At 2:00 PM, the US NWS National Hurricane Center issued a Special Tropical Weather Outlook concerning an expected area of low pressure expected to develop southwest of Bermuda in the far western Atlantic. This expected area of low pressure has medium chances of tropical development near 40%, over the next 48 hours, and medium chances of development over the next 5 days, at 40%. This system is of no threat of Trinidad, Tobago and the remainder of the Eastern Caribbean.
The National Hurricane Center (NHC) is monitoring an area in the Western Atlantic for the expected development of low-pressure southwest of Bermuda on Monday. According to the NHC, this system could develop into a short-lived subtropical or tropical cyclone late Monday or Tuesday while moving northward or northeastward. Environmental conditions are expected to become unfavorable for further development by Wednesday.
Of the top three global models for forecasting tropical development, only the GFS (both GFS and FV3-GFS) and the UKMET show a brief window late Monday into Tuesday of a closed, relatively compact, surface circulation with tropical or subtropical characteristics. The EMCWF is less optimistic for development, with its EPS ensembles dropping all chances for development, and the operational model showing lower pressure in the area, but no closed low-pressure center.
However, for the models that show some development, they also show quick degeneration as a stronger non-tropical low-pressure system to the north will steer this weaker, potentially tropical or sub-tropical system northward to northeastward, by Wednesday into Thursday 23rd May.
Regardless of formation, interests in Bermuda should monitor the progress of this system. An Air Force Reserve reconnaissance aircraft is scheduled to investigate the disturbance Monday afternoon, if necessary.
The next Special Tropical Weather Outlook will be issued by 8 PM EDT this evening.
This system poses NO threat to the Eastern Caribbean, including Trinidad and Tobago.
If this system were to develop, the first name on the list of names for the 2019 Atlantic Hurricane Season is Andrea.
Tropical Weather Outlook Elsewhere Across the Atlantic Basin
No tropical development is forecast elsewhere across the Atlantic Basin over the next 5 days. According to the National Hurricane Center, there are no tropical waves in the Atlantic Basin currently being monitored in their latest tropical weather outlook or discussion.
Other meteorological offices such as the Barbados Meteorological Service and U.S. NOAA NWS Weather Prediction Center – International Desks may be monitoring features they designate as tropical waves, likely due to the origins near Africa.
However, the National Hurricane Center has not determined classical genesis from the African Easterly Jet and convection over North Africa for these features.
This whole designation issue may come across to the layman as pedantic, as the impacts of locally heavy rainfall, thunderstorms, and gusty winds are generally the same. However, the designation is significant to Trinidad and Tobago because the passage of the first Tropical Wave (or the first time the ITCZ modulates across T&T) signals the start of the wet season for the islands. Following the passage of the first true tropical wave, as designated by either the National Hurricane Center or by the discretion of the Trinidad and Tobago Meteorological Service, the wet season is declared.
May Tropical Cyclone Climatology
Tropical Cyclone Points of Origin for May (1851-2015). Credit: NWS/NOAA/NHC
While the official start to the Atlantic Hurricane Season isn’t until June 1st, early season tropical cyclones are not unheard of. 50 of the 89 out of season tropical cyclones in the Atlantic Basin have formed in the month of May, with the most recent being Tropical Storm Alberto on May 25th 2018. Thankfully, for Trinidad and Tobago, these early season systems tend to form in the Western Caribbean and Southwestern Atlantic, with no impact to the Eastern Caribbean and T&T.
However, it serves as a reminder that the 2019 Hurricane Season is rapidly approaching and it is important to become prepared for both the hurricane season and the rainy season ahead!