Hello everyone and happy Friday! For today’s tropical outlook, we will continue to monitor the current conditions, as well as take a look at the model data and how the conditions will change over time. As always we will wrap up with a conclusions section which will condense everything that we went over and important information to take away.
Since the NHC is not currently expecting tropical activity over the next 5 days, we will start with a breakdown of whats happening currently.
Current Tropical Conditions
As you can see from the image, much of the Tropical Atlantic Basin is devoid of any significant shower and thunderstorm activity. In the circled area, we can see tropical waves making their way out into the Atlantic, however given the lack of structure to the storms and abundance of dry air present in the Atlantic, these storms are very unlikely to undergo any significant development, which has led to a quiet tropical season so far.
Looking at the Mid-level water vapor image currently, we can see that the only real areas of moisture are areas with convective activity such as the circled area. You can quickly begin to realize that as the tropical waves make their way off of the coast of Africa, they will quickly run into the Saharan dust intruding into the Atlantic region. This dry air intrusion leads to evaporative cooling, disrupting the warm core tropical systems need to thrive.
If we take a look at the wind shear currently across the Atlantic, we can pick out areas of higher wind shear values near Hispaniola and Cuba, as well as just off the coast of Africa. For the region we highlighted above, storms would actually be in a favorable area in terms of wind shear moving into the MDR (Main Development Region) of the Atlantic, however, the dry air will prevail and prevent significant organization from the tropical waves.
Model Prognosis
With the amount of dry air limiting any tropical development, the main thing we would want to see change would be an increase in moisture availability in order for tropical cyclogenesis to occur.
If we take a look at both the GFS and ECMWF models for relative humidity for next Friday, we can see that both models provide similar results. Dry air will continue to make its way into the Tropical Atlantic Basin, however expected to decrease slightly from the current levels. We can also continue to see moisture transport from the tropical waves as they make their way off the coast of Africa.
Looking at the wind shear from both the Euro and the GFS, we can see high shear just off of the coast of Africa, which weakens moving closer to the Caribbean. Tropical waves moving off of the coast of would initially encounter shear disrupting any development, and then encounter a region with low amounts of shear. If storms could maintain enough moisture, development could be possible given the other ingredients such as sea surface temperatures being well above the threshold to support tropical systems.
Conclusions
Well once again, we have a discussion that mainly focuses on the conditions for the tropics, as we don’t gave any active storms to track and forecast. Nothing much has changed over the past few days, with the lack of available moisture across the MDR leading to thunderstorms and showers being short lived and not well organized. Still, I would like to reiterate that it is important not to let your guard down and to continue to monitor forecasts and be prepared. We are quickly approaching the peak of the Atlantic Hurricane Season in late August and early September, and conditions can change in the future. That’s all for now, be sure to check back to monitor any changes!
