AXNT20 KNHC 131135
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
634 AM EST Fri Dec 13 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
The monsoon trough passes through the coastal areas of Liberia
near 07N11W to 06N14W. The ITCZ continues from 06N14W to 03N28W,
04N35W, and 03N39W. Precipitation: Isolated to widely scattered
moderate and locally strong are from 08N southward between 17W and
50W. Isolated moderate elsewhere from 10N southward from 50W
GULF OF MEXICO...
A stationary front is in the Atlantic Ocean, passing through
28N77W, to the Florida east coast along 27N. The front becomes
a dissipating stationary front from the Florida coast at 27N,
just to the south of Lake Okeechobee, into the central Gulf of
Mexico, and curving southward to the Isthmus of Tehuantepec of
southern Mexico. A second stationary front passes through NE
Florida, to the west coast of Florida near 28.5N, curving through
the NE Gulf of Mexico, to SE Louisiana, ending near 27N91W.
Precipitation: widely scattered moderate to isolated strong is
from 24N northward from 92W eastward. An upper level trough is
moving through the middle sections of the U.S.A. The southern
part of the trough is making its way through Texas. Some upper
level cyclonic wind flow is in the NW corner of the Gulf of
Mexico. Upper level moisture is streaming northeastward, from the
areas of Mexico that are between 94W and 104W, from 20N southward,
into the Gulf of Mexico.
The current stationary front, that is in the NE corner of the Gulf
of Mexico, will transition into a surface trough, slowly, by tonight.
Fresh southerly winds are expected in the western Gulf of Mexico
on Sunday and Monday. A strong cold front will reach the Texas
coast on Monday night. The cold front will extend from northern
Florida to the SW corner of the Gulf of Mexico on Tuesday night.
Gale-force northerly winds are possible west of the front near
the coast of Mexico.
An upper level trough passes through 22N61W in the Atlantic
Ocean, to 14N66W in the Caribbean Sea. A surface trough is along
64W from 10N at the coast of Venezuela to 20N. Precipitation:
Isolated moderate within 360 nm to the east of the surface trough,
and within 600 nm to the west of the surface trough, in the trade
wind flow. Comparatively drier air in subsidence covers the
Caribbean Sea on the western side of the trough, and elsewhere
from 11N northward from 87W eastward.
Broad surface low pressure covers the SW corner of the Caribbean
Sea. The monsoon trough passes through Costa Rica and Panama, into
northern Colombia along 75W from 08N to 09N. Satellite data and
the GFS forecast for 250 mb show upper level anticyclonic wind
flow in the SW corner of the Caribbean Sea. The GFS model
forecasts for 500 mb and for 700 mb show NE wind flow in the same
area. Precipitation: rainshowers are possible from 12N southward
from 78W westward.
The wind speeds and the sea heights will diminish across the
region, gradually, as high pressure in the Atlantic Ocean shifts
eastward. The trade winds in the central and eastern Caribbean Sea
will increase early next week. Fresh trade winds and moderate NE
swell are expected in the Tropical N Atlantic Ocean during the
A cold front passes through the Atlantic Ocean, just to the east
and southeast of Bermuda, to 31N69W. The front becomes stationary
from 31N69W to the Florida east coast along 27N. A second
stationary front passes through 32N80W, and beyond NE Florida near
30N81W. Precipitation: isolated moderate to locally strong is from
25N northward from 70W westward.
An upper level trough extends from a 34N41W cyclonic circulation
center, to a second cyclonic circulation center that is near
26N51W, to 22N61W, and eventually to 14N66W in the Caribbean Sea.
A surface trough is along 32N38W 30N41W, to 30N44W 20N48W, and to
17N50W. Precipitation: Scattered moderate to isolated strong is
from 31N to 36N between 35W and 40W. Isolated to widely scattered
moderate and isolated to locally strong from 12N to 20N between
35W and 48W, and from 20N to 29N between 40W and 53W.
The current stationary front will weaken to a trough by tonight.
Southerly winds will increase tonight and on Saturday, in advance
of a weak cold front that is expected to move E across the
northern waters during the weekend. It is possible that a stronger
cold front may move into the NW part of the area, off NE Florida,
on Tuesday night.