September 2024 was a fairly quiet month of weather in the East, except for the last week when Hurricane Helene impacted the Southeast US and brought devastating impacts. Hurricane Helene brought strong winds, high storm surge, tornadoes, and flooding. The most severe impacts were caused by flooding across Georgia, South Carolina, North Carolina, and Tennessee with 10-30 inches of rain.

October will see cooler weather return to the East and fall foliage shine through many states. The southern half of the East will see normal temperatures while the northern half of the East through New England will see above-normal temperatures. Precipitation has a 30-50% chance of being above-normal along the southern Atlantic Coast through the Carolinas, with normal precipitation for the northern half of the East. Read on to learn more about the weather in September and the forecast for October.

September 2024 Review:

September was a fairly normal month of weather except for the last week of the month when Hurricane Helene impacted the Southeast. Temperatures during September were mostly above-normal, particularly in the interior Northeast, with several short-lived heat waves throughout the month.

A couple of areas along the Atlantic coast and in the Southeast saw normal to below-normal temperatures due to several storm systems bringing clouds and precipitation throughout September.

September finally saw severe weather decrease throughout the East due to cooler temperatures as fall arrived. Hurricane Helene brought an exception to this, which caused many tornadoes through the Southeast with the most occuring in South Carolina.

Below is a look at the preliminary severe weather reports from the Storm Prediction Center (SPC) in September 2024.

Hurricane Helene also brought flooding to much of the East. Florida, Georgia, South Carolina, North Carolina, and Tennessee were hit hardest with 5-30 inches of rain as Helene tapped into tropical moisture with very heavy rain falling over the same areas for several days.

Check out the rainfall reports from September 25-28.

All of this rain caused above-normal precipitation in many southern states. Coastal areas along the Gulf Coast and through the Smoky Mountains saw the most rain from Helene with over 20 inches across many areas. This amount of rain over a few days has caused devastating impacts for many communities.

Check out a closer look at rainfall totals in the South Carolina and North Carolina.

The rest of the East through the Mid-Atlantic and New England saw normal to slightly below-normal precipitation in September. 

October 2024 Outlook:

The outlook for October shows 30-50% of above-normal temperatures in the northern half of the East, especially through New England. The rest of the East, except for southern Florida, will see equal chances of above and below-normal temperatures.

The precipitation forecast for October shows above-normal precipitation chances (30-50%) along the southern Atlantic Coast through the Carolinas and Florida due to an increased chance of tropical systems. A strong high-pressure system through the center of the country is expected to bring below-normal precipitation that will extend through the Ohio River valley.

The rest of the East through the Mid-Atlantic and New England will see equal chances of above and below-normal precipitation.

 

Tropical Outlook:

As of October 2, there has been an increase in tropical cyclones with a season total of 11 named storms, which means were are now near the climatological average (1990-2020) for tropical cyclone activity. We are also now past the peak of tropical cyclone activity and into the second half of the season.

September started inactive and quiet due to several factors related to unfavorable atmospheric conditions despite nearly record sea surface temperatures in the Atlantic Ocean. 

Learn more about the quiet start -> Quiet Atlantic Hurricane Season September 2024 Update

Since the second half of September though, we have seen an increased activity in tropical cyclone activity due to more favorable atmospheric conditions. This increase in activity culminated in Hurricane Helene, which impacted the Gulf Coast and Southeast US from September 25 - 28.

The Atlantic tropical cyclone season is expected to remain active over the coming weeks at the start of October. The biggest concern is a disturbance slowly moving into the Gulf of Mexico, which has a 40-60% chance of developing into a tropical cyclone. It is too early to determine how strong this system will become and where/when/if it will impact land.

Check out the 7-day forecast for tropical disturbances from Wednesday, October 2 through Tuesday, October 8. 

Fire and Smoke Outlook:

The Western US saw a very active fire season at the start of September. Since the second half of September, wildfire activity has decreased due to cooler temperatures and light precipitation. October will see a slight increase in wildfire activity in the Western and Central US due to above-normal temperatures and below-normal precipitation.

Below is a look at the wildfire potential across the US in October 2024.

The wildfires in Canada saw quiet conditions in September and will continue to see quiet conditions in October due to improved drought conditions and cooler temperatures!

Happy October and enjoy the start of fall. Snow will soon be on the way and I will have the next monthly review at the start of November.

Zach Butler