Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather
By: Dr. Jeff Masters , 5:03 PM GMT on July 28, 2005
Tropical Storm Franklin continues its defiant trek across the Atlantic, but its days are surely numbered. It's currently moving over warm Gulf Stream waters, but in two days time, it will pass north of the Gulf Stream and encounter waters below 80F, which cannot sustain a tropical storm.
With Franklin likely to finally die, that means it must be time for a new storm to develop--after all, this is the Hurricane Season of 2005. We've had at least one active tropical storm continuously since Cindy formed on July 3, making this year's stretch of 25 straight days with tropical cyclone activity the longest such July stretch on record. The previous record was in 1979, with 21 consecutive days of July activity. And sure enough, we have a potential Tropical Depression Eight brewing in the Atlantic. The tropical wave near 20N 50W approaching the Lesser Antilles began forming a more concentrated area of thunderstorms last night, and that trend has continued today as the wave moves steadily west-northwestward at 15 mph. An impressive upper-level outflow channel has opened to the north, and satellite loops show high cirrus clouds blowing off the tops of the wave's thunderstorms streaming to the northeast. There is no obvious circulation yet. The wave is over 28 - 29C water, with warmer 29 - 30C water ahead of it. By tonight, the wave looks to have lower wind shear affecting it as well, and I expect we will have Tropical Depression Eight by tomorrow night.
If the storm develops, the immediate threat will be to the northern Leeward Islands and Puerto Rico. However, the steering flow looks to be west-northwesterly over the system the next few days, and the GFS model (which does not develop it and keeps it a tropical wave) has the system tracking north of the islands and approaching the East Coast of the U.S. At this point, it's anybody's guess what part of the East Coast might be most at risk. There is a moderately strong trough pushing off of the East Coast on Tuesday, and it's quite possible that this trough would recurve the storm out to sea before it hits the coast. I think the Hurricane Season of 2005 owes us a break!
Dr. Jeff Masters
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