--------------------------------------------------------------------------- TROPICAL WEATHER DISCUSSION (NORTH ATLANTIC AREA) MESSAGES T1T2: AX A1A2: NT Date: 2026-09-18 --------------------------------------------------------------------------- Message File: T_AXNT20KNHC180006_C_KWBC_20260918000716_4522426-3866-TWDAT.txt ****0000006094**** AXNT20 KNHC 180006 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Fri Sep 18 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 2345 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave has its axis along 35W from 03N to 18N, moving westward near 15 kt. Numerous moderate convection is within 240 nm west of the wave from 11N to 16N, and from 08N to 13N between 32W and the wave. A central Caribbean tropical wave has its axis along 72W. It is moving westward at 10 to 15 kt. Only isolated showers and thunderstorms are near the wave north of 16N. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic near 17N16W and continues southwestward to 12N30W to 10N40W and to 09N50W, where it transitions to the ITCZ to 11N59W. Aside from convection associated to the tropical waves as described above, scattered moderate to isolated strong convection is evident from 06N to 11N between 18W-21W, and from 10N to 14N east of 20W to inland Africa. Scattered moderate convection is within 120 nm north of the trough between 47W-50W. ...GULF OF AMERICA... A trough axis is analyzed from just west of the Bahamas, southwestward across extreme South Florida and to just north of the Florida Keys, reaching to near 24N86W. A western Gulf trough extends from 28N96W to 24N97W and to near 19N93W. An upper-level low is seen in water vapor imagery to be shifting westward over the northern Yucatan Peninsula. Satellite imagery shows scattered moderate convection over the Gulf waters from 23N to 26N between 84W and 92W. Isolated showers and thunderstorms are elsewhere south of about 28N and west of 83W. Similar activity is over some sections of the Straits of Florida. Another trough extends from the western Atlantic to south Florida to 24N86W. The pressure gradient between a 1025 mb high center centered over eastern Tennessee and the aforementioned trough that is over the southeastern Gulf continues to sustain fresh northeast to east winds over the NE and north-central Gulf waters. Moderate seas are occurring with these winds. Elsewhere, moderate or weaker winds, and slight seas, are noted. For the forecast, the aforementioned pressure gradient will spread westward over the remainder of the northern Gulf waters through tonight before improving Fri into Sat. Meanwhile, a rather broad upper-level low will move toward Florida from the western Atlantic on Fri. This feature will lead to increasing shower and thunderstorm activity over Florida, then across the eastern and central Gulf waters. ...CARIBBEAN SEA... The pressure gradient between weakening high pressure over the western Atlantic and relatively lower pressure in northern South America is allowing for fresh to strong trades over the south- central Caribbean. Seas in the range of 6 to 8 ft are over these waters. Moderate to fresh trades along with moderate seas are elsewhere E of 82W while gentle to moderate trades and seas of 2 to 4 ft are W of 82W, except for higher seas of 4 to 5 ft south of 17N as noted in a satellite scatterometer data pass. Upper-level divergence east of an upper-level low that is over the northern Yucatan Peninsula is supporting scattered showers and isolated thunderstorms over the northwestern Caribbean. An upper-level disturbance riding along a jet stream branch is keeping active weather in the form of numerous moderate convection over the waters from 11N to 17N west of 80W to inland (near 85W) of Honduras and Nicaragua. Scattered moderate convection is over the interior of Honduras. For the forecast, the aforementioned pressure gradient will generally maintain fresh to strong trades along with moderate to locally rough seas over most of the central Caribbean through Fri night. The trades will diminish to moderate to fresh speeds over the upcoming weekend as the pressure gradient relaxes across the area. Moderate or weaker winds and slight to moderate seas are forecast elsewhere. ...ATLANTIC OCEAN... A stationary front extends from near 31N68W southwestward to 27N75W and to extreme South Florida. Moderate to fresh northeast winds and seas 5 to 6 ft are north of of the front. Scattered moderate convection is seen north of about 23N and west of 66W in association to this frontal boundary. Light to gentle winds and slight seas are southeast of the front north of 23N and west of 55W. An upper-level trough that extends from north of Puerto Rico and the U.S. Virgin Islands to around 31N is supporting scattered moderate to isolated strong convection between 59W and 62W, and also north of 26N between 40W and 59W. Fresh to locally strong north to northeast winds and moderate seas per latest satellite scatterometer data passes are near the Canary Islands. They extend westward to near 30W. Elsewhere, gentle to moderate winds and moderate seas prevail. For the forecast west of 55W, the pressure gradient between high pressure over the southeastern U.S. and a stationary front that extends from near Bermuda to the NW Bahamas will maintain moderate to fresh NE winds and moderate seas west of the front through this evening. Conditions