--------------------------------------------------------------------------- TROPICAL WEATHER DISCUSSION (NORTH ATLANTIC AREA) MESSAGES T1T2: AX A1A2: NT Date: 2026-09-12 --------------------------------------------------------------------------- Message File: T_AXNT20KNHC120930_C_KWBC_20260912093030_31523192-3341-TWDAT.txt ****0000005109**** AXNT20 KNHC 120930 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Sat Sep 12 2026 Tropical Weather Discussion for North America, Central America Gulf of America, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0925 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 38W, south of 25N, moving westward at 15 to 20 kt. The portions of the wave N of 18N is shifting northwestward, forced by middle level southeasterly flow behind it. Scattered moderate convection is from 21N to 25N near this portion of the wave. Scattered moderate convection is also about the southern portion of the wave, from 07N to 12N between 34W and 44W. The tropical wave previously analyzed around 86W has moved into the eastern Pacific, please read the Tropical Weather Discussion (TWDEP) for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 14N17W, and continues to 10N22W to 14N33W to 10N43W. The ITCZ extends from 10N45W to the coast of Venezuela near 10N61W. Numerous moderate to scattered strong convection is noted from 08N to 12N between 46W and 62W. ...GULF OF AMERICA... High pressure over northern Florida and lower pressures over Mexico support moderate to locally fresh southerly winds and moderate seas west of 94W and north of 23N. Moderate easterly winds and seas of 2-4 ft are occurring in the Bay of Campeche. ELsewhere, light to gentle winds and slight seas prevail. A few showers and isolated thunderstorms are occurring in the eastern Gulf waters. For the forecast, high pressure will prevail over the NE Gulf waters during the weekend. Winds will pulse to fresh speeds each night off the W Yucatan peninsula due to a diurnal trough moving toward the SW Gulf. By Tue night, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh to locally strong speeds and build seas over the Gulf waters N of 23N into late next week. Conditions will improve late next week. ...CARIBBEAN SEA... Weak high pressure is centered N of the basin, between the Bahamas and Bermuda. The pressure gradient between the associated ridge and the Colombian low supports fresh to near gale-force easterly trade winds and rough seas over much of the central Caribbean S of 18N. A buoy near 14N76W is showing seas to 10 ft. Moderate to fresh easterly winds and moderate seas are found in the eastern Caribbean, while moderate winds and seas are prevalent elsewhere. An upper-level trough over the NW Caribbean is producing scattered showers and isolated thunderstorms. Fair weather prevails across the area E of 78W. For the forecast, a tight pressure gradient between a subtropical ridge north of the islands and lower pressures associated with the Colombian Low will continue to support strong to locally near-gale easterly trade winds and rough to locally very rough seas over the central Caribbean for the next several days. Gusts to gale force may occur tonight off Colombia. Meanwhile, moderate to fresh easterly breezes are expected over the next few days in the eastern Caribbean. Winds will pulse to strong speeds in the Gulf of Honduras this evening through Mon morning. Elsewhere, moderate or weaker winds and slight to moderate seas will prevail. ...ATLANTIC OCEAN... An upper-level trough in the SW N Atlantic is producing scattered showers and isolated thunderstorms over a good portion of the basin, especially between Bermuda and the Bahamas. At the surface, a weak high pressure dominates forcing moderate or weaker winds and slight to moderate seas west of 55W. A broad high pressure centered off Portugal supports moderate to locally fresh easterly winds between the Lesser Antilles and 35W. Moderate to fresh NE winds and moderate seas are noted east of 35W. Elsewhere, moderate or lighter winds and moderate seas prevail. For the forecast west of 55W, scattered moderate to isolated strong convection is noted between Bermuda and the Bahamas associated with an upper- level trough. At the surface, the subtropical ridge will dominate the SW N Atlantic waters over the next several days. Trades north of Hispaniola into the Windward Passage will be fresh to locally strong through early next week. Looking ahead, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh to locally strong speeds and build seas to rough north of the Bahamas and W of 70W starting Tue and continuing into Thu. Elsewhere, moderate or weaker winds and slight to moderate seas will prevail. $$ Delgado ########################### END OF MESSAGE SET ############################ --------------------------------------------------------------------------- Message File: T_AXNT20KNHC121706_C_KWBC_20260912170658_4522426-3370-TWDAT.txt ****0000005281**** AXNT20 KNHC 121706 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Sat Sep 12 2026 