New disturbance slowly organizing, but no threat to land

A tropical wave featuring a broad surface circulation about 1100 miles west of the Cape Verde Islands has become better organized since yesterday. There is more heavy thunderstorm activity, and the cloud pattern is a bit more circular. QuikSCAT winds from this morning's 5:11am EDT pass were 25-35 mph in a few isolated patches. This system (96L) probably needs at least another two days to organize into a tropical depression as it moves northwest over the open Atlantic. The storm is moving towards a weakness in the Bermuda High created by Hurricane Helene. Most of the forecast models indicate that this break will close up as Helene races off to the northeast over the next few days. The Bermuda High will then re-establish itself and a high pressure ridge will build in, forcing 96L more to the west-northwest. A long range threat to Bermuda is possible late next week. I think it is likely that a trough of low pressure will recurve 96L northwards and out to sea before it reaches Bermuda, though. The storm is not a threat to the Caribbean or U.S. Two models--the GFDL and Canadian--forecast that 96L will eventually become a hurricane. The storm is over warm waters, and under just 10 knots of wind shear.


Figure 1. Preliminary model tracks for Invest 96L.

Hurricane Helene headed out to sea
Hurricane Helene is headed northeast out to sea. Helene is expected gradually weaken and morph into a powerful extratropical storm with hurricane force winds later today. Swells from Helene and high winds are combining to produce seas up to 12 feet high off of Cape Cod today.

I'll have an update Sunday morning.
Jeff Masters