AXNT20 KNHC 140528
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
127 AM EDT Thu Jun 14 2018
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 0000 UTC surface analysis and satellite imagery through
A tropical wave is in the E Atlc with axis extending from 11N25W
to 02N26W, moving W at 10-15 kt. The wave is in a favorable wind
shear environment, and the CIRA LPW show moderate moisture
associated with it. The GOES-16 Geocolor RGB imagery shows the
presence of the Saharan Air Layer dust and dry air N of the wave
at 15N. Scattered showers are within 120 nm of the wave axis.
A tropical wave is in the central Atlc with axis extending from
11N41W to 01N42W, moving W at 15 kt. GOES SAL and Dust RGBs show
the wave has dry air and dust N of 12N. Upper level diffluent flow
and shallow moisture in the vicinity of the ITCZ supports
isolated moderate convection from 03N to 08N between 37W and 44W.
A tropical wave is E of the Windward Islands with axis extending
from 12N56W to 03N58W, moving W at 5-10 kt. The Saharan Air Layer
dust and dry air is N of 11N. This factor along with strong wind
sheer in the region is hindering the development of deep
convection. Isolated showers are from 06N-10N between 55W and
A tropical wave is in the central Caribbean with axis extending
from 19N74W to 10N75W, moving west at 20 kt. Meteosat Split
Window imagery show SAL dry air moving across the central and E
Caribbean, which along with strong wind sheer hinders the
development of deep convection at the time.
A tropical wave is over the Yucatan Peninsula from with axis
extending from 22N89W to 12N91W, moving west at 10-15 kt.
Scattered moderate to strong convection is within 120 nm of the
The monsoon trough extends from the coast of Africa near 12N15W
to 07N20W. The ITCZ extends from 07N20W to 07N25W, then resumes
west of a tropical wave near 06N28W and continues to 05N41W. The
ITCZ resumes again W of another tropical wave near 05N44W and
continues to 06N56W. Besides the convection mentioned in the
tropical waves section, scattered moderate to strong convection is
inland over W Africa from 08N-15N between 10W-17W. Scattered
showers are within 120 nm of the remainder of the ITCZ.
GULF OF MEXICO…
The Atlantic subtropical ridge extends W to the NW Gulf of Mexico
along 29N. Scattered showers are advecting from the Caribbean to
the SW Gulf and the Bay of Campeche due to the tropical wave over
the Yucatan Peninsula. More scattered showers are over the Straits
of Florida, the Florida, and the NE Gulf N of 29N.
In the upper levels, a large upper level trough is over the Gulf
with axis along 90W with upper level moisture.
Expect the tropical wave to move to the the SW Gulf tonight.
The wave will gradually weaken into a broad and elongated area of
low pressure across the southwest gulf waters on Fri and Sat,
with the pressure gradient supporting fresh to strong southeast
flow across the western Gulf of Mexico on Sun.
A tropical wave is over the central Caribbean, and another
tropical wave is over the Yucatan Peninsula. See above. In
addition, scattered moderate to isolated strong convection is over
the W Caribbean and Central America W of 82W. Mostly fair weather
is over the E Caribbean.
In the upper levels, an upper level trough is over the W
Caribbean W of 80W. A large upper level ridge is over the
remainder of the Caribbean with axis along 72W.
Expect the Yucatan tropical wave to exit the peninsula Thu. Expect
the central Caribbean tropical wave to move west across the central
Caribbean through early Fri, and continue through the west
Caribbean into the upcoming weekend. Another tropical wave will
enter the southeast Caribbean on Thu night and Fri, and reach the
central Caribbean during the upcoming weekend. Strong trades
currently across the central Caribbean will shift slightly west
across the waters between 70W and 85W then begin to diminish.
Southerly surface flow continues to advect moisture to the W
Atlantic. Diffluent upper level flow is also over the W Atlantic.
Widely scattered moderate convection is W of 74W, to include the
Bahamas. Farther east, an upper level trough in the central
Atlantic supports a cold front from 32N53W to 26N62W. A prefrontal
trough is 120 nm E of the front. Scattered showers are within 240
nm E of the front. Otherwise, a 1030 mb high is centered over the
E Atlantic near 34N32W producing surface ridging over the E
Atlantic E of 50W and N of 20N. This ridge is forecast to shift
east Fri and Sat allowing the cold front to move east through the
waters north of 26N over the weekend.
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