Special Features

Tropical Storm Chantal: Tropical Storm Chantal was centered near 31.1N 78.7W at 05/1500 UTC or 115 nm SSE of Charleston South Carolina, and moving N at 1 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained winds are 35 kt with gusts to 45 kt. Seas near and NE of the center ranches from 11 to 13 ft. Numerous heavy showers and scattered thunderstorms are occurring up to 130 nm NE of the center. A general northward motion with a gradual increase in forward speed is expected this afternoon through Sunday night, bringing Chantal across the coast of South Carolina Sunday morning. Some additional strengthening is anticipated before Chantal reaching South Carolina. Rainfall of 2 to 4 inches, up to 6 inches locally are probable across the coastal plain of the Carolinas. The combination of storm surge and tide can cause 1 to 3 ft of water above ground level along the coast. Life- threatening surf and rip currents will persist for the next couple of days

Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Three NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details.

Gale Warning E of 35W: A tight pressure gradient between a 1036 mb high pressure system located north of the Azores and low pressures in northwest Africa will continue to support gale-force NE winds with severe gusts and 7 to 9 ft seas, for the waters between the Canary Islands, and nearby waters until at least 06/1200 UTC according to Meteo Fran.

For more details, please visit the Meteo France High Seas Forecast listed on the website https://wwmiws.wmo.int

Tropical Waves

A far eastern Atlantic tropical wave is near 31W from 19N southward, and moving west around 15 kt. Scattered moderate convection is seen from 06N to 08N between 30W and 35W.

An eastern Atlantic tropical wave is near 43W from 16N southward, and moving west at around 15 kt. Widely scattered showers are found from 06N to 08N between 40W and 43W.

A central Caribbean tropical wave is near 71W from western Dominican Republic southward to northwestern Venezuela. It is moving west around 15 kt. Isolated thunderstorms are noted from 15N to 17N between 71W and 75W.

Another tropical wave is near 89W from northern Belize southward extends across Honduras and El Salvador into the far eastern Pacific. No significant convection is present in the Caribbean Sea.

Monsoon Trough/ITCZ

A monsoon trough enters the Atlantic through the coastal border of Senegal and Gambia, then extends southwestward across 10N30W to 07N45W. An ITCZ continues westward from 07N45W to just north of Guyana near 09N50W. Scattered moderate convection is noted near and south of the monsoon trough from 06N to 13N between the Senegal-Guinea coast and 30W.

The eastern end of the East Pacific monsoon trough is causing scattered heavy showers and isolated strong thunderstorms across the southwestern Caribbean Seas, south of 11N.

Gulf Of America

A surface trough curves southwestward from TS Chantal across central Florida to the Florida Straits. Another surface trough curves northwestward from the northeastern Gulf to near New Orleans. Aided by an upper-level low near 27N88W, scattered showers and isolated strong thunderstorms are dominating the eastern Gulf. Otherwise, a 1016 mb high at the central Gulf is providing gentle to moderate N to NE winds and seas of 2 to 4 ft for the northeastern Gulf. Moderate SE to S winds with seas of 2 to 4 ft are seen off the Texas coast and the Bay of Campeche. Light to gentle winds and 1 to 3 ft seas prevail for the rest of the Gulf.

For the forecast, scattered showers and thunderstorms will continue to develop along these troughs over the waters near Florida. Weak high pressure will then prevail into early next week. Fresh NE to E winds will pulse along and just north of the Yucatan Peninsula each afternoon and evening through early next week as a trough develops inland daily and then drifts westward over the Bay of Campeche at night.

Caribbean Sea

Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for convection in the Caribbean Sea. A 1024 mb Bermuda High near 32N56W continues to supply a trade-wind pattern for much of the basin. Moderate to fresh ENE to ESE winds and seas of 4 to 6 ft dominate the southwestern, central and eastern basin. Gentle with locally moderate E to SE winds and 1 to 3 ft seas prevail for the northwestern basin.

For the forecast, the pressure gradient between the Atlantic ridge and the Colombian low will continue to support pulsing fresh to strong trades and rough seas across the south-central basin through midweek next week. Moderate to fresh easterly winds and moderate seas are expected in the eastern basin while gentle to moderate E to SE winds and slight to moderate seas will prevail elsewhere, with the exception of moderate to fresh E winds in the Gulf of Honduras tonight through Wed night.

Atlantic Ocean

Please see the Special Features section for details on Tropical Storm Chantal and a Gale Warning issued by Meteo-France for the Canary Islands.

Convergent southerly winds are generating widely scattered showers and isolated thunderstorms from the northwest Bahamas northward to beyond 31N between 73W and the Florida/southern Georgia coast. A surface trough is triggering scattered moderate convection from 23N to 27N between 62W and 70W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections at the beginning for additional convection in the Atlantic Basin.

Fresh to strong S to SW winds and seas of 7 to 11 ft are present north of 28N and west of 75W. Otherwise, the subtropical ridge is sustaining gentle winds with 3 to 4 ft seas north of 26N between 40W and Florida/southern Georgia coast. Farther east between 35W and 40W, and farther south from 10N to 26N between 35W and the Lesser Antilles/Bahamas, gentle to moderate NE to E winds and seas of 4 to 7 ft exist. Gentle winds and seas at 3 to 5 ft in mixed moderate swells prevail elsewhere of the Atlantic Basin.

For the forecast west of 55W, Tropical Storm Chantal will move to 31.8N 79.0W this evening, then inland to 33.1N 79.3W Sun morning. It will remain inland and weaken to a tropical depression near 34.6N 79.2W Sun evening, then to 35.8N 78.0W Mon morning, and dissipate Mon evening. High pressure will prevail elsewhere. This pattern will support generally gentle to moderate winds except for moderate to fresh winds off the northern coast of Hispaniola through Mon.

Posted 4 hours ago by NHC Forecaster Chan