles, cutting a swath of near destruction through the southeastern suburbs of Ruskin Heights and Hickman Mills. The tornado claimed the lives of 45 people and left hundreds homeless.

For more weather news and information from James Spann and his team, visit AlabamaWx.