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Atlantic Tropical Weather Discussion



000
AXNT20 KNHC 251557
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1156 AM EDT Mon Sep 25 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 1200 UTC surface analysis and satellite imagery through 
1800 UTC.

...SPECIAL FEATURES... 

Hurricane Maria is centered near 31.2N 72.9W at 25/1500 UTC or 
about 270 nm south-southeast of Cape Hatteras North Carolina, 
moving north at 6 kt. Minimum central pressure is 963 mb. Maximum
sustained winds are 70 kt with gusts to 85 kt. Scattered moderate
convection is within 180 nm in the northeast semicircle from the 
center. See the latest NHC Forecast/Advisory under AWIPS/WMO 
headers MIATCMAT5/WTNT25 KNHC for more details.

Hurricane Lee is centered near 30.8N 49.9W at 25/1500 UTC or 
about 770 nm east of Bermuda. Lee drifting slowly to the south- 
southwest. Estimated minimum central pressure is 980 mb. Maximum 
sustained winds are 80 kt with gusts to 100 kt. Scattered moderate
convection within 90 nm of the center. See the latest NHC 
Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC 
for more details.

...TROPICAL WAVES... 

A tropical wave extends along 33W/34W from 07N to 20N, moving 
west at 10 kt. The wave shows up well in GOES high density winds
in the lower to mid levels of the atmosphere. No significant 
convection is associated with this tropical wave.

A tropical wave is in the eastern Caribbean along 65W/66W, from
the U.S. Virgin Islands to central Venezuela, moving west at 10 
to 15 kt. The position of the main axis of the wave was aided by 
12Z sounding data. The wave is on the southwestern periphery of a
700 mb ridge and the western periphery of an upper- level trough 
axis to the east. No significant convection is noted at this time,
but earlier convection was active through the Leeward Islands due
to divergence aloft between the upper ridge and upper trough.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from Senegal coast near 15N17W to 
10N31W. The Intertropical Convergence Zone extends from 09N35W to
07N55W. Scattered moderate convection is from 11N to 19N and east
of 20W.

...DISCUSSION...

GULF OF MEXICO...

A sharp mid to upper-level trough reaches from the Great Lakes to
the western Florida Panhandle, supporting scattered showers and 
thunderstorms off the Panhandle coast. A broad surface trough has
formed over the north Gulf related to the mid to upper level
trough. Another surface trough is located over the far southwest
Gulf, the remnant of the overnight troughing that forms off the
western coast of the Yucatan peninsula and drifts westward
overnight. A weak pressure pattern has set up overall, supporting
minimal winds and seas. Little change is expected in overall 
conditions. By Tuesday night into Wednesday, easterly flow will 
increase slightly into moderate to occasional fresh conditions as 
ridging noses in from the lower Mississippi River valley region 
into the eastern Gulf waters.

CARIBBEAN SEA...

Scattered showers and thunderstorms are active across much of the
western Caribbean this morning. This activity is enhanced by
divergence aloft on the southeastern edge of a sharp upper trough
reaching into the far northwest Caribbean, and a broad mid to
upper ridge extending from Nicaragua through the Windward Passage.
Northerly flow aloft over the eastern Caribbean is limiting
convection. Surface ridging over the central Atlantic building in
the wake of the tropical wave in the eastern Caribbean will
support fresh to strong trade winds, which will gradually shift
from the southeast Caribbean to the south central Caribbean
through mid week. 

...HISPANIOLA...

Slightly drier northerly flow aloft associated with a mid to 
upper level ridge across Hispaniola will limit widespread shower 
and thunderstorm development, although lower level moisture
remains high, and some development is still possible this 
afternoon over higher terrain. Scattered showers and thunderstorm 
may form off the south coast tonight, especially ahead of tropical
wave moving into the central Caribbean.

ATLANTIC OCEAN...

A tropical wave is moving across the basin. Refer to the section
above for details. Outside the influence of Maria in the west 
Atlantic and Lee in the central Atlantic, surface ridging prevails
across much of the remainder of the region. 

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

$$
Christensen