[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091205
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 AM EDT Thu Aug 9 2018

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 0600 UTC surface analysis and satellite imagery through
1100 UTC.

...SPECIAL FEATURES...

...Tropical Storm Debby...

The center of Tropical Storm Debby, at 09/0900 UTC, is near 43.6N
45.1W. The estimated minimum central pressure is 1002 mb. Debby is,
moving northeastward 15 kt. The maximum sustained wind speeds are
40 knots with gusts to 50 knots. Debby is expected to continue
moving northeastward while weakening. Debby is forecast to
dissipate on Friday. Please read the latest NHC Forecast/Advisory
under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 22W/23W from 21N
southward, moving W 15 knots. The wave is associated with a 700 mb
trough, and an embedded 700 mb low centered near 13N20W. SSMI TPW
shows a moist area S of 14N, and dry air N of 14N. Scattered
moderate to strong rainshowers in the monsoon trough area, from
10N to 13N between 20W and 25W.

An Atlantic Ocean tropical wave is along 37W/38W from 12N
southward, moving W 15 to 20 knots. This is a low amplitude and
low latitude wave with Saharan dry air N of the wave. SSMI TPW
shows a moist area along the wave axis. Widely scattered moderate
to isolated strong rainshowers are from 07N to 10N between 32W and
38W.

An Atlantic Ocean tropical wave is along 53W/54W from 18N
southward, moving W 20 knots. This wave has a well defined
inverted V surface pattern noted on satellite imagery. The wave
also has a large 700 mb trough associated with the wave. The wave
is affected by Saharan dry air intrusion W of the wave axis and N
of 12N. Isolated moderate to locally strong rainshowers are within
180 nm on either side of the line that runs from 20N51W to 13N55W
to 08N60W.

A tropical wave is inland, in central America, along 89W/90W from
18N southward, from Guatemala southward. Scattered strong
rainshowers are from 16N to 19N between 86W and 88W, in the
coastal plains/coastal waters. isolated moderate to locally strong
rainshowers are elsewhere from 15N to 22N between 85W and 89W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of Mauritania
near 17N16W, to 10N29W and 07N40W. The ITCZ continues from 07N40W
to 07N50W, to 08N56W, and into northern sections of Guyana near
08N60W.  enters the eastern Atlantic near 18N16W and extends
southwestward to 10N28W to 08N40W. The ITCZ extends from 08N40W to
07N52W. Besides the convection mentioned in the tropical wave
section, scattered showers are observed within 180 nm S of the
ITCZ.

...DISCUSSION...

GULF OF MEXICO...

An area of high pressure extends from the western Atlantic into
the basin. A surface trough extends over the Bay of Campeche from
21N90W to 17N93W with scattered moderate convection within 120 nm
of the trough. An upper-level low is centered over the SE Gulf
near 27N84W. Another small upper level low is centered near Tamico
Mexico at 23N98W.

A surface trough will develop in the Yucatan Peninsula from the
early evenings to overnight hours during the next several days.
The surface trough will be accompanied by a surge of fresh to
occasionally strong winds. A surface ridge will prevail across
the area through into early next week, supporting moderate to
fresh SE flow over the west central Gulf of Mexico, and off Texas
early next week.

CARIBBEAN SEA...

A tropical wave is exiting the basin. Refer to the section above
for details. Gale force winds are along the coast of N Colombia.
Please read the Special Features section above for details.

The monsoon trough in the SW Caribbean supports scattered moderate
convection south of 10N and west of 80W. This pattern will
continue through the week. The next tropical wave is forecast to
reach the waters east of the Lesser Antilles by early Friday, and
move across these islands this weekend.

High pressure that is to the north of the area will support fresh
to strong trades in the central Caribbean Sea. A tropical wave
will approach the Windward and Leeward Islands later today, moving
through the central Caribbean Sea by Sunday. A second tropical
wave will move into the eastern Caribbean Sea and the central
Caribbean Sea on Monday. The winds will pulse to fresh in the
Gulf of Honduras through the week, reaching fresh to strong
tonight. Winds will approach minimal gale force again on Sunday
night NW of the Coast of Colombia as the pressure gradient
tightens temporarily.

ATLANTIC OCEAN...

Tropical storm Debby is in the north-central Atlantic Ocean.
Please read the SPECIAL FEATURES section for details.

A 1021 mb high is centered over the west Atlantic near 26N74W.
A small surface trough is over the W Atlantic from 29N64W to
26N65W. Scattered showers are within 90 nm of the trough. The
remainder of the basin is under the influence of a surface ridge,
anchored by a 1030 mb high centered near 41N24W. Little change is
expected through the next 24-48 hours.

A 27N surface ridge will shift southward to 25N today. The ridge
will be to the east of a trough, that will be moving off the
southeastern coast of the U.S.A. through Friday. The ridge then will
move N to 28N through Monday. The wind speeds will pulse to fresh
to strong offshore of the northern coast of Hispaniola through
the next several days.

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

$$
MT
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