Tropical Weather Discussion
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AXNT20 KNHC 111756

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1256 PM EST Sat Nov 11 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.


The monsoon trough extends across Africa to 11N15W then extends SW
to E Atlc waters to 10N19W. The Intertropical Convergence Zone
axis extends from 10N19W to 08N30W to 07N50W to the coast of South
America near 06N55W. Scattered moderate convection is from 07N-11N
between 22W-30W.



The tail end of a cold front has pushed south of Melbourne
Florida. Radar imagery shows scattered showers extending 60 nm
inland. A surface trough is over the E Gulf of Mexico from 30N86W
to 24N87W. Broken low clouds are over the NE Gulf. Further S,
scattered moderate convection is over the Yucatan Channel.
Elsewhere, a surface trough is over the W Gulf from 25N87W to
19N96W, producing scattered showers along the coast of NE Mexico.
In the upper levels, a trough is over the central Gulf of Mexico
with strong subsidence. Expect the E Gulf surface trough to move
to the central Gulf over the next 24 hours with possible showers.
Also expect the the W Gulf trough and showers to persist along the
coast of NE Mexico.


A 1007 mb low is centered over the SW Caribbean near Providencia
Island at 13N81W. A surface trough extends from 17N81W to the low
center to 10N81W. Scattered moderate convection is within 90 nm of
the trough. Scattered moderate convection is over the Gulf of
Honduras from 16N-18N between 85W-88W. Scattered moderate to
isolated strong convection is also near Jamaica from 16N-19N
between 73W-78W. Scattered showers are over Costa Rica and Panama
due to the eastern extent of the Eastern Pacific monsoon trough.
In the upper levels, upper level diffluence is over the W
Caribbean enhancing convection. Expect additional convection over
the central and western Caribbean over the next 48 hours.


Cloudiness with possible isolated showers are across the Island
being supported by a broad area of low pressure across the western
half of the Caribbean and middle level diffluent flow. The shower
activity is forecast to continue through Monday, increasing during
the afternoon hours due in part to daytime heating.


A cold front is over the W Atlantic from 31N68W to 28N74W to
Melbourne Florida. Scattered showers are within to nm N of the
front. A prefrontal trough is extends from 31N65W to 26N69W.
Scattered moderate convection is within 90 nm E of the trough.
Scattered moderate convection is also N of Puerto Rico from 20N-
24N between 64W-69W. A surface trough is over the tropical
Atlantic from 25N53W to 18N50W. Isolated moderate convection is
from 17N-21N between 46W-50W. Of note in the upper levels, an
upper level trough is over the W Atlantic supporting the surface
trough. A large upper level low is centered over the E Atlantic
near 31N35W with a trough axis extending SW to 17N50W. Upper level
diffluence is E of this trough axis to the coast of W Africa.
Expect the cold front in 24 hours to extend from 31N65W to S
Florida with showers.

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