[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 172329
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Fri Jun 18 2021

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
2315 UTC.

...SPECIAL FEATURES...

Potential Tropical Cyclone Three is centered near 22.9N 92.4W at
17/2100 UTC or 410 nm S of Morgan City Louisiana moving N at 8
kt. Estimated minimum central pressure is 1008 mb. Maximum
sustained wind speed is 25 kt with gusts to 35 kt. At this time,
scattered to numerous moderate convection prevails from 20N-29N
and east of 90W. On the forecast track, the system will approach
the north-central Gulf Coast late Friday or early Saturday. A
northeastward motion across the southeastern United States is
likely after landfall.

Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for
more details.

...TROPICAL WAVES...

An Atlantic tropical wave axis is analyzed along 25W from the
Cabo Verde islands near 18N southward, and is moving west at 10
to 15 kt. Scattered moderate convection is noted from 01N to 09N
between 20W and 34W.

Another Atlantic tropical wave axis is along 45W from 19N
southward, moving west at 15 to 20 kt. Scattered showers are
noted from 06N to 13N between 43W and 50W.

A Caribbean tropical wave axis is analyzed near 64W from 19N
southward into Venezuela, and is moving W at around 15 to 20 kt.
Scattered moderate convection is present from 07N to 18N between
60W and 70W. Stronger thunderstorms might produce fresh gusty
winds across the Lesser Antilles.

Another Caribbean tropical wave axis is analyzed along 83W from
18N southward over western Panama, and is moving west at 5 to 10
kt. Scattered moderate convection is evident along the coasts of
Colombia, Panama, and Costa Rica mainly in association with the
monsoon trough currently extending along 09N.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Africa near 11N16W
to 05N27W. Segments of the ITCZ then continue westward from
05N27W to 06N38W and from 05N47W to 06N53W. Aside from the
convection described with the tropical waves in the section
above, no significant activity is noted at this time.

GULF OF MEXICO...

Refer to the Special Features section above for details on
Potential Tropical Cyclone Three.

A surface trough extends northeastward from the low to 26N88W.
Fresh to strong winds were detected by the latest scatterometer
passes. Aided by upper-level divergent flow, scattered to
numerous moderate convection is occurring from the Yucatan
Channel north to 29N between the Florida Gulf coast and 90W.
This convection is also impacting portions of the Yucatan Channel
and NW Caribbean.

A stationary front stretches eastward from 29N95W across the
northeastern Gulf to northern Florida at 30N86W. No convection
is noted with the front at this time. Gentle to moderate E winds
are noted in the northern Gulf north of 26N, moderate to locally
fresh E-SE winds are noted south of 26N and east of 94W, with
moderate to fresh NE-N winds west of 94W. Finally, in the Bay of
Campeche, winds shift cyclonically to S around the broad low
pressure. Seas are mainly in the 3-5 ft range, except 4-6 ft in
the south central Gulf, southeast Gulf, and Straits of Florida.

For the forecast, Potential Tropical Cyclone Three will move to
24.5N 92.5W Fri morning, 26.5N 92.5W Fri afternoon, 29.0N 92.0W
Sat morning, inland to 31.5N 89.5W Sat afternoon, inland to 34.0N
87.0W Sun morning, and inland to 35.0N 84.0W Sun afternoon.
Three will dissipate Mon afternoon. Heavy rainfall will continue
to affect most of the basin through Fri night, and the N and NE
basin offshores the remainder weekend. High pressure is forecast
to build in across the basin in the wake of Three Sat night into
early next week.

CARIBBEAN SEA...

Two tropical waves are moving across the basin. Refer to the
Tropical Waves section above for details.

The eastern Pacific monsoon trough extends across Panama to NW
Colombia near 10N76W. In the NW Caribbean, scattered moderate
convection is noted north of 19N and west of 83W, including
inland over the Yucatan Channel and Peninsula.

Fresh to strong tradewinds were detected by the latest
scatterometer pass in the south central Caribbean. The strongest
winds extend from the coast of Colombia north to 13N between 71W
and 77W. Mainly moderate to fresh trades prevail elsewhere in the
basin, except gentle to moderate in the SW Caribbean south of
11N. Seas of 4-8 ft throughout the basin, except 6-9 ft in the
area of strong winds off in the south central Caribbean.

For the forecast, a ridge of high pressure north of the basin
combined with lower pressure over Venezuela and Colombia will
continue supporting pulses of fresh to strong trades over the S
central Caribbean and Gulf of Honduras during the weekend and
into early next week. Fresh to strong trades will expand in
areal coverage and reach Hispaniola adjacent waters over the
weekend. Elsewhere, moderate to fresh trades will prevail, except
light to gentle variable winds over Panama and Costa Rica
adjacent waters.

ATLANTIC OCEAN...

A pair of tropical waves are moving across the basin. Refer to
the Tropical Waves section above for details.

Diffluent flow aloft continues to support scattered moderate
convection over the Florida Peninsula and western Atlantic mainly
north of 27N and west of 66W. To the east, a surface ridge
dominates the entire Atlantic forecast area anchored by the
Bermuda-Azores High located north of the area. Fresh to locally
strong SW winds are occurring in the W Atlantic north of 30N
between 68W and 71W. Moderate to fresh trades dominate south of
22N west of 50W. Gentle to moderate trades prevail elsewhere,
except from 18N to 24N between the west coast of Africa and 24W
where fresh N-NE winds persist due to a locally tight pressure
gradient. Seas are 7 to 10 ft in this area of fresh winds. In the
Bahamas, seas are 2-4 ft. Outside of these areas, seas of 5 to 8
ft prevail across the waters south of 22N, with mainly 4 to 7 ft
seas north of 22N.

For the forecast west of 65W, the ridge of high pressure across
the area will retreat eastward this evening enabling a trough to
move through the northern forecast waters through Fri. High
pressure will then return to the area over the weekend into early
next week. Fresh to strong winds are expected to pulse at night
over Hispaniola adjacent waters during the forecast period and
over Puerto Rico adjacent waters tonight.

$$
ERA
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