000 AXNT20 KNHC 150602 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 102 AM EST Fri Dec 15 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 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...SPECIAL FEATURES... ...Gale Warning Gulf of Mexico... As of 0300 UTC a cold front extends from SW Louisiana to southern Texas. Northerly winds behind the front will rapidly increase from fresh to near-gale force through sunrise Friday when minimal gale-force winds are expected to develop offshore of Mexico. Seas will build to 8 ft in the area with the highest winds. These conditions are forecast to diminish by sunrise on Saturday. See the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...Caribbean Gale Warning... Strong high pressure will build north of the Caribbean by Friday evening resulting in a tight pressure gradient in the south central basin where trades will increase to fresh to strong. A strong pressure gradient will continue during the weekend allowing for the development of gale-force winds northwest of the Colombian coast starting Friday night through early Monday. Seas will build to 13 ft in this area. See the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the west coast of Africa near 07N13W to 07N15W where the ITCZ continues along 04N27W to 01S46W. Scattered moderate convection is observed from 01N-10N between 07W and 34W. ...DISCUSSION... GULF OF MEXICO... Surface ridging extends from the central Atlc SW across the Florida peninsula and into the eastern half of the Gulf where it provides with light to gentle anticyclonic flow. Gentle to moderate SSE flow is in the SW basin ahead of a cold front that extends from SW Louisiana to near Brownsville, Texas. Northerly winds behind the front will rapidly increase from fresh to near- gale force through sunrise Friday when minimal gale-force winds are expected to develop offshore of Mexico. Looking ahead, the cold front will reach from the Florida Big Bend area in the northeast Gulf to near Tampico Mexico by Friday night. The front will stall from Tampa to the Bay of Campeche on Saturday before lifting back to the northwest through Sun. Gale-force winds are forecast along the coast of Mexico near Tampico from Friday night to Saturday morning. See the Special Features section for further details. CARIBBEAN SEA... Shallow moisture associated with the remnants of a former stationary front support isolated showers over the NW Caribbean. In the SW basin, a surface trough extends from 17N79W to 09N81W supporting similar shower activity W of 80W. A nearly stationary surface trough N of the area may support isolated to scattered showers over NE Puerto Rico and and Dominican Republic. Middle to Upper level ridging and dry air subsidence support stable conditions elsewhere. Strong high pressure will build north of the Caribbean by Friday evening resulting in a tight pressure gradient in the south central basin where trades will increase to fresh to strong. A strong pressure gradient will continue during the weekend allowing for the development of gale-force winds northwest of the Colombian coast starting Friday night through early Monday. See the Special Features section for further details. ...HISPANIOLA... Cloudiness prevail mainly over the Dominican Republic due to the proximity of a nearly stationary trough in the SW N Atlc extending to eastern Cuba. Isolated showers are possible mainly over higher terrain through Friday morning. Then, moisture will diminish as the trough continues to weaken and drift westward. ATLANTIC OCEAN... Strong surface high pressure anchored south of the Azores extends a ridge axis into SW N Atlc waters as well as the central and eastern Atlc. A weakness in the ridge, remnants of a former stationary front, is analyzed as a surface trough from 30N54W SW to the southern Bahamas to eastern Cuba. Isolated showers are within 120 nm either side of this boundary. A cold front will move off the northeast Florida coast early on Friday, reach from Bermuda to south Florida Saturday, then will stall and gradually dissipate along 25N through early next week as high pressure from the southeast United States builds eastward across the area. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos