There continues to be two areas of interest in the Atlantic today, both only having a low chance of development within the next five days. Models continue to indicate that a broad area of low pressure will likely form over the Northwestern Caribbean during the next few days, eventually emerging into the Gulf of Mexico. The National Hurricane Center continues to give this system a near zero percent chance of development within 48 hours, and a 20 percent chance of development within 5 days. In the deep tropical Atlantic, a vigorous tropical wave has a low chance to develop into a tropical cyclone. The NHC gives this system a 10 percent chance of development within 48 hours, and a 20 percent chance of development within five days.  Having two simultaneous areas of interest in the month of June is somewhat rare, but neither is very impressive at the moment and tropical cyclone development is far from a certainty at this time.

Caribbean/Gulf Monsoon Gyre

Global models have predicted for over a week that a broad area of low pressure would develop in the Northwestern Caribbean associated with a monsoon gyre. During the past couple of days, however, models have begun to show a weaker system struggling to consolidate. The 12z Wednesday GFS model does not even predict a tropical cyclone to develop at all, and the 12z Wednesday ECMWF shows a broad area of low pressure that lacks a well-defined center. While heavy rainfall in the Yucatan Peninsula seems like a certainty, it is beginning to look less likely that a tropical cyclone will develop over the Northwestern Caribbean. I only give this system a 10 percent chance of developing into a tropical cyclone before it crosses over the Yucatan Peninsula late this weekend. In total, I give this system a 30 percent chance of developing into a tropical cyclone during the next ten days, most likely in the Bay of Campeche. The large size of this system will be a major detriment to intensification, and anything more than a moderate tropical storm is unlikely. There is still a slight chance that this system could make landfall in the United States Gulf Coast, but a Mexico landfall is more likely if development does occur.

An Unusual June Tropical Wave

The tropical wave mentioned yesterday was first mentioned by the National Hurricane Center in its tropical weather outlook early this morning. The tropical wave has changed little in overall organization since yesterday, but showers and thunderstorms have decreased significantly today. Model support for the development of this wave remains somewhat limited, with the 12z Wednesday GFS showing a strong tropical wave with tropical storm-force winds by next week as it approaches the Lesser Antilles.  The 12z Wednesday CMC also predicts the possible development of a weak tropical cyclone from this wave. However, the 12z Wednesday ECMWF model forecasts the tropical wave to remain at a low latitude and eventually run into South America without development. I only give this system a 20 percent chance of developing during the next ten days – the same as the NHC – due to the fact that it is very rare for this time of year and the lack of Coriolis Force at its low latitude. However, conditions are otherwise favorable for development, with warmer than normal sea surface temperatures of 27-28°C (80.6-82.4°F) and a fairly moist environment. This wave is the earliest African tropical wave to be included in a NHC tropical weather outlook since 2010 – which ended up being a very active Atlantic hurricane season with 19 named storms, 12 hurricanes and 5 major hurricanes. In most cases, except for 2013, early activity in the deep tropical Atlantic often foretells an above-average season is on the way.

I think Tropical Storm Bret has about a 50 percent chance of forming during the next ten days, so it is far from certain we will see our second named storm of the season just yet. I will be back for another post tomorrow afternoon discussing these two systems, which we will likely be monitoring for several days.