At 1:00 PM, the US NWS National Hurricane Center issued a Special Tropical Weather Outlook concerning an area of low pressure expected to develop southwest of Bermuda in the far western Atlantic. This expected area of low pressure has low chances of tropical development near 0%, over the next 48 hours, and low chances of development over the next 5 days, at 30%.
The National Hurricane Center (NHC) is monitoring an area in the Western Atlantic for the expected development of low pressure south or southwest of Bermuda late this weekend or early next week. According to the NHC, the gradual development of this system into a tropical or subtropical cyclone is possible during the early and middle part of next week while it moves northward or northeastward.
All of the top three global models forecasting tropical development, the UKMET, EMCWF and GFS, in their 0Z and 12Z runs on Friday, have shown support for brief development of this system, with a closed, low-level center of low pressure developing by Tuesday 21st May, into Wednesday 22nd May 2019.
However, as quickly as it develops, models show that 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.
The next Special Tropical Weather Outlook will be issued by 2 AM EDT Saturday, or sooner if conditions warrant.
This system poses NO threat to the Eastern Caribbean, including Trinidad and Tobago.
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.
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!