AXNT20 KNHC 181056
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
656 AM EDT Sun Aug 18 2019
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
An Atlantic Ocean tropical wave is along 32W, from 19N southward,
moving W 15 knots. Rainshowers are possible from 10N to 20N
between 30W and 40W.
A Caribbean Sea tropical wave is along 65W/66W from 18N
southward, moving W 15 knots. Isolated moderate to locally strong
rainshowers are within 150 nm on either side of the line that runs
from 21N56W to Guadeloupe, 14N64W, and to 11N63W near the NE coast
A Caribbean Sea tropical wave is along 88W/89W, from 21N
southward, moving W 15 knots. The GFS model shows that a 250 mb
trough passes from the central Bahamas, across the SE half of
Cuba, to eastern Honduras. The satellite imagery easily confirms
the trough. Scattered moderate to strong rainshowers are in the
coastal areas of NE Nicaragua, in eastern El Salvador, and in
southern sections of Guatemala.
The monsoon trough extends from Senegal near 15N17W to 05N43W.
The ITCZ extends from 05N43W to 04N48W, and to the coast of French
Guiana near 05N53W. Isolated to Widely scattered moderate and
isolated strong rainshowers are within 120 nm on either side of
the line that runs from the coast of Gambia, to 09N23W, to 07N31W,
07N45W, 08N49W to 08N59W. Rainshowers are possible elsewhere from
12N southward from 60W eastward.
GULF OF MEXICO...
A surface trough extends from the Florida Big Bend, to a 1013 mb
Gulf of Mexico low pressure center that is near 29.5N86.3W, and
continuing to 29N89W. A middle level to upper level trough is in
the SE U.S.A. and the NE corner of the Gulf of Mexico. The GFS
model for 500 mb and for 700 mb shows an inverted trough in the
eastern half of the Gulf of Mexico. Isolated moderate to locally
strong rainshowers are from 20N northward from 92W eastward.
Fresh to strong south to southwest winds in the far NE Gulf will
diminish to fresh speeds today, then increase again to fresh to
strong speeds tonight, and diminish to gentle speeds on Monday.
Scattered rainshowers and thunderstorms in the NE Gulf will
continue through today and possibly tonight, accompanied by
locally strong wind gusts and rough seas. Strong winds will pulse
in the waters just west of the Yucatan Peninsula each evening
through Monday night. The northern part of a tropical wave will
move from the western Caribbean Sea to the Bay of Campeche,
from Tuesday through Wednesday, and in the far western Gulf of
Mexico from late Wednesday through Thursday night. It is expected
to increase the chances for showers and thunderstorms across
those areas of the Gulf. Otherwise, relatively weak high pressure
will extend from the Atlantic to across the central Gulf through
the upcoming week.
An upper level trough passes from the central Bahamas, across the
SE half of Cuba, to eastern Honduras. Isolated moderate to locally
strong rainshowers are within 800 nm to the NW of the line that
runs from the Anegada Passage to the coast of Venezuela along 67W.
Other rainshowers are possible in the rest of the NW Caribbean
In the wake of a recent tropical wave, the gradient
will tighten enough to allow for fresh to strong east winds over
some sections of the northwestern Caribbean today. Fresh to
strong northeast to east winds will resume over the south-
central Caribbean this evening also in the wake of a tropical
wave, that is presently over the eastern Caribbean. These winds
are expected to last well into the upcoming week.
A surface trough is between the Bahamas and the east coast of
Florida, from Andros Island to 30N. Rainshowers are possible
within 90 nm on either side of the trough.
A surface trough is along 30N66W 26N67W 21N67W. Isolated moderate
to locally strong rainshowers are within 800 nm to the east of
the trough, and within 500 nm to the west of the trough.
The current surface ridge, that extends from Bermuda to south
central Florida, will continue to move northward slowly through
Monday, as an area of broad low pressure northwest of the
forecast waters tracks northeastward. An inverted surface trough,
currently along 66W/67W, will track westward across the eastern
and central forecast waters through tonight, then over the western
Bahamas Mon before moving inland over Florida Tue. Scattered
showers and thunderstorms will accompany this trough. The gradient
between the high pressure ridging and the trough will allow for
generally gentle to moderate east to southeast winds to the north
of about 22N and for moderate to fresh east winds S of 22N through
most of the forecast period. Fresh to locally strong winds will
pulse at night between the Turks and Caicos Islands and Hispaniola