Tropical Weather Discussion
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AXNT20 KNHC 072349

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
649 PM EST Thu Dec 7 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 1800 UTC surface analysis and satellite imagery through
2345 UTC.



A stationary front extends from the Tampa Bay area of Florida to
26N87W then through a 1013 mb low centered near 24N94W to 18N94W.
A strong pressure gradient is noted across the northern Gulf of
Mexico as another low is centered over southern Texas interacting
with a high pressure area that prevails over eastern US. With
this, gale-force winds have developed north of 21N and west of
93W. These conditions will spread to the southwest Gulf this
evening and through Friday morning as a reinforcing push of cooler
and drier air moves into the region. Wave heights will peak to 14
ft. Please read the latest NWS High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 for more details.


The monsoon trough extends across the Africa coast near 11N15W
and extends to the east Atlantic near 07N20W. The Intertropical
Convergence Zone extends from 07N20W to 03N46W. A surface trough
extends from 09N41W to 07N41W. Scattered moderate convection is
noted along and within 300 nm north of these boundaries between



A stationary front extends from the Tampa Bay area of Florida to
26N87W then through a 1013 mb low centered near 24N94W to 18N94W.
Gale force winds have developed to the north and west of these
features. Please refer to the section above for details. Scatterometer
data depicts gentle to moderate winds to the south and east of
the front/low. Expect for the low to move east- northeast through
the next 24 hours. Thereafter, the upper-level trough supporting
the frontal system will dig farther south, and allow the low to
accelerate NE and bring its cold front across the remainder of the


Deep moisture over the west Caribbean is interacting with a
diffluent flow aloft and a surface trough to support scattered
moderate convection west of 80W. This activity is impacting
Honduras, Nicaragua, and the Cayman Islands. To the southwest, the
monsoon trough extends along 10N enhancing convection over Costa
Rica, Panama, and adjacent waters between 78W-83W. To the east,
the tail end of a dissipating stationary front extends from the
central Atlantic to the Lesser Antilles near 16N61W to 16N66W.
Isolated showers prevail along this boundary. Generally fair
weather covers the remainder of the basin, with scatterometer data
depicting moderate to strong trades across the area. Expect for a
frontal boundary to enter the northwest Caribbean during the next
48 hours with strong to near gale-force winds mainly behind the


Fair weather prevails across the island as a surface high centered
over the central Atlantic extends through the area. Isolated
convection could develop in the afternoon hours through the
weekend due to daytime heating.


A stationary front extends across the west Atlantic from 31N76W to
28N81W. To the southeast, a surface trough is from 31N75W to
27N80W. Isolated showers are noted along these boundaries. To the
east, a 1023 mb surface high is centered near 29N60W. A cold front
extends across the east Atlantic from 31N33W to 19N42W to 15N58W,
then becomes weak and stationary to 16N61W. Scattered moderate
convection is north of 24N between 31W-34W. A surface ridge
prevails elsewhere with fair weather. During the next 24 hours,
the frontal boundary over the west Atlantic will push southeast
through Saturday. A new low pressure area will develop under the
upper-level low in the central Atlantic and will move southwest
over our area of discussion enhancing convection.

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