AXNT20 KNHC 120605
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
204 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 0000 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 and Jamaica. Scattered
moderate to strong rainshowers are from 23N to 26N between 66W and
70W, from 21N to 23N between 70W and 72W, and from 21N to 23N
between 73W and 75W. The second and third areas of rainshowers are
on top of and/or just to the east of the SE Bahamas. Atmospheric
conditions are forecast to become a little more conducive for
tropical cyclone formation during the weekend. It is likely that
a tropical depression may form, as the system moves slowly toward
the west-northwest, across the Florida Straits and southeastern
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 on Thursday
afternoon, if necessary. The chance of tropical cyclone formation
during the next 48 hours is medium.
An Atlantic Ocean tropical wave is along 26W, passing through the
western section of the Cabo Verde Islands, from 20N southward.
The wave is moving W 10 knots. Widely scattered moderate to
isolated strong rainshowers are near the monsoon trough, from 04N
to 15N from 33W eastward to Africa. This wave is forecast to move
westward, quickly, during the next several days. Some development
is possible during the weekend, or early next week, while the
tropical wave moves through the tropical Atlantic Ocean.
An Atlantic Ocean tropical wave is along 39W/40W, from 19N
southward, moving W 10 to 15 knots. Widely scattered moderate to
isolated strong rainshowers are from 06N to 16N between 35W and
An Atlantic Ocean tropical wave is along 52W/53W, from 20N
southward, moving W 10 knots. A 1010 mb low pressure center is
along the wave near 14N. Widely scattered moderate to isolated
strong rainshowers are from 12N to 17N between 51W and 59W.
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 72W/73W, from 17N
southward, moving W 15 knots. Scattered to numerous strong
rainshowers, in clusters, is in northern sections of Colombia.
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 17N
northward from 80W westward, with the upper level cyclonic wind
The monsoon trough extends from Senegal near 14N17W, to 10N30W,
to 12N39W, and 13N52W, and to 12N56W. Much of the precipitation
that is in the area of the monsoon trough also is close to the
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 covers the
Gulf of Mexico to the north of the line that runs from the central
coast of Louisiana through the Yucatan Channel. Isolated moderate
to locally strong rainshowers are from 24N northward between the
west coast of Florida and 86W.
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 27N southward from 90W westward. Numerous
strong rainshowers are in the Isthmus of Tehuantepec of southern
Broad surface anticyclonic wind flow spans the Gulf of Mexico.
A surface ridge extends from a northern Alabama 1021 mb high
pressure center, through SE Louisiana, into the SW corner of the
Gulf of Mexico.
High pressure, centered N of the basin, will support moderate to
fresh NE to E winds into the weekend. Weak low pressure in the SW
corner of the Gulf of Mexico will remain nearly stationary. A
trough of low pressure, possibly as a tropical cyclone, will move
W from Florida into the eastern Gulf of Mexico from this weekend
into early next week, accompanied by widespread rainshowers,
thunderstorms, gusty winds and building seas.
Isolated moderate rainshowers are from 17N northward from 75W
westward, in an overall area of multiple 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 and Jamaica.
The monsoon trough is along 08N/09N, between 75W in Colombia and
beyond southern Costa Rica, into the eastern Pacific Ocean.
Scattered moderate to strong rainshowers are in the coastal plains
and coastal waters of Colombia, on the Pacific Ocean side of
Colombia, and especially from 07N to 10N between 77W and 80W,
near the border of Colombia and Panama.
High pressure, centered N of the region, will maintain moderate
trade winds, that will at times pulse to fresh to strong 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
showers 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
Another surface trough is over the central Atlantic from 28N49W to
20N56W. Widely scattered moderate convection is within 180 nm of
the trough axis. In the far E Atlantic, northerly strong to near
gale force winds are expected off the coast of Morocco through
A trough of low pressure, from the SE Bahamas to eastern Cuba,
will move WNW slowly, through the end of the week. It is possible
that the feature may become a tropical cyclone, reaching the
Florida Peninsula late on Friday, accompanied by widespread
showers, thunderstorms, gusty winds and building seas. High
pressure will weaken slowly, and move northward in advance of
this trough. A strong tropical wave may approach the waters S of
22N, by the end of the weekend into early next week.