[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040600
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
200 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 0000 UTC surface analysis and satellite imagery through
0600 UTC.

...SPECIAL FEATURES...

A 1010 mb surface low is centered near 09N33W. Scattered moderate
and isolated strong convection is located within 120 nm in the
western semi-circle of the low.  The low has a large area of
cyclonic winds extending about 300 nm in diameter and ASCAT scatterometer
data showed peak winds of near gale in the southeastern quadrant.
The low is expected to move slowly westward today, and then move
toward the west-northwest at 10 to 15 mph by tonight and on
Wednesday. The system has 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 30W
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 28W and 33W. 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 37W
extending from 05N to 15N, moving west at about 10 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 well-defined tropical wave is locate along the Lesser Antilles
and has been moving westward at about 15 to 20 kt. Its axis is
near 62W and extends from 10N to 20N. However, scatterometer data
arriving after the 00 UTC analysis was completed shows that the
wave axis may be closer to 59W. The wave has isolated moderate
convection within 120 nm of the wave axis.

A tropical wave is in the central Caribbean with axis near 74W
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 12N16W to 08N44W. The Intertropical Convergence Zone extends
from 08N45W to the coast of Guyana near 08N59W. 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, scattered moderate convection is located
from 06N to 10N between 16W and 23W.

...DISCUSSION...

GULF OF MEXICO...

A 1019 mb surface high is centered over the northeastern Gulf near
28N87W. A weak surface trough exists over the Yucatan of Mexico
for 22N88W to 16N93W. Scattered moderate convection is occurring
mainly over Mexico within 120 nm of the trough axis. 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. Isolated 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 over Cuba, the
northwestern Bahamas, 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...

During the afternoon and early evening, scattered moderate
convection occurred over central Haiti and Dominican Republic.
This is currently waning. Expect convection to diminish some on
Tuesday 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 details. A large Bermuda/Azores
high centered north of the area near 35N41W 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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