10pm Update Forecast for Helene

10pm EDT:  Based on the latest information from the Hurricane Hunters, the barometric pressure has dropped another 3 millibars to 971 mb but the winds are about the same -- 85 mph -- as they are when the 5:25 update (below) was written. The storm is still not terribly well organized. 

The hurricane is, yet again, attempting to form an eye. It looks like it is fighting off some unexpectedly dry air. 

So, the information below is still valid. I'll have another update during the mid- to late morning tomorrow (Thursday).

The National Hurricane Center is starting to release its 5pm EDT package of data and forecasts. Helene is intensifying and is now forecast to be Cat 4 at landfall with a catastrophic storm surge up to 20'. In addition, they are now forecasting trees to be toppled as far north as northern Georgia and northwest South Carolina. 

Position and Wind Speed

Landfall of the eye will be late Thursday evening but damaging winds will precede the eye and extend about 100 miles to the east. Note the hurricane warning (red) extended into central Georgia, nearly to Macon. That is a forecast of sustained winds of 80 mph with stronger gusts. See below for starting time estimates of 40 mph winds. Trees are forecast to topple as far north as northern Georgia and northwest South Carolina. Power will be out for days!

Here is an explanation of the map. 

• M = major hurricane with sustained winds to 130 mph at landfall
• H = hurricane.
• S = tropical storm. 
• Red = hurricane warning
• Blue = tropical storm warnings, well into North Carolina and even Tennessee.
• Pink = hurricane watch
• Yellow = tropical storm watch 
• Amber = area of tropical storm force winds (40 to 80 mph, at this time)

What would I do now if I lived in a coastal area with this storm potential? All of this should be done by 8am Thursday.

• Make sure infirm relatives and friends will be cared for. 
• Refill prescriptions. 
• Purchase any essentials.
• Fully fuel your auto and/or chain saw. 
• Electric vehicles should be evacuated from the coastal areas as their batteries and salt water do not mix. 
• Make sure your "go kit" is up-to-date and ready. There will likely be evacuations in coastal areas of the Panhandle, in Tampa Bay and most of the area of the Florida Big Bend!
• If you live in a mobile home, make plans to shelter elsewhere if the storm reaches hurricane strength. 
• There will be power failures that, in many cases, will last for days. Prepare accordingly.

Time of Arrival of 40 mph Winds

These are the earliest reasonable times of arrival of the 40 mph winds. Winds will only increase until tomorrow evening. I recommend that all precautions be taken by these specific times. 

Catastrophic Storm Surge

Evacuations have been ordered in much of the area from around Tampa Bay to Apalachacola.

This illustrates storm surge heights and why everyone in the area needs to evacuate. 

Tornado Forecast

There will be a few, isolated tornadoes today and tonight in Florida and the Southeast. By far, the greater threat will be tomorrow (Thursday).

In the brown area, there is a significant risk of tornadoes Thursday and Thursday night. In the yellow area, there is an enhanced risk of tornadoes. 

Flood Forecast 

The NWS has finally updated its flood forecast. The purple area in the southern Appalachians is where catastrophic flooding is forecast to occur. In the Atlanta area, the flooding is forecast to be either moderate or major.