000 AXNT20 KNHC 251741 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 PM EST SUN DEC 25 2016 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 1715 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the the east Tropical Atlantic near 6N11W to 4N18W where the ITCZ begins and continues along 6N38W to 2N50W. Scattered moderate to isolated strong convection is within 45 nm of 3.5N between 10W-16W. Clusters of scattered moderate convection are within 120 nm north of the ITCZ between 24W-35W and from 2N to the ITCZ between 28W-39W. ...DISCUSSION... GULF OF MEXICO... An upper ridge extends from the Caribbean across central Cuba and the Florida peninsula to over the east CONUS giving the Gulf southerly flow aloft. At the surface is a weak surface ridge extending from the northeast Gulf to the southwest Gulf. A weakening diurnal surface trough extends from 24N95W to the coast of south Mexico near 18N94W. This is splitting the main surface ridge from a 1018 mb high over east Mexico near Tuxpan. The southerly surface, return flow is generating isolated showers from 22N-25N between 91W-94W with isolated showers moving west through the Straits of Florida south of the Florida Keys. Little change is expected through Thursday, with the diurnal surface trough developing over the Yucatan peninsula each night and dissipating in the southwest Gulf each morning. A cold front may enter the Gulf Thursday night. CARIBBEAN SEA... An upper ridge extends from Colombia across the west Caribbean and central Cuba into the Gulf of Mexico and west Atlantic. Difflunce on the west side of this upper ridge coupled with easterly trade winds are developing scattered to numerous showers and isolated thunderstorms over the west Caribbean and portions of Central America from 12N-17N between 80W-87W. The easterly trade winds are generating a swath of isolated showers across the basin from 12N-17N from the Lesser Antilles and 80W. The west Atlantic surface ridge will increase the winds and seas across the Caribbean through Tuesday then diminish on Wednesday and Thursday as the ridge shifts east and weakens. HISPANIOLA... Isolated showers are possible across the Dominican Republic this afternoon compliments of the easterly trade winds. Fair weather is expected elsewhere. This scenario will continue through Thursday. ATLANTIC OCEAN... The upper ridge over the Gulf of Mexico covers the west Atlantic west of 60W. An upper trough north of the area is supporting a cold front that extends through 32N74W to 31N79W. A weak surface ridge covers the remainder of the west Atlantic. The upper trough over the central Atlantic continues to shift northeast supporting a frontal boundary that has begun to shift north as a warm front with a surface trough extending from 31N54W to 26N58W. Scattered showers are within 60 nm of the surface trough. An upper low is in the east Atlantic just north of the Canary Islands with an upper trough covering the area north of 25N east of 30W and is supporting a surface trough that extends from 27N26W to 21N32W. Scattered showers are associated with the upper low covering the area north of 27N east of 20W to over west Africa and including the Canary and Madeira Islands. The west Atlantic surface ridge will persist through Thursday night. The west Atlantic cold front will clip the north portion of the basin as it moves into the central Atlantic. For additional information please visit http://www.hurricanes.gov/marine $$ PAW