[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 050004
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM EDT SUN SEP 04 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
2245 UTC.

...SPECIAL FEATURES...

Post-tropical cyclone Hermine is centered near 37.2N 69.3W,
about 265 nm SSE of the eastern tip of Long Island, and about
290 nm E of Ocean City Maryland. Hermine is moving slowly ENE,
or 70 degrees, at 4 knots. The center of Hermine is forecast to
meander slowly offshore of the mid-Atlantic coast for the next
couple of days. The estimated minimum central pressure is 999
mb. Maximum sustained winds are 60 knots with gusts to 75 knots.
Convective precipitation: Scattered moderate in the Atlantic
Ocean from 38N to 40N between 62W and 69W and from 34N to 37N
between 61W and 64W. Please read the latest NHC Intermediate
Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC
and the Forecast/Advisory under the AWIPS/WMO headers
MIATCMAT4/WTNT24 KNHC for more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave extends from 09N33W through low
pres 1012 mb centered at 20N35W to 21N35W. The wave is moving
westward at 10 to 15 knots. The wave shows up well in satellite
imagery. Convective precipitation: Isolated moderate from 20N to
27N between 30W and 37W. Scattered moderate from 05N to 14N
between 29W and 39W and in the vicinity of the low from 21N to
26N between 33W and 38W. A layer of Saharan air is inhibiting
convection on the W side of this wave between 14N and 21N.

An Atlantic Ocean tropical wave extends from 11N61W through low
pres 1008 mb centered at 15N60W to 19N60W. The wave is located
just E of the Windward Islands and is moving westward at 15 to
20 knots. Convective precipitation: scattered moderate and
isolated strong from 12N to 17N between 55W and 66W. Latest
satellite-derived wind data show an area of fresh to strong NE to
E winds accompanies this wave from 13N to 19N between 54W and
67W. Model guidance suggests this wave will continue westward
and bring associated convection to the central Caribbean between
Colombia and Hispaniola on Tue.

A Caribbean Sea tropical wave entering central America extends
from 10N84W to 17N84W. Convective precipitation: Scattered
moderate and isolated strong convection is mainly located
over Costa Rica...Nicaragua and Honduras from 10n to 16N between
82W and 88W. An upper-level trough over southeastern Mexico is
providing an area of divergent upper-level winds over this system.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough heads westward from Senegal on the African
coast at 14N17W to 11N35W to 12N49W. The ITCZ continues from
12N49W to 14N58W. Convective precipitation: Scattered moderate
from 03N to 09N between 17W and 27W, and from 07N to 13N between
39W and 50W.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level cyclonic circulation center is in the NW corner
of the area, along the Texas coast. Upper-level cyclonic wind
flow covers the Gulf of Mexico from 23N northward from 90W
westward. A surface trough follows the United States gulf coast
from eastern Texas to northern Florida. Another surface trough
was situated along the Mexican gulf coast from near Veracruz to
near Ciudad Victoria. Only minimal convection is associated with
the trough over eastern Mexico. Scattered moderate and isolated
strong convection associated with the trough along the northern
Gulf coast is seen from 28N to 31N between 81W and 98W. Upper-
level ridging is aiding the convection along the northern Gulf
coast. An area of upper-level convergence to the E of an upper-
level trough is approaching the Mexican gulf coast. This should
begin to restrict convection in this area on Monday.

...THE CARIBBEAN SEA...

An upper-level low is centered SW of Haiti near 17N75W. Upper-
level convergence in the vicinity of this feature is
restricting convection over much of the Caribbean. Divergent
upper-level winds on the W and E sides of the low are aiding
convection associated with the tropical waves about to enter the
eastern Caribbean and central America. The upper-level low will
continue to progress westward during the next several days.

Convective precipitation associated with tropical waves cover
the Caribbean Sea E of 67W and W of 82W. See the tropical
waves section for more details.

...HISPANIOLA...

Fair weather prevails across the island due to strong subsidence
aloft as indicated by water vapor imagery. Stable and fair
weather is expected to continue tonight. On Monday and Tuesday,
a moist air mass associated with an approaching tropical wave
will bring increased shower coverage. Drier weather is expected
by Thursday as the wave moves away to the W.

...THE ATLANTIC OCEAN...

Post-tropical cyclone Hermine remains N of forecast waters.
Please refer to the special features section for details. Two
tropical waves are moving across the basin. Please refer to the
tropical waves section for details.

A weak surface trough stretches from along the Cuban coast at
23N80W to east of Florida at 27N78W. Only minimal deep
convection is found in the vicinity of the trough. The trough is
moving W away from Andros Island in the western Bahamas toward
the east coast of Florida. The remainder of the basin is
dominated by a weak and broad surface ridge stretching from
30N34W to 27N75W. Model guidance suggests this ridge will be
reinforced by high pressure building southeastward from north
America.

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

$$
CAM
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