Introduction: How tropical

The expected downpour is a
combination of factors as subtropical
moisture flow interacts with pre-stagnation

and Appalachian topography to create a recipe
for sustained rain ahead of Helen’s expected arrival on Thursday.
ATLANTA – Despite being hundreds of miles away,

much of the Southeast, including metro Atlanta,
remains at risk of dangerous flooding in the wake of Tropical Storm Helen.
The expected heavy rains will depend on several

factors as tropical moisture moves in ahead of Helen’s
arrival on Thursday and interacts with both the stationary
front and the topography of the Appalachian
Mountains to create a recipe for persistent rain.

The pattern is good for flash flooding on its own,

But the storm will contend with terrain in the southern Appalachians as it reaches northern Georgia, western Carolina and far eastern Tennessee, according to the FOX Prediction Center.

Mountains can contribute to increased humidity, more rainfall and flash floods.

“(Helen) is going to bring all this moisture from the Gulf of Mexico. Some of them will come from the western Atlantic,” said FOX Weather meteorologist Steve Bender. “We know that a warm current, the Gulf Stream, throws everything over the mountains. This leads to heavy rains.”

According to the FOX Forecast Center, it appears to continue to linger in or near Atlanta to the south, and increased runoff from urban impacts, especially over roads, small streams and creeks, will increase the risk of flash flooding. FOX’s forecast. .

NOAA’s Weather Prediction Center puts the risk of flash flooding in the region at 3 out of 4 Wednesday, as rainfall totals could reach 4 inches or more if they occur.

This sets the stage for the country to become saturated with possible flooding and now prepare for the arrival of Helen on Thursday and her immediate tropical downpours.

By the time Helen moves out on Friday, parts of Georgia, particularly the Northeast, could see more than 8 inches of rain. Meanwhile, up to 10 inches or more of rain is possible in western North Carolina and eastern Tennessee through Friday.

The FOX Forecast Center says a few inches of rain could fall just before the rainfall associated with a severe storm, which would significantly worsen the effects of flooding in Helen.