Talking the Tropics With Mike: T'storms more concentrated over W. Caribbean

Oct. 5, 2018 — The "Buresh Bottom Line": Always be prepared!.....First Alert Hurricane Survival Guide... City of Jacksonville Preparedness Guide... Georgia Hurricane Guide.  

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Leslie continues to crawl over the Central Atlantic.  The storm's swell will affect the Florida coastline & much of the U.S. east coast through the weekend & - when combined with onshore flow - result in a high rip current risk at area beaches.  Otherwise Leslie will stay far away from any land areas as the tropical cyclone turns sharply eastward.

Atlantic Basin:

Clusters & bands of strong convection persist over the Caribbean.  Broad low pressure has developed, but the t'storms lack organization & there is a good deal of mid & upper level shear at the moment. Tropical development over/near the Gulf &/or Caribbean appears probable next week but the end result is still - as one would expect at this early juncture - far from certain.  Long range global forecast models have at times "lost" this system.  I would expect models to become more consistent in developing this potential tropical cyclone in the coming days.  There is a lot of low pressure over a wide area from the Caribbean through the Gulf which may cause a delay in the "bundling" - or organization - of a single area of low pressure.  In any case.... tropical moisture will begin to surge northward next week & will likely result in an increase in rainfall for Jacksonville/NE Fl./SE Ga.

Spaghetti plots for the potential disturbance below (not a lot of tracks because not all forecast models are onboard for development):

The overall pattern through the first 2+ weeks of Oct. will favor tropical development over the Atlantic Basin.  The velocity potential anomaly map below indicates expansive green lines - upward motion - spreading from the E. Pacific into the Atlantic Basin, part of a MJO (Madden-Julian Oscillation) pulse.  While tropical development could occur just about anywhere, it would appear we especially need to be vigilant of the Caribbean &/or Southwest Atlantic from approximately Oct. 8 through the 16th.

Note the secondary peak of the hurricane season in mid Oct.:

CIMMS satellite below shows the extent of dry air but also indicates it doesn't necessarily shut down the basin.  Note the considerable dry air between Leslie & Florida which will help to shut down widespread rainfall for Jacksonville/NE Fl./SE Ga. through Friday/Saturday.

E. Atlantic:



Mid & upper level wind shear (enemy of tropical cyclones) analysis (CIMMS). The red lines indicate strong shear:

The Atlantic Basin.... note the disturbance/tropical wave over the far E. Atlantic....


Gulf of Mexico:

Water vapor imagery (dark blue indicates dry air) - notice the dry air spinning into Leslie:

Deep oceanic heat content is seasonably high over the Caribbean, Gulf of Mexico & SW Atlantic as one would expect early in the fall....

Sea surface temp. anomalies:

SE U.S. surface map:

Surface analysis centered on the tropical Atlantic:

Surface analysis of the Gulf:


The E. Pacific remains active....

"Sergio" is a strong hurricane well offshore of Mexico, far to the south/southwest of the Baja & will turn northwest over open water through late week then veer back to the west.  Eventually the tropical cyclone - or its remnants - may affect parts of Mexico, the Baja & Southwest U.S. next week when a deep upper level trough sets up shop over the Western U.S.