Tropical Weather Discussion
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621
AXNT20 KNHC 060600
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
100 AM EST Fri Dec 6 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
0540 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal areas of Sierra
Leone near 07N12W to 04N20W to 02N28W. The ITCZ continues from
02N28W to 02N40W, curving to the Equator along 47W, to the coastal
sections of Brazil near 01S49W. Precipitation: isolated moderate to
locally strong is within 240 nm to the north of the monsoon
trough/ITCZ between 20W and 35W. Widely scattered moderate to
isolated strong is from the monsoon trough southward from 25W
eastward.

GULF OF MEXICO...

A surface ridge extends from a 1020 mb NW Florida Gulf coast high
pressure center that is near 30N84W, into the SW corner of the
Gulf of Mexico. Broad upper level anticyclonic wind flow spans the
Gulf of Mexico.

High pressure in the NE Gulf of Mexico will shift to the east of
the area tonight, in response to a cold front that will move off
the Texas coast on Friday. An area of weak low pressure will form
along the front in the northern Gulf of Mexico on Friday. The area
of low pressure will shift northeast of the area into Sunday,
allowing the front to stall and weaken in the western Gulf of
Mexico. A ridge will build across the central Gulf of Mexico on
Monday. The area of high pressure will shift to the east of the
area late on Monday, in advance of a stronger cold front, that is
expected to move off the Texas coast early on Tuesday, and reach
from the NE Gulf of Mexico to the western Gulf by late Tuesday.
This front will be followed by strong northerly winds, possibly
reaching to gale-force, in parts of the far western and SW Gulf
of Mexico on Tuesday and Tuesday night.

CARIBBEAN SEA...

A stationary front is in the Atlantic Ocean, from 22N69W to NW
Haiti. A shear line continues from NW Haiti, to 16N78W and 11N82W.
Precipitation: Widely scattered moderate to isolated strong is
along the coast of SE Nicaragua near the border with Costa Rica,
and from 10N to the coast of Costa Rica between 80W and 81W.
Isolated moderate in western Jamaica. Rainshowers are possible
elsewhere from 12N southward between 77W and 80W.

High pressure, building to the north of the area, will support
moderate to fresh trade winds across the region through early next
week. Expect fresh to strong winds to be pulsing off the coast of
Colombia. Long-period northeast to east swell will begin to
propagate through the Tropical N Atlantic Ocean from Saturday
night and into early next week.

ATLANTIC OCEAN...

A cold front passes through 32N56W to 28N60W, to 22N69W. The
front becomes stationary from 22N69W to NW Haiti. A shear line
continues from NW Haiti, into the Caribbean Sea, in a
southwestward direction. Precipitation: scattered moderate to
strong is within 180 nm to the SE of the cold front from 24N
northward. Isolated moderate to locally strong is elsewhere within
240 nm to the SE of the frontal boundary from the Mona Passage and
Hispaniola to 24N. Widely scattered moderate to isolated strong
is from 30N northward between 48W and 60W.

A second cold front is about 400 nm to the NNW of the central
Atlantic Ocean cold front. Precipitation: Rainshowers are
possible within 180 nm to the S and SE of the front.

A third cold front is moving across parts of Morocco, the Western
Sahara, and Mauritania. The cold front extends from a 1010 mb low
pressure center that is just off the coast of southern Morocco,
into Africa, to the Atlantic Ocean along 21N17W 20N25W 21N30W and
24N35W. A surface trough continues from 24N35W to 29N39W. No
significant deep convective precipitation is apparent.
Scatterometer winds are reaching 30 knots within 400 nm of the
1010 mb low pressure center in the NW quadrant. Scatterometer
winds of at least 20 knots or faster cover the Atlantic Ocean from
20N northward from 30W eastward.

The current 31N57W-to-24N65W-to-W Hispaniola cold front will move
eastward tonight, become stationary from near 25N65W to E
Hispaniola on Friday evening, and dissipate gradually on Saturday.
The secondary cold front is moving across the far northwest
waters. This front will move quickly across the northern waters
through Friday, to east of the area by late Friday night. A third
cold front will move across the northwest waters on Friday night
and Saturday. The third front will weaken to a stationary front
late on Saturday, and to a trough on Sunday. The trough will
retrograde westward through Sunday night, as strong high pressure
builds southward across the waters to the northeast and east of
the Bahamas. The associated tight surface pressure gradient will
bring increasing winds along with building seas into these same
waters beginning late on Sunday. These conditions are expected to
begin to diminish from Monday afternoon through Tuesday night.

$$
MT



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