Tropical Weather Discussion

Full Alert Message

Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Mon Sep 15 2025 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 0345 UTC. ...TROPICAL WAVES... The axis of a far eastern Atlantic tropical wave is near 35W from 01N to 20N, with a 1012 mb low where the tropical wave intersects the monsoon trough. This system is moving westward at around 10 to 15 kt. Scattered moderate to isolated strong convection is noted from 04N to 16N between 30W and 40W. Although dry and stable air is expected to limit development during the next day or so, gradual development is anticipated thereafter, and a tropical depression is likely to form during the middle to latter part of this week as the system moves west-northwestward at 10 to 15 mph over the central tropical Atlantic. There is a low chance of development within the next 48 hours and a high chance within the next 7 days. The axis of a central Atlantic tropical wave is near 48W from 01N to 20N. It is moving westward at around 10 to 15 kt. Scattered moderate and isolated strong convection is noted from 14N to 20N between 45W and 50W. The axis of an eastern Caribbean tropical wave is near 68W south of 20N. It is moving westward at around 15 kt. Scattered moderate convection is noted from 15N to 17N between 65W and 68W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 18N16W and continues southwestward through a 1012 mb low near 10.5N35W to 10N40W. The ITCZ continues from 10N40W to 10N47W. It resumes from 10N50W to 10N61W. Aside from convection described in the tropical waves section above, scattered moderate and isolated strong convection is noted from 04N to 10N east of 30W, and from 05N to 09N between 40W and 47W. ...GULF OF AMERICA... High pressure dominates the Gulf basin. Gentle to moderate anticyclonic wind flow prevails. Seas are in the 1-3 ft range. For the forecast, high pressure will dominate the basin through the week supporting mainly gentle to moderate winds. Winds will freshen in the N-central and NW Gulf Mon night as the high gets reinforced. Moderate to locally fresh winds will pulse offshore the Yucatan Peninsula each night. Winds may increase to moderate to fresh in the SE Gulf and Straits of Florida by Wed night due to a passing tropical wave just to the S combined with a stationary front or coastal trough off the SE U.S. coast. ...CARIBBEAN SEA... Fresh to strong winds prevail over the south central Caribbean. Moderate winds are elsewhere E of 80W. Over the western Caribbean, gentle to moderate winds are noted. Seas are in the 3-5 ft range E of 80W, and 1-2 ft W of 80W. For the forecast, a tropical wave in the central Caribbean will move through the western Caribbean Tue night through Thu night. Expect fresh winds over the central Caribbean Mon through Tue in the wake of the tropical wave. Scattered showers and isolated thunderstorms will accompany the wave. Fresh to strong winds will pulse in the S-central waters through mid-week. Otherwise, gentle to moderate trades, and mostly moderate seas will remain through the week, except slight to moderate seas in the NW Caribbean. ...ATLANTIC OCEAN... A surface trough extends over the western waters, from 31N74W to the Straits of Florida. Moderate winds, and seas of 6-8 ft prevail W of the trough. High pressure dominates the remainder of the discussion waters N of 20N, anchored by a 1029 mb high centered near 37N34W. Moderate to fresh winds prevail over the waters N of 15N and E of 50W, where seas are in the 4-7 ft range. Elsewhere, gentle to moderate winds, and seas of 3-5 ft are noted. For the forecast west of 55W, the trough will weaken through Mon. Otherwise, Atlantic high pressure will generally maintain moderate winds and seas elsewhere across the region through the week. A tropical wave over the eastern tropical Atlantic is likely to develop into a tropical depression during the middle to latter part of this week as the system moves west- northwestward over the central tropical Atlantic. Regardless of development, expect increasing winds and building seas over the southeastern waters by the end of the week.