Catastrophic Inland Flooding Likely With Hurricane Helene

Catastrophic flooding is likely with Hurricane Helene as the storm moves inland. The NWS rainfall amount forecast has been bumped up to more than 22 inches with this storm! Details below based on updated rainfall amount data from the National Weather Service.

Above is an updated rainfall amount forecast from the National Weather Service in Washington. The bright purple is where more than 18" of rain is forecast to fall with a maximum of just over 22 inches. 

The heaviest rains have been expanded to the north as well as increased in amount. 

The rainfall forecast for the Atlanta Metro is now between 7 and 9 inches. Also note there will be serious flooding in the central Florida Panhandle. 

In the strongest possible terms, if you live in a flood-prone area in these regions, plan for an evacuation. Major to catastrophic flooding is likely. Get your "go kit" ready now!

South of I-20 to the Florida Panhandle and north Florida, there will be trees toppled which will block some roads (in addition to causing power outages). That is why evacuating sooner, rather than later, is a good idea. 

Please keep in mind that high water and EV's do not mix and that is especially true if it is salt water. 

In hurricane situations, I wish to work with the National Weather Service (NWS) so as not to confuse the public. However, the flooding information yesterday and today is of poor quality and confusing. 

For example, at 2:45pm EDT, I went to their National Flood Outlook and it does not reflect the meteorological situation. 

There are no areas of catastrophic flooding. The dot in the Atlanta area says "minor" flooding. If you look southeast of Washington, DC, moderate flooding is forecast by the red dots but the blue tinting does not cover that area. 

If you look at the Atlanta Metro on the National Water Center's site, most of the rivers and streams have no forecast at all! Look below, for example: there is no forecast to the right of the dashed vertical line. They are depicted by green dots which misleadingly imply there is no problem. 

Back in May, the NWS completely redid its flood warning system. It didn't work properly then and, now, four months later, it still doesn't work properly.

I will continue to provide the best information I can here on the blog and on my Twitter account @usweatherexpert.