Tropical Weather Discussion for North America, Central America Gulf of America, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 41W from 06N to 20N, moving westward at around 20 kt. Scattered showers are seen near the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 13N17W, and continues to 10N24W to 13N35W to 10N44W. The ITCZ extends from 10N44W to the coast of Venezuela near 10N61W. Numerous moderate convection is noted from 08N to 14N between 44W and 63W. The eastern extension of the East Pacific monsoon trough extends across the far SW Caribbean. Scattered moderate and isolated strong convection are seen along and near the coasts of Nicaragua, Costa Rica, and Panama. ...GULF OF AMERICA... An upper level shortwave trough over the SE US and convergent surface winds over the eastern Gulf are supporting widely scattered moderate convection across a large region N of 24N and E of 95W. Elsewhere, the pressure gradient between higher pressure inland over Mexico and a surface trough in the Bay of Campeche supports moderate to locally fresh SE to S winds and seas of 3-5 ft across the Bay of Campeche and the far west Gulf. Gentle to moderate or weaker winds and seas of 1-3 ft prevail elsewhere. For the forecast, high pressure centered over the NE Gulf will dominate into the start of next week. Winds will pulse to fresh speeds each night off the W Yucatan peninsula due to a diurnal trough moving toward the SW Gulf. By Tue night, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh to locally strong speeds and build seas over the Gulf waters N of 23N into late next week. ...CARIBBEAN SEA... The pressure gradient between surface ridging over the western N Atlantic and the Colombian low supports fresh to near gale-force easterly trade winds and rough seas over much of the central Caribbean S of 18N. Moderate to fresh easterly winds and moderate seas are found in the eastern Caribbean, while moderate or weaker winds and slight seas are prevalent elsewhere. An upper-level trough over the NW Caribbean is producing scattered showers and isolated thunderstorms. All other convection is described in the monsoon trough/ITCZ section above. Fair weather prevails across most of the Caribbean E of 77W. For the forecast, a tight pressure gradient between a subtropical ridge north of the islands and lower pressures associated with the Colombian Low will continue to support strong to locally near- gale easterly trade winds and rough to locally very rough seas over the central Caribbean for the next several days. Gusts to gale force are likely tonight off Colombia. Winds will pulse to strong speeds in the Gulf of Honduras this evening through Mon morning. Meanwhile, moderate to fresh easterly breezes are expected over the next few days in the eastern Caribbean. ...ATLANTIC OCEAN... An upper-level trough in the SW N Atlantic and surface trough paralleling the SE US coast are producing scattered moderate convection N of 23N and W of 72W. To the east, A frontal remnant trough extends from 31N44W to 26N55W to just south of Bermuda. A 1017 mb low is analyzed SE of Bermuda. Interactions between these features and the upper-level trough are supporting more scattered moderate convection from 24N to 30N between 56W and 67W, while scattered showers and isolated thunderstorms are occurring along the trough axis from 52W northeastward. Finally, a surface trough N of the tropical wave near 41W is also supporting isolated moderate convection along the trough axis. Outside of convection, surface ridging dominates much of the tropical Atlantic. Moderate to fresh NE to E winds and moderate seas dominate much of the basin E of 34W, as well as S of 20N and W of 40W. Gentle to moderate or weaker trades and 3-5 ft seas prevail elsewhere. For the forecast west of 55W, scattered thunderstorms between Bermuda and the Bahamas in association with an upper-level trough should diminish tonight. At the surface, the subtropical ridge will continue to dominate for the next several days. Trades north of Hispaniola into the Windward Passage will be fresh to locally strong into early next week. Looking ahead, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh to locally strong speeds and build seas to rough north of the Bahamas and W of 70W starting Tue and continuing into Thu. Elsewhere, moderate or weaker winds and slight to moderate seas will prevail. $$ Adams ########################### END OF MESSAGE SET ############################ --------------------------------------------------------------------------- Message File: T_AXNT20KNHC122233_C_KWBC_20260912223402_4522426-3393-TWDAT.txt ****0000006079**** AXNT20 KNHC 122233 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Sun Sep 13 2026 Tropical Weather Discussion for North America, Central America Gulf of America, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2230 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: Recent scatterometer data indicate fresh to strong winds over the central Caribbean, with near gale-force winds offshore