After a roller-coaster start to meteorological fall, NOAA’s Climate Prediction Center expects the possibility of warmer-than-average temperatures across much of the country, including the Southeast, during October.
The month is usually one of the more difficult periods for extended outlooks, as temperatures can vary widely depending on the jet stream.
An El Niño phase of the El Niño–Southern Oscillation often produces a warmer fall for much of the U.S., while La Niña is generally associated with cooler, wetter conditions.
This year, neither phase is in control of climate patterns, a neutral status sometimes referred to as “La Nada.”
During a neutral event, there are usually fewer kinks in the jet stream, so any hint of chilly Canadian air tends to stay bottled up well to the north.
On average, October days in Columbia start around 53 degrees and climb into the mid-70s.
Further north in Greenville, temperatures average about 3 degrees cooler in the morning and afternoon, while Charleston typically runs about 3 degrees warmer.
Typically, the first frost of the season occurs in October in the higher elevations, so with the month potentially being warmer than average, this might lead to a delay in the colder mornings.
On the precipitation front, NOAA expects conditions to run closer to average rather than leaning toward either excessive rainfall or drought-breaking totals.
The lack of any enhanced rainfall could be problematic, as 90% of the state is experiencing abnormally dry conditions and nearly 20% is facing moderate drought.
Without significant rain, drought conditions will likely worsen heading into November, which is usually the driest month of the year.
Tropics always a wildcard
With the departure of Hurricane Humberto and Imelda, the tropics are expected to quiet down again across the Atlantic basin.
October is typically the third-busiest month of the hurricane season, producing an average of three named storms and at least one hurricane. That means the risk of tropical activity impacting South Carolina is not completely over.
Over the coming weeks, forecasters will keep an eye on the western parts of the basin, including the Gulf and Caribbean, for development. These areas are climatologically favorable, with warm waters and less hostile upper-level winds.
If South Carolina makes it through the month without a landfall, the season could essentially be over for the state, as no tropical cyclone has ever made landfall along the coast during November.
So far, nine named storms have formed this season, with three reaching hurricane strength - well below preseason forecasts.
The only U.S. landfall came from Tropical Storm Chantal, which struck near Litchfield Beach, South Carolina, on July 6.
Mixed bag for fall foliage
October is typically the peak month for fall foliage across much of the Palmetto State, but in some communities, the colors may be more muted than in past years.
For the brightest yellows, oranges and reds, trees usually require warm, sunny days followed by cool nights under minimal drought conditions.
While some of these conditions are being met, the drought and warm overnight lows could alter the chemistry inside trees, reducing the vibrancy of leaves.
The best opportunity to see autumn colors across most of the state is expected between October 13 and November 3, though timing will vary with terrain and elevation.
