[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251738
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
138 PM EDT Wed Oct 25 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.

...TROPICAL WAVES...

A tropical wave is E of the Lesser Antilles with axis extending
from 19N56W to 13N59W to 07N59W, moving W at 5-10 kt. The wave is
in an area of abundant moisture as depicted on SSMI TPW imagery.
There is also a distinct 700 mb trough axis associated with this
wave. Scattered moderate to isolated strong convection is within
120 nm of the wave axis.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 10N14W to
08N20W. The Intertropical Convergence Zone axis extends from
08N20W to 08N42W to 07N50W to 06N55W. Aside from the convection
associated with the tropical wave, scattered moderate to isolated
strong convection is from 03N-12N between 30W-42W, and from 08N-
13N between 42W-50W.



A middle to upper level trough continues to progress eastward out
of the Great Lakes and Mississippi River valley region towards
the eastern US seaboard this morning. The trough supports a cold
front extending from 30N77W to south Florida near 25N80W. Scattered
showers and isolated tstms are occurring ahead of the front
within 150 nm. The remainder of the SW North Atlc is under the
influence of a surface ridge anchored by a 1028 mb high centered
near 38N57W. To the E of the ridge, a cold front extends from
30N32W continuing to 28N36W where it becomes stationary to 25N42W
then it starts to dissipate. Scattered showers and tstms are
occurring W of the front from 25N- 29N between 50W- 59W. Weak
surface ridging is elsewhere N of 20N.

...DISCUSSION...

GULF OF MEXICO...

As of 1500 UTC a cold front is over the Straits of Florida from
24N80W to W Cuba at 23N81W. Scattered showers are within 60 nm of
the front. A 1029 mb high is centered over N Mexico near 27N102W.
The surface pressure gradient between this high and the cold front
is rather tight thus 20-25 kt northerly winds are over the Gulf of
Mexico. Mostly fair weather is over the remainder of the Gulf. S
Mexico S of 21N to the base of the mountains, has overcast low
clouds and showers. In the upper levels, a large upper level
trough is over the Gulf with axis along 85W supporting the frontal
system now mostly over the W Atlantic. Expect in 24 hours for the
surface high to move to the NW Gulf of Mexico, with fair weather
and weaker surface winds.

CARIBBEAN SEA...

As of 1500 UTC, a cold front extends from W Cuba near 23N81W to
20N86W to the Gulf of Honduras near 16N88W. Widely scattered
moderate convection is over the NW Caribbean from 16N- 21N between
82W-88W. A surface trough extends from 20N79W to a 1008 mb low off
the coast of Nicaragua near 12N82W. Scattered moderate to strong
convection is from 10N-17N between 78W-84W. Further E, a tropical
wave is approaching the Lesser Antilles, see above. Of note in the
upper levels, an upper level ridge is over the NW Caribbean and
Central America. A small upper level low is centered over the E
Caribbean near 13N63W. Upper level diffluence E of the low is
enhancing the convection E of the Lesser Antilles. Expect the
surface low off the coast of Nicaragua to remain quasi-stationary
for the next 24 hours with continued convection. Also expect the
tropical wave to gradually move into the E Caribbean with
convection mostly E of the wave axis.

...HISPANIOLA...

Dry air northerly flow aloft will support fair weather across the
island through Thursday. Moderate trades are also expected to
persist.

ATLANTIC OCEAN...

A cold front is over the W Atlantic from 31N76W to the Straits of
Florida near 24N80W. Scattered moderate convection is within 120
nm E of the front. A cold front is over the central Atlantic from
31N29W to 25N40W to 25N46W. Scattered showers are within 90 nm of
the front. Of note in the upper levels, an upper level low is
centered over the central Atlantic near 29N59W. Widely scattered
moderate convection is from 26N-29N between 51W-57W. Expect the
two fronts to move E over the next 48 hours with convection.

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

$$
Formosa
This weather bulletin was brought to you by:
www.nashvilleweather.net