Tropical Weather Discussion

Full Alert Message

Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Tue Dec 16 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 1010 UTC. ...SPECIAL FEATURES... Western Atlantic Significant Swell Event: A cold front extends from near 31N55W to the SE Bahamas and across western Cuba and the Yucatan Channel. Strong high pressure across the SE U.S. is building in behind the front. Winds behind the front have diminished significantly in the past 12 hours, with fresh to strong N to NE winds now prevailing north of the front to 28N. Large NW to N swell generated behind the front continues to spread into the area waters behind the front, producing seas of 12 to 16 ft at 11 to 13 seconds, to the north of 26N and between the front and 73W. The large northerly swell will reach the islands of the northeast Caribbean this evening and tonight as it merges with easterly trade wind swell moving through the regional waters. Seas will begin to gradually subside from NW to SE during the middle of the week. 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. East Atlantic Significant Swell Event: Large, long-period north to northeast swell mixed with northwest swell continues to affect most of the eastern tropical and subtropical Atlantic. Seas of 12 ft or greater are currently from 10N to 21N between 32W and 50W, peaking around 13 ft per recent satellite altimeter data. Global wave models show northerly swell of 12 to 15 seconds mixing with northeast swell of 9 to 10 seconds across this area. With persistent fresh to strong northeast trade winds, the area of 12 ft or greater seas is expected to persist this morning before they slowly subside from NE to SW later today. For information east of 35W please read the latest High Seas Forecast issued by Meteo- France at website: https://wwmiws.wmo.int/index.php/metareas/affiche/2. For information west of 35W, please read the latest High Seas Forecast issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic near 07.5N12.4W and continues southwestward to 05N22W, where it transitions to the ITCZ and continues to 03.5N38W to 01N50W. Numerous moderate to isolated strong convection is seen from the Equator to 06N east of 20W to inland over portions of western Africa. Scattered moderate to strong convection is seen from 01.5N to 06N between 03W and 41W. ...GULF OF AMERICA... A stationary front extends southeastward across western Cuba, the Yucatan Channel and into the central Yucatan Peninsula. A somewhat tight pressure gradient remains over the E and SE part of the basin where fresh NE to E winds and moderate seas prevail. Strong to near-gale NE to E winds were present over the Straits Florida and across the SW Florida coastal waters overnight according to recent ASCAT data. Moderate to fresh NE to E winds are present over all but NW portions of the basin along with moderate seas. Scattered showers continue along and north of the front across the Straits of Florida. For the forecast, the aforementioned front will drift southward today. Fresh NE winds and rough seas across much of the southern half of the basin will gradually decrease by early Wed. High pressure will dominate the Gulf region in the wake of the front today through Thu. The next cold front is expected to move into the NW Gulf Thu evening and reach from SW Florida to SE Texas Fri evening, then begin to lift northward and dissipate through Sat. ...CARIBBEAN SEA... A cold front moving through the western Atlantic has begun to stall from 25N65W through the SE Bahamas, across western Cuba and the Yucatan Channel and into the central Yucatan. A broad area of strong high pressure is building in behind. This front has weakened the pressure gradient south of it, with mainly moderate to locally fresh trades noted across most of the basin, highest in the S-central portion where the pressure gradient is the tightest due to low pressure near the northern coast of Colombia. Seas are 5-8 ft in the central Caribbean due to the persistent fetch of the trades, and 4-6 ft elsewhere except slightly lower between Cuba and Jamaica including the approach to the Windward Passage. Scattered moderate isolated strong convection is confined to the far western section of the basin, 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. Similar convection is also noted in the Gulf of Honduras due a surface trough. For the forecast, fresh to locally strong trade winds and moderate 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. An Atlantic cold front has become nearly stationary from western Cuba across the Yucatan Channel and into the central Yucatan and is accompanied by fresh winds and building seas. This front will drift southward today then stall and gradually dissipate Wed. 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 two significant swell events, one for a portion of the northwest Atlantic waters, and the other in the eastern Atlantic. A cold front extends from near 31N55W to 25N65W then has begun to stall through the SE Bahamas, and across W Cuba and the Yucatan Channel. 1029 mb high pressure across the SE U.S. coast extends a ridge eastward behind the front, and is forcing fresh to strong N to NE winds between the front and 28N. Large N swell behind the front is producing seas of 12 to 16 ft east of 73W and 8 to 12 ft in N to NE swell to the west of 73W. Scattered showers and isolated thunderstorms continue within 150 nm N and NW of the front and extend into the Straits of Florida. To the east, high pressure of 1030 mb is N of the area near the Azores, with an associated ridge bridging across a dissipating front that extends from the Iberian Peninsula through 31N17W to 29N34W. This high combined with lower pressures to the S with the monsoon trough and ITCZ supports a large area of fresh to strong trades S of 26N and E of 55W where large NE to E swell prevails as detailed above. Mainly moderate winds and 6-10 ft seas are present across the remainder of the open waters N of 26N and E of 60W. For the forecast W of 55W, fresh to strong N to NE winds prevail north of the front to 28N this morning and will generally persist through Wed before diminishing. The front will drift southeastward to the east of 65W through Wed, and remain nearly stationary west of 65W before dissipating late Wed. Large N swell will continue to build across the regional waters behind the front through Tue night before subsiding. The Bermuda High will briefly dominate the regional waters Wed through Thu night as the front dissipates. Low pressure is forecast to develop along the frontal remnants Thu, across the far NE offshore zones, and move northeastward and exit the area Fri. The next cold front will move into the NW waters Fri, reach from near Bermuda to the Straits of Florida Sat morning, the quickly weaken and dissipate Sat night.