Final Update 8:45pm: Another Day of Tornadoes and Damaging Winds

The derecho as of 8:45pm CDT:

The storm has left a huge swath of power outages:

This is worst since the Iowa derecho this past Augusta. Total people without power will be in the 500,000 to 700,000 range and it will be days before power is restored to everyone.

Below is a map of reports of wind gusts above 60 mph (blue) and tornadoes (red),

Earlier reports:

This equals more than 300,000 people without power in Mississippi as of 3:48pm CDT.

Derechoes are notorious for extensive power failures -- and, it will be at least five days before 100% of the power is restored. 

Radar at 2:18pm along with the threats:

The derecho will cause the winds of 75 mph or stronger (see red area below). The storms ahead of the line are the reason for the tornado watch (farther down). The west-east line of storms through Birmingham and Atlanta will cause flooding rains until swept away by the derecho. 

Very high thunderstorm-generated winds accompanied by tornadoes in the Southeast. 

The red area has a high risk tornadoes and thunderstorm-generated wind gusts stronger than 75 mph. Power failures and toppled trees are likely in this area -- please prepare accordingly. 

As of this time, much of the South is under a tornado watch (purple).

So, please monitor the weather the rest of the day. Now is the time to prepare:

• Charge your laptop and cell phone but disconnect them when you hear thunder or see lightning. 
• If you have children or an infirm friend or relative, make provisions for them now. 
• The above is true if you live in a mobile home -- make plans to quickly leave or stay with a friend with a basement or well-constructed home. 
• Put your car in the garage. 
• Make sure your tornado shelter area is ready to go. Put a couple of bottles of water in it. Always wear shoes when you shelter from the tornado. 

I'll be providing additional information on Twitter @usweatherdata.