Special Features

Hurricane Gabrielle is centered near 30.0N 62.5W at 22/0900 UTC or 180 nm SE of Bermuda, moving NNW at 9 kt. Estimated minimum central pressure is 978 mb. Maximum sustained wind speed is 80 kt with gusts to 100 kt. Seas are peaking to 33 ft northeast of the center. Convection is becoming better organized, with moderate to strong convection forming a large spiral band within 90 nm to the northeast and 60 nm to the southwest of the center, although an eye is not fully developed at this time. A turn towards the north is expected today and tonight as Gabrielle rounds the western periphery of a subtropical ridge, and will pass well to the east of Bermuda. The system will then be steered within stronger west- southwesterly mid- latitude flow, and accelerate towards the northeast and east- northeast during the next few days. The hurricane is within a favorable environment for strengthening, over the next 24 hours or so, with warm sea surface temperatures and light to moderate wind shear, and is expected to become a major hurricane tonight. Weakening is forecast thereafter due to moderate to strong westerly wind shear and slightly drier mid- level air.

Swells generated by Gabrielle will continue to affect Bermuda during the next few days. These swells are now reaching the east coast of the United States from North Carolina northward, as well as Atlantic Canada, and should continue during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.

Please read the latest HIGH SEAS and OFFSHORE WATERS FORECASTS issued by the National Hurricane Center at websites - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and https://www.nhc.noaa.gov/marine/offshores.php for more information. For the latest Gabrielle NHC Forecast/Advisory and Public Advisory, please visit www.hurricanes.gov for more details.

Tropical Waves

A tropical wave was added to the surface map over the eastern Atlantic near 23W south of 15N, moving west at 10 kt. A few thunderstorms are noted along the wave axis near 09N.

A central Atlantic tropical wave is near 38W from 21N southward, and moving west at 10 kt. Scattered moderate convection is noted from 13N to 18N between 33W and 42W.

A central Atlantic tropical wave is near 53W from 20N southward, and moving west at 10 to 15 kt. Scattered moderate to isolated strong convection is present from 13N to 21N between 48W and 57W.

A western Caribbean tropical wave is near 85W from 20N southward to far western Panama, moving west at 10 kt. A few thunderstorms are evident along the wave axis near 18N.

Monsoon Trough/ITCZ

A monsoon trough enters the Atlantic near 19N16W and continues southwestward to 10N40W. Scattered moderate to isolated strong convection is occurring from 07N to 10N between 25W and 28W.

Gulf Of America

An upper-level trough over the central Gulf is generating scattered moderate convection over the south-central Gulf. Weak ridging from the Carolinas to Texas is supporting gentle to moderate NE to SE winds and seas of 1 to 3 ft for the entire Gulf, except the Bay of Campeche where light to gentle winds and 1 to 2 ft seas prevail.

For the forecast, the weak high pressure over the northeast Gulf will support gentle to moderate E to SE winds and slight seas across the Gulf through mid week. Looking ahead, a weak cold front will enter the northwest Gulf by Thu night, and reach from the northeast Gulf to near Tampico, Mexico by late Fri.

Caribbean Sea

Moderate to locally fresh trade winds persist over the south- central Caribbean this morning, along with 3 to 5 ft seas. This is in between a tropical wave over the Gulf of Honduras and another tropical wave over the Atlantic approaching the Lesser Antilles. Light to gentle breezes and 1 to 3 ft seas are noted elsewhere.

For the forecast, the tropical wave over the Gulf of Honduras will move west of the Caribbean through tonight, just as other tropical wave in the Atlantic enters the eastern Caribbean. Expect moderate to fresh trade winds across the south-central Caribbean through the early part of week between the tropical waves, with fresh to strong winds off Colombia tonight and Tue night along with seas to 6 ft. These winds will diminish by mid week as the tropical wave moves across the central basin.

Atlantic Ocean

Refer to the Special Features section for details on Hurricane Gabrielle.

A trough extends from 31N74W through the northern Bahamas. Gentle to moderate NE winds and 4 to 5 ft seas are occurring west of this trough. Enhanced by modest SW wind shear aloft, scattered heavy showers and isolated strong thunderstorms are present over the northwestern Bahamas to just off the Florida Keys. Farther east, an upper level trough is producing scattered moderate convection from 22N to 25N between 62W and 65W. Broad ridging extends elsewhere over the open waters, from a 1023 mb high pressure centered near 32N43W, supporting moderate to locally fresh trade winds and 5 to 7 ft seas. Farther east, north of 20N and east 20W fresh to locally strong winds with seas 5 to 7 ft are found.

For the forecast west of 55W, Hurricane Gabrielle will move to 31.3N 62.1W this afternoon, then well east of Bermuda near 32.9N 60.5W by Tue morning before continuing to move away from the region and into the north-central Atlantic. Meanwhile, a surface trough will persist off the SE U.S. Coast to the northern Bahamas into the middle of the week enhancing convection in the vicinity. Otherwise, in the wake of Gabrielle, central Atlantic high pressure will build westward providing gentle to moderate winds into midweek. Seas associated with Gabrielle southeast of Bermuda will gradually subside by midweek. Looking ahead, weak and broad low pressure along the northern portion of a tropical wave may increase winds and seas well north of the Leeward Islands by the end of the week.

Posted 4 hours ago by NHC Forecaster Christensen