AXNT20 KNHC 230529

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
129 AM EDT Sat Sep 23 2017

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 0000 UTC surface analysis and satellite imagery through 0515 UTC.


Hurricane Maria is centered near 24.1N 71.7W at 23/0300 UTC, or about 335 nm east of Nassau, moving north-northwest at 8 kt. Minimum central pressure is 954 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Numerous moderate to strong convection is within 90 nm of the center, except within 120 nm in the south quadrant. Scattered moderate convection is elsewhere from 21N-30N between 66W-75W. Maria is forecast to slowly decrease in intensity during the next couple of days while it turns more northward. Please see the latest NHC Public Advisory under AWIPS/WMO headers MIATCPAT5/WTNT35 KNHC and the complete NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC for the complete details.

Tropical Storm Lee is centered near 31.5N 49.0W at 23/0300 UTC, or about 904 nm east of Bermuda moving north at 6 kt. Estimated minimum central pressure 1009 mb. Maximum sustained winds 35 kt with gusts to 45 kt. Scattered moderate convection is within 60 nm in the north quadrant. Additional scattered moderate convection is located to the southeast of Lee from 24N-30N between 41W-52W associated with a middle to upper-level low. Lee forecast to turn to the northeast over the next couple of days. Please see the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for the complete details.


A tropical wave is off the coast of Africa with axis extending from 17N18W to 02N21W, moving west at 5 to 10 kt. Abundant moisture is present with the tropical wave axis as measured by SSMI TPW imagery. Isolated moderate convection is from 05N-10N between 15W-25W.

A tropical wave is in the central Atlantic with axis extending from 19N49W to 05N53W, moving west at 10 kt. Plentiful moisture is present near the tropical wave axis as indicated by SSMI TPW imagery. Scattered moderate convection is from 08N-20N between 49W-55W.


The monsoon trough axis extends from the African coast near 13N17W to 06N31W. The ITCZ extends from 06N31W to 06N51W. Besides the convection mentioned in the tropical waves section, no activity is present along these boundaries at this time.



A surface ridge extends across the basin anchored over the northeast CONUS. This pattern is maintaining gentle to moderate east to southeast flow with mainly 1 to 3 ft seas across the Gulf of Mexico. Isolated showers are observed over the eastern portion of the basin supported by a middle to upper level trough extending from an upper-level low centered over southwest Georgia. Little change is expected through the next 24 hours.


A surface trough trails Hurricane Maria which is moving north- northwest away from the north coast of Hispaniola. The trough extends from 20N74W to 13N78W. Associated outer rainbands of Maria continue to induce flash flooding over Puerto Rico although this activity should gradually diminish during the next couple of days as Maria continues to move away from the area. The remainder of the Caribbean is fairly tranquil with gentle to moderate winds west of the surface trough, and moderate to fresh easterly flow in the east Caribbean east of the trough. Aloft, a middle to upper-level trough extends across the northwest Caribbean with mainly dry and stable air, while upper anticyclonic flow prevails elsewhere.


Outer rainbands associated with Hurricane Maria, which continues to move north-northwest away from the north coast of the island, continue to support scattered rainfall and localized flash flooding mainly over the far east portion of the island. Activity should gradually diminish during the next couple of days as Maria continues away from the area.


Please refer to Special Features section for more information on Hurricane Maria and Tropical Storm Lee.

Otherwise, a surface trough is over the northwest portion of the basin reaching from near 31N77W to 26N80W. This trough is supporting scattered showers from the western Bahamas to the Florida Peninsula. Another trough extends south of Lee from 28N51W to 22N55W. No significant convection is observed at this time. The remainder of the basin is under the influence of a surface ridge, anchored by a 1022 mb high centered near 27N38W.

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