000 AXNT20 KNHC 151205 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT Mon Oct 15 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. ...SPECIAL FEATURES... A broad area of low pressure, called a Central American Gyre, is centered over the southwestern Caribbean Sea. Scattered moderate to isolated strong convection is noted from 12N to 16N between 78W and 82W. There is a medium probability that a tropical cyclone may develop within this broad circulation as the system moves westward toawards Central America. Regardless of tropical cyclone development, this gyre will bring abundant moisture which will produce heavy rainfall across portions Central America for the next several days, including areas which have already seen heavy rainfall earlier this month. This heavy rainfall will bring the potential for flash flooding and mudslides over areas of mountainous terrain. Refer to your local meteorological service for specific information on this potentially dangerous weather pattern. A cold front will enter the far NW and W central Gulf of Mexico by Tue morning. Ahead of the front, numerous showers and thunderstorms are expected over the far NW and W central Gulf beginning late this morning and increasing this afternoon. This front will slowly shift southward over the western Gulf through Wed night. Fresh to strong northerly winds behind the front will increase to minimal gale force in the W central and SW Gulf behind the front Tue night through Thu night. Winds will diminish below gale force by Fri. Due to the combination of the front with the Central American Gyre mentioned above, expect enhanced shower and thunderstorm activity over the southwestern Gulf of Mexico by Wed. ...TROPICAL WAVES... A low amplitude tropical wave extends its axis along 46W from 01N-12N, moving west at 15-20 kt. A 700 mb trough is shown by model analyses with this wave. TPW imagery indicates abundant moisture in its environment. Scattered moderate to strong convection is occurring from 02N-14N between 42W-49W. A tropical wave extends its axis along 53W from 08N-21N, moving west at 10-15 kt. A 700 mb trough is depicted by model analyses with the wave, and there is a local maximum in TPW. A recent ASCAT pass shows that the tropical wave is well- defined at the surface with 25-30 kt winds from 16N-18N within 60 nm of the wave axis. Scattered moderate to strong convection is noted from 11N-18N between 49W-52W. It is likely that the tropical wave along 46W will be merging with this wave over the next 24 hours. Expect plenty of convective activity near and in between both waves. Moisture associated with these waves is likely to enhance showers and thunderstorms over the Lesser Antilles Tuesday into Wednesday, and this activity will spread to the eastern Caribbean Sea during the middle of the week. A tropical wave extends its axis along 64W from 08N-21N moving west at 10 kt. Scattered moderate convection is over Puerto Rico. Scattered showers are noted over the northern Leeward Islands and Virgin Islands. This wave is expected to continue weakening into Tuesday as it moves toward the central Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the eastern Atlantic from the coast of Africa near 12N17W to 08N21W to 06N30W. The ITCZ extends from 06N30W to 07N43W. Scattered moderate convection is S of the monsoon trough from 01N-07N between 14W-24W. GULF OF MEXICO... See Special Features section above for discussion of an expected gale behind a cold front in the western Gulf Tue night into Thu. An upper-level anticyclone over central Mexico extends an upper- level ridge over the western and north-central Gulf of Mexico. A surface ridge prevails across the northeastern and north-central Gulf. Isolated moderate convection is over the north central Gulf from 26N-28N between 88W-90W. Scattered moderate convection is along the coast of NE Mexico from 22N-26N between 97W-98W. CARIBBEAN SEA... Two tropical waves will affect the Lesser Antilles over the next few days. See the Tropical Waves section for more details. Also see the Special Features section for information relating to the Central American Gyre. A mid to upper level trough extends from 23N66W to the Mona Passage. Elsewhere, scattered showers are within 60 nm of the northwest coast of Venezuela and the northeast coast of Colombia. ATLANTIC OCEAN... See above about the tropical waves in the tropical Atlantic. A cold front extends across the west Atlantic from 32N59W to 30N66W, where it becomes a stationary front. The stationary front extends from that point to 28N74W, where it becomes a dissipating stationary front. The dissipating stationary front extends from that point to near 27N79W. Isolated showers are along and within 60 nm SE of the front. A 1024 mb high is centered near 30N47W, leading to relatively quiet weather elsewhere. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa