[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 300548
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
148 AM EDT Fri Jun 30 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 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

Gale-force northerly winds will continue overnight over the areas
of AGADIR, TARFAYA, and CANARIAS. The outlook for the 24 hours
that follow the forecast that is valid until 01/0000 UTC, consists
of the threat of severe northerly gale winds over AGADIR, TARFAYA,
MADEIRA, and CANARIAS. Please refer to the METEO-FRANCE High Seas
Forecast listed on the website: WWW.METEOFRANCE.COM/PREVISIONS-
METEO-MARINE/BULLETIN/GRANDLARGE/METAREA2.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis extending from
19N21W to a 1012 mb surface low near 09N20W to 03N20W, moving
westward at 10-15 kt. This wave remains embedded within an
envelope of southwesterly monsoonal moisture that observed in
satellite imagery just offshore the coast of Africa. Isolated
showers are observed in the vicinity of the low. A surface trough
is along 32W from 20N-24N. This trough is part of the energy of
the northern vorticity center that accompanies this tropical wave.
No significant deep convection is noted with this feature.

A central Atlantic tropical wave has its axis from 16N46W to
02N46W, moving westward at about 15 knots. A large plume of
Saharan African dust is observed to the north of this wave. This
appears to be suppressing deep convection from developing along
and near the wave axis at this time. Only isolated showers and
thunderstorms are observed from 09N-12N between 48W-50W. This
wave is forecast to enter the eastern Caribbean by Saturday.

A strong tropical wave is moving through the eastern Caribbean
with its axis extending from 19N67W to 08N68W, moving westward at
about 15 knots. This wave maintains a good track history going
back several days, and continues to mark the leading edge of an
extensive area of unsettled weather with scattered showers and
thunderstorms. Some of this activity is capable of producing
gusty winds. At this time, isolated showers extend east of 72W
while the strongest activity remains over land affecting portions
of north-central Venezuela. The wave will continue moving west
across Caribbean enhancing convection over Puerto Rico and
Hispaniola through the weekend.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends from 12N16W to 08N26W. The Intertropical
Convergence Zone then extends from that point to 09N46W then
resumes west of a tropical wave near 08N48W to 08N58W. Aside from
the convection related to the tropical waves, isolated showers are
observed within 50 nm on either side of the ITCZ.

...DISCUSSION...

GULF OF MEXICO...

A mid to upper-level trough is evident on water vapor imagery to
be just inland the Texas and southwest Louisiana coasts. An
upper-level low has developed over the northwest Gulf near 26N97W
while an anticyclonic circulation is centered over the eastern Gulf
near 27N84W. At this time, fair weather prevails across the Gulf
waters as a surface ridge extends across the area from the
northeast. The western periphery of this ridge is controlling the
wind regime keeping mainly moderate to fresh southeast to south
winds through the weekend, except for lighter winds in the
northeast Gulf through Saturday. Little change in the synoptic
pattern is expected through the next 24-48 hours.

CARIBBEAN SEA...

The main feature presently in the basin is a strong tropical wavethat is currently located over the eastern Caribbean. This
feature is discussed in the section above. Aside from the
convection related to the wave, generally fair weather prevails
elsewhere. Scatterometer data depicts moderate trades across the
basin, except in the east-central Caribbean near the wave's axis
where moderate to strong winds prevail between 65W-72W. Convection
is expected to continue across the basin as the wave moves west.
The impacts of this wave as related to marine interests will be
mainly highlighted in the Offshore Waters Forecast and High Seas
Forecast products.

...HISPANIOLA...

Fair weather prevails across the island at this time as subsidence
aloft and resultant dry air dominates. Moisture associated with
the strong eastern Caribbean tropical wave is moving across the
Mona Passage, and is approaching the eastern portion of
the island. Expect for this moisture to bring increasing shower
and thunderstorm activity across the area today. Gusty winds can
be expected with some of this activity.

ATLANTIC OCEAN...

Two tropical waves were analyzed across the basin. Refer to the
section above for details. A weakening stationary front extends
along 30N between 71W-76W with no significant convection. The
remainder of the basin is under the influence of a surface ridge,
anchored by a stationary 1035 mb high centered near 39N29W. The
wind flow pattern around the southern periphery of this high
pressure will continue to transport Saharan African dust westward
to the the central Atlantic through the next 24-48 hours.

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

$$

ERA

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