Tropical Weather Discussion
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607 AXNT20 KNHC 131017 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Sun Jul 13 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave is along 34W-35W, south of 18N, moving westward at 15 kt. Scattered moderate convection is noted ahead of this wave, from 03.5N to 10.5N between 34W and 39W. A central Atlantic tropical wave is along 49W, south of 18N, moving westward at 15-20 kt. Scattered moderate convection is observed from 03N to 12N and between 42W and 50W. A western Caribbean tropical wave is along 86W, south of 20N, moving westward at 15 kt. Scattered moderate isolated strong convection is found south of 17N between 82W and 89W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic through the coast of Mauritania near 18N16W, continuing southwestward to 11N22W to 10N31W to 1014 mb low pres near 11N43W to 12N47W. Associated convection is described above with the tropical waves. ...GULF OF AMERICA... A nearly stationary upper level low over the NW Gulf continues to provide unstable conditions across most of the northern half of the Gulf this morning, where widely scattered showers dot the Gulf waters north of 25N. A broad subtropical ridge reaches across central Florida and extends northwestward across the NE Gulf of America, resulting in moderate to locally fresh E to SE winds and seas of 3-4 ft across the SW half of the basin. Elsewhere, moderate or weaker winds and slight seas prevail in the rest of the basin. For the forecast, weak high pressure across the NE Gulf this morning will drift slowly westward and into the NW Gulf by Wed. This will allow a broad area of low pressure expected to form across the Atlantic east of Florida, to shift westward across Florida and into the eastern Gulf on Tue, then continue to drift westward into the central Gulf through Thu, accompanied by active weather. Environmental conditions could become marginally conducive for the gradual development of this system by mid to late next week. ...CARIBBEAN SEA... Scattered showers and thunderstorms are seen across the SW Caribbean south of 12N, about the monsoon trough, and behind a tropical wave moving into Central America. No other significant convection is noted across the basin, as Saharan Air generally prevails east of 77W. A broad subtropical ridge over the central Atlantic extends westward along 30N to near 70W and then west- southwestward into central Florida, supporting strong easterly trade winds in the south-central Caribbean. Seas in these waters are 8-10 ft. Moderate to locally fresh easterly breezes and moderate seas are found elsewhere south of 20N. In the rest of the NW Caribbean, moderate or weaker winds and slight to moderate seas prevail. For the forecast, weak Atlantic high pressure along 69W will shift NE and collapse today, leaving a weak Atlantic ridge east of 75W through Mon. High pressure will then build westward across the region and into Florida Tue through Thu. This pattern will continue to support pulsing fresh to strong trades and rough seas across the south-central Caribbean through early Tue then expand across much of the central basin late Tue through Thu. Fresh E winds are expected across the Gulf of Honduras through Tue, pulsing to locally strong tonight. Moderate to fresh winds and moderate seas are expected in the eastern Caribbean through Tue while gentle to moderate winds and slight to moderate seas will prevail NW portions. ...ATLANTIC OCEAN... An expansive subtropical ridge over the central Atlantic is centered on a 1025 mb high near 30N38W, and dominates the tropical Atlantic waters between 20W and the Bahamas. A broad upper level low is noted between Bermuda and Hispaniola, sustaining a few clusters of scattered showers and thunderstorms north of 21N between 62W and the Bahamas. Overnight satellite scatterometer data showed moderate to fresh easterly winds south of 25N and between 25W and 65W, and south of 23N west of 65W. Seas across the trade wind zone east of 65W are 4-7 ft, and 2-4 ft west of 65W. A tighter pressure gradient in the eastern Atlantic is forcing fresh to locally strong N-NE winds north of 19N and east of 25W, where seas are 6-9 ft. Elsewhere, moderate or weaker winds and slight to moderate seas are prevalent. For the forecast west of 55W, 1020 mb Atlantic high pressure near 29N69W will shift NE and collapse today, leaving a weak Atlantic ridge along 30N and east of 75W through Mon. High pressure will then build westward across the region and into Florida Tue through Thu. A broad area of low pressure is expected to form over the next few days offshore of the southeastern U.S. coast, and build into the waters north of the Bahamas. This system is expected to move generally westward across the Florida Peninsula Mon and over the eastern and north-central portion of the Gulf of America Tue through Wed. Active weather is expected over the waters west of 75W today through Tue associated with this system. The pressure gradient between the Atlantic ridge building westward and the area of low pressure will support moderate to fresh SE to S winds across the Bahamas and through the NW zones Tue through early Thu. $$ Stripling