000 AXNT20 KNHC 171030 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 630 AM EDT Tue Apr 17 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 1000 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 06N10W to 03N20W. The ITCZ continues from 03N20W to 02N30W to 03S40W. Scattered moderate convection within 60 nm either side of monsoon trough and ITCZ axes east of 25W. ...DISCUSSION... GULF OF MEXICO... 1023 mb high pressure centered over the north central Gulf near 26.5N 90W is maintaining generally fair weather across the basin. Moderate to fresh SE return flow is commencing over the northwest Gulf between the high pressure and lower pressure over the southern Plains, with seas building to 7 ft. Seas are 4 to 6 ft over the southeast Gulf mainly due to linger NW swell following yesterday's frontal passage. The front left the Gulf fairly dry, and no shower or thunderstorm activity is noted. Visibility remains unrestricted across the Gulf. The high pressure over the north central Gulf will shift east and weaken through mid week ahead of cold front moving into the northern Gulf Thu. The front will stall from southwest Florida to south Texas Fri, before lifting north as a warm front Sat ahead of another cold front over Texas approaching the northwest Gulf. CARIBBEAN SEA... A dissipating stationary front is across the northwest Caribbean from central Cuba to eastern Honduras. Some showers are noted near the front, but are steadily diminishing in intensity and areal extent. Fresh to strong northerly winds are active west of the front, especially in the Gulf of Honduras where an earlier altimeter satellite pass showed seas reaching 8 ft. Farther south, a recent scatterometer satellite pass indicated strong trade winds off the coast of Colombia. Farther east, a vigorous upper trough moving across the eastern Caribbean into the tropical Atlantic was supporting areas of heavy showers and a few thunderstorms across the northern Windward Islands late yesterday. An earlier scatterometer satellite pass indicated fresh to strong easterly winds between Saint Vincent and Martinique. Media sources on Martinique reported small hail Monday in scattered thunderstorms from this disturbance. An associated surface trough west of the Lesser Antilles and diffluent flow aloft from the upper trough is continuing to enhance clouds and showers in the Windward Islands. Gusty winds and higher seas are possible near these thunderstorms through early morning as the supporting upper trough shifts slowly east of the area. Meanwhile, NE to E swell to 8 ft is still present in the tropical Atlantic waters east of the Windward Islands. The front dissipate through late Tue. The trough over the eastern Caribbean will move through Hispaniola and dissipate through mid week. A building ridge north of the region will the area of winds and seas off Colombia to expand across the south central Caribbean into the southwest Caribbean late Wed through late Fri, while maintaining pulses of strong winds off Colombia through late Sat. ATLANTIC OCEAN... A cold front reaches from 31N70W to eastern Cuba. Scattered showers and a few thunderstorms are active along the frontal boundary. Strong SW winds are noted north of 29N within 120 nm east of the front. Strong NW winds are also noted in a recent scatterometer satellite pass north of 30N off northeast Florida, related a reinforcing front moving off the Carolina coast toward the front. Seas are 8 to 11 ft north of 30N west of 68W. Elsewhere over open waters, seas are 5 to 7 ft. The fronts will merge this morning and continue east. The merged front will will slow as it reaches from Bermuda to eastern Cuba late today, before stalling and weakening from 28N65W to central Cuba late Wed, then dissipating Thu as it lifts northward. Another cold front will move off the northeast Florida coast late Thu, reach from Bermuda to south Florida by late Fri, before stalling from 25N65W to the Straits of Florida by late Sat. Farther east, ridging north of 22N between 45W and 65W will dissipate today ahead of a cold front approaching the region from the north central Atlantic. The front will slide east of 35W Wed, accompanied by a large area of NW swell with wave heights of 8-15 ft covering a large portion of the area north of 20N and east of 45W Wed through Fri, before starting to decay below 8 ft through Sat. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen