Caribbean: A surface trough with ITCZ is bringing some light to heavy showers around the Windwards. This will interact with the South American cold surge from Thursday to Friday to first produce scattered thunderstorms and heavy showers, mainly interior Guianas. Then late Thursday to Friday, spreading to the T&T, Windwards as ITCZ pushes north but with lesser chances for thunderstorms.
Late Thursday to Friday, an upper low/trough will dig in over Bahamas and Hispaniola, which will enhance the moist surge of cloudiness, showers and thunderstorms in the east Caribbean Sea. This will create 1 or 2 surface troughs of low pressure that will move NE and spread periods of heavy showers and thunderstorms into Puerto Rico, Virgin Islands and Leewards… Saturday to Sunday being best chance for heavy.
NHC has tagged this as 20% to form east/near Bahamas. Another low pressure is forecast to form in the SW Caribbean and move NE north of ABC islands towards Puerto Rico/VI by Monday to maintain heavy rainfall chances.
The ITCZ with SE moist surge will be established across the Windwards on weekend and continue into Monday. Periods of heavy rainfall are expected.
1 more thing to watch for is a Central/Eastern Atlantic tropical wave currently being enhanced by upper trough. In recent forecasts by GFS it’s slowing down due to upper trough weakening steering flow both in the Caribbean basin and the Atlantic. This tropical wave is reaching the Guianas areas by late weekend but doesn’t get to the Windwards till Wed-Thurs. Thereafter it could be influenced by upper tough enhancement and provide another wet period thru the next weekend… some other models have some hint of this but Euro keeps it moving a bit faster.
The heavy rainfall period with possible tropical cyclone development is supported in the large scale by forecasts of a strong Kelvin Wave and an already established favorable MJO. In Last pic, the 2nd map is MJO and 3rd map shows strong Kelvin Wave (purple) in East Pacific which will move east into the Caribbean basin weekend to early next week.
Its effect will last into mid-November. We should take the higher rainfall threat more seriously given this plus recent heavy rainfall in the northern islands and southern islands. Flash flooding and mudslides will be easier to occur during periods of heavy rainfall.
Anglina Byron, developed a deep-seated passion for journalism. Anglina is recognized for her tenacity, strength, and unwavering commitment to delivering honest and reliable news across the Caribbean. She covers general affairs of the region.