[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 110541
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Jul 11 2023

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 0000 UTC surface analysis and satellite imagery through
0500 UTC.

...TROPICAL WAVES...

A eastern Atlantic tropical wave has its axis along 23W from 02N
to 15N. It is moving westward at 10-15 kt. Isolated showers are
ahead of this wave within 30 nm of 11N24W.

A western Atlantic tropical wave, with a very noticeable
signature on satellite imagery, has its axis extending from 19N52W
to inland Suriname. This wave is moving westward at about 20 kt.
Scattered moderate convection is seen from 14N to 18N between
49W-59W. Resent scatterometer data shows fresh easterly trade
winds. Seas of 6-9 ft are occurring in the vicinity of the
tropical wave, mainly north of 13N.

A western Caribbean Sea tropical wave has its axis along 80W,
south of 20N. It is moving westward at 10-15 kt. This wave
extends from central Cuba to Panama. Scattered moderate
convection is present near the northern portion of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis reaches the Atlantic through the coast
of Guinea/Bissau near 18N16W and extends south-southwestward to
to 13N22W. The ITCZ begins at 11N24W and continues to 07N33W and
northwestward to 10N53W. It resumes at 13N55W to 13N61W. Aside
from convection that is associated to tropical waves, numerous
moderate isolated strong convection is occurring from 05N to 09N
between 29W-36W and within 60 nm south of the ITCZ between
38W-44W.

GULF OF MEXICO...

The combination of divergence aloft associated to broad
troughing with a surface cold front and pre-frontal boundary that
is just inland the southern United States has resulted in the
development of scattered showers and thunderstorms north of 26N
and east of 91W. Scattered showers and thunderstorms are seen west
of Cuba moving westward as it dissipates. Another area of
scattered showers and thunderstorm is noted in the Bay of
Campeche is association with a surface trough. Stronger winds and
higher seas may occur near the strongest convection. The
remainder of the Gulf of Mexico is in the southwestern periphery
of the broad subtropical ridge positioned over the central
Atlantic. This pattern is suppressing the development of deep
convection, especially in the southeastern part of the Gulf, where
a batch of dry Saharan dust is noted. Moderate to locally fresh
anticyclonic winds are found in the NE Gulf and Bay of Campeche,
along with seas of 3-4 ft. Elsewhere, light to gentle winds and
1-3 ft prevail.

For the forecast, a ridge will continue to dominate the Gulf
waters while a trough will develop over the Yucatan Peninsula each
evening and move offshore. Under this weather pattern, moderate
to fresh winds will pulse north and west of the Yucatan peninsula
during the late afternoon and evening hours. Elsewhere, gentle to
moderate anticyclonic flow and slight seas will prevail.

CARIBBEAN SEA...

Please see the Tropical Wave section above for convection
associated with waves in the Carribbean Sea. The rest of the
basin is under a generally dry weather pattern that is suppressing
the development of showers and thunderstorms, thanks to the
presence of Saharan Dust.

The pressure gradient between the 1025 mb high pressure in the
Central Atlantic and lower pressure in NW South America sustain
strong to locally near gale force easterly trade winds in the
south- central Caribbean. This was confirmed by the latest
scatterometer pass over that part of the basin. These winds also
support seas of 8-10 ft in the area described. Fresh to strong
easterly trade winds and seas of 5-8 ft are found in the north-
central Caribbean. Moderate to fresh easterly breezes are
occurring in the eastern Caribbean and Gulf of Honduras, along
with seas of 3-6 ft. Elsewhere, light to moderate winds and 2-4 ft
seas prevail.

For the forecast, fresh to strong winds and rough seas will
continue over the central Caribbean through the weekend as two
tropical waves moves across the region. Strong to near gale force
winds are likely off Colombia. Fresh winds will reach strong
speeds at night in the Gulf of Honduras through Tue, and resume
Sat night. Moderate to fresh trade winds will prevail over the E
Caribbean and tropical Atlantic waters through Sat night. One of
the aforementioned tropical wave is forecast to bring an increase
in winds and seas across the waters E of the Leeward Islands on
Tue, and over the NE Caribbean on Wed. Fresh to strong NE winds
are expected in the Windward Passage ahead of the wave axis by Wed
night.

ATLANTIC OCEAN...

Please see the Tropical Wave and Monsoon Trough/ITCZ sections
above for convection in the Tropical Atlantic.

The central Atlantic is dominated by an expansive subtropical
ridge located in the area. The basin is mostly devoid of deep
convection aside from scattered showers and thunderstorms found
off the coast of central Florida. The pressure gradient between
the ridge and a frontal system off the eastern United States is
sustaining moderate to fresh southwest winds north of 28N and west
of 55W. Moderate easterly trade winds are noted south of 24N and
west of 55W. Seas in the waters described are 4-7 ft. Elsewhere W
of 55W, light to gentle anticyclonic winds and seas of 3-5 ft
prevail.

Satellite imagery reveals that another outbreak of Saharan dust
is occurring off the coast of Africa and will be propagating
westward over the next several days. Moderate to locally strong
northerly winds are present in the eastern Atlantic, especially
south of 29N and east of 35W. Seas over these waters are 5-8 ft.
Light to moderate winds and moderate seas are prevalent over the
remainder of the basin.

For the forecast W of 55W, a ridge will remain in place across
the SW N Atlantic while a weak frontal boundary will come off the
SE CONUS Tue and move E over the waters N of 30N through late Wed.
The pressure gradient between these two features will support
moderate to fresh SW winds north of 27N through Tue. A developing
low pressure N of the forecast region could bring increasing winds
over the NE waters Tue night into Wed. The northern end of a
tropical wave is forecast to impact the waters north of the
Leeward Islands and Puerto Rico on Wed, and north of Hispaniola,
including approaches to the Windward Passage by Wed night. Light
to gentle winds will persist elsewhere along the ridge axis.

$$
KRV
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