For the North Atlantic, Caribbean Sea and the Gulf of Mexico:
Special Tropical Weather Outlook issued to discuss the potential for subtropical development over the northwest Atlantic.
Northwestern Atlantic: A non-tropical low pressure system centered over the northwestern Atlantic Ocean about 300 miles north of Bermuda is producing storm-force winds. Although the cyclone is producing some thunderstorm activity near the center, it is embedded in a cold air mass with nearby frontal boundaries. The low is expected to move northeastward today and northward tonight, bringing the system over much colder waters and across Atlantic Canada by early Tuesday. Therefore, it is unlikely that the low will transition to a subtropical or tropical cyclone. Nevertheless, the system is expected to remain a strong non-tropical low during the next day or so, and additional information, including storm-force wind warnings, can be found in High Seas Forecasts issued by the National Weather Service.
No additional Special Tropical Weather Outlooks are scheduled for this system. Regularly scheduled Tropical Weather Outlooks will resume on May 15, 2023, while Special Tropical Weather Outlooks will be issued as necessary during the off-season. * Formation chance through 48 hours, low, near 0 percent. * Formation chance through 5 days, low, near 0 percent.
High Seas Forecasts issued by the National Weather Service can be found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php
Posted 2 months ago by NHC Forecaster Forecaster Cangialosi
The monsoon trough enters the Atlantic Ocean through the coast of Sierra Leone near 08N13W and continues southwestward to 02N20W and to 01N28W where it transitions to the ITCZ. The ITCZ continues from 01N28W to 01N35W and southwestward to the coast of Brazil near 02S45W.
Scattered moderate convection is mainly within 120 nm of the ITCZ axis west of 30W. Similar convection is also observed within 60 nm of the coast of Brazil from the end of the ITCZ to the mouth of the Amazon River.
Gulf Of Mexico
A cold front has entered the NW corner of the basin stretching from central LA to near Corpus Christi, TX. Scattered showers and thunderstorms with frequent lightning are in the vicinity of the front offshore of TX and LA, mainly north of 28N. Fresh to strong NE winds are behind the boundary, where seas are 3 to 5 ft. Elsewhere, a north to south oriented trough extends from the south-central Gulf to the southern Bay of Campeche. Fresh to strong southeasterly winds are on the east side of the trough, shifting to ENE on the west side. Seas are mainly 4 ft in the central and southern Gulf.
High pressure dominates the remainder of the basin allowing for moderate winds and seas below 3 ft. Dense fog within 30 nm of the northern Gulf Coast states should dissipate throughout the morning.
For the forecast, the cold front will move southeastward and reach from the Florida Big Bend area to north of Tampico, Mexico tonight, then weaken from South Florida to near Veracruz, Mexico, Wed evening. Fresh to strong NE to E winds are expected in the northwestern Gulf behind the front today through early Wed. High pressure will build over the SE United States by the end of the week, and will support moderate to fresh E-SE winds across the basin, with locally fresh to strong winds off the Yucatan Peninsula. Winds will weaken slightly for the start of the upcoming weekend.
The Gale Warning offshore northern Colombia has ended.
The pressure gradient between high pressure over the SW Atlantic and low pressure over Colombia supports strong to near- gale force winds over the Colombian basin, where seas are 9 to 12 ft south of 15N and are mainly between 74W and 80W. Similarly, fresh to strong winds are over the Gulf of Honduras, where seas are 6 to 9 ft noted in a recent altimeter pass. Fresh trades cover the remainder of the eastern and central Caribbean basin where seas are 5 to 7 ft. Moderate to fresh NE winds are within the Windward and Mona Passages, where seas are 4 to 6 ft.
For the NW Basin, moderate to fresh SE winds are noted with 4 to 6 ft seas, except in the lee of Cuba, where there are moderate winds and 3 to 5 ft seas.
For the forecast, the tight pressure gradient will continue supporting fresh to strong easterly winds over the central Caribbean most of the week. Winds N of Colombia will pulse to gale-force each night starting Thu night through Sat night. Fresh to strong trade winds will persist in the Gulf of Honduras through Wed morning, occasionally reaching near-gale force. Winds will pulse to fresh to strong across the approach to the Windward Passage Fri through Sat. Moderate to fresh trade winds will prevail elsewhere across the Caribbean.
Fair weather conditions prevail over the western Atlantic for the forecast area due to high pressure of 1022 mb, which extends a ridge to the northern Bahamas. West of 55W, moderate to fresh anticyclonic flow surrounds the high with W winds N of 28N and E winds S of 24N with the strongest breezes near the entrance of the Windward Passage. These conditions are allowing for 3 to 5 ft seas, except to the NE of the Lesser Antilles, where 4 to 6 ft seas are noted.
Elsewhere, moderate to fresh NE winds prevail mainly south of 25N and west of 35W. The remnants of moderate to rough seas continue over the open Atlantic from a dissipating frontal boundary. 8 to 10 ft N swell is south of 20N and west of 30W to the Lesser Antilles. 9 to 11 ft NW swell continues to propagate eastward and is mainly north of 20N and east of 40W at this time. 9 ft swells also reached the northern Canary Islands this morning.
For the forecast W of 55W, high pressure will prevail over the western Atlantic today. A cold front is forecast to move off the SE United States coast this afternoon, then slowly track southeastward through Fri when it will reach 22N/23N. Fresh to strong winds and higher seas are forecast N of 29N in the vicinity of the front Wed, with moderate to fresh winds elsewhere in the vicinity of the front. High pressure building in the wake of the front will tighten the pressure gradient, generating fresh to strong NE to ENE winds across the Bahamas by Thu night. NE swell will build seas to around 8 ft east of the Bahamas by the end of the week.
Posted 28 minutes ago by NHC Forecaster Mora