[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131732
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
132 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 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...TROPICAL WAVES...

A new tropical wave has entered the Atlantic Ocean. Its axis
extends from 12N16W to 05N17W. A large area of moderate and
isolated strong convection is related to this wave extending from
05N to 10N between 15W and 22W. The wave shows up very well in
the TPW animation, where abundant moisture is observed. A wind
surge follows the wave.

A tropical wave extends from 13N31W to 05N32W moving westward at
15-20 kt. The wave remains embedded within an area of deep-layer
moisture as depicted on the TPW product. The wave also coincides
with an inverted trough at 700 mb. Visible satellite imagery
indicates some inverted-V pattern in association with this
feature. Scattered showers are near the wave axis.

Another tropical wave extends from 15N54W to 08N55W. The wave is
well depicted in the moisture product. A small swirl of low clouds
is along the wave axis near 12N. Scattered moderate convection is
mainly on the east side of the wave axis, covering the waters
from 10N-13N between 50W-54W.

A weak tropical wave is over the central Caribbean with axis from
16N72W to 08N72W moving westward at 15-20 kt. This wave is
associated with 700 mb troughing. TPW imagery shows a modest
surge of moistened air in association with this wave. Scattered
showers are within about 75 nm E of the axis over W Venezuela and
N Colombia.

Another tropical wave is over the Caribbean Sea and extends from
16N82W to a 1008 mb low pressure near 11N82W to the coast of
Panama near 09N82W. The wave shows up well in the moisture product
and 700 mb streamlines analysis. Satellite imagery and lightning
data indicate scattered showers and thunderstorms near the low
pressure area.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough extends from the coast of west Africa near
09N13W to 07N20W to 09N26W to 06N40W. The ITCZ continues from
06N40W to 08N50W to 09N53W to 08N60W. 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 1021 mb located over the SE CONUS extends a ridge
across much of Gulf region producing a moist and humid SE flow
over the western half of the Gulf, and mainly and easterly flow
across the eastern half of the Gulf, including the Straits of
Florida. Fresh to strong southeast winds are noted in scatterometer
data over the Bay of Campeche, likely associated with the thermal
trough, that moves across this area during the morning hours. A
weak low pressure of 1008 mb has developed near Veracruz, and it
is forecast to move NW toward the Tuxpan area in about 24 hours. A
strong cluster of moderate to strong convection was previously
noted in association with this low. Currently, some shower
activity is only observed near the low center. Veracruz has
reported around three inches of rain (76 mm) over the past 24
hours ending this morning. Abundant cloudiness, with some
convective activity, covers the majority of the Gulf. Mosaic
Doppler radar from the SE U.S. shows showers with embedded
thunderstorms across the north Gulf states, including also much of
the Florida Peninsula. 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...

Two tropical waves are moving across the Caribbean Sea. Please
see the tropical waves section for more details. Scatterometer
data show moderate to fresh trades across the east and central
Caribbean, particularly south of 18N. Gentle to moderate winds
are seen over the NW Caribbean. This wind pattern will persit on
Wednesday. Winds will diminish into Thursday as the high pressure
north of the area lifts farther to the north. Some convective
activity is south of central Cuba due to a diffluent pattern
aloft. A patch of moisture is generating some shower activity
across the Windward Islands. Moisture associated with the tropical
wave, currently located near 55W, will bring more showers to
those islands on Wednesday. Shallow moisture embedded in the trade
wind flow is noted elsewhere. Looking ahead, a broad low pressure
area is forecast to develop across central America and the NW
Caribbean by the end of the week.

...HISPANIOLA...

An upper-level trough extending southward over Puerto Rico into
the Caribbean is inhibiting convection somewhat. Expect scattered
showers and isolated thunderstorms in association with the local
effects, mainly during the afternoon and early evening hours.

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 weak surface trough remains off NE
Florida and stretches from 31N80W to 28N81W. This trough is
supporting some shower and thunderstorm activity. This trough is
expected to dissipate in about 12-24 hours as the Atlantic ridge
builds farther west across the western Atlantic. Another surface
trough extends from 28N60W to 21N62W. This trough is likely a
reflection of an upper-level trough extending from 31N66W to the
Turks and Caicos Islands. Some shower activity is near the
northern end of the trough. Farther east, another surface trough
extends from a very weak 1020 mb low near 28N38W to 24N39W. A
swirl of clouds is associated with the low. 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. A surge of
African dust is reaching 30W as noted in the Saharan Air Layer
Tracking Product from CIMSS.

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

$$
GR
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