AXNT20 KNHC 260556

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
156 AM EDT Tue Sep 26 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 32.6N 73.2W at 26/0600 UTC or about 195 nm southeast of Cape Hatteras North Carolina, moving north at 6 kt. Minimum central pressure is 970 mb. Maximum sustained winds are 70 kt with gusts to 85 kt. Maria is a very large cyclone with hurricane-force winds extending outward up to 90 nm from the center. Scattered moderate convection extends out to 240 nm from the center in the northeast semicircle. Dry air is entraining into the overall circulation with scattered moderate convection out to 150 nm in the southwest semicircle. The Morehead City, N.C. WSR- 88D indicated narrow bands of scattered showers approaching the N.C. coast between Cape Lookout and Cape Hatteras with additional showers over the northern Outer Banks and the Albemarle Sound. NOAA Buoy 41025 just southeast of Cape Hatteras recently reported seas to 14 FT. See the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC for more details.

Hurricane Lee is centered near 30.2N 51.5W at 26/0300 UTC or about 735 nm east of Bermuda. Lee is now moving to the west- southwest at 7 kt. Estimated minimum central pressure is 979 mb. Maximum sustained winds are 80 kt with gusts to 100 kt. Lee is a small cyclone with scattered moderate isolated strong convection confined to within 60 nm of the center. Lee is forecast to remain a hurricane and turn toward the west Tuesday, and then move toward the west-northwest by Wednesday. See the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details.


A tropical wave extends along 35W/36W from 07N to 21N, moving west at 10 kt. The wave shows up well in GOES high density winds in the lower to mid levels of the atmosphere. Most of the wave is embedded within a fairly dry and stable environment per recent SSMI TPW imagery. As such no significant convection is associated with this tropical wave.

A tropical wave is in the eastern Caribbean along 67W/68W, from 07N to 20N, moving west at 10 to 15 kt. The wave is situated on the eastern periphery of an upper level anticyclone over the NW Caribbean in an area dominated by mid to-upper level northerly flow. No significant convection is noted at this time.


The monsoon trough extends from Senegal coast near 15N17W to 10N30W to 09N35W. The Intertropical Convergence Zone extends from 08N38W to 09N44W to the coast of South America near 06N57W. Scattered moderate isolated strong convection is from 05N-10N between 10W-14W. Isolated moderate convection is from 05N-09N between 33W-40W.



Slight surface ridging is over the Gulf of Mexico with mostly 5-15 kt SE flow. Strongest winds are over the W Gulf. In the upper levels, a large upper level trough is over the western half of the U.S. with axis along 114W. Upper level diffluence E of the axis is producing convection over Texas and Mexico between 95W-105W. An upper level low is centered over the NE Gulf of Mexico near 28N85W with strong subsidence. Again upper level diffluence is SE of the center producing showers and convection over W Cuba, the Straits of Florida, and the Bahamas. Expect over the next 24 hours for an increase of showers and convection over the Yucatan Channel, Yucatan Peninsula, and the Bay of Campeche.


A tropical wave is over the E Caribbean. Scattered showers are well E of the wave axis, over the Leeward Islands, N of 14N between 58W- 65W. A surface trough is over the W Caribbean from 21N79W to 14N80W. Scattered moderate convection is over most of Cuba, Haiti, and Jamaica, from 16N-22N between 72W-83W. Much of this convection is also enhanced by upper level diffluence. Lastly, the eastern extent of the E Pacific monsoon trough is well into the SW Caribbean extending from NE Nicaragua to N Colombia. Scattered moderate convection is from 11N-16N between 77W-84W. Expect over the next 24 hours for continued showers and convection over the W Caribbean and Central America W of 70W.


Presently Haiti has more showers and convection than the Dominican Republic. The precipitation is moving W with the easterlies. Expect over the next 24 hours for more precipitation to advect over the Island from the SE.


A tropical wave is moving across the basin. Refer to the section above for details. Outside the influence of Hurricanes Maria in the western Atlantic and Lee in the central Atlantic, surface ridging prevails across much of the remainder of the west-central Atlantic, anchored by a 1022 mb high centered near 36N59W.

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

$$ Formosa