The upper level low just east of Florida and a tropical wave along 70 west are our main concerns for any possible tropical development. At this point we don either system within the next couple of days due to strong shear and higher than normal surface pressure. The wave along 70 west is handled differently by various computer models. There is some attempt by one model to show some organization of this wave within the next 3 days. However, we don't see that on other model output. A large area of African dust that we have been stating over the past few days continues to advance westward and is now entering the eastern Caribbean. This African dust represents drier than normal air at about 10,000 feet. This tends to put a lid on thunderstorm development. This drier air is feeding into the back of the wave along 70 west and this will also hinder development.
We are tracking other tropical waves. They are along: 30 west south of 15 north, along 45 west south of 15 north and along 85 west south of 13 north. These tropical waves are moving west at 15-20 knots or about 7 degrees longitude per day. We see no support for any development by any of these waves.
Looking back a year ago for July 4-5 we had two tropical depressions one became Cindy and the other was Dennis. We have had only one tropical cyclone so far this season and this is much closer to a near normal season. We believe the reason we have not seen any quick development like last year is due to several factors. As stated above we are seeing surface pressures a bit higher than normal over the Caribbean compared to lower than normal last year. We also continue to see strong shearing over the eastern Gulf of Mexico down into the Caribbean due to frequent upper level troughs forming over the eastern U.S.. through the Caribbean. Current trends in longer range computer output suggests these conditions should persist through the next 5-7 days and perhaps longer.
