Tropical Weather Discussion
Issued by NWS
AXNT20 KNHC 112356
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
655 PM EST Wed Jan 11 2017
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
...Atlantic Gale Warning...
A 1009 mb low is centered 28N55W that is
supported aloft by a mid to upper-level low nearly collocated with
the surface feature near 29N56W. Its associated cold front
extends from the low to 23N55W to 19N61W while a stationary front
extends from the low to the north near 31N56W. Near gale to gale
force northeast winds are prevailing within close proximity to the
low within the northwest quadrant. These winds will continue
through Thursday afternoon. Please see the latest NWS High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more
...Caribbean Gale Warning...
The pressure gradient generated between a surface high centered in
the west Atlantic and lower pressures over the northern portion
of South America will support gale-force winds from 10.5N-12N
between 72W-75.5W starting tonight at 12/0600 UTC. These winds
will pulse every night through the next 48 hours. Please see the
latest NWS High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02 KNHC for more details.
The Monsoon Trough extends from the African coast near 09N13W to
05N20W. The Intertropical Convergence Zone extends from 05N20W to
03N34W to 01S46W. Isolated moderate convection is observed along
the ITCZ between 32W-38W.
GULF OF MEXICO...
Mid-level ridging and dry air aloft noted on water vapor imagery
supports a surface ridging that extends from across NE Florida
southwestward to southern Mexico near 21N97W. Moderate to fresh
anticyclonic winds are prevailing across the basin. Radar imagery
depicts scattered showers moving across the Florida Straits and
southeast Gulf waters. This overall synoptic pattern is expected
to persist through the remainder of the week and into the weekend.
The next front is expected to approach the region by late Tuesday.
A broad surface high centered over the west Atlantic extends
across the west Caribbean mainly north of 12N and west of 70W. A
shear line extends across the central and east Caribbean from
11N84W to 17N63W. Isolated showers are observed along the
shearline between 80W-84W. Scatterometer data depicts fresh to
strong northeasterly winds behind the shear line including the Windward
and Mona passage regions while moderate to fresh northeasterly
winds prevail east of the line. The shear line is expected to
remain nearly stationary or drift slightly southeastward through
Thursday as it becomes diffuse by Thursday night into Friday.
Scattered moderate convection is expected to develop over
portions of northern Venezuela and Colombia as the shear line
approaches. Gale force winds will develop across the waters north
of Colombia starting tonight. Please refer to the section above
Fresh to strong northeasterly winds prevail across the island and
adjacent coastal waters. These winds are generated by a relatively
strong pressure gradient across the region and southwest Atlantic
waters. Isolated showers will continue as the northeast flow
persists through the remainder of the week and the weekend.
A surface ridge prevails across the west Atlantic anchored by a
1033 mb high centered near 35N70W. To the east, a mid to upper-
level low is centered near 29N56W supports a nearly collocated
1009 mb surface low, as mentioned in the Special Features section
above. The associated cold front extends from the low to 18N62W.
These features are supporting gale force winds in the central
Atlantic. Please refer to the section above for details. Scattered
showers and thunderstorms are observed east of the front/low
mainly north of 22N between 48W-56W. The remainder of the basin
dominated by a surface ridge anchored by a 1033 mb high near
43N25W. The low pressure area along the front are expected to
drift southward through the remainder of the week and weaken well
E of the Lesser Antilles by the weekend. Little change is
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