Small town USA guy. Politics nerd. Soccer fan. Interested in eyewalls, deformation zones, and hook echos.
By: TropicalAnalystwx13, 2:56 AM GMT on August 09, 2011
The Atlantic basin is relatively quiet tonight, but we are monitoring a few tropical waves across the Atlantic basin. The first area of interest is the remnants of Emily, which are now located several hundred miles to the east-northeast of Bermuda. There has been an impressive convective burst with this area, and earlier visible satellite imagery reveals that there may be some sort of circulation embedded within this. However, whether or not the circulation is well-defined or weak is up in the air at this point, without the accessibility to visible satellite imagery. This area is moving towards the east, into an area of unfavorable wind shear. Fortunately for the system, there is an upper level anticyclone located just to the west/west-northwest of Emily's remnants, which is providing low shear for the time being. If Emily's remnants can align itself with this anticyclone, it will become embedded within an area of low wind shear, which will help its development chances. CIMSS 850 MB vorticity product shows an area of strong, consolidated vorticity associated with this blob, and it is stacked through all levels (although the 500 MB reflection is very weak). I will be monitoring this area for development over the coming days, as Cindy also developed in this area. At this time, I believe the National Hurricane Center at least give this area a Near 0% chance at development over the next 48 hours.
Figure 1. Infrared satellite imagery of the remains of what was Tropical Storm Emily, now located to the ENE of Bermuda.
Central Atlantic Tropical Wave
The second area I am watching tonight is a tropical wave located in the Central Atlantic, near 55W. Visible satellite imagery from earlier today revealed a low-level circulation that appeared closed and well-defined. However, due to the presence of dry air, all of the convection associated with the wave was well to the west of the low-level swirl. Because of the dry air the wave is dealing with right now, no development should be expected at this time. This area has a relatively well-defined reflection in the lower-levels on the CIMSS 850 MB. vorticity, although it isn't stacked in the mid to upper levels, and any reflection in those areas are weak. Due to the presence of an anticyclone just to the north/northwest of the system, wind shear is a low 5-10 knots, which is conducive for development. However, as aforementioned, dry air is a major problem, and the main reason while this will not develop anytime soon. Regardless, the Windward/Lesser Antilles are likely to receive scattered showers and thunderstorms from this area, along with breezy conditions. I do not think that this area should be mentioned in the National Hurricane Center's Tropical Weather Outlook at this time.
Figure 2. Infrared satellite imagery of a tropical wave in the Central Atlantic.
The last area of interest I am watching for the time being is a tropical wave located in the far Eastern Atlantic, which was designated 92L yesterday morning, but dropped this morning. As noted by satellite imagery, this area does have a very broad spin, although dry air is a problem at this time. The CIMSS 850 MB. vorticity product reveals a very elongated area of rotation just to the south/southwest of the Cape Verde Islands, with strong reflection in the mid-levels of the atmosphere. Wind shear is a low 5-10 knots, but the wave itself is convection-less and looks disorganized due to the vast amount of Saharan Air Layer (SAL) that it has had to deal with over the past few days. However, as more tropical waves emerge off the coast of Africa, the environment as a whole is moistening in that area, and eventually, SAL shouldn't be much a problem. When the models were run on this system yesterday, all of the intensity forecasts took this up to tropical storm status, and most even took it up to hurricane status. However, early cycle runs are not to be trusted, especially since the invest is no longer active, and it is disorganized. At this time, I do not believe the National Hurricane Center should give this area any kind of reflection in the Tropical Weather Outlook.
Figure 3. Rainbow satellite imagery of the tropical wave in the Eastern Atlantic.
Overall, the tropical Atlantic is relatively quiet for the time being. There are no active tropical cyclones at this current time, and I do not expect any development any time soon, unless Emily decides to return from the dead after returning from the dead. While it is quiet, I encourage residents living along the United States coastline to review their Hurricane Preparedness plans, as there are several indications of a significant uptick in tropical cyclone activity by mid-late August. If you wait until a tropical cyclone is threatening the United States, it may be a little too late. Overall for the rest of August, I forecast three more named storms, give or take one or so. The pattern favors a track very close to the United States, so I hope everyone is prepared.
With the Atlantic quiet, it may be a while before my next blog entry. However, if we do have a surprise storm pop-up, I will have an update. Other than that, I hope you enjoyed my blog entry!
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.