There are two areas of interest Sunday in the Atlantic. Invest 90L south of Jamaica has organized some the past 24 hours. While convection blossoms early Sunday, moderate northwesterly shear displaces it on the eastern side of the tropical wave. Sunday’s Hurricane Reconnaissance mission was rescheduled for Monday afternoon. During this time upper levels will favor further organization, and there is a high chance Invest 90L becomes a tropical depression/Tropical Storm Franklin over the next 5 days. It is moving west-northwest towards Belize and the Yucatan Peninsula Monday.

Beyond Monday/early Tuesday models are in line with a track into the Bay of Campeche. This area is known for its very warm waters. Tropical cyclones often strengthen rapidly here. Many models are on board with a Hurricane Franklin (GFS/ECMWF/HWRF) by Wednesday or Thursday moving onshore in mountainous East Mexico. Models have trended a bit further north, so interest in extreme southern Texas should keep a watchful eye.

Invest 99L has not organized in the Atlantic. Some dry air in the mid levels of the atmosphere keeps convection disorganized early Sunday. The area of low pressure is elongated due to some marginally favorable upper level winds. Wind shear increases as Invest 99L moves west-northwest at 15 mph towards the Lesser Antilles. There is a medium chance it becomes a tropical depression over the next 5 days.

12Z computer models have really backed off on the intensity of Invest 99L. A few days ago some were anticipating a hurricane in the long run. More models are trending towards a west-northwest path north of the eastern Caribbean.

Even if Invest 99L does not become a tropical depression/named storm over the next 5 days it will still be monitored late in the week. Water temperatures are plenty warm for tropical cyclone intensification in the Eastern Caribbean and near the Bahamas.

The Atlantic Basin is active Saturday. Invest 90L in the Caribbean and Invest 99L in the Atlantic are worth keeping an eye on in the days ahead. Invest 90L is a little more organized early Saturday. Scattered convection trying to consolidate under lighter upper level winds circled in orange. It has a medium chance of development the next 5 days, especially if it survives the track across Central America/the Yucatan and enters the Bay of Campeche Tuesday or Wednesday.  This is a hot spot for tropical cyclone development this time of year. Meanwhile Invest 99L southwest of Cabo Verde Islands still battles some dry African air and is disorganized. The likelihood is still high a depression forms over the next 5 days. It moves northwest at 15 mph and approaches the Lesser Antilles mid work-week. The next named storms are Franklin and Gert.

As is always the case with a disorganized, developing tropical disturbance there are some model discrepancies with the forecast track and intensity. The Bermuda High guides Invest 99L on a  general west-northwest track towards the Caribbean over the couple of days. The European model is not impressed at all with Invest 99L and does not develop a tropical depression. The GFS is trending weaker too, but shows some development in the days ahead. A weaker system would tend to head more westerly towards the Caribbean while a stronger system would head more northerly. It is way too early to speculate possible U.S. impacts, if at all.

If Invest 99L survives the track into the Eastern Caribbean/interaction with some of the islands we need to keep an eye on it.  Water temperatures are in the mid to upper 80s. Some areas are running 0.5°C-2°C above average, especially in the western Caribbean. Also of note is an incredibly warm Bay of Campeche where Invest 90L may head.

Upper level winds favor further organization of Invest 90L as it moves west-northwest at 10-15 mph. If some of the energy holds together and spills in the southern Gulf of Mexico mid to late work week it could rapidly intensify.

The ECMWF wind shear model shows favorable upper level winds over a very warm Bay of Campeche next Thursday morning. The Euro still suggests a strengthening named storm late work week. The 0Z brings a strong tropical storm into mountainous East Mexico Thursday. (either Franklin or Gert). The GFS also spins up a low, albeit weaker, in the southern Gulf Wednesday. It also suggests a track into East Mexico.