Tropical Storm Nadine is the only lone storm churning in the Atlantic here in mid-September. Just like its predecessors Leslie and Michael, it will get deflected away from the East Coast in the coming days.
September is historically known for producing the greatest number of tropical cyclones. As a matter of fact, September 10th is the day when over the last 100 years there is the most number of active named storms.
Now that we are past that point, the numbers will likely fall off dramatically. This can be contributed to cooling ocean temperatures as the lower sun angle results in less heating and increasing amounts of upper-level wind shear or higher velocity jet stream winds that move south from the polar region to impede on tropical development.
The prospects for an East Coast landfalling hurricane are diminishing as well. The weather pattern across the lower 48 by the end of September becomes rather progressive. The jet stream dipping south tends to send frequent cold fronts and disturbances across the U.S. into the eastern Atlantic. The upper-level winds tend to deflect storms away from the coast for this reason.
We’ve already surpassed the average of named storms that form in a season. That number is 12 and Nadine marks the 14th named storm so far. Isaac has been the only landfalling U.S. hurricane this year, similar to the “I” storm Irene last year. Prior to Irene last year, the last landfalling tropical cyclone was Ike in 2008.
Wondering about other land falling hurricanes prior to Ike? Check out this great NOAA site that shows landfall location, name of the storm and year it happened.
By October, south Florida becomes most at risk for a landfalling hurricane. Florida was hit by 6 of the 8 major hurricanes that hit the U.S. in October between 1900 and 2000. Wilma was the last major hurricane to hit the U.S. in October.