[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161805
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 PM EST WED NOV 16 2016

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 1200 UTC surface analysis and satellite imagery through
1800 UTC.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends across Africa into the east Tropical
Atlantic to the coast of Sierra Leone near 08N113W where it
transitions to the ITCZ. The ITCZ continues into the Atlantic to 10N25W
then terminates off the coast of Guyana near 08N58W. Scattered
moderate convection is noted within 120 nm to the north of the
ITCZ between 25W and 30W. Scattered moderate to isolated strong
convection is also noted in the western Atlantic within 120 nm
north of the ITCZ between 50W and 55W.

...DISCUSSION...

...GULF OF MEXICO...

A dry and stable airmass remains in place across the entire basin
this morning, in the wake of a frontal passage that swept across
the region since early this week. Mid and high level clouds
related to the subtropical jet blanket the far southwest Gulf of
Mexico, along the coast from Tampico to Veracruz to Ciudad del
Carmen. Nearly calm winds persist over the far northwest Gulf,
under the influence of high pressure. Moderate to fresh northerly
flow is noted over the southeast Gulf however, between the ridge
over the northwest and central Gulf, and developing low pressure
over the Bahamas. Seas range from 1 to 3 ft over the northern
Gulf, and 3 to 5 ft over much of the southern Gulf. Looking ahead,
the high pressure over the northwest Gulf will shift eastward
ahead of a strong cold front expected to sweep across the basin
this weekend. Gale conditions are possible over the far southwest
Gulf behind the front Saturday and Sunday.

...CARIBBEAN SEA...

A few showers and thunderstorms are active along a cold front
reaching from central Cuba to the Gulf of Honduras. The front is
slowing down, and is expected to stall from northern Haiti to
eastern Honduras Thursday, then gradually become diffuse through
the weekend. Northerly winds have increased to 15 to 20 kt
recently at Buoy 42056 in the northwest Caribbean behind the
front. Farther south, a developing area of low pressure remains in
place over the southwest Caribbean, near 12N80W. Scattered showers
and thunderstorms are noted in a broad area within 270 nm in the
northeast semicircle of the low pressure. A surge of moist
southwest flow out of the eastern Pacific has been sustaining this
gyre for the past several days. Further development is expected
over the next couple of days as the low pressure remains over the
southwest Caribbean, and tropical cyclone development cannot be
ruled out through the next five days. Farther east, a well defined
surface trough continues to move west, reaching the central
Caribbean by early Friday, then stalling as it moves toward the
southwest Gulf Saturday.

...HISPANIOLA...

Divergent flow aloft between a broad upper trough moving off
Florida into the northern Bahamas, and an upper anticyclone over
the eastern Caribbean Sea is enhancing scattered showers and a few
thunderstorms across northern Haiti currently. While this activity
is weakening, a few showers and thunderstorm may develop over
higher terrain inland this afternoon. A cold front will move
across eastern Cuba and the Windward Passage through Thursday,
eventually stalling over northern Haiti by Friday. This will serve
as the focus for additional showers and a few thunderstorms
through the weekend over much of Haiti and western Dominican
Republic. Given persistent high amounts of deep layer moisture,
locally heavy rainfall is possible from late Thursday through the
weekend.

...ATLANTIC OCEAN...

A broad upper trough reaching from off New England to east central
Florida is moving eastward, supporting a cold front at the surface
currently reaching 31N68W to central Cuba. The associated comma
cloud pattern suggests a surface low may starting to form east of
the northern Bahamas. Further evidence is provided by a
scatterometer pass from 15 UTC indicating a surface is indeed
starting to form along the front near 26N74W. The scatterometer
also indicated fresh northerly flow within 150 nm to the north of
the front, reaching across much of the central Bahamas. Scattered
showers and thunderstorms are evident ahead of the front near the
Turks and Caicos Islands. The low pressure is expected to move
rapidly to the northeast toward Bermuda through early Thursday. The
front will continue to move eastward, reaching from 31N55W to
northern Haiti by early Saturday, before stalling and weakening
from 31N50W to northeast Dominican Republic by early Sunday.
Meanwhile a stronger cold front is expected to move into the
waters off northeast Florida by Sunday.

Farther east, a broad ridge dominates much of the remainder of
the east Atlantic anchored by a 1034 mb high about 300 nm
northwest of the Azores. A trough is noted west of the Cabo Verde
Islands, north of 25N along 23W. This is supporting scattered
showers and thunderstorms and winds of 20 to 25 kt within 180 nm
to the north of the trough.

For additional information please visit
http://www.hurricanes.gov/marine

$$
CHRISTENSEN
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