000 AXNT20 KNHC 161017 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 617 AM EDT Sun Apr 16 2017 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 1015 UTC. ...SPECIAL FEATURE... Strong high pressure over the west Atlantic behind a cold front extending from 30N48W to 24N60W to 23N68W is supporting strong to gale force winds N of 29N within 120 nm E of the front and west of the front to 55W. Seas east of the front are to 11 ft while west of the front are up to 16 ft. Winds are forecast to diminish below gale by early Monday morning. Please refer to the high seas forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across the western Africa coast near 06N11W and continues to 03N20W. The Intertropical Convergence Zone continues from 03N20W to 02N34W to 1N50W. Scattered to isolated showers are within 210 nm either side of the ITCZ and S of the Monsoon Trough. ...DISCUSSION... ...THE GULF OF MEXICO... Broad surface high pressure anchored by a 1029 mb high over NW Atlc waters continue to extend a ridge axis SW across the Florida peninsula and Gulf of Mexico. This is supporting moderate to fresh easterly-southeasterly flow across the basin according to latest surface and scatterometer data. Water vapor imagery show middle to upper level dry air across almost the entire basin, which supports fair weather conditions this morning. No major changes are expected through Tuesday. CARIBBEAN SEA... The pressure gradient between strong high pressure over the west Atlantic and lower pressure over northern Colombia supports fresh to near gale-force winds from 10N to 15N between 64W and 78W. This synoptic pattern is expected to continue through Monday night. Water Vapor and CIRA LPW imagery continue to show very stable conditions over the NW Caribbean while SW winds aloft advects moisture from South America to the eastern basin. All this moisture may induce the development of showers mainly over the NE basin. Shower activity for this region and Hispaniola is expected through Tuesday. Southwest middle to upper level flow from the EPAC waters is supporting scattered showers and isolated tstms over Costa Rica adjacent waters. Model guidance indicate that convection in this region will prevail through Monday night. ...HISPANIOLA... Low and upper level dry air is across the majority of the Island supporting fair weather this morning. Some cloudiness is observed in the southern portion of Hispaniola due to middle level moisture from the EPAC being advected by SW flow. This moisture along with trailing moisture associated with the passage of a cold front to the north will support the development of showers over the Island and adjacent waters today and possibly Monday. ATLANTIC OCEAN... A cold front extends from a 995 mb center of low pressure N of the area near 34N50W and continues to 30N48W to 24N60W to 23N67W. A strong pressure gradient between the high and the front supports gale force winds N of 29N east and west of the front. See the special features section for further details. Otherwise, a stationary front continues to weaken over NE Atlc waters from 30N23W to 26N25W. To the SE, scatterometer data indicate the presence of a 1013 mb low near 21N21W with associated trough extending SE to 22N19W. There is no shower activity associated with either the front or the low. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos