AXNT20 KNHC 190005

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT Tue Sep 18 2018

Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through 2330 UTC.


The center of Tropical Depression Joyce at 18/2100 UTC is near 30.9N 27.8W. JOYCE is moving SSW, or 205 degrees, 06 knots. The estimated minimum central pressure is 1010 mb. The maximum sustained wind speeds are 25 knots with gusts to 35 knots. Widely scattered moderate to isolated strong rainshowers are from 31N to 32N between 26W and 27W. The PUBLIC ADVISORIES for JOYCE are transmitted via the WMO header WTNT35 KNHC, and via the AWIPS header MIATCPAT5. The FORECAST/ADVISORIES for JOYCE are transmitteed via the WMO header WTNT25 KNHC, and via the AWIPS header MIATCMAT5.


An Atlantic Ocean tropical wave is along 15W/16W from 23N southward, partially in Africa and partially in the ocean. The accompanying precipitation is in Africa.

An Atlantic Ocean tropical wave is along 59W/60W from 19N southward. Isolated moderate to locally strong rainshowers cover the Atlantic Ocean and the Caribbean Sea from 10N to 20N between 54W and 63W.


The monsoon trough passes through the coastal areas of Guinea- Bissau near 12N16W, to 09N20W. The ITCZ continues from 09N20W to 08N30W, 08N40W, and to 06N56W. Scattered moderate to isolated strong rainshowers are within 180 nm on either side of the line that runs from 08N13W 05N30W 05N37W 10N46W. Isolated moderate rainshowers are elsewhere from 13N southward between Africa and 60W.



A weak 1015 mb surface high is over the western Gulf near 27N94W. Another 1017 mb surface high is centered over northern FL near 30N82W. Light to gentle breezes and minimal seas will continue over most of the Gulf during the next few days. An upper-level low is near 26N94W with upper-level cyclonic flow covering the western Gulf. A surface trough, associated with the remnants of Isaac, is over the northwest Caribbean along 83W from western Cuba to near Cabo Gracias a Dios, Nicaragua.

Weak high pressure extends across the northern Gulf, supporting light breezes and minimal seas. A trough over the northwest Caribbean will move across the Yucatan Channel through Wed, into the southwest Gulf Thu and Fri, then dissipating Sat.


A trough over the northwest Caribbean along 83W from western Cuba to near Cabo Gracias a Dios, Nicaragua is associated with the remnants of Isaac. Scattered moderate convection is within 60 nm west and 120 nm east of the trough axis from 17N-21N. The trough will move west of the area on Wednesday.

A trough in the northwest Caribbean will pass west of the area through Wed. A tropical wave near Barbados will move into the eastern Caribbean tonight, the central Caribbean Thu into Fri, and pass west of the area through late Sat into Sun. Meanwhile high pressure building from the central Atlc into the central Bahamas will support moderate to fresh trade winds and building seas across the entire basin late Wed through Fri.


Please refer to the Special Features section for details on Tropical Depression Joyce.

An upper-level low with a surface reflection is spinning just south of Bermuda. A surface trough extends from this feature southwestward to the southeastern Bahamas. Scattered showers and thunderstorms are located along and east of the trough axis west of 65W. This convective activity is affecting the southeast Bahamas and the Turks and Caicos Islands. Abundant cloudiness and showers extend elsewhere east of the trough from 20N-31N between 56W-65W. The surface trough will likely weaken over the next 24-48 hours. Another trough extends into the forecast area from T.D. Joyce southward to near 21N32W. A narrow band of mainly low clouds with showers is associated with the trough. A 1023 mb surface high is located in between the two aforementioned troughs near 31N47W.

A surface trough reaching from roughly Bermuda to the southern Bahamas will shift slowly NW and weaken through tonight as the central Atlantic ridge builds into the central Bahamas. Low pressure moving off the Carolinas will drag an attendant frontal trough across the waters north of 27N Thu and Fri. The low will move to near 31N71W Fri evening then drift W and slowly weaken Sat and Sun.

For additional information please visit http://www.hurricanes.gov/marine

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