Heavy rains are forecast to fall further north along the U.S. East Coast later in the week, with a "marginal" risk of excessive rainfall, enough to cause isolated flash flooding, over the Appalachians and portions of the Ohio and Tennessee valleys on the evening of Oct. 29 and morning of Oct. 30.

The U.S. Air Force Reserve's 53rd Weather Reconnaissance Squadron, known as the "Hurricane Hunters," were forced to turn back at one point due to heavy turbulence after flying into the eye of Hurricane Melissa on Monday.

Melissa is only the fifth Atlantic hurricane on record to achieve sustained winds of 185 m.p.h. or greater, joining the Labor Day Hurricane of 1935, Hurricane Gilbert (1988), Hurricane Wilma (2005) and Hurricane Dorian (2019).

Historic, life-threatening flash flooding and landslides are expected in portions of Jamaica, southern Haiti and the Dominican Republic through the weekend, the NHC said. Peak storm surge heights could reach 9 to 13 feet above normal tide levels when the storm makes landfall, accompanied by large and powerfully destructive waves.

Scientists have debated adding a "Category 6" to the Saffir-Simpson scale for storms with winds over 192 mph. The already dangerously powerful Category 5 hurricane Melissa surged up to 180 mph maximum sustained winds with gusts over 210 mph Tuesday morning,