[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 122250
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat Aug 13 2022

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2230 UTC.

...TROPICAL WAVES...

A tropical wave is analyzed with axis along 19W, from 20N
southward, moving W at 10-15 kt based on 700 mb wind speeds. A
1008 mb low pressure is along the wave axis near 14N19W.
Scatterometer data depicts moderate to fresh winds in the vicinity
of the wave axis. Scattered moderate convection, enhanced by the
Monsoon Trough, is west of the wave axis from 07N to 18N and E of
29W.

A tropical wave extends its axis along 51W from 23N southward,
moving westward at 15-20 kt. Scattered showers are noted in the
vicinity of the wave axis, mainly where it meets the monsoon
trough.

A tropical wave approaching the Lesser Antilles arc, with axis
extending along 60W from 21N southward, moving westward at 10-15
kt. No significant convection is noted over the waters at this
time.

A tropical wave located in the central Caribbean is along 74W,
from 21N southward, moving westward at 10-15 kt. Scattered
moderate convection is east of the wave axis, from 16N to 20N
between 67W and 74W, affecting Hispaniola and La Mona Passage.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Senegal near 16N17W
to 1008 mb low pressure near 14N19W to 11N38W to 10N60W. Aside
from the convection described in the Tropical Waves section above,
scattered showers prevail from 07N to 19N between 41W and 59W.

GULF OF MEXICO...

1014 mb low pressure is centered in the NW Gulf near 29N92W, with
a trough extending from 30N91W to 25N97W. These features,
combined with broad surface convergence across the northern Gulf,
is producing scattered moderate convection across the northern
half of the basin north of 24N. Winds and seas may be locally
higher in the convection. Elsewhere in the Gulf of Mexico, gentle
to moderate SE to S winds prevail along the periphery of the
subtropical Atlantic ridge, with seas of 2-4 ft.

For the forecast, the weak Atlantic high pressure will sink
southeast through Tue. This will allow for gentle to moderate
winds over the basin to weaken to light to gentle into next week.
Moderate NE to E winds will pulse to fresh during the late
afternoon and evenings off the NW Yucatan peninsula through early
next week. Scattered to numerous showers and thunderstorms
associated with a low pressure trough and weak low pressure that
is along it are over most of the northern Gulf waters. This system
will drift west-southwestward over the NW Gulf and toward the
Texas coast during the weekend. Development, if any, of this
system is expected to be slow to occur. Strong gusty winds and
rough seas can be expected with this activity. Meanwhile, a weak
frontal boundary is expected to stall just north of the central
and NE Gulf during the weekend.

CARIBBEAN SEA...

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

The latest scatterometer data depicts gentle to moderate trades in
the eastern and central Caribbean, with light to gentle trades in
the western Caribbean. A 1010 mb Colombian/Panamanian low is in
the SW Caribbean near 12N83W, along the extension of the East
Pacific Monsoon Trough. Scattered moderate convection is to the
northwest of the low, from 11N to 14N west of 81W including
coastal regions of Nicaragua.

For the forecast, the Atlantic high pressure will drift southward
and weaken through early next week. Moderate to fresh trade winds
over the central Caribbean will weaken to moderate Sat through
Mon, then increase to fresh late Mon through Tue night. A broad
surface trough accompanies a tropical wave across the central
Atlantic, and is expected to move across the Tropical N Atlantic
tonight night through Sat night, across the eastern Caribbean
early Sun through early Mon, across the central Caribbean Mon
through late Wed.

ATLANTIC OCEAN...

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

An outflow boundary is analyzed in the deep tropics, from 14N41W
to 10N43W, moving west at 15-20 kt. E winds to 30 kt were captured
well in scatterometer data this morning behind this boundary. The
remainder of the tropical Atlantic continues to be dominated by
the subtropical ridge located north of the area. NE to E winds are
gentle to moderate across the basin, except from 18N to 24N east
of 30W where NE winds are fresh. Seas are 3-5 ft north of 19N and
west of 55W, and 5-7 ft elsewhere in open waters. Seas are locally
8 ft NE of the Cabo Verde Islands.

For the forecast W of 55W, the ridge that extends from the
central Atlantic WSW to northern Florida along 29N, will weaken
and sink southward through early next week as a frontal boundary
moves off the eastern seaboard and begins to weaken as it stalls
from across NE Florida east-northeastward to north of 31N78W.
Moderate to fresh E winds S of 25N will veer to the SE and weaken
to gentle early Sat and change little into next week. Light to
gentle variable winds are expected elsewhere through the period. A
tropical wave will reach the southeast forecast waters by early
Sat, bringing a slight increase in winds and seas over those
waters through early Mon. A cold front may move over the waters
northeast of NE Florida late Tue, then stall and weaken through
Wed night.

$$
ERA
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