AXNT20 KNHC 121053
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
653 AM EDT Thu Sep 12 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
A surface trough extends from the Atlantic Ocean, about 200 nm to
the N of the SE Bahamas, to SE Cuba. Scattered moderate to strong
rainshowers are from 23N to 26N between 66W and 69W, from 20N to
23N between 69W and 72W, and from 22N to 24N between 72W and 74W.
The second and third areas of rainshowers are on top of and/or
just to the east of the southern half of the Bahamas. Atmospheric
conditions are forecast to become a little more conducive for a
tropical cyclone to form during the weekend. It is likely that a
tropical depression may form, as the system moves NW 5 to 10 mph,
across the Florida Straits and southern Florida, and into the
eastern Gulf of Mexico. It is likely that this disturbance may
produce periods of locally heavy rainfall and gusty winds across
the Bahamas through Friday, and across Florida during the weekend.
An Air Force Reserve reconnaissance aircraft is scheduled to
investigate the system this afternoon, if necessary. The chance of
tropical cyclone formation during the next 48 hours is medium.
An Atlantic Ocean tropical wave is along 28W/29W, from 20N
southward. The wave is moving W 10 to 15 knots. Widely scattered
moderate to isolated strong rainshowers are near the monsoon
trough, from 04N to 16N from 35W eastward to Africa. Atmospheric
conditions appear conducive for development of this system. It is
possible that a tropical depression may form early next week,
while the tropical wave moves westward in the tropical Atlantic
Ocean toward the Lesser Antilles.
An Atlantic Ocean tropical wave is along 40W/41W, from 19N
southward, moving W 10 to 15 knots. Widely scattered moderate to
isolated strong rainshowers are from 05N to 15N between 35W and
44W, and from 14N to 16N between 44W and 48W.
An Atlantic Ocean tropical wave is along 53W/54W, from 20N
southward, moving W 10 knots. Widely scattered moderate to
isolated strong rainshowers are from 13N to 16N between 50W and
60W. This system is forecast to move westward, toward unfavorable
upper level winds, and tropical cyclone formation is not
A Caribbean Sea tropical wave is along 74W/75W, from 20N
southward, moving W 15 knots. Numerous strong rainshowers are
in northern sections of Colombia, from 07N to 10N between the
border of Colombia and Venezuela and the Caribbean Sea coast of
Colombia near 76W. The monsoon trough is close also.
A western Caribbean Sea tropical wave is along 86W/87W, from
18N southward, moving W 10 knots. The wave passes through Honduras
and Nicaragua. Isolated moderate rainshowers are from 15N
northward from 80W westward. Upper level cyclonic wind flow, from
the Gulf of Mexico, is in the NW corner of the Caribbean Sea.
The monsoon trough extends from Senegal near 14N17W, to 09N33W,
to 14N47W, and 13N56W. Much of the precipitation that is in the
area of the monsoon trough also is close to the tropical waves.
GULF OF MEXICO...
The upper level cyclonic circulation center, that was in SE
Georgia/NE Florida nearly 24 hours ago, now is in the NE corner of
the Gulf of Mexico. Upper level cyclonic wind flow and isolated
moderate rainshowers cover the Gulf of Mexico to the north of the
line that runs from the central coast of Louisiana through the
Upper level cyclonic wind flow continues from East Texas into
southern interior sections of Mexico, including in the coastal
waters from Texas into the SW corner of the Gulf of Mexico. Widely
scattered moderate to isolated strong rainshowers are in the Gulf
of Mexico from 26N southward from 90W westward. Isolated moderate
rainshowers are elsewhere in Gulf of Mexico.
Broad surface anticyclonic wind flow spans the Gulf of Mexico.
A surface ridge extends from a SW Georgia 1021 mb high pressure
center, into the SW corner of the Gulf of Mexico.
High pressure N of the basin will support moderate to fresh NE to
E winds into the weekend. A trough, possibly as a tropical
cyclone, will move into the eastern Gulf of Mexico, from this
weekend into early next week. This weather system will be
accompanied by widespread rainshowers, thunderstorms, gusty winds
and building seas.
Isolated moderate rainshowers are in the area that is to the NW of
the line that runs from the Windward Passage to eastern Honduras.
This precipitation is in an overall area of more than one smaller
areas of cyclonic wind flow. Part of the precipitation that is in
the NW corner is related to the NE Gulf of Mexico upper level
cyclonic circulation center. Another part of the precipitation is
related to the surface trough that is reaching SE Cuba.
The monsoon trough is along 09N/10N, between Lake Maracaibo in NW
Venezuela, across northern Colombia, through Panama, and beyond
southern Costa Rica, into the eastern Pacific Ocean. Scattered
to numerous strong rainshowers are in northern Colombia, about 100
nm to the north of Panama between Colombia and 79W, and 180 nm to
the south of Panama from 80W eastward, and within 60 nm of the
Panama from 80W westward.
High pressure N of the region will maintain moderate trade winds,
that will pulse to fresh to strong, at times, in the S central
Caribbean Sea. A tropical wave will cross from the central
Caribbean Sea into the western Caribbean Sea on Friday. A strong
tropical wave will approach the tropical N Atlantic Ocean and the
eastern Caribbean Sea, during the time from the weekend into
early next week. This feature also will bring widespread
rainshowers and thunderstorms, gusty winds and building seas.
An upper level trough extends from a 34N46W cyclonic circulation
center, to a 30N51W cyclonic circulation, to a 19N56W cyclonic
circulation center, across the NE Caribbean Sea to a 16N74W
central Caribbean Sea cyclonic circulation center, toward Costa
A surface trough is along 30N51W 25N53W 21N55W. Widely scattered
moderate to isolated strong rainshowers are within 180 nm on
either side of the line that runs from 32N49W to 26N48W, and then
within 90 nm on either side of the line that runs from 26N48W to
23N50W 21N54W 20N59W.
A trough, from the Bahamas to eastern Cuba, will move WNW slowly,
possibly as a tropical cyclone. This weather feature is forecast
to reach the Florida Peninsula late on Friday. It will be
accompanied by widespread rainshowers, thunderstorms, gusty winds
and building seas. A strong tropical wave may approach the waters
S of 22N, early next week.