TROPICAL WEATHER OUTLOOK JUNE 21, 2018... 0316 PM EDT

National Hurricane Center

...TROPICAL WAVES...

As of 1200 UTC, there are four tropical waves between the west 
coast of Africa and the Lesser Antilles. 

A tropical wave is along 25W from 03N-12N, moving W at 20 kt. The
Hovmoller Diagram shows the westward propagation of the wave, 
that coincides with a modest surge of moistened air based on the 
TPW product. Abundant cloudiness surrounds the wave's axis but 
convection is limited.

A tropical wave is along 34W from 3N-11N, moving W at 20 kt. This
wave shows up well as a low amplitude moisture surge on the TPW 
animation. Scattered showers are noted where the wave meets the 
ITCZ.

A tropical wave is along 43W from 3N-11N, moving W at about 15 
knots. The wave is well depicted in the moisture product, and
model diagnostics guidance. Scattered moderate convection is 
noted on either side of the wave's axis from 6N-8N between 40W- 
46W.

Another tropical wave is along 60W from 6N-17N, moving W at about
10 knots. The wave coincides with a high amplitude northward bulge
of moisture, and is also well depicted in model diagnostics 
guidance. Scattered moderate convection is already affecting 
Trinidad and Tobago as well as Barbados, where showers and some 
tstms have been reported. Moisture associated with this feature 
will continue to affect the Windward Islands today. The wave will 
then move across the eastern Caribbean this afternoon through Fri 
night. The associated moisture is forecast by the GFS computer 
model to spread out reaching the Leeward Islands later today and 
tonight, and Puerto Rico on Fri, then Dominican Republic Fri night
into Sat.

A tropical wave is moving across the Caribbean Sea. Its axis is 
along 73W, and extends from Hispaniola to northern Colombia. 
The wave is interacting with an upper-level trough that crosses 
eastern Cuba. Lingering moisture from this tropical wave will 
continue to support scattered showers and isolated thunderstorms 
across Hispaniola today. Moisture and instability related to this 
wave will also affect the Windward Passage and eastern Cuba, 
as well as Jamaica today. Currently, scattered showers and tstms 
are noted in the Windward Passage, across the waters between 
eastern Cuba and Jamaica, and E of Jamaica. This wave is forecast 
to move across Jamaica tonight, entering the western Caribbean 
Fri.

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The tropics remains quiet for now... RTW

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