[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261203
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
803 AM EDT Thu Jul 26 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.

...TROPICAL WAVES...

A tropical wave is near the Cabo Verde Islands with an axis
extending from 10N21W to 07N21W, moving westward at 10 to 15 kt.
This wave is well defined with a notable 700 mb trough in model
guidance. Deep moisture interacting with the wave S of 12N
is generating scattered moderate convection from 07N to 12N
between 18W and 24W. The remainder wave environment lacks
convection due in part to the presence of Saharan dry air and
dust.

A tropical wave is over central Atlantic with an axis extending
from 20N35W to 07N36W, moving westward at 10 to 15 kt. A large
area of Saharan dry air and dust continue to hinder convection
from developing around this wave.

A tropical wave is over the central Atlantic with an axis
extending from 18N49W to 05N50W, moving westward at 10 to 15 kt.
Strong deep layer wind shear and Saharan dry air and dust are
hindering deep convection at this time.

A tropical wave is over the central Caribbean with an axis
extending from 21N71W to 11N73W, moving westward at 15 to 20 kt.
Precipitable water satellite imagery shows a very dry environment
across the central Caribbean, which along with strong deep layer
wind shear are hindering convection S of Hispaniola. Only shallow
moisture and middle level diffluence support scattered showers
and tstms ahead of the wave in the Windward Passage...off SW
Haiti.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coast of Africa near
12N16W to 09N32W. The ITCZ extends from 09N37W to 08N48W...then
resumes W of a tropical wave near 09N52W and continues to the
coast of South America near 09N61W. Aside from convection
associated with the tropical waves, scattered moderate convection
is from 06N to 11N E of 18W, and within 150 nm N of the ITCZ axis
between 52W and 60W.

...DISCUSSION...

GULF OF MEXICO...

An upper level trough prevails across the E Gulf with base
extending SW from central Florida to the Bay of Campeche. This
trough supports a weak stationary front that extends across the
Florida Panhandle to SW Louisiana. It also supports a surface
trough that extends from the Florida Big Bend SW to 24N89W.
Isolated showers and tstms are within 75 nm SE of this trough.
The trough is forecast to dissipate today while the front lifts
NE of the area. Otherwise, the Atlantic subtropical ridge covers
the remainder SE Gulf and will continue to build northwestward
across the remainder basin through the weekend. Light to gentle
variable flow will dominate the basin during this time period.

CARIBBEAN SEA...

An upper level low centered near Jamaica along with shallow
moisture in the NW Caribbean support scattered showers and tstms N
of 17N between 72W and 82W. In the SW basin, the monsoon trough
supports scattered showers and tstms S of 11N. A tropical wave is
crossing the central Caribbean waters. See the tropical waves
section above for further details. GOES-16 water vapor imagery
indicates very dry conditions across the remainder of the basin
while enhanced RGB satellite imagery indicates a thin layer of
Saharan Air Dust moving across the area. Strong deep layer wind
shear is also noted in the E Caribbean. These hostile factors are
suppressing convection across the remainder of the Caribbean
basin. A new tropical wave is forecast to move across the Lesser
Antilles Friday night.

ATLANTIC OCEAN...

Three tropical waves are moving across the basin. Please refer to
the tropical waves section above for more details. Scattered
showers and tstms are N of the Bahamas W of 76W being supported by
an upper trough along the eastern United States that extends to
the W Atlc waters. Farther east, an upper level low supports a
surface trough that extends from 27N62W to 23N67W which is
supporting isolated showers and tstms N of 25N between 61W and
68W. Otherwise, the Atlantic subtropical ridge dominates the
remainder of the basin being anchored by a 1031 mb high centered
near 36N56W. Surface ridging will dominate the central and eastern
Atlantic through the end of the week providing stable and dry
conditions.

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

$$
Latto
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