Special Features

Central Subtropical Atlantic (Invest-AL95): A broad 1016 mb area of low pressure centered a few hundred nautical miles east- southeast of Bermuda near 30.5N60.5W continues to show signs of organization. Scattered moderate isolated strong convection is noted from 20N to 31N between 48W and 61W. Fresh to strong winds are noted mainly on the NE side of the low, north of 29N between 55W and 61W where seas are 5 to locally 8 ft just north of the area. Additional development of the low is possible, and this system could become a short-lived tropical depression or storm during the next couple of days while it moves northward and north- northeastward, well northeast of Bermuda. This system has a medium chance of tropical cyclone formation in the next 48 hours and through the next 7 days. Please refer to the latest NHC Tropical Weather Outlook at website: https://www.hurricanes.gov/text/MIATWOAT.shtml for more details.

Tropical Waves

A far eastern Atlantic tropical wave has emerged off the west coast of Africa near 18W south of 22N, moving westward 15 to 20 kt. Scattered to numerous moderate isolated strong convection is noted from 05N to 17N between 15W and 25W. Environmental conditions are forecast to be marginally conducive for development, and a tropical depression could form by the middle to latter portions of the week while the system moves generally westward at 15 to 20 kt across the eastern and central tropical Atlantic.

An central Atlantic tropical wave has its axis near 41.5W south of 19N, moving westward around 15 kt. Please refer to the Monsoon Trough/ITCZ section below for details on any nearby convection as it is elongated along the ITCZ axis.

A Tropical N Atlantic offshore waters tropical wave has its axis along 59W south of 21N, moving westward around 10 kt. Convection near the wave is limited however some isolated to widely scattered showers near the axis are possible.

A central Caribbean tropical wave is near 71W south of 21N across central portions of the Dominican Republic to northwest Venezuela, moving westward around 10 kt. Scattered moderate convection is noted from 17N to 18.5N between 69W and 72W.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic through the coast of Africa near 14.5N17W and continues west-soutwhestward to 12N33W. The ITCZ extends from 12N133W to 10N40W, then resumes west of a tropical wave from 08N42W to along the coast of northern South America to 06N50W, with another segment to the west just inland of the Caribbean coast. Aside from the convection associated with the tropical waves, scattered moderate to isolated strong convection is noted within 180 nm either side of the ITCZ between 33W and 54W.

Gulf Of America

Weak surface ridging that is anchored by a 1017 mb high center located near 26N89W is generally allowing for anticyclonic light to gentle winds across the basin, except moderate in the eastern Bay of Campeche to the western Yucatan Peninsula. Seas of slight state remain over the basin per buoy observations. Scattered showers and isolated thunderstorms are confined the Bay of Campeche south of 21N. Isolated showers and thunderstorms are over portions of the N-central and NE Gulf due to a weak low level trough.

For the forecast, weak high pressure will remain centered over central Gulf through Wed, with the western Atlantic ridge building westward into the basin thereafter. This will maintain gentle to locally moderate winds and slight seas this week. A surface trough will generate locally fresh winds north and west of the Yucatan Peninsula in the early evenings through the period.

Caribbean Sea

The pressure gradient associated to high pressure over the western Atlantic and relatively lower pressure in northern South America continues to allow for fresh to strong trades over the central Caribbean from the coast of Hispaniola to the coasts of NW Venezuela and northern Colombia. Seas up to 7 ft are with these trades. Moderate to fresh trades and moderate seas are elsewhere from 11N to 18N, with gentle to moderate trades and moderate seas elsewhere, except slight north of 20N in the lee of Cuba. Scattered moderate to isolated strong convection is occurring from 09N to 15N between 78.5W and 85W including over portions of northern Costa Rica and eastern Nicaragua.

For the forecast, the pressure gradient between western Atlantic high pressure and low pressure in northern South America will continue to maintain fresh to strong trades and resultant rough seas over the south-central Caribbean this week. Elsewhere, mainly moderate to fresh trades and moderate seas will prevail, aside from light to gentle winds and slight seas in the NW part of the basin. Winds will pulse at times through the week following passages of a series of relatively weak tropical waves that will quickly move west across the basin.

Atlantic Ocean

Please refer to the Special Features section for more details on low pressure, Invest AL95, with the potential for tropical cyclone formation, and on a tropical wave that has recently emerged off Africa.

A couple of weak surface troughs are analyzed off the coast of the SE United States and Florida with isolated to widely scattered showers and thunderstorms from roughly 27N to 31N between 73W and 79W. Moderate to fresh winds are noted from the southern Bahamas and Turks and Caicos Islands to near the approach to the Windward Passage with low level troughing in place. Gentle to moderate winds prevail elsewhere north of 20N and west of 61W. Slight to moderate seas prevail north of 20N and west of 61W.

Another pair of weak surface troughs are in the NE portion of the basin from near the Canary Islands westward as the remnants of an old frontal boundary. No significant convection is noted near these features. Otherwise, broad high pressure ridging prevails. Moderate to fresh trades dominate from north of the monsoon trough and ITCZ between Africa and 56W, with 4 to 7 ft seas. Winds are mainly moderate and seas moderate across any remainder waters.

For the forecast west of 55W, broad low pressure of 1016 mb centered near 29N62W is producing scattered moderate convection and strong winds E of its center to about 52W. This low is expected to move N and out of the area by tonight, and is showing signs of tropical organization. Additional development of this system is possible, and a short- lived tropical depression or storm could form during the next couple of days well E of Bermuda. Regardless of development, conditions will improve over area waters by Tue as the system moves away. Elsewhere,moderate to fresh trades will prevail S of 23N, with slightly higher winds pulsing at times as the northern extent of tropical waves most westward across the far southern waters this week.

Posted 0 minutes ago by NHC Forecaster Lewitsky