Tropical Weather Discussion
Issued by NWS
AXNT20 KNHC 222333
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT FRI JUL 22 2016
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 1800 UTC surface analysis and satellite imagery through
Tropical wave in the east Tropical Atlantic extends along
32W/33W from 9N-20N moving west near 15 kt over the past 24
hours. Wave coincides with a well defied 700 mb trough as
depicted in the global models and within a highly amplified
surge of moisture as seen on the SSMI Total Precipitable Water
imagery. No associated deep convection.
Tropical wave in the central Caribbean extends along 77W/78W
from the south coast of Cuba across Jamaica to 10N moving west
10 to 15 kt over the past 24 hours. Wave is within a surge of
moisture as seen on the SSMI Total Precipitable Water imagery.
No associated deep convection.
Tropical wave remains inland over the Yucatan this evening along
89W moving west near 10 kt over the past 24 hours. Wave
coincides with a weak 700 mb trough as depicted in the global
models. No associated deep convection in the Caribbean and Gulf
of Mexico basins.
The monsoon trough extends across Africa into the east Tropical
Atlantic near 21N16W and continues along 13N23W to 7N40W where
the ITCZ begins and continues along 5N45W 7N53W to South America
near 6N57W. Clusters of scattered moderate convection are from
10N-13N east of 28W to the coast of west Africa and from 5N-8N
GULF OF MEXICO...
A large upper ridge anchored over northwest Texas and north
Alabama covers the Gulf of Mexico this evening and extends a
ridge axis east into the northwest Atlantic. An inverted upper
trough extends over the Gulf of Honduras to central Cuba
creating a diffluent environment across the southeast Gulf to
generate scattered showers and isolated thunderstorms from 24N-
28N east of 90W to over the Florida peninsula. Afternoon heating
is generating scattered showers and thunderstorms inland over
the Florida peninsula. A surface trough is in the southwest Gulf
extending from 23N97W to Mexico near 18N94W and is generating
scattered showers and isolated thunderstorms within 120/150 nm
northeast of the surface trough between 19N-22N. Similar
activity is over west Cuba and the Yucatan Channel. A weak
surface ridge remains across the north Gulf anchored by a a 1020
mb high in the northeast Gulf near 28N83W and a 1018 mb high
over the lower Mississippi Valley. The surface ridge will
persist through the weekend.
An inverted upper trough extends across Central America through
the Gulf of Honduras to over central Cuba near 22N80W generating
clusters of scattered showers and isolated thunderstorms north
of 19N to over Cuba and west of 82W including the Yucatan
Channel. An upper ridge is anchored near 13N76W covering the
central Caribbean between 71W-80W and is providing difflunce
aloft to generate scattered showers and thunderstorms from 13N-
19N between 78W-83W including the west tip of Jamaica. This
activity is being enhanced by the tropical wave along 77W/78W.
The last visible satellite images show an area of Saharan dust
has moved over the east Caribbean east of 73W leaving skies
mostly clear across Puerto Rico to the Windward Islands. The
tight pressure gradient between the west Atlantic surface ridge
and the lower pressure over South America is producing fresh to
strong trade winds across the south-central Caribbean that will
continue through the weekend. The tropical wave over the Yucatan
will enter the southwest Gulf of Mexico late in the weekend. The
central Caribbean tropical wave will move across the remainder
of the Caribbean through Saturday night.
Isolated showers and thunderstorms are over the central portion
of the island this evening due to daytime heating and orographic
lifting. Afternoon/evening isolated showers and thunderstorms
are possible through Saturday night. Sunday will see an increase
in moisture with an increase in showers and thunderstorms Sunday
evening into Monday.
The upper trough is digging southwest over the the far west
Atlantic through 32N74W to south Florida supporting a frontal
boundary north of the discussion area and a pair of surface
troughs. The western surface trough extends from 31N73W to
27N79W and an eastern surface trough extends from 31N59W to
28N66W. Scattered to numerous showers and scattered
thunderstorms cover the area within 330 nm southeast of the
western surface trough south of 30N, with isolated showers and
thunderstorms within 75 nm southeast and 120 nm northwest of the
eastern surface trough. The inverted upper trough that extends
to over central Cuba is generating scattered showers and
isolated thunderstorms within 75 nm along the north coast of
Cuba east of 80W. Otherwise, high pressure dominates the
remainder of the Atlantic with a surface ridge extending from a
1031 mb high northeast of the Azores through 32N45W to 27N60W.
The western most surface trough will weaken as it begins to
drift west tonight through Sunday night. The surface ridge will
begin to build westward across the west Atlantic Sunday into
next week. Fresh to strong winds will pulse off the north coast
of Hispaniola each evening through the weekend.
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