{"msg": "934\nAXNT20 KNHC 180435\nTWDAT \nTropical Weather Discussion\nNWS National Hurricane Center Miami FL\n0615 UTC Fri Sep 18 2026\nTropical Weather Discussion for North America, Central America\nGulf of America, Caribbean Sea, northern sections of South\nAmerica, and Atlantic Ocean to the African coast from the\nEquator to 31N. The following information is based on satellite\nimagery, weather observations, radar and meteorological analysis.\nBased on 0000 UTC surface analysis and satellite imagery through \n0430 UTC.\n...TROPICAL WAVES...\nA central Atlantic tropical wave has its axis along 36W from 03N \nto 18N, moving westward near 15 kt. Scattered moderate convection\nis from 08N to 15N between 31W and 42W.\nA central Caribbean tropical wave has its axis along 72W, moving \nwestward at 10 to 15 kt. Scattered moderate convection is noted\nalong the wave axis and N of 17N.\n...MONSOON TROUGH/ITCZ...\nThe monsoon trough enters the Atlantic near 18N16W and continues \nsouthwestward to 10N39W, where it transitions to the ITCZ to \n07N58W. Aside from convection associated to the tropical waves as\ndescribed above, scattered moderate convection is evident from \n09N to 12N between 47W and 51W.\n...GULF OF AMERICA...\nA trough is analyzed from just west of the Bahamas, southwestward\nacross extreme South Florida and to just north of the Florida \nKeys, reaching to near 24N86W. A western Gulf trough extends from \n25N96W to 24N97W and to 19N94W. Scattered moderate convection is\nnoted along both troughs. The pressure gradient between high \npressure over the southeastern U.S. and a weakening frontal trough\nover the SE Gulf supports fresh NE to E winds and moderate seas \nover the NE and north-central Gulf. Elsewhere, moderate or weaker\nwinds, and slight seas, are noted.\nFor the forecast, fresh NE to E winds and moderate seas \nover the NE and north-central Gulf will spread westward over the \nremainder of the northern Gulf waters through tonight before \nimproving Fri into Sat. Meanwhile, a rather broad upper-level low\nwill move towards Florida from the western Atlantic on Fri, and \ninto the NE Gulf on Sat. This feature will lead to increasing \nshower and thunderstorm activity over Florida, and then over the \neastern and central Gulf waters. Fairly tranquil marine conditions\nare forecast by the end of the weekend into early next week.\n...CARIBBEAN SEA...\n \nThe pressure gradient between weakening high pressure over the \nwestern Atlantic and relatively lower pressure in northern South \nAmerica is allowing for fresh to strong trades over the south- \ncentral Caribbean. Seas in the range of 6 to 8 ft are over these \nwaters. Moderate to fresh trades along with moderate seas are \nelsewhere E of 82W while gentle to moderate trades and seas of 2 \nto 4 ft are W of 82W, except for higher seas of 4 to 5 ft south \nof 17N as noted in a satellite scatterometer data pass.\nUpper-level divergence east of an upper-level low that is over \nthe northern Yucatan Peninsula is supporting scattered showers \nand isolated thunderstorms over the northwestern Caribbean. An\nupper-level disturbance riding along a jet stream branch is \nkeeping active weather in the form of numerous moderate convection\nover the waters from 11N to 17N west of 80W to inland (near 85W) \nof Honduras and Nicaragua. Scattered moderate convection is over \nthe interior of Honduras.\nFor the forecast, the pressure gradient between high pressure \nover the western Atlantic and the Colombian Low will generally \nmaintain fresh to strong trades along with moderate to locally \nrough seas over most of the central Caribbean through Fri night. \nWinds will diminish to moderate to fresh speeds over the upcoming \nweekend into early next week as the pressure gradient relaxes \nacross the area. Moderate or weaker winds and slight to moderate \nseas are forecast elsewhere. \n...ATLANTIC OCEAN...\nA stationary front extends from near 31N68W southwestward to\n27N75W and to extreme South Florida. Moderate to fresh northeast \nwinds and seas 5 to 6 ft are north of of the front. Scattered \nmoderate convection is seen north of about 23N and west of 66W \nin association to this frontal boundary. Light to gentle winds \nand slight seas are southeast of the front north of 23N and west \nof 55W. A surface trough is analyzed along 48W and N of 23N.\nScattered moderate convection is noted along the trough and in its\nvicinity mainly N of 26N between 43W-51W. An upper-level trough \nthat extends from north of Puerto Rico and the U.S. Virgin Islands\nto around 31N is supporting scattered moderate convection north \nof 24N and W of 60W. To the east, fresh to strong north to \nnortheast winds and moderate seas per latest scatterometer data \npasses are near the Canary Islands. They extend westward to near \n30W. Elsewhere, gentle to moderate winds and moderate seas \nprevail. \nFor the forecast west of 55W, the pressure gradient over the W\nAtlantic will maintain moderate to fresh NE winds and moderate \nseas west of the front through tonight. Conditions will improve \nearly on Fri as high pressure becomes the dominant feature across \nthe basin into the weekend into early next week. Meanwhile, \nabundant tropical moisture, combined with an upper-level low \nlocated east of Florida, will continue to support scattered to \nnumerous showers and thunderstorms, mainly W of 70W, through at \nleast Sun. \n", "title": "Atlantic Tropical Weather Discussion", "id": "1211222471424049154", "issued": "2026-09-18T06:15:00Z", "wmo": "AXNT20", "source": "NOAA/NWS National Hurricane Center, received via the National Weather Wire Service", "page": "https://hurricane.terrapin.com/text/1211222471424049154"}