[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 261717
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
117 PM 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 1200 UTC surface analysis and satellite imagery through
1600 UTC.

...TROPICAL WAVES...

A tropical wave is near the Cabo Verde Islands with an axis
extending from 18N22W to 05N23W, 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 10N
is supporting scattered moderate convection from 07N to 10N
between 21W and 26W. The remainder of the 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 20N37W to 05N38W, moving westward at 10 to 15 kt. This wave
is associated with a well defined trough at 700 mb. 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 11N52W to 06N52W, moving westward at 10 to 15 kt.
Scattered thunderstorms are S of 13N within 90 nm of the wave
axis. Strong deep layer wind shear and Saharan dry air and dust
are hindering deep convection across the northern portion of the
wave.

A tropical wave over the central Caribbean has been re-analyzed as
of 1500 UTC along 71W based off both long term satellite imagery
and 700 mb model field data. 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.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coast of Africa near
12N16W to 07N33W. The ITCZ extends from 07N39W to 09N51W...then
resumes W of a tropical wave near 09N54W and continues to 10N60W.
Aside from convection associated with the tropical waves,
scattered moderate convection is from 06N to 11N E of 20W, and
within 180 nm N of the ITCZ axis between 54W and 60W.

...DISCUSSION...

GULF OF MEXICO...

An upper level trough prevails across the E Gulf with its base
extending SW from central Florida to the Bay of Campeche. This
trough supports a weakening stationary front that extends across
the Florida Panhandle to SE Louisiana. It also supports a surface
trough that extends from the Florida Big Bend SW to 26N89W.
Numerous showers and tstms are within 120 nm SE of this trough.
The front is transitioning to a surface trough. Both troughs are
expected to lift north through tonight. Otherwise, the Atlantic
subtropical ridge covers the remainder of the SE Gulf and will
continue to build northwestward across the remainder of the basin
through the weekend. Light to gentle variable flow will dominate
the basin during this time period.

CARIBBEAN SEA...

A weak upper level low centered near Jamaica along with shallow
moisture in the NW Caribbean support scattered showers and tstms N
of 17N between 75W and 83W. In the SW basin, the monsoon trough
supports numerous showers and tstms S of 11N. A tropical wave is
crossing the central Caribbean waters. Please refer to the
tropical waves section above for further details. GOES-16 water
vapor imagery continues to indicate 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, with showers and
thunderstorms beginning to spread across the southern Leeward
islands starting this evening in advance of the wave.

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 N of 23N W of 75W are being supported by an
upper trough along the eastern United States that extends across
the Florida peninsula. This upper trough will prevail through
Friday, enhancing shower and thunderstorm activity over this
area. Farther east, an upper level low supports a surface trough
that extends from 31N63W to 28N66W. These features support a broad
area of cloudiness with scattered showers and isolated tstms from
20N to 31N between 62W and 70W. The Atlantic subtropical ridge
dominates the remainder of the basin being anchored by a 1030 mb
high centered near 37N54W. 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
This weather bulletin was brought to you by:
www.nashvilleweather.net