Tropical Storm Nadine forms; Newfoundland cleans up after Leslie

Tropical Storm Nadine formed last night, midway between Africa and the Lesser Antilles Islands, and continues to grow more organized today as it heads west-northwest at 17 mph. The models unanimously predict that Nadine will recurve to the north well east of the Lesser Antilles Islands later this week, on a track that would likely keep this storm far out at sea away from any land areas. Nadine is in a low-shear environment favorable for strengthening, and will likely become Hurricane Nadine by Thursday. A NASA remotely-piloted Global Hawk research aircraft is currently flying a 26-hour mission in Nadine, as part of the HS3 Hurricane and Severe Storm Sentinel Program. The data collected will help scientists decipher the relative roles of the large-scale environment and internal storm processes that affect hurricanes.

With fourteen named storms already this season, 2012 is now one of just 19 hurricane seasons over the past 162 years to have fourteen or more tropical storms. Nadine's formation date of September 10 puts 2012 in 5th place for earliest formation date of the season's 14th tropical storm. Only 2005, 2011, 1936, and 1933 had earlier formation dates of the season's 14th storm.


Figure 1. Morning satellite image of Tropical Storm Nadine.

Elsewhere in the Atlantic
Most of the models predict that a trough of low pressure about 600 miles off the U.S. East Coast will serve as the focus for development of a non-tropical low pressure system on Sunday or Monday. This low may spend enough time over water to acquire tropical characteristics and become a named storm by the middle of next week.

Newfoundland cleans up after Tropical Storm Leslie
Tropical Storm Leslie made landfall in Southern Newfoundland at 8 am EDT September 11 as a tropical storm with 70 mph winds and a central pressure of 969 mb. Leslie brought sustained winds to Newfoundland's capital, St. Johns, of 58 mph, gusting to 82 mph, at 10:30 am local time. Cape Pine record the highest gust from Leslie, 85 mph. The storm tore off roofs, downed trees, and toppled power lines, and 45,000 households were without power Tuesday afternoon in Newfoundland, including much of the capital of St. Johns. Leslie's tropical moisture collided with the cold front drawing the storm to the north, resulting in heavy rains over eastern Nova Scotia and western Newfoundland in excess of 4 inches, which caused considerable flooding of homes and streets. However, the rains were far less than those experienced during Hurricane Igor, which hit Newfoundland as a Category 1 hurricane in 2010, causing $200 million in damage. I expect damage from Leslie will be less than $20 million. Leslie is now a powerful extratropical storm bringing rain and strong winds to Iceland.

Jeff Masters

Hurricane