will improve early on Fri as high pressure becomes the dominant feature across the basin into the weekend. Meanwhile, abundant tropical moisture, combined with an upper-level low located east of Florida, will continue to support scattered to numerous showers and thunderstorms, mainly west of 70W through at least Sun. $$ Aguirre ########################### END OF MESSAGE SET ############################ --------------------------------------------------------------------------- Message File: T_AXNT20KNHC180435_C_KWBC_20260918043631_31523192-3914-TWDAT.txt ****0000005591**** AXNT20 KNHC 180435 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Fri Sep 18 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 0000 UTC surface analysis and satellite imagery through 0430 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave has its axis along 36W from 03N to 18N, moving westward near 15 kt. Scattered moderate convection is from 08N to 15N between 31W and 42W. A central Caribbean tropical wave has its axis along 72W, moving westward at 10 to 15 kt. Scattered moderate convection is noted along the wave axis and N of 17N. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 18N16W and continues southwestward to 10N39W, where it transitions to the ITCZ to 07N58W. Aside from convection associated to the tropical waves as described above, scattered moderate convection is evident from 09N to 12N between 47W and 51W. ...GULF OF AMERICA... A trough is analyzed from just west of the Bahamas, southwestward across extreme South Florida and to just north of the Florida Keys, reaching to near 24N86W. A western Gulf trough extends from 25N96W to 24N97W and to 19N94W. Scattered moderate convection is noted along both troughs. The pressure gradient between high pressure over the southeastern U.S. and a weakening frontal trough over the SE Gulf supports fresh NE to E winds and moderate seas over the NE and north-central Gulf. Elsewhere, moderate or weaker winds, and slight seas, are noted. For the forecast, fresh NE to E winds and moderate seas over the NE and north-central Gulf will spread westward over the remainder of the northern Gulf waters through tonight before improving Fri into Sat. Meanwhile, a rather broad upper-level low will move towards Florida from the western Atlantic on Fri, and into the NE Gulf on Sat. This feature will lead to increasing shower and thunderstorm activity over Florida, and then over the eastern and central Gulf waters. Fairly tranquil marine conditions are forecast by the end of the weekend into early next week. ...CARIBBEAN SEA... The pressure gradient between weakening high pressure over the western Atlantic and relatively lower pressure in northern South America is allowing for fresh to strong trades over the south- central Caribbean. Seas in the range of 6 to 8 ft are over these waters. Moderate to fresh trades along with moderate seas are elsewhere E of 82W while gentle to moderate trades and seas of 2 to 4 ft are W of 82W, except for higher seas of 4 to 5 ft south of 17N as noted in a satellite scatterometer data pass. Upper-level divergence east of an upper-level low that is over the northern Yucatan Peninsula is supporting scattered showers and isolated thunderstorms over the northwestern Caribbean. An upper-level disturbance riding along a jet stream branch is keeping active weather in the form of numerous moderate convection over the waters from 11N to 17N west of 80W to inland (near 85W) of Honduras and Nicaragua. Scattered moderate convection is over the interior of Honduras. For the forecast, the pressure gradient between high pressure over the western Atlantic and the Colombian Low will generally maintain fresh to strong trades along with moderate to locally rough seas over most of the central Caribbean through Fri night. Winds will diminish to moderate to fresh speeds over the upcoming weekend into early next week as the pressure gradient relaxes across the area. Moderate or weaker winds and slight to moderate seas are forecast elsewhere. ...ATLANTIC OCEAN... A stationary front extends from near 31N68W southwestward to 27N75W and to extreme South Florida. Moderate to fresh northeast winds and seas 5 to 6 ft are north of of the front. Scattered moderate convection is seen north of about 23N and west of 66W in association to this frontal boundary. Light to gentle winds and slight seas are southeast of the front north of 23N and west of 55W. A surface trough is analyzed along 48W and N of 23N. Scattered moderate convection is noted along the trough and in its vicinity mainly N of 26N between 43W-51W. An upper-level trough that extends from north of Puerto Rico and the U.S. Virgin Islands to around 31N is supporting scattered moderate convection north of 24N and W of 60W. To the east, fresh to strong north to northeast winds and moderate seas per latest scatterometer data passes are near the Canary Islands. They extend westward to near 30W. Elsewhere, gentle to moderate winds and moderate seas prevail. For the forecast west of 55W, the pressure gradient over the W Atlantic will maintain moderate to fresh NE winds and moderate seas west of the front through tonight. Conditions will improve early on Fri as high pressure becomes the dominant feature across the basin into the weekend into early next week. Meanwhile, abundant tropical moisture, combined with an upper-level low located east of Florida, will continue to support scattered to numerous showers and thunderstorms, mainly W of 70W, through at least Sun. $$ ERA ########################### END OF MESSAGE SET ############################ --------------------------------------------------------------------------- Message File: T_AXNT20KNHC180849_C_KWBC_20260918085020_4522426-3895-TWDAT.txt ****0000005714**** AXNT20 KNHC 180849 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Fri Sep 18 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 0810 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave has its axis along 37W from 02N to 17N, moving westward around 10 kt. Scattered moderate isolated strong convection is from 06N to 175N between 29W and 42W. A central Caribbean tropical wave has its axis along 73W from portions of Haiti southward to near the border of Colombia and Venezuela, moving westward at around 10 kt. Scattered moderate convection is noted from 16N to 19N between 69W and 77W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 18N16W and continues southwestward to 10N39W, where it transitions to the ITCZ to the border of French Guiana and Suriname at 06N54W. Aside from convection associated to the tropical waves as described above, scattered moderate isolated strong is evident south of the monsoon trough to 04N between 18W and 29W. ...GULF OF AMERICA... A frontal trough continues to be analyzed from the NW Bahamas southwestward to across the Florida Keys and into the SE Gulf to the north of the Yucatan Peninsula. Scattered moderate convection is noted from 19N to 25N to the east of 90W. Moderate to fresh easterly winds are across the Gulf waters north of 24.5N, along with 4-7 ft seas. Gentle to moderate easterly winds are south of 24.5N, along with 2-4 ft seas. A weak diurnal surface trough is noted west of the Yucatan Peninsula with another trough offshore SE Texas and NE Mexico, supporting scattered showers and thunderstorms within 90 nm of Veracruz, Mexico. For the forecast, the pressure gradient between high pressure over the southeastern U.S. and a weakening frontal trough over the SE Gulf supports fresh NE to E winds and moderate seas over the northern Gulf. These conditions will gradually improve later today into Sat. Meanwhile, a rather broad upper-level low will move towards Florida from the western Atlantic today, and into the NE Gulf on Sat. This feature will lead to increasing shower and thunderstorm activity over Florida, and then over the eastern and central Gulf waters. Fairly tranquil marine conditions are forecast by the end of the weekend into early next week. ...CARIBBEAN SEA... Please refer to the tropical wave section for details on a wave in the central Caribbean including associated convection. The pressure gradient between weakening high pressure over the western Atlantic and relatively lower pressure in northern South America is allowing for fresh to strong trades over the central Caribbean from 11N to 18N between 64W and 76W, where seas are 6-9 ft. Moderate to fresh trades are found elsewhere from 10N to 19N to the east of 80W, along with 4-7 ft seas. Gentle to moderate winds and 2-5 ft seas prevail across the remainder of the basin. Upper-level divergence east of an upper-level low that is over the northern Yucatan Peninsula is supporting scattered showers and isolated thunderstorms over the northwestern Caribbean. An upper- level disturbance riding along a jet stream branch is keeping active weather in the form of numerous moderate convection over the waters from 16N to 20N west of 76W. For the forecast, the pressure gradient between high pressure over the western Atlantic and the Colombian Low will generally maintain fresh to strong trades along with moderate to locally rough seas over most of the central Caribbean through Sat. Winds will diminish to moderate to fresh speeds thereafter as the pressure gradient relaxes across the area. Moderate or weaker winds and slight to moderate seas are forecast elsewhere. ...ATLANTIC OCEAN... A stationary front extends from near 31N72W southwestward to across the NW Bahamas and to the Florida Keys. Moderate to locally fresh northeast winds and 4-6 ft seas are north of of the front. Scattered moderate convection is seen north of about 23N and east of the front to around 68W. Well to the east, fresh to strong N-NE winds and 6-9 ft seas are found from 17N to 22N between Africa and 21W due to a tight pressure gradient, with moderate to fresh N-NE winds and 6-9 ft seas elsewhere from 16N to 31N to the east of 28W. Moderate or weaker winds and moderate seas dominate the remainder of the tropical Atlantic waters. Other than the convection described above with the tropical wave in the central Atlantic and the monsoon trough, scattered moderate isolated strong is found from 22N to 26N between 29W and 42W, and from 25N to 31N between 41W and 54W where a couple of surface troughs are present. For the forecast west of 55W, a stationary front that extends from near Bermuda to the NW Bahamas will gradually wash out today. Conditions will improve early on Fri as high pressure becomes the dominant feature across the basin into the weekend into early next week. Meanwhile, abundant tropical moisture, combined with an upper- level low located east of Florida, will continue to support scattered to numerous showers and thunderstorms, mainly W of 70W, through at least Sun. $$ Lewitsky ########################### END OF MESSAGE SET ############################ --------------------------------------------------------------------------- Message File: T_AXNT20KNHC180908_C_KWBC_20260918090920_4522426-3899-TWDAT.txt ****0000005714**** AXNT20 KNHC 180908 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Fri Sep 18 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 0810 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave has its axis along 37W from 02N to 17N, moving westward around 10 kt. Scattered moderate isolated strong convection is from 06N to 175N between 29W and 42W. A central Caribbean tropical wave has its axis along 73W from portions of Haiti southward to near the border of Colombia and Venezuela, moving westward at around 10 kt. Scattered moderate convection is noted from 16N to 19N between 69W and 77W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 18N16W and continues southwestward to 10N39W, where it transitions to the ITCZ to the border of French Guiana and Suriname at 06N54W. Aside from convection associated to the tropical waves as described above, scattered moderate isolated strong is evident south of the monsoon trough to 04N between 18W and 29W. ...GULF OF AMERICA... A frontal trough continues to be analyzed from the NW Bahamas southwestward to across the Florida Keys and into the SE Gulf to the north of the Yucatan Peninsula. Scattered moderate convection is noted from 19N to 25N to the east of 90W. Moderate to fresh easterly winds are across the Gulf waters north of 24.5N, along with 4-7 ft seas. Gentle to moderate easterly winds are south of 24.5N, along with 2-4 ft seas. A weak diurnal surface trough is noted west of the Yucatan Peninsula with another trough offshore SE Texas and NE Mexico, supporting scattered showers and thunderstorms within 90 nm of Veracruz, Mexico. For the forecast, the pressure gradient between high pressure over the southeastern U.S. and a weakening frontal trough over the SE Gulf supports fresh NE to E winds and moderate seas over the northern Gulf. These conditions will gradually improve later today into Sat. Meanwhile, a rather broad upper-level low will move towards Florida from the western Atlantic today, and into the NE Gulf on Sat. This feature will lead to increasing shower and thunderstorm activity over Florida, and then over the eastern and central Gulf waters. Fairly tranquil marine conditions are forecast by the end of the weekend into early next week. ...CARIBBEAN SEA... Please refer to the tropical wave section for details on a wave in the central Caribbean including associated convection. The pressure gradient between weakening high pressure over the western Atlantic and relatively lower pressure in northern South America is allowing for fresh to strong trades over the central Caribbean from 11N to 18N between 64W and 76W, where seas are 6-9 ft. Moderate to fresh trades are found elsewhere from 10N to 19N to the east of 80W, along with 4-7 ft seas. Gentle to moderate winds and 2-5 ft seas prevail across the remainder of the basin. Upper-level divergence east of an upper-level low that is over the northern Yucatan Peninsula is supporting scattered showers and isolated thunderstorms over the northwestern Caribbean. An upper- level disturbance riding along a jet stream branch is keeping active weather in the form of numerous moderate convection over the waters from 16N to 20N west of 76W. For the forecast, the pressure gradient between high pressure over the western Atlantic and the Colombian Low will generally maintain fresh to strong trades along with moderate to locally rough seas over most of the central Caribbean through Sat. Winds will diminish to moderate to fresh speeds thereafter as the pressure gradient relaxes across the area. Moderate or weaker winds and slight to moderate seas are forecast elsewhere. ...ATLANTIC OCEAN... A stationary front extends from near 31N72W southwestward to across the NW Bahamas and to the Florida Keys. Moderate to locally fresh northeast winds and 4-6 ft seas are north of of the front. Scattered moderate convection is seen north of about 23N and east of the front to around 68W. Well to the east, fresh to strong N-NE winds and 6-9 ft seas are found from 17N to 22N between Africa and 21W due to a tight pressure gradient, with moderate to fresh N-NE winds and 6-9 ft seas elsewhere from 16N to 31N to the east of 28W. Moderate or weaker winds and moderate seas dominate the remainder of the tropical Atlantic waters. Other than the convection described above with the tropical wave in the central Atlantic and the monsoon trough, scattered moderate isolated strong is found from 22N to 26N between 29W and 42W, and from 25N to 31N between 41W and 54W where a couple of surface troughs are present. For the forecast west of 55W, a stationary front that extends from near Bermuda to the NW Bahamas will gradually wash out today. Conditions will improve early on Fri as high pressure becomes the dominant feature across the basin into the weekend into early next week. Meanwhile, abundant tropical moisture, combined with an upper- level low located east of Florida, will continue to support scattered to numerous showers and thunderstorms, mainly W of 70W, through at least Sun. $$ Lewitsky ########################### END OF MESSAGE SET ############################