[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 032339
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
739 PM EDT Tue Oct 3 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
2315 UTC.

...SPECIAL FEATURES...

A tropical wave over the SW Caribbean extends from 20N81W to
08N81W moving W at 10 kt. A 1008 mb low is embedded on the wave
axis near 11.5N81W. Clusters of scattered moderate to isolated
strong convection are from 08N-16N between 76W-86W. Environmental
conditions are forecast to steadily become more conducive for
development, and this system is expected to become a tropical
depression within the next few days. The large disturbance should
move slowly northwestward to northward across or near the eastern
portions of Nicaragua and Honduras, move into the northwestern
Caribbean Sea on Thursday or Friday, and emerge over the southern
Gulf of Mexico by the weekend. Interests in Nicaragua and Honduras
should monitor the progress of this system over the next couple of
days. Regardless of development, this system will likely produce
heavy rains over portions of Central America during the next few
days. There is a medium chance of tropical cyclone formation
within the next 48 hours.

...TROPICAL WAVES...

A tropical wave extends from 17N34W to 08N37W moving W at 15-20
kt. The wave remains low amplitude and coincides with modest
troughing at 700 mb. Satellite TPW imagery indicates this wave is
embedded in an area of deep-layer moisture. Scattered moderate to
isolated strong convection is from 07N-11N between 37W-44W.
Scattered showers are elsewhere within 180 nm of the wave axis.

A tropical wave over the E Caribbean extends from 23N60W to
09N59W moving W at 10-15 kt. The wave coincides with broad 700 mb
troughing and continues to interact with an upper-level low
centered near 16N61W. Divergent upper-level winds on the east side
of the upper low are supporting widely scattered moderate
convection over the Atlantic from 10N-22N between 51W-61W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 09N13W to
09N22W. The Intertropical Convergence Zone axis extends from
09N22W to 09N30W to 07N43W to 09N53W. Besides the convection
associated with the tropical waves, scattered moderate to isolated
strong convection is along the coast of W Africa from 06N-13N
between 08W-15W.


...DISCUSSION...

GULF OF MEXICO...

Surface ridging is over the northern Gulf of Mexico with 20-25
easterly winds. The surface pressure gradient is fairly tight and
30 kt winds may occur over the NE Gulf over the next 24 hours. A
surface trough is over the SW Gulf of Mexico from 24N99W to
17N94W. Scattered moderate convection is within 90 nm of this
trough. In the upper levels, a small upper level high is centered
over the S Texas near 28N96W. A good amount of upper level
moisture is along the Texas and Mexico coasts. Expect over the
next 24 hours for convection with wind gusts to advect over S
Florida. Also expect the surface trough to persist over the Bay
of Campeche with convection. Furthermore, expect the surface
ridging to persist over the northern and central Gulf of Mexico.

CARIBBEAN SEA...

A tropical wave with an embedded low is over the SW Caribbean that
merits watching. Another tropical wave is over the E Caribbean.
See above. In addition, the eastern extent of the E Pacific
monsoon trough extends from S Guatemala to N Costa Rica to N
Colombia. Scattered moderate to isolated strong convection is over
all of Central America S of 20N. Otherwise, 10-20 kt tradewinds
are over the Caribbean.

...HISPANIOLA...

Currently skies remain mostly fair across the island. Some showers
are over the southern and southwestern coastal waters, moving
south. Hispaniola is presently in between tropical waves.

ATLANTIC OCEAN...

A surface trough extends from the N Bahamas near 26N78W to central
Cuba near 21N80W. Scattered moderate to strong convection is
within 240 nm E of the trough axis. Reports from land stations and
from nearby ships, indicate that wind gusts of 40 kt have been
occurring in some of the heavier convection. Although significant
development of this system is not expected due to strong upper-
level winds, brief squalls will likely produce locally heavy
rainfall and strong gusty winds over portions of the Bahamas and
the southern Florida peninsula during the next couple of days.
Elsewhere, the tail end of a cold front is over the central
Atlantic from 31N49W to 26N64W. A stationary front continues to
26N74W. Widely scattered moderate convection is within 120 nm of
the fronts. Broad surface ridging extends SW from a 1027 mb
surface high centered over the Azores near 40N26W. The ridging
dominates the Atlantic N of 22N and E of 45W.

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

$$
Formosa
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