AXNT20 KNHC 141159
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
759 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 0600 UTC surface analysis and satellite imagery through
A tropical wave is in the E Atlc with axis extending from 11N26W
to 03N27W, 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 moderate convection is from 06N to 08N between
24W and 27W.
A tropical wave is in the central Atlc with axis extending from
11N42W to 03N43W, 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
scattered moderate convection from 06N to 11N between 37W and
A tropical wave is E of the Windward Islands with axis extending
from 14N57W to 03N59W, 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
A tropical wave is in the central Caribbean with axis extending S
from the southern coast of Cuba near 20N76W to near the NW coast
of Colombia near 10N76W, moving west at 15-20 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 SW Gulf of Mexico just W of the Yucatan
Peninsula with axis extending from 23N91W to across SE Mexico,
moving west at 10-15 kt. Scattered moderate to strong convection
is S of 23N W of the wave axis to the coast of Mexico.
The monsoon trough extends from the coast of Africa near 12N16W
to 08N18W. The ITCZ extends from 08N18W to 06N25W, then resumes
west of a tropical wave near 06N28W continuing to 05N42W, then
resumes again W of another tropical wave near 05N44W and
continues to the coast of South America near 05N53W. Besides the
convection mentioned in the tropical waves section, scattered
moderate to strong convection is within 300 nm SW of the coast of
Africa from 05N to 11N. Scattered moderate convection from 04N to
07N between 21W and 25W, and from 03N to 06N between 36W and 39W.
GULF OF MEXICO…
The Atlantic subtropical ridge extends W to the NW Gulf of Mexico
along 29N. Scattered showers and thunderstorms extend from the
Yucatan Channel northward to 27N to the E of 87W.
In the upper levels, a large upper level trough is over the Gulf
with axis along 90W with upper level moisture.
The tropical wave in the SW Gulf will gradually weaken into a
broad and elongated area of low pressure through Fri into early
Sat, with the pressure gradient supporting fresh to strong
SE flow across the western Gulf of Mexico on Sun.
The tropical wave in the central Caribbean will continue westward
across the remainder of the basin through the early part of the
weekend, while another tropical wave currently in the Tropical N
Atlantic will move into the eastern Caribbean on Fri and Sat.
Scattered showers and thunderstorms are S of 11N in the SW
Caribbean, and in the NW Caribbean W of 85W. Otherwise, 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.
Strong trades currently across the central Caribbean will shift
slightly W across the waters between 70W and 85W through the end
of the week, then begin to diminish into the early part of the
Southerly surface flow continues to advect moisture to the W
Atlantic. Diffluent upper level flow is also over the W Atlantic.
Widely scattered showers and thunderstorms is N of 22N and W of
74W including across the Bahamas.
Farther E, an upper level trough in the central Atlantic supports
a cold front from 32N51W to 25N62W. A pre-frontal trough is 60 nm
SE of the front. Scattered showers and isolated thunderstorms are
within 240 nm E of the front.
Otherwise, a 1029 mb high is centered over the E Atlantic near
35N31W producing surface ridging over the E Atlantic E of 50W and
N of 20N. This ridge is forecast to shift E Fri and Sat allowing
the cold front to progress eastward through the waters north of
26N over the weekend.
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