000 AXNT20 KNHC 251738 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 138 PM EDT Thu Oct 25 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... A surface trough is along 24N46W, to a 1010 mb low pressure center that is near 21N48W, to 17N58W. The broad area of surface low pressure and cyclonic wind flow is becoming better defined, gradually. The surrounding precipitation pattern is showing signs of organization. Widely scattered to scattered moderate and isolated strong rainshowers are within 460 nm of the 1010 mb low pressure center in the NE quadrant. The expected movement of the low pressure center is northward during the next few days, into an area where the environmental conditions are forecast to be conducive for more development. It is likely that a tropical storm or a subtropical storm may form by early this weekend. The system is forecast to turn westward well to the north or northeast of the Lesser Antilles through early next week. The chance of formation into a tropical cyclone during the next 48 hours is high. Please refer to the TROPICAL WEATHER OUTLOOK, MIATWOAT/ABNT20 KNHC, for more details. ...TROPICAL WAVES... An Atlantic tropical wave is along 40W/41W from 12N southward. The position was changed slightly, based on long-loop satellite imagery. Nearby isolated moderate rainshowers probably are more related to the ITCZ. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border sections of Guinea and Guinea-Bissau, to 08N16W. The ITCZ continues from 08N16W, curving to 05N20W 07N32W, and 07N38W, and from 06N43W to 06N50W. Disorganized widely scattered moderate to isolated strong rainshowers are within 180 nm on either side of the line that runs from 03N at the Prime Meridian, to 03N06W 05N15W 06N27W 06N50W. Isolated moderate rainshowers are elsewhere from 14N southward between 50W and 60W. GULF OF MEXICO... A dissipating stationary front extends from Marco Island Florida to 27N89W. A warm front extends from that point to a 1010 mb low just off the coast of Texas near 28N96W. A stationary front extends southward from the low to 23N96W. National Weather Service Doppler Radar indicates scattered to numerous showers and thunderstorms are along the Texas and western Louisiana coasts from Houston to Lake Charles and extending inland. Scattered showers and isolated thunderstorms extend offshore of Texas and Louisiana north of 28N. An upper level cyclonic circulation center is over the southern Gulf of Mexico near 19N92W. Upper level cyclonic wind flow covers the area that is from 22N southward between 89W and 96W. GOES-16 water vapor channels indicate relatively dry air over the southwest Gulf, and mostly clear to partly cloudy skies are present. A 1009 mb low pressure center, that is just inland along the Texas/Louisiana border, will move E-NE across the Gulf coast states through Friday. The low pressure center will be dragging a cold front across much of the Gulf basin. The front will be nearly stationary from central Cuba to the SW Gulf of Mexico by Saturday night. A second cold front will cross the northern Gulf of Mexico beginning on Sunday night. CARIBBEAN SEA... Broad middle level to upper level anticyclonic wind flow spans the entire area. Surface low pressure/cyclonic wind flow covers the Caribbean Sea from 19N southward between 66W and 84W. Widely scattered moderate to isolated strong rainshowers are within 75 nm on either side of the line that runs from NW Costa Rica to 14N80W. Isolated moderate rainshowers are elsewhere in the area of the surface low pressure/cyclonic wind flow. The monsoon trough is along 09N/10N between 75W in Colombia beyond southern Costa Rica. Isolated moderate rainshowers are from 12N southward from 76W westward. Some enhanced rainfall is possible through the remainder of the work week, in the SW Caribbean Sea and in the southern half of Central America from Nicaragua southward, due to an active monsoon trough in the region. Gentle to moderate trade winds will prevail across the Caribbean Sea through Saturday. A cold front, that is crossing the Gulf of Mexico, will become stationary across the Yucatan Channel on Saturday night and Sunday. Fresh trade winds are expected in the south central Caribbean Sea early next week. ATLANTIC OCEAN... An upper level trough has been digging through the Atlantic Ocean, now reaching near 18N62W, just outside the NE corner of the Caribbean Sea. A cold front passes through 32N61W, to 29N67W, and 28N71W. The front becomes stationary from 28N71W to 29N80W. A surface trough is along 31N60W 26N61W 23N67W 22N73W, reaching the SE Bahamas. A second surface trough extends from 22N77W to 26N79W to 28N79W, in the NW Bahamas. Widely scattered moderate to isolated strong rainshowers are within 480 nm to the east and southeast of the 31N60W-22N73W surface trough, from 21N northward. Other rainshowers are within 120 nm on either side of the rest of the 31N60W-22N73W trough, and within NW Bahamas surface trough also. 24-hour rainfall totals that are listed for the period that ended at 25/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.96 in Bermuda. Upper level cyclonic wind flow covers the Atlantic Ocean from 22N northward from 35W eastward. A surface trough extends from a 1014 mb low pressure center that is near 34N24W, to 31N23W, to 29N24W. Isolated moderate rainshowers cover the area that is from 24N northward between Africa and 30W. Isolated moderate rainshowers also are from 10N to 20N between Africa and 40W. The current frontal boundary that is along 28N will transition to a warm front later today, ahead of a developing low pressure center. E to SE winds will increase E of Florida tonight and on Friday, as the low pressure center moves into Georgia. A trailing cold front from the low pressure center will reach from 31N75W into the NW Bahamas on Saturday, then stall and weaken from 31N69W to central Cuba on Sunday. For additional information please visit http://www.hurricanes.gov/marine $$ MT