Late October may seem a little late to the party for the tropics but history shows that it an be an active and impactful time. While The National Hurricane Center (NHC) is watching two systems with potential to get named this week, the primary region is the Caribbean. This system has been given an 80% chance from NHC to developing into a tropical storm by Wednesday. That would include sustained winds of 40 mph and get named Sandy.
The current system is called Invest 99L for classification purposes. See video loop attached here for the Water Vapor satellite loop centered on the Caribbean and western tropical Atlantic Ocean. The two systems can be seen trying to organize. A few hundred miles south of Jamaica is where Invest 99L is located, while Invest 90L looks more impressive, but is less threatening in the Atlantic. Heavy rain is spreading north into western Cuba, Jamaica, and Hispaniola. The is nearly stationary, but is expected to get a lift to the north.
Computer model forecast projections show that Tropical Storm Sandy will form and move north during the week. It will cut across western Cuba and then into the Bahamas by Friday. Beyond this period, it is seen mainly shifting east. The concern is that it might hug the US coast closer. Some mid latitude computer models show this storm closer to the US coast and interacting with an arctic air mass over The Great Lakes and eastern Canada. This would increase the pressure field and bring a large area of strong winds along the east coast. It should be noted that there is a wide divergence of computer model outlooks at this point and I would caution against the worse case scenario. It is possible based on history that we could have a threatening set up for the US, but all the ingredients must fit perfectly.
We only have to look back to Isaac to see how models have been slow to develop tropical systems and project the track. Initially this storm was expected to hit Florida, but it took a few extra days, traveled farther west and formed into a hurricane just before stalling on the Louisiana coast.
I will be tracking the East Coast potential threat on my Baltimore Weather Examiner Page. Also follow along for updates through:
Facebook: Justin Berk, Meteorologist
Tropical storm and hurricane history of naming. 2012 Atlantic list
Tropical Storm formation history: Storm origin maps every 10 days of season
Hurricane Preparedness Week: Storm Surge is the most deadly and destructive
Hurricane Destruction animation based on Saffir Simpson Scale
NASA Global Hawk: Hurricane drone planes run by locals at Goddard