Dangerous heatwave set to blanket much of the country More heat alerts have been issued in the Southwest.

Thirteen states from Texas to Kentucky in the South are under heat alerts today with some areas expecting the heat index to rise to 115 Fahrenheit.

It has already been an extremely hot week for those in places like Laredo, Texas, which set a record of 109 degrees on Monday, and Galveston, Texas, tying its own record with an overnight temperature of 86 degrees.

Meanwhile, more heat alerts have been issued in the Southwest and California in areas like Phoenix, Las Vegas, Palm Springs, and Sacramento, where temperatures are all expected to exceed triple digits.

The Midwest, meanwhile, has been suffering through a period of heavy rainfall and severe storms.

St. Louis recorded 2.68 inches of rainfall in a single day -- a record for the city -- while a number of streets and neighborhoods were flooded, stranding some people in their homes.

Severe storms continue this morning in the Midwest and could produce damaging winds and flash flooding.

This afternoon and evening could see the severe storm threat move away from the Midwest and into the mid-Atlantic and Tennessee Valley regions with alerts of potential flash flooding and isolated tornadoes.

A flash flood watch has been issued for eastern Pennsylvania, Philadelphia and parts of New Jersey, where up to 3 inches of rain could fall this afternoon in just a matter of hours.