000 AXNT20 KNHC 111659 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1259 PM EDT Sun Mar 11 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... ...Atlantic Gale Warning... A A cold front will emerge off the Georgia and NE Florida coasts late tonight into early on Mon. The front will reach from near 31N79W to West Palm Beach early Mon afternoon, from near 31N75W to NW Cuba Mon evening, from near 31N67W to 26N70W to eastern Cuba early on Tue before stalling from near 27N65W to central Cuba Tue night. The cold front will gradually weaken through Thu as high pres builds eastward over the area. Minimal to strong gale force winds are expected N of about 29N E and W of the front Mon through Tue. Currently, the GFS computer model suggests 30-35 kt SW winds ahead of the front, and 30-40 kt W-NW winds in the wake of the front. Please see the latest Atlantic Ocean High Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC, for more details. ...Gulf of Mexico Gale Warning... A cold front will move off the Texas coast this afternoon, then race southeastward across the entire basin through Mon, and across the Straits of Florida on Mon evening. A brief gale is expected behind the front over the far west-central Gulf near Tampico, Mexico on Mon, then across the SW Gulf near Veracruz, Mexico late on Mon. Strong northerly winds will follow the front elsewhere. Seas are forecast to build to 10-12 ft with the strongest winds, particularly over the SW Gulf. Please see the latest Atlantic Ocean High Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC, for more details. ...MONSOON TROUGH/ITCZ... The monsoon enters the Atlantic Ocean near the Sierra Leone/ Liberia border, and continues to 04N20W. The ITCZ extends from 04N20W to 00N50W. No significant convection is noted at this time. ...DISCUSSION... GULF OF MEXICO... Currently, a weak ridge dominates most of the Gulf region while a surface trough is noted over the SW Gulf. The weather pattern is forecast to change this afternoon as a cold front moves off the Texas coast. The cold front will race SE across the entire basin through Mon, and across the Straits of Florida on Mon evening followed by strong northerly winds and building seas. Minimal gale conditions are also expected behind the front over the west-central Gulf and SW Guf. Please, see Special Features Section for more details. Sattelite imagery and lightning data show widespread showers and tstms across the N Gulf states as deep moisture from the Gulf interacts with a frontal boundary extending from Georgia to Texas. CARIBBEAN SEA... The most recent scatterometer passes continue to show fresh to strong NE-E winds across the east and central Caribbean, and moderate to locally fresh E-SE winds over the western Caribbean. An area of strong to near gale force winds is south of Hispaniola. These winds are the result of the pressure gradient between the Atlantic ridge, that now extends into the NE Caribbean, and Colombian low. Buoy 42058 located near 15N75W is reporting seas of 13-14 ft. Fresh to strong trades will continue across the waters east of 80W, except near gale force off the NW coast of Colombia and Gulf of Venezuela tonight. Shallow moisture embedded in the trade wind flow will move across the region producing isolated to scattered passing showers. Patches of low level moisture are also reaching Jamaica and the Caribbean plains of Nicaragua. A strong cold front will enter the Yucatan channel and far NW Caribbean Mon night, reach from central Cuba to the Gulf of Honduras Tue, stall from Hispaniola to Nicaragua Tue night, and dissipate by Thu. Moderate to fresh northerly winds and building seas in the 5-7 ft range are expected in the wake of the front over the NW Caribbean. ATLANTIC OCEAN... The short-wave trough and the associated convective active is now affecting mainly the central Bahamas. This activity is capable of producing strong gusty winds and frequent lightning as it quickly moves ENE. This convective activity is also merging with the remnants of a frontal boundary analyzed as a trough on the 1200 UTC surface map. The trough extends 28N63W to 26N71W based on a recent ASCAT pass that shows the wind shit associated with this feature. Showers and tstms are noted near the trough axis. The cold front now extends from 31N44W to 26N60W. Another cold front is forecast to emerge off the Georgia and NE Florida coasts late tonight into early on Mon. Minimal to strong gale force winds are expected on either side of the front. Please, see Special Features section for more details. The remainder of the Atlantic Ocean is under the influence of a ridge with three high pressure centers of 1025 mb. Long period NW swell continues to affect the waters N of 20N E of 30W with sea heights of 9-13 ft. For additional information please visit http://www.hurricanes.gov/marine $$ GR