Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Wed Dec 17 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 2000 UTC. ...SPECIAL FEATURES... Southwest N Atlantic Gale Warning: A low pressure is forecast to develop along a frontal boundary, extending from 31N49.5W to 25.5N60.5W where it continues southwestward to the Turks and Caicos near eastern Cuba as a stationary front, over the far NE offshore zones on Thu. Gale force winds are expected in the NW quadrant of the low center Thu through Fri as it lifts N of the forecast region, along with building very rough seas. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more information this event. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic near 05N09W and continues southwestward to 04.5N11W. The ITCZ extends from 04.5N11W to 03.5N35W to offshore of northern Brazil at 02N47W. Numerous moderate to isolated strong convection is seen from 01N to 07N between Africa and South America. Scattered moderate convection is seen from 08N to 10N between 24W and 30W. ...GULF OF AMERICA... High pressure of 1026 mb is over the southern border of Alabama and Georgia, controlling conditions across the Gulf. Moderate to fresh winds are in the SE Gulf including the Straits of Florida due to a diffuse surface trough near 87W, locally strong near the Straits. Gentle to moderate winds prevail across the remainder of the waters. Seas are 5-8 ft in the SE Gulf, 4-7 ft elsewhere S of 26N in residual NE swell, and 2-5 ft N of 26N. For the forecast, fresh to strong NE winds and rough seas across the SE waters, including the Straits of Florida, will gradually decrease by early Wed. A ridge will dominate the Gulf region through Thu, with winds veering to the S and SW ahead of the next cold front forecast to move into the NW Gulf Wed evening. This front will reach from SW Florida to NE Mexico Fri evening, then begin to lift northward and dissipate through Sat. ...CARIBBEAN SEA... A surface trough is analyzed offshore Nicaragua and Costa Rica with scattered moderate convection noted inland and just offshore Nicaragua, as well as offshore of northern Honduras. Similar convection is over the remainder of the SW Caribbean due to the combination of low-level convergence of the trade winds along with instability provided by the close proximity of the eastern Pacific Ocean monsoon trough that extends eastward across southern Costa Rica and across Panama. A frontal system just N of the basin has allowed for a slightly weaker pressure gradient than normal with moderate to fresh winds in the central Caribbean, highest offshore northern Colombia with 1009 mb low pressure near the coast, and moderate to fresh trades elsewhere in the basin. Seas are 5-8 ft in the S-central portion, and 3-6 ft elsewhere, except 3-4 ft N of 17N between 64W and 84W. For the forecast, fresh to locally strong trade winds and moderate to rough seas will prevail over the south-central Caribbean through Thu as high pressure shifts eastward into the western Atlantic. Elsewhere, fresh to locally strong trade winds and rough seas in large E swell will persist over the tropical Atlantic waters, through the Atlantic passages and into the eastern part of the basin through Thu night. High pressure will strengthen north of the basin Fri into the weekend to bring a return to fresh to strong trades across the central and southwest Caribbean. ...ATLANTIC OCEAN... Please see the Special Features section for more information on a developing Gale Warning in the Southwest N Atlantic. A cold front extends from 31N49.5W to 25.5N60.5W where it continues southwestward to the Turks and Caicos near eastern Cuba as a stationary front. Fresh to strong NE winds are noted S of 27N and W of the front, with moderate to fresh winds elsewhere W of the front. Seas of 8-12 ft in NW-N swell is noted W of the front to 77W, with 5-8 ft offshore northern Florida. Scattered moderate convection is noted within 300 nm NW of the front. Strong 1030 mb high pressure is noted just N of the eastern Atlantic waters near 33N23W with a ridge reaching SW of the high and ahead of the front to 25N55W. The tight pressure gradient between the ridge and the ITCZ supports a large area and fetch of fresh to strong winds S of 25N and E of 60W with resultant 8-12 ft seas. Fresh to strong winds are noted S of 31N to the and through the Canary Islands to the E of 20W with gale-force N of 31N offshore of the Iberian Peninsula, supporting seas of 8-16 ft. Refer to the Meteo-France High Seas Forecast listed on their website at https://wwmiws.wmo.int for more details. Mainly moderate winds and 5-8 ft seas are across the remainder of the waters which is primarily between the front and the ridge axis. For the forecast W of 55W, a cold front extends from 30N50W to near 26N60W where it becomes a stationary front that continues SW across the SE Bahamas. Fresh to strong N to NE winds prevail north of the front to about 28N, and these winds will generally persist through Wed before diminishing. Large N swell will continue to build across the regional waters behind the front through tonight before subsiding. The front will remain nearly stationary, extending from 26N55W to near 21N70W by Wed morning. A low pressure is forecast to develop along the frontal boundary, and over the far NE offshore zones on Thu. Gale force winds are expected in the NW quadrant of the low center Thu through Fri as it lifts N of the forecast region. The next cold front will move into the NW waters Fri, reach from near Bermuda to the Straits of Florida Sat morning, and from 31N55W to the central Bahamas on Sun morning. Another cold front may move off NE Florida by Sun night.