[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192350
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
650 PM EST SAT NOV 19 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 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...SPECIAL FEATURES...

A 1006 mb surface low remains over the SW Caribbean near 11N81W.
Showers and thunderstorms have increased and the low is becoming
better organized. The combination of this low with a stationary
front located north of the low is enhancing scattered moderate
convection across the south-central Caribbean south of 18N between
77W-85W. Scatterometer data depicts moderate to fresh winds mainly
in the northern semicircle of the low due to the pressure gradient
between the low and high pressure to the north. Although environmental
conditions are only marginally conducive for additional development,
only a small increase in the organization of the low could result
in the formation of a tropical depression. This system is expected
to move slowly and erratically during the next few days. The latest
Tropical Weather Outlook gives this system a medium change of tropical
cyclone formation during the next 48 hours.

Gulf of Mexico Gale Warning: A strong cold front is moving across
the Gulf waters. At 2100 UTC, the front extends from the Florida
Big Bend coast near 30N83W to 26N90W to 19N96W. A sharp ridge is
currently building across eastern Mexico and the western Gulf
anchored by a 1038 mb high pressure over NE Mexico. These features
are generating a tight pressure gradient that supports gale force
winds noted in Scatterometer data from 20N-25N and west of 96W,
with seas ranging between 10-18 ft. These winds will prevail
across the southwest Gulf waters through the next 24 hours. Please
refer to the High Seas Forecast product under AWIPS/WMO headers
HSFAT2/AXNT20 KNHC for more details.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends across Africa into the east Tropical Atlantic
near 08N13W to 06N15W where it transitions to the ITCZ and continues
to 05N23W to 09N37W to 06N57W. Scattered moderate convection is within
100 nm north of the ITCZ between 20W-38W.

...DISCUSSION...

...GULF OF MEXICO...

A gale warning is in effect for the west central and southwest Gulf
in association with a strong cold front currently moving across the
area. Please see the Special Features section above for details. The
remainder of the Gulf region is under the influence of a surface
ridge. Scatterometer data depicts gentle to moderate northeasterly
flow across the remainder of the basin. The cold front will continue
moving across the basin reaching South Florida on Sunday morning. The
frontal passage will be mainly dry, followed by gusty northerly wind
and chilly temperatures on Monday morning.

...CARIBBEAN SEA...

A 1006 mb surface low is centered north of Panama near 11N81W.
Please refer to the Special Features section above for more details.
A stationary front extends from the central Atlantic, across the
Mona Passage, then reaching the north central Caribbean near 18N69W
to the coast of Nicaragua near 14N83W. Fresh to strong NE winds
are noted in scatterometer data behind the front north of 18N and
east of 85W, including the Windward Passage, the lee of Cuba and
Hispaniola. Scattered moderate convection is observed within 200
nm on either side of the front between 68W-79W. Scatterometer data
depicts fresh northerly winds north of the front while moderate
trades prevail elsewhere. Expect for the southern extension of the
front to weaken and transition to a shear line during the next 24
hours. The front is forecast to remain nearly stationary over
Hispaniola enhancing cloudiness and convection. A cold front will
move into the north Caribbean on Sunday followed by fresh to
strong northeast winds.

...HISPANIOLA...

Atmospheric conditions across Hispaniola remain very moist and unstable
due to the presence of a frontal boundary. This weather pattern will
persist through the next 24 hours with additional showers and thunderstorms
activity expected and the potential for locally heavy rain and flash
flooding.

...ATLANTIC OCEAN...

A cold front, associated with an occluded low pressure system, enters
the forecast region near 31N55W and continues to 24N59W where it becomes
stationary, extending over the Windward Passage and the Caribbean
Sea. Scatterometer data depicts fresh to strong southerly winds
just ahead of the front. Scattered showers are also ahead of the
front, mainly north of 24N. A ridge dominates the remainder of
the east and central Atlantic anchored by a 1027 mb high pressure
located west of the Azores near 38N38W. A surface trough, reflection
of an upper-level low, persists across the Atlantic and stretches
from 26N39W to 23N40W. Some shower activity persists in association
with this trough. Another surface trough extends from 18N33W to
14N35W witn no significant convection. Expect for the front in
the central Atlantic to remain nearly stationary through Monday
while gradually weakening. At the same time, another cold front
will move off the northeast Florida coast tonight. This front will
extend from 31N68W to the Northern Bahamas on Sunday, and from
27N65W to the Southern Bahamas on Monday. Fresh to strong NW winds
will follow the second front tonight and early Sunday.

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

$$

ERA
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