AXNT20 KNHC 121000 
Tropical Weather Discussion 
NWS National Hurricane Center Miami FL 
600 AM EDT Thu Oct 12 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 0600 UTC surface analysis and satellite imagery through 
1000 UTC. 
Hurricane Ophelia is centered near 30.3N 35.6W at 12/0900 UTC or 
630 nm southwest of the Azores moving northeast at 3 kt. 
Estimated minimum central pressure is 986 mb. Maximum sustained 
winds are 75 kt with gusts to 90 kt. Scattered to numerous 
moderate convection is from 28N-32N between 32W-38W. See the 
latest Forecast/Advisory under AWIPS/WMO headers MIATCMAT2/WTNT22 
KNHC for more details. 
A tropical wave is over the central Atlantic with axis that extends 
from 16N48W to 06N51W, moving west at 15-20 kt. The wave 
coincides with 700 mb troughing and 850 mb relative vorticity max 
along the wave axis near 10N. Scattered moderate isolated strong 
convection is from 07N-18N between 43W-51W. 
A tropical wave is over the southwest Caribbean with axis extending 
from 14N79W to 06N79W, moving west at 10-15 kt. A low amplitude 
700 mb troughing is noted over Central America. Despite the fact 
that abundant moisture prevails in the area, no significant 
convection is observed with this wave at this time. 
The monsoon trough extends from the African coast near 11N16W to 
07N25W. The ITCZ continues from 07N25W to 07N47W. Aside from the 
convection related to the tropical wave along 50W, no significant 
convection is observed at this time with any of these boundaries. 
A stationary front extends from 30N87W across the northwest Gulf 
to 26N96W to the Bay of Campeche near 19N95W. Scattered moderate 
convection is from 18N-24N and west of 95W. A thermal trough is 
noted to the east of the front extending from 22N91W to 19N93W 
with scattered showers. Another surface trough was analyzed over 
the northeast waters from 30N83W to 26N83W. Gentle to moderate 
easterly winds prevail across most of the basin except to the west 
of the front from 19N-26W. In this area, moderate to fresh 
northwesterly winds are noted in scatterometer data. Expect for 
the front to weaken to a trough and become diffuse through Friday. 
Moderate to fresh easterly winds are expected through the upcoming 
Convection associated with an upper-level low centered over 
northern Cuba near 22N78W has diminished. At this time, isolated 
moderate convection is from 16N-20N and west of 82W. A tropical 
wave is moving across the southwest Caribbean. See the section 
above for details. Latest scatterometer data depicts gentle to 
moderate trades across the whole basin. Little change is expected 
through the next 24 hours. 
An upper-level low centered west of the island and is expected to 
continue drifting west during the next couple of days. Upper 
level divergent southwesterly flow is expected to develop over the 
area supporting scattered showers and thunderstorms through the 
next 24-48 hours mostly in the afternoon/evening hours. 
Hurricane Ophelia is over the central Atlantic, while a tropical 
wave is along 51W. See the sections above for details. An upper- 
level low centered over northern Cuba near 22N78W is supporting 
scattered showers affecting the waters west of 70W. A surface 
trough extends from 28N76W to 24N77W. To the east, another trough 
extends from 28N68W to 21N71W. Isolated showers are noted along 
these features. An area of scattered showers and thunderstorms 
accompanies a surface trough that extends from 24N53W to 21N58W. 
The convection is from 19N-24N between 51W-55W. Surface ridging 
prevails elsewhere. 
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