Tropical Weather Discussion
Issued by NWS
Issued by NWS
927 AXNT20 KNHC 222345 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Sat Aug 23 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Southwestern Atlantic (AL90): Showers and thunderstorms have not become any better organized this evening in association with a trough of low pressure located a couple hundred miles northeast of the northern Leeward Islands. Environmental conditions appear conducive for further development of this system, and a tropical storm is very likely to form this weekend while it moves northwestward and then northward over the southwestern Atlantic. Interests in Bermuda should monitor the progress of this system as watches or warnings could be required on Saturday. There is a high chance of formation within the next 48 hours. Please read the latest Tropical Weather Outlook for more information regarding AL90 at website: https://www.nhc.noaa.gov/cyclones/?atl for more details. ...TROPICAL WAVES... Please see SPECIAL FEATURES above for more on the tropical wave associated with AL90. A far eastern Atlantic tropical wave is near 22W between the coast of Africa and the Cabo Verde Islands, from 22N equatorward, moving west around 5 kt. Scattered moderate convection is found from 10N-13N east of 28W. An central Atlantic tropical wave is near 42W from 21N equatorward through a 1010 mb low (AL99) near 10N42W, moving west at 15-20 kt. Scattered moderate convection is occurring from 07N-13N between 42W- 49W. While there is still some chance that a short-lived tropical depression could form during the next day or so, the system is expected to move through a less conducive environment on Saturday. The wave could reach a slightly more favorable environment late this weekend into early next week as it approaches the Windward Islands. There is a low chance of formation within the next 48 hours and the next 7 days. A tropical wave is over the eastern Caribbean near 65W from 20N equatorward, moving west around 15-20 kt. No significant convection is occurring at this time. A Caribbean tropical wave is over the western Caribbean along 85.5W from 18N southward through Honduras and Nicaragua into the eastern Pacific. No significant convection is occurring in the Caribbean near this wave. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the Mauritian coast near 17N16W, then curves southwestward through a 1010 mb low pressure area, AL99, near 10N42W to 09N45W. The ITCZ begins at 09N45W and extends to the coast of Venezuela near 09N61W. The eastern Pacific monsoon trough extends from the coast of Costa Rica near 10N83W to a low 1008 mb at 11N77W. Scattered moderate convection is occurring from 07N to 10N between 50W and 55W. ...GULF OF AMERICA... A stationary front is straddling the US Gulf coast from southeastern Louisiana through southern Georgia with a weak 1012 mb low near the mouth of the Mississippi River. Scattered moderate convection is occurring north of 27N. Away from the convection, winds are moderate or weaker and seas are 1-3 ft across the entire Gulf. For the forecast, a weak pressure pattern will continue over the Gulf region through the period, maintaining mostly tranquil marine conditions. Moderate to fresh NE to E winds will develop over the south-central Gulf each afternoon through evening this weekend into early next week as a trough develops over the Yucatan Peninsula and moves westward at night. ...CARIBBEAN SEA... The pressure gradient between low pressure in the south-central Caribbean and a ridge north of the Greater Antilles is forcing moderate to fresh trades across most of the Caribbean except strong trades just north of Colombia. Seas are 5-8 ft over the central Caribbean and 2-4 ft elsewhere. For the forecast, fresh to strong trades and moderate to locally rough seas will prevail over the central Caribbean Sat night through the next several days as central Atlantic high pressure builds W-SW across the western Atlantic, in the wake of exiting Hurricane Erin. Fresh to strong E to SE winds will pulse across the Gulf of Honduras at night. Moderate to fresh trades are expected in the eastern Caribbean and across the approach to the Windward Passage with moderate or weaker winds elsewhere. For AL90, showers and thunderstorms have not become any better organized this evening in association with a trough of low pressure located a couple hundred miles northeast of the northern Leeward Islands. Environmental conditions appear conducive for further development of this system, and a tropical storm is very likely to form this weekend while it moves northwestward and then northward over the southwestern Atlantic. ...ATLANTIC OCEAN... Please see the Special Features section at the beginning for information on Invest Area AL90. The outer circulation of Hurricane Erin is causing moderate to fresh SW winds north of 29N between 55W-65W. Seas are 8-12 ft north of 25N between 55W-78W. Fresh winds, 5-7 ft seas, and scattered moderate and isolated strong convection are occurring from 20N-26N between 58W-63W in association with a surface trough (AL90). Elsewhere, weak ridging along 25N-28N across the Atlantic in conjunction with lower pressure over the ITCZ and monsoon trough is forcing only moderate to locally fresh trades across the Atlantic with seas 4-8 ft. For the forecast, Hurricane Erin continues to move NE away from the region. Large northerly swell generated by Erin will continue to affect the W Atlantic waters through the next few days. In the wake of Erin, central Atlantic high pressure will build W-SW toward the central Bahamas and the Straits of Florida. For AL90, Showers and thunderstorms have not become any better organized this evening in association with a trough of low pressure located a couple hundred miles northeast of the northern Leeward Islands. Environmental conditions appear conducive for further development of this system, and a tropical storm is very likely to form this weekend while it moves northwestward and then northward over the southwestern Atlantic. Interests in Bermuda should monitor the progress of this system as watches or warnings could be required on Saturday. $$ ADAMS