Support this site:

Add our blog feed to your favorite reader.


Posts by Date

August 2016

Invest 99L not an Imminent Threat – Future Development Uncertain

   Posted by Levi at 5:02pm on August 20, 2016

Invest 99L, a broad area of low pressure in the eastern Atlantic, will continue moving westward toward the Lesser Antilles during the next 3-4 days. This low, being large in size and lacking in thunderstorms, is not an imminent threat to become a tropical storm. However, large waves such as this one have the potential to survive for several days until they reach a more favorable environment and/or become more compact, at which point they sometimes develop. Whether 99L will be able to eventually develop into a tropical storm is uncertain. The large circulation means that 99L’s exact track is difficult to predict, and its track will have a large impact on its future. A track over the Greater Antilles or the central Caribbean could destroy the disturbance, but a track north of Hispaniola could allow some development in the longer term if 99L survives that long. The large circulation also means 99L will need a lot of time to become more compact, which is necessary for development. For now, 99L is not showing any signs of organizing further, and model forecasts have trended less aggressive with 99L’s development over the last 24 hours, usually a sign that the system will struggle, at least for a while. Large-scale descent is also present across the tropical Atlantic right now, generally suppressing convection, which makes it more difficult for 99L to form thunderstorms and consolidate its circulation.

The National Hurricane Center currently gives 99L a 50% chance of developing into a tropical storm over the next 5 days, and I agree with these odds given the uncertainties currently present. At this point, 99L is not an imminent threat to the Lesser Antilles. However, even if 99L does not become a tropical storm before reaching the Caribbean, these waves always have the potential to generate tropical storm-like conditions in the Lesser Antilles if they are healthy. Potentially adverse conditions from 99L could reach the Lesser Antilles by Wednesday next week.




  • Akshay says:

    Video update?

  • Anonymous says:

    Hi. I saw your GFS Model.

  • Harrycane says:

    Thank You for your input Levi

  • Anonymous says:

    Thanks Levi appreciate your feedback

  • Hank Dolce says:

    Chances for development for me have gone down significantly. The strong presence of wind shear, dry air, and a stable atmosphere show me this system will have a hard time getting started in near and west of the Lesser Antilles. However, if it’s circulation remains intact as it nears the Bahamas, I believe it will have a much better shot for development.

  • RebLBrown says:

    Previous two posts are spam.

    • Crist Cace says:

      Yes indeed. It is unbelievable that people want to spam that way. This is supposed to be a place for weather research and information. Not a place for spam.

    • RebLBrown says:

      Levi has deleted the spam posts. I don’t want anyone to think I was complaining about Hank or Patrick. Unfortunately, the spammer has resurfaced below, if all will pardon the apparent contradiction in terms.

  • Dave says:

    Thank you Levi for all of your information! You are my number one source for information on what is really going on with these storms. I can’t believe the spam on your site. I would be happy to help you moderate these posts if you are interested. I would delete any non-sense and let the rest post to your site. Just reply and we can exchange emails. Again, thank you for your hurricane insight!!

  • Nuno says:

    I’m more hyped on 90L. Also, Poo Sharer, can you please go off the internet and do less stupid stuff? Thanks if you do.

  • Jay says:

    I agree Poo has no place here. Maybe Levi can flush him

  • Alex says:

    Levi, 6z run of HWRF-P shows 99L as a moderate tropical storm when in the Bahamas at 126 hours out, yet the same run shows it as a Cat 2 in the Bahamas when I click on Fiona for 126 hours out. Is there a bug in the model? Which one should i trust?

    • Levi says:

      The runs for Fiona and the runs for 99L are separate, so you can get two different forecasts if the model domains both happen to contain 99L. You shouldn’t really trust either model – it takes professional interpretation of all of the models to come up with the best forecast. Right now it is highly uncertain what 99L might do after moving into the Bahamas.

  • ronboc says:

    Sorry if this off-topic, but as a total new-comer to your site I couldn’t find anywhere else to express my gratitude for your work. Easily understandable to the casual observer and at the same time completely detailed enough to make some definitive personal analyses as to what’s happening weather-wise.

    I wish to thank you many times over, both figuratively and literally.

    Keep up the excellent stuff!

  • Anonymous says:

    Hi Levi,

    So the Euro is turning the blog into mayhem right now. Lol. Just curious if you think this a plausible run? It seems as though anything that comes in from that set-up is normally an issue for a lot of people. The reason I ask if it’s plausible, Dr Masters really doesn’t mention this set-up in his blog today. Thanks for the knowledge….

  • Poo Sharer says:

    Rate My Poo Is Alive.

  • Anonymous says:

    NHC 5 Day Tropical Weather Outlook:

  • BeachFoxx says:

    Thank you Levi! You are the best!

  • J says:

    Watch it beeline from Florida to Baton Rouge, Louisiana at about a 45 degree angle.

  • Comments closed

    Basic HTML is allowed.