[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041140
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
740 AM EDT Tue Jul 4 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 0600 UTC surface analysis and satellite imagery through
1100 UTC.

...SPECIAL FEATURES...

A 1009 mb surface low is centered near 09N34W. Scattered moderate
and isolated strong convection is located within 120 nm of the
center of the low. The low has a large area of cyclonic winds
extending about 300 nm from the center. Satellite-derived wind
data shows peak winds of near gale force in the southeastern
quadrant. The low is expected to move slowly westward today, then
move toward the west-northwest at 10 to 15 mph tonight and
Wednesday. The system still possesses a high chance of becoming a
tropical cyclone during the next 48 hours.

...TROPICAL WAVES...

A tropical wave is in the eastern Atlantic with axis near 31W
extending from 07N to 18N, moving west at about 20 kt within the
last 24 hours. Scattered moderate convection is occurring from 08N
to 12N between 29W and 34W. The wave is embedded in a moist
monsoonal flow, as seen in the Total Precipitable Water imagery,
and extends across the monsoon trough. Little to no surface
signature of the wave is apparent from ship and scatterometer
observations, though the SUNY-Albany Trough Diagnostics well
depict the wave at 700 mb and the TPW shows a distinct maximum in
moisture on the east side of the wave axis.

A tropical wave is in the central Atlantic with axis near 40W
extending from 08N to 20N, moving west at about 15 kt during the
last 24 hours. No significant deep convection is occurring in
association with the wave, though scattered showers exist within
120 nm of the wave axis south of 12N. This wave had spun off the
surface low - described in the Special Features section - which is
now to the east of the wave. The wave is only distinguishable in
the Trough Diagnostics at 700 mb, with little to no surface
circulation.

A tropical wave is located along the Lesser Antilles and has been
moving westward at about 15 kt. Its axis is near 61W and extends
from 08N to 20N. ASCAT scatterometer and surface station
observations indicate that the system has a well-defined surface
trough.  The wave has isolated moderate convection within 120 nm
of the wave axis.

A tropical wave is in the central Caribbean with axis near 76W
extending from 10N to 20N. The wave is moving westward at about 10
to 15 kt. The wave is not readily apparent in either the surface
observations, nor in the Trough Diagnostics and there is no active
convection associated with it at this time.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough axis extends from the west coast of Africa
near 14N17W to 08N45W. The Intertropical Convergence Zone extends
from 08N45W to the coast of Suriname near 06N54W. Convection
observed near the Monsoon Trough and ITCZ is mainly related to
tropical waves and the surface low. Refer to the section above for
details. Otherwise, widely scattered moderate convection is
located from 05N to 11N between 11W and 22W.

...DISCUSSION...

GULF OF MEXICO...

Weak surface ridging exists across the northern Gulf.  A weak
surface trough exists in the southwestern Gulf from 23N90W to
18N92W. No deep convection is occurring; however, scattered
showers are also occurring in the southeastern Gulf within 120 nm
of the Florida peninsula as well as the Florida Straits. Winds are
generally 10-20 kt across the Gulf with easterlies in the eastern
Gulf and veering to southeasterlies in the western Gulf. Little
change in the synoptic pattern is expect in the next couple of
days.

CARIBBEAN SEA...

The moderate pressure gradient across the Caribbean between the
Bermuda high to the north and the Colombia low to the south is
generally producing 10 to 20 kt tradewind easterlies. The
exception is the 25 kt easterlies just north of Colombia and
Venezuela. Scattered moderate convection is located over the
southwestern Caribbean including portions of Honduras and
Nicaragua, in association with the eastern extension of the
Northeast Pacific's monsoon trough. An upper low is centered over
the northwestern Caribbean near 20N81W, as seen in both the water
vapor imagery as well as rawindsonde data from Cancun, Grand
Cayman, Key West, Miami, Nassau, and Kingston. This upper low is
helping to promote isolated moderate convection near Jamaica and
the northwestern Caribbean. The upper low is anticipated to open
up to a broad trough in the next day or two, but still helping to
promote some enhanced convection.

...HISPANIOLA...

Currently there is no deep convection over Hispaniola. Expect
diurnal peak in convection to diminish some on this afternoon and
early evening before being enhanced again on Wednesday as the
moisture associated with the wave over the Lesser Antilles reaches
Hispaniola.

ATLANTIC OCEAN...

Two tropical waves are analyzed over the basin. Refer to the
Tropical Waves section above for their details. Also a surface low
is detailed in the Special Features section.  A large 1031 mb
Bermuda/Azores high centered north of the area near 36N41W is
dominating the weather across the tropical north Atlantic. Away
from the surface low described above, winds generally are 10 to 20
kt across the basin. This synoptic pattern will change little
through Wednesday.

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

$$
Landsea
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