000 AXNT20 KNHC 181042 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 642 AM EDT Wed Apr 18 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 1030 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 09N14W to 05N15W to 03N25W. The ITCZ continues from 03N25W to 02N45W. Scattered moderate convection is within 30 nm south of the monsoon trough axis between 15W and 20W, and within 60 nm north of the ITCZ between 35W and 45W. ...DISCUSSION... GULF OF MEXICO... Fresh SE winds persist off the coast of Texas between the ridge and lower pressure forming over Texas. Seas are 5 to 7 ft in the northwest Gulf accordingly, with 2 to 4 ft elsewhere. No shower or thunderstorm activity is noted, and visibility remains unrestricted across the basin. The ridge over the northern Gulf will continue to shift east ahead of a cold front moving east through the Southern Plains, allow the fresh SE return flow over the northwest Gulf to diminish through late Wed. The front will enter the northern Gulf Thu, stall from southwest Florida to south Texas Fri, before lifting back north as a warm front Sat ahead of yet another cold front moving across Texas. The second front is expected to move across the northwest Gulf, and reach from near the western Florida panhandle to the SW Gulf Sun night. A warm front will extend out ahead this front across the eastern Gulf. CARIBBEAN SEA... A few showers linger between Jamaica and eastern Honduras along the remnants of a dissipated frontal boundary that moved into the northwest Caribbean earlier in the week. Farther west, a few showers are active over the northeast Caribbean, with a thunderstorm active briefly south of Puerto Rico earlier this evening, related to a trough moving through the Virgin Islands and Puerto Rico. Farther south, a couple of ship observations in the ABC Islands indicate fresh to strong trade winds are active along the coast of northwestern Venezuela and northeast Colombia. Meanwhile, swell is still reaching 8 ft east of Windward Islands as noted in a recent altimeter satellite pass. The trough over the eastern Caribbean will gradually become diffuse as it passes across eastern Hispaniola Thu. Ridging north of the region will maintain fresh to strong winds off Colombia through late in the week, expanding from the south central into the southwest Caribbean late Wed through late Fri. These winds then diminish Sat afternoon, before pulsing back up to fresh to strong Sat night into Sun. ATLANTIC OCEAN... A frontal boundary from 31N65W to the southern Bahamas and Turks/Caicos Islands is starting to stall and weaken. Showers and isolated thunderstorms remain active along the boundary from 24N to 28N. Seas are still reaching 8 to 10 ft north of 26N west of front to 75W in NW swell. Seas in open waters are 4 to 6 ft elsewhere except 2 to 4 ft off northeast Florida. The front start to dissipate later today and the remains of the front will lift northward through Fri ahead of the next cold front. This next 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. The gradient will tighten between the front and high pres that builds eastward north of 28N on Sat night into Sun allowing for east winds to increase over much of the waters west of 70W. Farther east, a 1028 mb high is over the central Atlantic near 33N44W. The tail-end of a cold front is over the east Atlantic from 32N22W to 29N30W. A large area of NW swell with wave heights of 8-15 ft will accompany this front covering a large portion of the area north of 20N and east of 45W Wed through Friday. Seas will gradually decay to below 8 ft Saturday into Sunday. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen