Tropical Weather Discussion
Issued by NWS
Issued by NWS
829 AXNT20 KNHC 102248 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Fri Sep 11 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 2245 UTC. ...TROPICAL WAVES... Clusters of moderate to isolated strong convection are moving westward over Guinea, Guinea Bissau and Sierra Leone reaching the Atlantic waters. Based on model guidance, a new tropical wave follows this convective activity. The axis of a tropical wave is near 30W, south of 20N, moving westward at 10 to 15 kt. Scattered moderate convection is noted ahead of the wave axis from 08N to 12N between 30W and 40W. The axis of a tropical wave is near 67W, south of 20N and extends into Venezuela, moving westward at 15 kt. The wave appears to enhance convection over western Venezuela. The axis of a tropical wave is near 76, south of 19N, moving westward at 15 to 20 kt. Convection is limited near the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Mauritania near 20N16W, and continues southwestward to 14N30W to 09N42W. The ITCZ extends from 09N42W to the coast of Guyana near 07.5N59W. Aside from convection associated with the tropical wave, scattered moderate convection is noted from 08N to 11N between 40W and 56W. ...GULF OF AMERICA... A 1016 mb low pressure is located over the north-central Gulf near the Mouth of the Mississippi River. A surface trough extends from the low center to near Galveston, TX. Scattered showers and thunderstorms are noted over most of the Gulf, mainly N of 22N. Numerous showers and thunderstorms are once again over most the Florida Peninsula. A diffluent pattern aloft is helping to induce this convective activity. Showers and thunderstorms are also noted over the Yucatan Peninsula and northern Guatemala. Otherwise, a weak pressure gradient is over the Gulf waters supporting gentle to locally moderate winds. Higher winds of 25 to 30 kt are observed per scatterometer data over the central Bay of Campeche, likely associated with the Yucatan trough. These winds are generating mainly slight seas over the basin, with the exception of slight to moderate seas over the central Bay of Campeche. For the forecast, weak high pressure will persist through early next week, supporting mostly light to gentle winds and slight seas. Starting this weekend, winds will pulse to fresh with moderate seas off the western Yucatan Peninsula during the evenings due to a diurnal surface trough moving westward from the peninsula each night. ...CARIBBEAN SEA... High pressure N of the area combined with the Colombian low continues to support fresh to strong trade winds and rough seas over much of the central Caribbean, particularly S of 16N, and in the Gulf of Venezuela. Three altimeter passes indicate seas of 8 to 11 ft within these winds, mainly offshore Colombia. Fresh to strong winds are also evident across the Windward Passage. Moderate to fresh winds, and moderate seas cover the remainder of the Caribbean waters. Convection has flared-up over most of Cuba, the Cayman Islands, and the NW Caribbean. An upper-level low spinning over the NW Caribbean is enhancing this convective activity. Showers and thunderstorms are also occurring over Hispaniola, and over parts of the SW Caribbean, including the Atlantic coast of SE Nicaragua. For the forecast, the western Atlantic ridge extends E to W along about 26N to the NW Bahamas. The pressure gradient between the ridge and the Colombian low will support fresh to strong winds offshore Colombia and western Venezuela through early next week. Moderate to rough seas will prevail over these waters. Elsewhere, moderate or weaker winds and slight to moderate seas will prevail. ...ATLANTIC OCEAN... A stationary front extends from 30N48W to 28N60W to near 30.5N75W. Scattered showers and thunderstorms are in the vicinity of the front, more concentrated from 26N to 29N between 60W and 65W. Gentle to moderate NE to E winds are in the wake of the front. The remainder of the forecast waters are dominated by high pressure, anchored by a 1023 mb high pressure located E of Bermuda near 32N60W, and another 1024 mb high pressure centered E of the Azores near 37N22W. The pressure gradient between the high pressure and lower pressures over NW Africa is promoting moderate to fresh NE winds N of 27N and E of 25W, including the Canary Islands. Moderate to fresh trade winds are observed over most of the tropical Atlantic, and S of 22N between 70W and 74W. Moderate or weaker winds prevail elsewhere. Seas are in general moderate across the Atlantic forecast waters. For the forecast west of 55W, high pressure will build SW into the waters into the weekend, with light to gentle winds expected N of 21N closest to the high, and moderate to fresh trades S of 21N. By the start of next week, winds will diminish some as the high weakens and the pressure gradient relaxes. $$ GR