[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 140004
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
804 PM EDT Tue Jun 13 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.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 10N19W
to 02N19W. CIRA LPW imagery show the wave is in a very moist
environment from the surface to 850 mb, that along with favorable
wind shear and upper level divergence support scattered heavy
showers from 01N to 08N between 18W and 27W and from 03N to 07N E
of 17W.

A tropical wave is in the central Atlc with axis extending from
13N31W to 04N33W, moving west at 15 kt within the last 24 hours.
CIRA LPW imagery show the wave is in a moderate moist environment,
with some patches of dry air. The wave coincides with a diffluent
environment at the middle levels and a col of low pressure in the
upper levels, and is in a region of favorable wind shear.
However, enhanced satellite imagery show Saharan dry air in the
wave environment, which seems to be the major factor for lack of
convection at the moment.

A tropical wave is in the W Atlc just SE of the Lesser Antilles
with axis extending from 15N57W to 07N58W, moving west at 20 kt
within the last 24 hours. CIRA LPW imagery show the wave is in a
moderate moist environment, with some patches of dry air.
Enhanced satellite imagery confirms the presence of Saharan dry
air. Unfavorable wind shear and dry air support lack of convection
at the time.

A tropical wave is in the central Caribbean with axis extending from
15N72W to inland Colombia near 07N72W, moving westward at 10 kt
within the last 24 hours. CIRA LPW imagery show shallow moisture
with patches of dry air in the wave environment that along with
unfavorable wind shear support lack of convection at the time.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from 06N21W to 07N31W to 07N40W. The
ITCZ continues from 07N40W to the coast of Guyana near 06N57W.
Three tropical waves are embedded within the monsoon trough/ITCZ.
Most of the convective activity is associated with the above
mentioned tropical waves.

...DISCUSSION...

GULF OF MEXICO...

High pressure of 1020 mb located over the SE CONUS extends a
ridge across the eastern Gulf region, thus supporting moderate to
locally fresh SE flow. Shallow moisture being advected from the
Caribbean along with the presence of a nearly stationary upper
level trough in the E basin support scattered showers E of 86W,
including the Florida peninsula and the Florida straits.
Otherwise, the remnants of a weak low over the W Bay of Campeche
are analyzed as a surface trough along the coast of SE Mexico from
23N97W to 18N96W, which support isolated showers over the Bay of
Campeche. Looking ahead, a broad area of low pressure is expected
to form over the western Caribbean Sea or Central America late
this week or this weekend. Some gradual development of this system
is possible thereafter while it moves slowly northwestward into
the Gulf region. Computer model indicates that southeast winds
will increase over the southwest Gulf by late Saturday ahead of
the aforementioned low pressure area expected to approach the
region through northern Central America.

CARIBBEAN SEA...

Shallow moisture and an upper level diffluent environment support
scattered heavy showers along Cuba and scattered to isolated
showers over the NW basin. A former tropical wave in the SW
Caribbean has merged with the broad monsoonal flow in the EPAC
and now is being analyzed as a surface trough off the coast of
Nicaragua from 13N82W across southern Costa Rica to 07N83W. Heavy
showers and isolated tstms are associated with this trough S of
14N W of 80W. Scattered showers are elsewhere S of 14N E of 80W.
An upper level trough in the SW Atlc extends S to a base over
southern Hispaniola coastal waters. This is supporting lifting of
moist warm air and the development of scattered heavy showers and
tstms over central Haiti and the NW Dominican Republic. A tropical
waves moves across the central Caribbean, however no convection is
associated with it. Please see the tropical waves section for
more details. Scatterometer data show moderate to fresh trades
across the east and central Caribbean, except for fresh to strong
winds near Colombia as well as in the Gulf of Honduras. Gentle to
moderate winds are over the NW Caribbean. This wind pattern will
persist through Wednesday. Winds will diminish into Thursday as
the high pressure north of the area lifts farther to the north.
Looking ahead, a broad are of low pressure is forecast to develop
across central America and the NW Caribbean by the end of the
week.

...HISPANIOLA...

An upper level trough in the SW Atlc extends S to a base over
southern Hispaniola coastal waters. This is supporting lifting of
moist warm air and the development of scattered heavy showers and
tstms over central Haiti and the NW Dominican Republic. This
shower activity is forecast through Wednesday morning as the upper
trough moves east to the N of Puerto Rico.

ATLANTIC OCEAN...

Three tropical waves are moving westward between the coast of
Africa and the Lesser Antilles. Please refer to the Tropical Waves
section above for details. A surface trough moved to inland
Florida supporting showers across the peninsula and Atlc waters W
of 76W. Another surface trough extends from 29N59W to 23N63W
lacking convection. Farther east, another surface trough extends
from a very weak 1021 mb low near 27N37W to 24N39W. Otherwise,
broad high pressure covers the Atlantic from the Azores to the
Carolinas. Moderate to locally fresh trades are around the
southern periphery of the ridge between the Windward Islands and
30W.

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

$$
Ramos
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