[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181027
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Thu May 18 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 0600 UTC surface analysis and satellite imagery through
0910 UTC.

...TROPICAL WAVES...

The axis of a tropical wave is along 22W, from 00N to 11N.
Westward motion is approximately 5 knots, in part due to weak low
to middle level winds. A slow forward motion is expected to
continue over the next couple of days. Upper level ridging across
the wave is supporting active convection described below.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from 10N14W to 05N20W. The ITCZ
extends from 04.5N24W to 02N34W to the coast of far NE Brazil
near 03N51W. Scattered to locally numerous moderate to strong
convection is noted from 03N to 08.5N between 15W and 26W. Scattered
moderate isolated strong convection associated with the ITCZ is
from 02N to 05N between 30W and 50W.

GULF OF MEXICO...

The frontal boundary in the north-central Gulf has all but dissipated
just east of the mouth of the Mississippi River, as of 0300 UTC.
However, the middle to upper level previously supporting the
front continues to move eastward across the north central Gulf and
is producing widely scattered moderate convection to the N of 28N
between 86W and 89W. Weak high pressure of 1011 mb is located
near 23N94W in the southwest Gulf. Light winds prevail across the
Gulf, except for moderate NE to E winds across the Bay of
Campeche. Seas are generally 1 to 2 ft with an area to 3 ft across
the eastern Bay of Campeche.

For the forecast, weak high pressure will continue to dominate
the weather pattern across the Gulf region through the upcoming
weekend producing mainly light to gentle winds and slight seas.
Gentle to moderate NE to E winds are forecast at night near and
NW of the Yucatan Peninsula through Thu night, increasing to
moderate to fresh speeds Fri night through Sun night.

CARIBBEAN SEA...

Light to gentle trades are found over the NW Caribbean, except
moderate E to SE winds across the Gulf of Honduras. Elsewhere
gentle to moderate trades prevail, except for fresh winds inside
the Gulf of Venezuela. Seas are 2-4 ft across most of the basin,
increasing to locally 5 ft in the south-central Caribbean, and in
the far SE Caribbean where easterly swell is moving through the
passages.

For the forecast, weak high pressure across the central Bahamas
will maintain a very weak pressure gradient across the Caribbean
Basin today. Winds will increase to fresh to locally strong
speeds across the south-central Caribbean, including the Gulf of
Venezuela this evening through Sat as high pressure builds
modestly N of the region. Winds will then weaken across the basin
Sun and Mon as an inverted surface trough develops N of the area
along 70W.

ATLANTIC OCEAN...

1014 mb high pressure was centered near 24N75W at 0000 UTC,
though more recent data suggests this high pressure has
collapsed into the broader ridge axis across the region. The
tropical Atlantic is very quiet. A 1035 mb Azores High extends SW
to near 25N65W, and is supporting fresh NE to E winds over the
northeastern discussion waters E of 45W, where seas are 6 to 8
ft. A middle to upper level trough is along about 62W shifting
slowly eastward, and supporting scattered moderate convection N of
21N between 58W and 63W. This feature also appears to extend
downwind into the lower atmosphere, and is blocking the Azores
ridge from building father W across the Atlantic. Moderate SE to S
winds generally prevail N of 20N and between 45W and 65W , where
seas are 4 to 6 ft. Elsewhere S of 20N, trades are mostly
moderate. Light and variable winds prevail W of 65W. Seas are 2-4
ft west of 65W, and 4-7 ft elsewhere in open waters.

For the forecast west of 55W, high pressure to the N of the area
will build modestly across the regional waters Thu night through
the weekend and produce moderate E to SE winds. An inverted
trough is expected to develop along 70W by early Mon and drift E,
with active weather expected along and E of the trough.

$$
Stripling
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