{"msg": "650\nAXNT20 KNHC 180006\nTWDAT \nTropical Weather Discussion\nNWS National Hurricane Center Miami FL\n0015 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 1800 UTC surface analysis and satellite imagery through\n2345 UTC.\n...TROPICAL WAVES...\nA central Atlantic tropical wave has its axis along 35W from 03N\nto 18N, moving westward near 15 kt. Numerous moderate convection\nis within 240 nm west of the wave from 11N to 16N, and from \n08N to 13N between 32W and the wave.\nA central Caribbean tropical wave has its axis along 72W. It \nis moving westward at 10 to 15 kt. Only isolated showers and \nthunderstorms are near the wave north of 16N.\n...MONSOON TROUGH/ITCZ...\nThe monsoon trough axis enters the Atlantic near 17N16W and\ncontinues southwestward to 12N30W to 10N40W and to 09N50W, where \nit transitions to the ITCZ to 11N59W. Aside from convection \nassociated to the tropical waves as described above, scattered \nmoderate to isolated strong convection is evident from 06N to 11N\nbetween 18W-21W, and from 10N to 14N east of 20W to inland\nAfrica. Scattered moderate convection is within 120 nm north of\nthe trough between 47W-50W.\n...GULF OF AMERICA...\nA trough axis is analyzed from just west of the Bahamas,\nsouthwestward across extreme South Florida and to just north of \nthe Florida Keys, reaching to near 24N86W. A western Gulf trough \nextends from 28N96W to 24N97W and to near 19N93W. An upper-level\nlow is seen in water vapor imagery to be shifting westward over \nthe northern Yucatan Peninsula. Satellite imagery shows scattered\nmoderate convection over the Gulf waters from 23N to 26N between\n84W and 92W. Isolated showers and thunderstorms are elsewhere \nsouth of about 28N and west of 83W. Similar activity is over some\nsections of the Straits of Florida. Another trough extends from \nthe western Atlantic to south Florida to 24N86W. The pressure \ngradient between a 1025 mb high center centered over eastern \nTennessee and the aforementioned trough that is over the \nsoutheastern Gulf continues to sustain fresh northeast to east \nwinds over the NE and north-central Gulf waters. Moderate seas \nare occurring with these winds. Elsewhere, moderate or weaker \nwinds, and slight seas, are noted.\nFor the forecast, the aforementioned pressure gradient will \nspread westward over the remainder of the northern Gulf waters \nthrough tonight before improving Fri into Sat. Meanwhile, a rather\nbroad upper-level low will move toward Florida from the western \nAtlantic on Fri. This feature will lead to increasing shower and\nthunderstorm activity over Florida, then across the eastern and \ncentral Gulf waters.\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\nconvection over the waters from 11N to 17N west of 80W to inland \n(near 85W) of Honduras and Nicaragua. Scattered moderate\nconvection is over the interior of Honduras.\nFor the forecast, the aforementioned pressure gradient will \ngenerally maintain fresh to strong trades along with moderate to \nlocally rough seas over most of the central Caribbean through\nFri night. The trades will diminish to moderate to fresh speeds \nover the upcoming weekend as the pressure gradient relaxes across\nthe area. Moderate or weaker winds and slight to moderate seas \nare 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. An upper-level trough that extends from north of Puerto \nRico and the U.S. Virgin Islands to around 31N is supporting \nscattered moderate to isolated strong convection between 59W and \n62W, and also north of 26N between 40W and 59W. Fresh to locally \nstrong north to northeast winds and moderate seas per latest \nsatellite scatterometer data passes are near the Canary Islands. \nThey extend westward to near 30W. Elsewhere, gentle to moderate \nwinds and moderate seas prevail. \nFor the forecast west of 55W, the pressure gradient between high \npressure over the southeastern U.S. and a stationary front that \nextends from near Bermuda to the NW Bahamas will maintain moderate\nto fresh NE winds and moderate seas west of the front through\nthis evening. Conditions will improve early on Fri as high \npressure becomes the dominant feature across the basin into the \nweekend. Meanwhile, abundant tropical moisture, combined with an\nupper-level low located east of Florida, will continue to support\nscattered to numerous showers and thunderstorms, mainly west of\n70W through at least Sun. \n\n", "title": "Atlantic Tropical Weather Discussion", "id": "1211169431535747074", "issued": "2026-09-18T00:15:00Z", "wmo": "AXNT20", "source": "NOAA/NWS National Hurricane Center, received via the National Weather Wire Service", "page": "https://hurricane.terrapin.com/text/1211169431535747074"}