The tropical wave that left the west coast of Africa this Saturday continues to generate disorganized showers and thunderstorms, which is why the National Hurricane Center (NHC, in English) raised its probability of development in the coming days.
The disturbance received the acronym AL95 mid-morning this Saturday after being considered an area of suspected cyclone. The use of these acronyms allows the generation of satellite images and analysis for any tropical disturbance that has or could encounter the conditions to achieve cyclone characteristics. Its use is part of the new changes that were implemented this year.
A “cyclone” is called any atmospheric system with low pressure developing over tropical waters (between latitude 25 degrees North and 25 degrees South), according to the National Oceanic and Atmospheric Administration (NOAA). Cyclones are even described as atmospheric systems that obtain their energy, mostly, vertically depending on how hot the ocean surface is. In addition, they are symmetrical and their core or center is warm.
In his outlook for tropical conditions at 8:00 am, the N.H.C. stipulated that this disturbance has a 20% probability of developing in the next 48 hours (two days) and a 70% probability of developing in the next seven days.
“Environmental conditions appear conducive to some gradual development of this system through the middle of next week, and a tropical depression is likely to form while moving west and west-northwest at 15 to 20 miles per hour over the eastern and central portions of the tropical Atlantic,” the NHC noted in its report.
The main global and regional models have remained consistent in projecting cyclogenesis (formation of a tropical system with cyclone characteristics) of this system in the middle of next week. However, there is no consensus on the intensity or trajectory in relation to this disturbance, so the margin of error remains wide.
For example, some models project a tropical depression within 96 hours (four days) while others suggest a tropical storm for the same period.
For now, projections with a relative trend regarding its movement suggest that the system will move west and west-northwest passing near the northeastern Caribbean for next weekend. But these projections will change because it is a long-term model, without a cyclone currently formed.
Furthermore, the models – which are computerized systems – tend to give more weight to the statistics from previous years that they use to make their projections, so in the context of the proximity of the peak day of the hurricane season – which is the 10th September – some models may be more aggressive with their projections than others.
Regardless of what these tools suggest, Environmental conditions in the tropical Atlantic are favorable for the development of any atmospheric system and should remain that way in the coming days. The main element in this equation is the warm waters in the Atlantic basin that have sufficient heat energy (water vapor) to enhance the formation of downpours and thunderstorms in this type of phenomena.
At this time, the only certainty regarding the weather forecast for Puerto Rico is that next week will be relatively dry, foggy and hot before, next Friday, a transition period to more humid and unstable weather begins. A tropical wave should approach the area at the beginning of the weekend, before the next system which is the current tropical wave with a high probability of developing within a week.
If it becomes a tropical depression, the system would be the 13th formed this year. Meanwhile, if it reaches storm strength, the cyclone would be named Lee, which is next on the list for this year.
Remember that you should not consume information from unreliable sources (especially on social networks) that propose a unique scenario for Puerto Rico in relation to any of these systems, because no scenario is certain. This factor is important, since some models simulate the worst scenario of an atmospheric phenomenon and any misinterpretation or visualization of these images without proper analysis can generate despair.
Follow official sources of information such as National Hurricane Center and the National Weather Service (SNM) in San Juan. Additionally, you will find all the details you need in the The Time of The New Day.
Carlos Tolentino Rosario is a journalist who covers weather, climate change and science, among others. He holds a certification in weather forecasting from the Department of Meteorology and Atmospheric Sciences at Pennsylvania State University (PSU). He is also a member of the American Meteorological Society (AMS).