000 AXNT20 KNHC 140555 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1255 AM EST Sun Jan 14 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...SPECIAL FEATURES... ...Gale Warning in the Caribbean Sea... A cold front extends from central Cuba to the northern sections of Nicaragua. The 12-hour forecast consists of the front becoming stationary, and extending from SE Cuba to W Panama. Expect N gale-force winds, and sea heights ranging from 10 feet to 12 feet, from 12N to 14N from 82W westward. Expect fresh-to-strong NW-to-N breezes, and sea heights reaching 10 feet, elsewhere to the west of the stationary front. Please read the latest NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...THE MONSOON TROUGH/THE ITCZ... The monsoon trough passes through southern/coastal sections of Ghana, the Ivory Coast, and beyond 05N09W in Liberia, to 04N16W and 03N21W. The ITCZ continues from 03N21W to 01N27W, to the Equator along 32W, and along the Equator to 39W. Precipitation: scattered strong rainshowers from 05N to 07N between 36W and 40W. Isolated moderate to locally strong rainshowers are elsewhere from 08N southward from 56W eastward. ...DISCUSSION... ...THE GULF OF MEXICO... A surface ridge passes through central Texas, to the coastal plains of Mexico, to the Isthmus of Tehuantepec of southern Mexico, to Honduras. Cold air stratocumulus clouds cover much of the Gulf of Mexico, except for maybe the NW corner of the area. A first cold front passes through 32N71W in the Atlantic Ocean, through central Cuba, to the northern sections of Nicaragua. Reinforcing cold air, that has been moving through the eastern half of the Gulf of Mexico during the last 24 hours, is behind a second cold front that is within 130 nm to the NW of the first front on the northern end, and within 280 nm to the NW of the first front on the southern end near NW Cuba. High pressure will continue to prevail across the area through early Monday. The high pressure will slide eastward on Tuesday night. Fresh to locally strong N winds will become moderate to fresh NE to E winds in the Gulf Monday and Tuesday. Another cold front will cross the Gulf from Tuesday night through Wednesday night. ...THE CARIBBEAN SEA... A cold front extends from central Cuba to northern sections of Nicaragua. Please read the SPECIAL FEATURES section for more details about the winds and the sea heights to be associated with the cold front. Cold air stratocumulus clouds are moving from the Gulf of Mexico into the NW corner of the Caribbean Sea. Precipitation: isolated moderate rainshowers mostly are within 360 nm to the E and SE of the front in the Caribbean Sea, and within 480 nm to the SE of the front including in parts of Hispaniola. A surface trough is along 77W/78W from 12N, crossing the western part of Jamaica, toward SE Cuba. Precipitation: isolated moderate rainshowers are from 14N to 20N between Hispaniola and the Windward Passage and 79W. This precipitation is included in the information that already is listed for precipitation with respect to the Caribbean Sea cold front. Rainshowers are possible elsewhere in the Caribbean Sea, from 73W eastward, in areas of broken low level clouds in surface tradewind flow. 24-hour rainfall totals that are listed for the period that ended at 14/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.49 in Guadeloupe. ...HISPANIOLA... The weather conditions that have been occurring during the last 12 hour or so have consisted of the following: scattered low level clouds, some cumulonimbus clouds, and isolated moderate rainshowers with possible thunder. The GFS MODEL forecast for 250 mb shows that a ridge will bring anticyclonic wind flow to the area for the next two days. The GFS MODEL forecast for 500 mb shows that N-to-NE wind flow will move across the area during the next two days, around a Windward Passage anticyclonic circulation center. The GFS MODEL forecast for 700 mb shows that the first two- thirds of day one will consist of anticyclonic wind flow with an Atlantic Ocean- to-Hispaniola ridge. The rest of day one and all of day two will consist of NE wind flow, and finally cyclonic wind flow, as an inverted trough moves across Hispaniola from east to west. ...THE ATLANTIC OCEAN... A first cold front passes through 32N71W in the Atlantic Ocean, through central Cuba, to the northern sections of Nicaragua. A second cold front is within 130 nm to the NW of the first front on the northern end, and within 280 nm to the NW of the first front on the southern end near NW Cuba. Precipitation: widely scattered moderate to isolated strong rainshowers are within 90 nm to the E and SE of the cold front, and within 45 nm to the NW of the first cold front. An upper level cyclonic circulation center is near 25N59W. Upper level cyclonic wind flow covers the Atlantic Ocean and the Caribbean Sea from 12N northward between 50W and 70W. A surface trough is along 23N49W 20N51W 17N51W. Precipitation: widely scattered moderate to isolated strong rainshowers are within 75 nm on either side of 21N50W 24N52W 26N56W. isolated moderate rainshowers are elsewhere from 16N to 28N between 48W and 62W. A second surface trough is along 15N53W 12N54W 08N55W. Precipitation: isolated moderate to locally strong rainshowers are from 09N to 15N between 53W and 61W in the SE corner of the Caribbean Sea. Strong high pressure in the central Atlantic Ocean will shift E slowly during the next few days. The current Atlantic Ocean-to- central Cuba-to-Nicaragua cold front will slow down and stall from 31N71W to E Cuba near 21N76W during the rest of tonight/early on Sunday morning. A secondary surge of cold air has been funneling S. That cold air will continue to the W of the front over the Bahamas on Monday and Monday night before the front weakens. For additional information please visit http://www.hurricanes.gov/marine $$ MT