James Spann forecasts rising heat, humidity for Alabama from Alabama News Center on Vimeo.

TRENDING WARMER: We are forecasting highs between 84 and 87 degrees across Alabama today, right at seasonal averages for the last day of May. The sky will be partly sunny, and a few isolated showers or storms could form this afternoon and early tonight. The chance of any one spot seeing rain is around 20%. This will be the formula for the rest of the week as heat and humidity continue to slowly rise.

THE ALABAMA WEEKEND: Expect only isolated afternoon showers; otherwise, we’ll have partly sunny days and fair nights with highs close to 90 degrees. The chance of any one place getting wet both days is 10-20%.

NEXT WEEK: We don’t see much reason for any major change in the weather. There’s no sign of any high-impact, widespread rain event, only isolated showers daily with highs between 87 and 91 degrees most days — pretty typical weather for early June in Alabama.

TROPICS: An area of disorganized showers and thunderstorms is associated with a surface trough of low pressure interacting with an upper-level trough over the central Gulf of Mexico. Environmental conditions appear only marginally favorable for additional development over the next several days as the system meanders over the eastern Gulf of Mexico. The system is then forecast to move across the Florida Peninsula this weekend and emerge into the southwestern Atlantic Ocean by early next week. Regardless of development, the system could produce heavy rainfall and gusty winds over portions of the Florida Peninsula later this week.

The National Hurricane Center gives it only a 20% chance of development through early next week, and any impact to the Central Gulf Coast (Gulf Shores to Panama City Beach) will be minimal. The rest of the Atlantic basin is quiet.

ON THIS DATE IN 1889: The Johnstown, Pennsylvania, disaster occurred, the worst flood tragedy in U.S. history. Heavy rains collapsed the South Fork Dam, sending a 30-foot wall of water rushing down the already flooded Conemaugh Valley. Traveling as fast as 22 feet per second, it swept away all structures, objects and people. The flood killed around 2,100 people.

ON THIS DATE IN 2013: An intense, long-track tornado formed southwest of El Reno, Oklahoma. This exceptionally wide tornado took a complex path, rapidly changing in both speed and direction. Radar data showed winds of at least 295 mph very close to the surface. The maximum tornado width was 2.6 miles.

Eight people were killed, all in vehicles. This included three severe storm researchers who were killed east of U.S. Highway 81 as the tornado overtook their position.

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