Colombia. Seas are near 13 ft with the strongest winds based on recent altimeter data. Buoy 42058 located at 14N76W is reporting seas of 10-11 ft. A tight pressure gradient between a subtropical ridge north of the islands and lower pressures associated with the Colombian Low supports these wind speeds. These marine conditions are forecast to persist for the next several days. Winds will pulse to gale force tonight offshore Colombia, where a Gale Warning has been issued. Please read the latest High Seas Forecast issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml ...TROPICAL WAVES... The axis of a tropical wave is near 43W from 06N to 20N, moving westward at around 20 kt. Scattered showers are seen near the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 14N17W, and continues westward to 10N24W to 12N35W to 10N45W. The ITCZ extends from 10N45W to the coast of NE Venezuela near 10N61W. Scattered moderate convection is noted from 08N to 13N between 44W and 61W. ...GULF OF AMERICA... Convection continues to develop over the Gulf region, mainly north of 26N, and over most of the Florida Peninsula as abundant tropical moisture remains in place. A diffluent pattern aloft is also helping to induce this convective activity. A surface trough is just E of SE Florida while another trough is over the central Bay of Campeche. Under this weather pattern, gentle to moderate winds with slight to moderate seas are noted. For the forecast, weak high pressure will bring relatively tranquil conditions to Gulf waters into the start of next week. The exception will be the Bay of Campeche, where a diurnal trough will move westward offshore the Yucatan Peninsula each evening, bringing nightly pulses of fresh NE winds. Starting later Tue, stronger high pressure building southward from the eastern United States will lead to increasing NE to E winds over the basin, with speeds reaching fresh to strong over the NE basin Wed and Thu. ...CARIBBEAN SEA... As previously mentioned, the pressure gradient between surface ridging over the western Atlantic and the Colombian low supports fresh to near gale-force easterly trade winds and rough seas over much of the central Caribbean, mainly S of 18N. Moderate to fresh easterly winds and moderate seas are found in the eastern Caribbean, while moderate or weaker winds and slight seas are prevalent elsewhere. An upper-level trough over the NW Caribbean is helping to induce convection over western Cuba and the NW Caribbean. Scattered showers and thunderstorms are noted over the remainder of the Greater Antilles due to local effects. For the forecast, a tight pressure gradient between a subtropical ridge north of the islands and lower pressures associated with the Colombian Low will continue to support strong to near-gale easterly trade winds and rough to locally very rough seas over the central Caribbean for the next several days. Winds will pulse to gale force tonight offshore Colombia, where a Gale Warning has been issued. Strong winds are expected tonight and Sun night in the Gulf of Honduras. Meanwhile, moderate to fresh easterly breezes are expected over the next few days in the eastern Caribbean. ...ATLANTIC OCEAN... An upper-level low located just N of Hispaniola, combined with upper diffluent over Florida and the far western Atlantic supports a band-like of showers and thunderstorms that roughly covers the area from 24N to 27N W of 55W. Farther E, another area of showers and thunderstorms is noted affecting the waters from 24N to 30N between 39W and 43W. This convective activity is related to a surface trough, that runs from 30N40W to 22N41W. A frontal trough remains over the forecast area, and extends from 31N44W to 26N55W to just south of Bermuda. A weak 1017 mb low is analyzed along the front and SE of Bermuda near 30N61W. The remainder of the forecast region is dominated by high pressure, with the main center of 1025 mb located well NE of the Azores. The pressure gradient between the high pressure and lower pressures over NW Africa is promoting moderate to fresh N to NE winds N of 20N and E of 30W, including the Canary Islands. Moderate to fresh trade winds are observed E of the Lesser Antilles to about 45W, and also just N of Hispaniola. Moderate or weaker winds prevail elsewhere. Seas are in general moderate across the Atlantic forecast waters based on altimeter data and Sofar buoys. Of note: A gale-force gap wind event is occurring in the Straits of Gibraltar. For the forecast west of 55W, the subtropical ridge will continue to dominate through Mon night, bringing mainly tranquil marine conditions. However, trades north of Hispaniola into the Windward Passage will be fresh to locally strong into Monday. On Tue, strong high pressure building SE through the eastern United States will bring a cold front into the NW waters, increasing NE winds to fresh to strong and causing seas to build to rough N of the Bahamas and W of 70W Tue night through Wed night. $$ GR ########################### END OF MESSAGE SET ############################