AXNT20 KNHC 231139

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
739 AM EDT Sat Jun 23 2018

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 0600 UTC surface analysis and satellite imagery through 1115 UTC.


The axis of a tropical wave is near the west coast of Africa along 16W from 04N-18N. Scattered moderate convection associated to this wave is noted from 06N-10N between 14W and 20W.

The axis of a tropical wave extends from 18N40W to 03N41W. Isolated moderate convection is noted at the base of this wave.

The axis of a tropical wave is near 57W from 04N to 18N, moving W at 20 kt. Scattered moderate convection is noted from 07N-09N between 54W and 59W.

The axis of a tropical wave is near 70W from the coast of western Venezuela to eastern Hispaniola, moving W at 10-15 knots. This wave, in conjunction with an upper level trough, is helping for active convection over the northeastern Caribbean east of the wave axis. This convective activity is affecting Puerto Rico and parts of Hispaniola.

The axis of a tropical wave is near 85W extending from the eastern north Pacific across western Panama to western Cuba. The wave is helping for enhanced convection over the NW Caribbean west of 78W, and the western half of Cuba. Clusters of moderate to strong convection are seen where the wave meets the monsoon trough.


The monsoon trough extends off western Africa near 16N16W to 12N23W to 06N28W. The ITCZ continues from 06N28W to 05N40W to the coast of NE Brazil near 0351W. Outside of the convection associated with the tropical waves, a cluster of moderate convection is noted from 04N-07N between 21W-25W. similar convection is from 07N to 09N between 44W and 54W.



A weak ridge dominates the Gulf waters, producing gentle to moderate winds with seas of 3-5 ft over the western Gulf, and seas of 3 ft or less across the eastern Gulf. Weak ridging from the southeast Gulf to Texas will drift into the northern Gulf early next week. SE return flow will increase over the western Gulf between the ridge and weak low pressure over northern Mexico starting tonight. A trough moving west off the western coast of the Yucatan Peninsula each night will further enhance overnight winds in the southwest Gulf.


A tropical wave is moving across the western Caribbean. Another tropical wave is over the central Caribbean. Please, see Tropical Waves section for more details. Expect increasing showers and isolated thunderstorms in association with the passage of these tropical waves.

Trade winds over the south central Caribbean will strengthen and expand in areal coverage across the basin through early next week as high pressure builds across the central Atlantic. Winds could reach near gale force along the coast of Colombia tonight.


High pressure of 1028 mb centered near 31N45W extends a ridge westward across the forecast area. Fresh trades are noted along the southern periphery of the ridge. This high pressure will slowly shift westward through tonight, then remain nearly stationary near 30N55W through Tue night. The tightening pressure gradient over the central Atlantic will support fresh to strong trade winds and seas of 8-9 ft E of the Lesser Antilles to about 45W by early this morning. These marine conditions will persist on Sun with seas building up to 10 ft. Fresh to strong winds are also expected off Hispaniola at night.

For additional information please visit http://www.hurricanes.gov/marine

$$ GR