Atlantic storm Nadine on verge of becoming hurricane
Tropical Storm Nadine is on the verge of becoming a hurricane in the central tropical Atlantic, forecasters said on late Wednesday, but there is no immediate threat to land. It is the fourteenth tropical cyclone of the 2012 Atlantic hurricane season.
Forecasters at the U.S. National Hurricane Center (NHC) have been tracking the weather system since September 7 when it emerged as a tropical wave between the west coast of Africa and the Cape Verde Islands. It slowly strengthened as it made its way halfway across the Atlantic.
As of 11 p.m. AST on Wednesday (0300 GMT Thursday), the center of Nadine was located about 820 miles (1,320 kilometers) east-northeast of the Lesser Antilles in the Caribbean. The storm is moving toward the northwest at a speed of about 16 miles (26 kilometers) per hour.
Maximum sustained winds of Nadine have increased to near 70 miles (110 kilometers) per hour, just below the 74 miles (120 kilometers) per hour mark to be considered a category one hurricane on the five-step Saffir-Simpson scale of intensity. The storm will likely reach hurricane strength on early Thursday morning.
"Nadine has been strengthening over the past 24 hours at just below the rate of rapid intensification," said NHC senior hurricane specialist Stacy R. Stewart. "The combination of a favorable outflow pattern and relatively low vertical wind shear should allow for some additional intensification to occur for the next 24 hours or so."
A sharp increase in westerly shear is expected ahead of a deep-layer trough which is approaching the storm from the west and will likely halt the intensification. "This should result in a capping of the intensity by 36 hours, and possibly induce some slight weakening at 48 hours and beyond," Stewart explained.
Nadine poses no immediate threat to land, but the storm is expected to turn toward the northeast over the weekend. Some computer models suggest this could send the storm in the direction of the the Portuguese Azores archipelago, but more reliable forecasts next week will determine if the islands are at risk.
Nadine is the fourteenth tropical cyclone of the 2012 Atlantic hurricane season, which officially began on June 1. It follows Category 1 hurricane Leslie which made landfall in Canada and Category 3 hurricane Michael which moved across the Atlantic but both caused no casualties.
According to a forecast released in August, NOAA's Climate Prediction Center is expecting a near-normal hurricane season in the Atlantic this year. The outlook calls for twelve to seventeen named storms, with five to eight becoming hurricanes and two to three of them expected to become a major hurricane (category 3 or higher).
Based on the period from 1981 to 2010, an average Atlantic hurricane season produces twelve named storms, with six becoming hurricanes and three becoming major hurricanes. The Atlantic hurricane season runs from June 1 through November 30, with peak activity between August and October.