937 
AXNT20 KNHC 181738 
TWDAT 
 
Tropical Weather Discussion 
NWS National Hurricane Center Miami FL 
138 PM EDT Thu May 18 2017 
 
Tropical Weather Discussion for North America, Central America 
Gulf of Mexico, Caribbean Sea, northern sections of South 
America, and Atlantic Ocean to the African coast from the 
Equator to 32N. The following information is based on satellite 
imagery, weather observations, radar and meteorological analysis. 
 
Based on 1200 UTC surface analysis and satellite imagery through 
1730 UTC. 
 
...SPECIAL FEATURES... 
 
A persistent upper-level trough is digging through the western 
Caribbean from western Cuba into eastern Honduras. A surface 
trough extends from 22N80W to 19N82W. Scattered moderate 
convection is north of 13N between 73W-82W. Although this activity 
has moved south of the islands during the past few hours, re- 
development could occur later today affecting the eastern portion 
of Cuba, Jamaica and Haiti. Please pay attention to advisories 
and bulletins from local meteorology offices, emergency management 
services, and other governmental agencies. 
 
Please refer to the METEO-FRANCE High Seas Forecast, listed on 
the website: WWW.METEOFRANCE.COM/PREVISIONS-METEO-MARINE/BULLETIN/ 
GRANDLARGE/METAREA2. Gale-force winds are forecast for the areas 
of AGADIR and CANARIAS. These conditions will dissipate during 
the next 24 hours. 
 
...TROPICAL WAVES... 
 
A tropical wave extends its axis from 11N42W to 01N43W, moving 
west at around 15 kt. Abundant moisture prevails in this wave''s 
environment as noted in TPW imagery. Scattered showers are 
observed from 04N-08N between 41W-46W. 
 
A tropical wave is moving across eastern Venezuela with axis 
from 11N63W to 00N63W, moving westward at 10 knots. No 
significant convection is related to this wave at this time. 
 
A tropical wave extends its axis from 15N79W then into the EPAC 
near 05N79W, moving west at 10 kt. Abundant moisture prevails in 
the wave''s environment, as noted in TPW imagery. Scattered 
moderate convection is observed within this wave affecting the 
south- central Caribbean from 13N- 18N between 73W- 79W. 
 
...ITCZ/MONSOON TROUGH... 
 
The Monsoon Trough extends from 18N16W to 06N26W. The ITCZ 
continues from that point to 05N41W. No significant convection is 
related to these features at this time. 
 
...DISCUSSION... 
 
GULF OF MEXICO... 
 
Upper-level westerly flow covers the Gulf of Mexico. At the 
surface, a ridge extends along 29N/30N anchored across the 
western Atlantic near 33N65W. Lower pressures prevail across 
Mexico and the far west Gulf waters. The pressure gradient 
generated by these pressure tendencies is supporting moderate to 
fresh southerly winds across the northern half of the basin. 
Light to gentle winds prevail elsewhere. Little change is 
expected during the next 24 hours. 
 
CARIBBEAN SEA... 
 
A tropical wave is moving across the south-central portion of the 
basin. Please refer to the section above for details. A deep- 
layer surface trough extends its axis across the western Caribbean 
and western Atlantic. A surface trough was analyzed from 22N80W 
to 19N82W. A diffluent flow prevails to the east of these troughs 
supporting scattered to numerous showers and thunderstorms north 
of 13N between 73W-82W. This activity has been very persistent 
during the past 24 hours. Despite the fact that the convection 
has moved south of the island of Jamaica, Cuba and Hispaniola, re- 
development could occur later today. Please pay attention to 
advisories and bulletins from local meteorology offices and other 
governmental agencies. Scatterometer data depicts moderate trades 
across the far west and far east portions of the basin while fresh 
to strong easterlies prevail between 70W-78W. A similar weather 
pattern is expected during the next 24 hours. 
 
...HISPANIOLA... 
 
Upper-level diffluence aloft prevails across the island supporting 
cloudiness and isolated convection over the island. The strongest 
activity remains offshore, but re-development over the island could 
occur during the next 12-24 hours. Please pay attention to 
advisories and bulletins from local meteorology offices and other 
governmental agencies. 
 
ATLANTIC OCEAN... 
 
A Gale Warning is in effect for the far east Atlantic waters. 
Please refer to the section above for details. A 1025 mb surface 
high is centered near 33N65W. Its associated ridge extends across 
the western Atlantic. Another surface ridge extends across the 
remainder of the basin, anchored by a 1031 mb high centered near 
41N24W. A tropical wave are moving across the basin. Refer to the 
section above for details. 
 
For additional information please visit 
http://www.hurricanes.gov/marine 
 
$$ 
 
ERA