Tracking the Tropics: Watching Invest 95L in East Atlantic

Good evening everyone! Back again after a break enjoying friends and family for once and ready to get back into the swing of things forecasting once again.

As usual, I'm tracking the tropics this time of year and we definitely have something that bares watching way out there in the Eastern Atlantic off Africa. Over the past few days a tropical disturbance within the ITCZ (Inter-Tropical Convergence Zone) had been brewing and coming off the African continent. Well yesterday morning (since its past midnight here in South Florida as I'm writing this) the NHC designated this disturbance as Invest 95L.

The latest fix on the system places the "center" of this broad low pressure at around 11 N and 27 W this evening. Based upon this fix, the system has been and continues to move westward tonight and appears will continue doing so during the next 24 to 48 hours. Current estimates place the pressure at 1009 mb and wind speeds around 30 mph. In looking at observations in the region, mainly from ships and buoys, pressure isn't falling significantly and winds remain relatively light, so development isn't taking place at this time.


Figure 1 - Water Vapor Imagery for Invest 95L (Source: NAVY/NRL Tropical Cyclones)

Analyzing satellite imagery tonight shows a very broad low pressure system with rather disorganized and unimpressive convection as the disturbance continues to battle moderate wind shear at around 20 kts. In looking at the water vapor imagery above, you can see dry air doesn't seem to be a problem with this system as this disturbance has a good moisture field and is broad enough to prevent entrainment of dry air and dust to the north.

Now what does the future hold for Invest 95L? This is a very good question and one thats difficult to answer so far out at sea and so broad and disorganized at this time. For right now, the computer models suggest that the disturbance should begin taking on a more northerly component to its track soon and be moving NW in the coming week while gaining strength to become either Tropical Storm or Hurricane Danielle. It appears the computer models all suggest that a relatively deep trough for this time of year will emerge off the United States in about a week and will erode the Bermuda High down enough to allow for the system to move northward coming close to Bermuda by late next week.


Figure 2 - Latest Computer Models for Invest 95L (Source: Weather Underground Tropical/Hurricane)

Given the current state of the disturbance, recent trends, and current steering patterns, I am not in total agreement with the computer models at this time. Reason for this is that most models strengthen this system too quickly for the current disorganized state of the disturbance and that the computer models all show a northerly component to the track almost immediately which has yet to happen and appears unlikely to happen for the next couple days as the Azores High has strengthened and built in some throughout the day. Once this system organizes further and consolidates better, then we shall have a better idea as to the future. For now, its all speculation as to the future track and strength this disturbance will have.

Stay tuned for further updates as the situation develops.