000 AXNT20 KNHC 140002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 802 PM EDT Fri Apr 13 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURE... A strong cold front will cross the Gulf of Mexico beginning Saturday, and will move SE Saturday through Sunday night over the Gulf basin. High pressure building behind the front will support gale force northerly winds S of 25N over the SW Gulf behind the cold front starting Saturday afternoon and continuing until midday Sunday. For more details please refer to the High Seas Forecast under AWIPS/WMO headers HSFAT2/FZNT02 KNHC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of western Africa near 09N13W to 04N20W. The ITCZ continues from 04N20W to 03N35W to 00N50W. Scattered moderate isolated strong convection is observed from 01N to 07N between 07W and 30W. Scattered moderate convection is from 01N to 06N between 30W and 48W. ...DISCUSSION... GULF OF MEXICO... No significant shower activity is occurring across the Gulf of Mexico today as the western extension of a surface ridge and abundant dry air aloft continues to support fair weather. The surface winds are generally out of the southeast or south and are strongest over the northwestern waters, where buoys and ships are reporting 20-25 kt winds. The highest seas are near 7 ft off the Texas and western Louisiana coasts this evening as confirmed by buoy 42002. Seas are notably lower over the eastern Gulf waters due to the lighter winds and limited fetch. Looking ahead to the weekend, a cold front is expected to move over the northwestern waters by Saturday morning. This boundary is then expected to sweep across the entire area by Sunday night, with strong northwesterly winds in its wake. Gale force winds are forecast behind the front over the SW Gulf for a portion of this weekend. Please refer to the Special Features section for more details. CARIBBEAN SEA... Fairly quiet weather conditions are occurring over the Caribbean Sea today, with only the typical patches of clouds and embedded showers moving westward across the region. The showers appear more concentrated over the eastern Caribbean, generally north of 15N and east of 72W. The trade wind flow is moderate due to weak ridging north of the area and strong flow is generally confined to the usual location, near the north coast of Colombia. Seas are also fairly moderate, generally 4 to 6 ft, except a little higher near the coast of Colombia. High pressure is expected to strengthen to the north of the area, this will cause winds and seas to increase by late this weekend. A late season cold front is expected to make it to the northwestern waters Sunday night or early Monday before weakening shortly thereafter. ATLANTIC OCEAN... A stationary front is producing scattered showers within 120 N mi of its axis and scattered showers and isolated thunderstorms within 120 nm S of its axis that extends from 32N53W to 26N61W. A weak trough has broken off the tail end of the front and is analyzed from 29N65W to 25N69W. Scattered showers and isolated thunderstorms are occurring within 120 n mi east and 60 n mi west of that axis. Winds are around 15-20 kt just north and northwest of the trough axis due to the pressure gradient between that feature and high pressure to the north of the area. Otherwise, generally tranquil weather prevails across the remainder of the western Atlantic. Looking ahead to the weekend, southerly flow is expected to increase over the far western Atlantic waters ahead of the next cold front. This front is expected to move over the western Atlantic Sunday night and early Monday. Farther east, a 1028 mb high pressure system is centered over the eastern Atlantic near 29N35W. This high pressure is maintaining light to moderate winds north of 20N and moderate to fresh trade winds farther south over the deep tropics of the eastern Atlantic. Earlier altimeter satellite passes indicate seas of 8 to 10 ft mainly south of 20N, likely in NE to E swell. For additional information please visit http://www.hurricanes.gov/marine $$ Latto