[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 022256
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
356 PM PDT Thu Jul 2 2020

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 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...TROPICAL WAVES...

A tropical wave is over western Africa, with axis near 13W, as
observed on long-term satellite imagery. The Hovmoller diagram
clearly shows the westward propagation of the wave. A cluster of
moderate to strong convection is noted ahead of the wave axis
covering from 9.5N-14N between 14W-19W. Scattered moderate to
isolated strong convection is seen behind the wave axis. It is
moving westward near 15 kt.

A low amplitude tropical wave with axis along 37W from 03N to
15N is moving westward near 15 kt. This wave is moving through a
surrounding stable atmospheric environment. Convection is limited
near the wave axis.

A tropical wave has reached the eastern Caribbean with its axis
along 63W S of 19N. It is moving westward near 20 kt. This wave
is surrounded by Saharan dust, although not as much as in recent
days. The wave is likely enhancing convection over NE Venezuela
and over Trinidad and Tobago.

A tropical wave with axis along 73W is moving westward at 20-25
kt. Scattered showers and thunderstorms are noted near the
northern end of the wave axis affecting Hispaniola. Similar
convection is also observed over northern Colombia, likely due
to a combination of the tropical wave and the eastern Pacific
monsoon trough. An inverted V-pattern is seen on visible
satellite imagery over the Caribbean Sea related to this wave.

The northern extension of a tropical wave crosses the Yucatan
Peninsula and Guatemala and is moving westward at 10-15 kt. The
700 mb GFS model winds indicate a sharp northeast to southeast
wind shift in the vicinity of this wave. The wave is situated to
the east of an upper-level low that is centered over the northern
Yucatan Peninsula. The combination of these systems is helping
to aid in the development of scattered showers and thunderstorms
over most of the Yucatan Peninsula, and parts of Belize and
northern Guatemala.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the W coast of Africa
across Guinea Bissau near 11N16W to 08N26W. The ITCZ continues
from 08N26W to 05N50W. Aside from the convection associated with
the tropical waves, scattered moderate convection is from 06N-10N
between 12N-30W. Scattered moderate isolated strong convection
can be found from 07N-10N W of 53W to the coast of NE Venezuela.

GULF OF MEXICO...

Broad anticyclonic flow is present over the western part of the
Gulf west of 93W, while an upper-level low is spinning over the
northern Yucatan Peninsula. At the surface, a 1018 mb high
pressure center is located near 27N93W producing generally light
and variable winds, except gentle to moderate E-SE winds over
the SW Gulf. As previously mentioned, convection has flared up
over the Yucatan peninsula and parts of SE Mexico due to a
combination of an upper-level low and the northern extension of
a tropical wave.

A ridge will continue to dominate the weather pattern across the
Gulf waters through the weekend, and is forecast to maintain
rather benign marine conditions across the region through Mon.
Fresh SE winds are possible at times over the SW Gulf early next
week.

CARIBBEAN SEA...

Refer to the section above for details on the tropical waves
moving across the basin.

Daytime heating, local sea breezes and available moisture are
helping to induce scattered showers and thunderstorms over the
Greater Antilles late this afternoon.

The pressure gradient between the Atlantic high pressure and the
Colombian/Panamanian low is supporting fresh to strong trades
across the south-central Caribbean. These winds are forecast to
change little through the weekend. Elsewhere, gentle to moderate
trades will prevail for the next several days. Pulses of fresh to
locally strong winds are also possible early next week in the
Gulf of Honduras.

ATLANTIC OCEAN...

Refer to the section above for details on the tropical waves.

The 1028 mb Bermuda-Azores High is located near 34N40W with a
ridge extending westward to the central Bahamas. Moderate to
fresh trades are noted along the southern periphery of the ridge.
Overall, high pressure will continue across the area through
early next week. Low pressure will develop late tonight east of
Jacksonville Florida and move east across the northern waters
through Sun, bringing some gusty winds as well as showers and
thunderstorms to areas north of 27N.

Mostly sunny and uncomfortably warm temperatures are expected
across South Florida the remainder of this week under the
influence of a ridge. Isolated to scattered showers and
thunderstorms are forecast in the afternoon and early evening
hours.

The Saharan Air Layer from CIMSS shows less African dust, than
observed in previous days, over some of the waters between the W
coast of Africa and the Lesser Antilles.

$$
GR
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