[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 AM EDT SAT AUG 20 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 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

Tropical Storm Fiona is centered near 18.7N 45.5W at 20/0300 UTC
or about 934 nm east of the Leward Islands moving west-northwest
at 10 kt. Estimated minimum central pressure is 1007 mb. Maximum
sustained wind speed is 35 kt with gusts to 45 kt. Numerous heavy
showers and isolated tstms are from 18N-22N between 43W-47W.
Please see the latest NHC Intermediate Public Advisory under
AWIPS/WMO headers MIATCPAT1/WTNT31 KNHC and the full Forecast/Advisory
under the AWIPS/WMO headers MIATCPAT1/WTNT21 KNHC for more
details.

...TROPICAL WAVES...

Tropical wave is in the central Atlantic extending from a 1009 mb
low near 10N33W to 15N31W, moving W at 15 kt within the last 24
hours. Intrusion of Saharan dry air and dust to the wave environment
continue to limit the convection to scattered showers and isolated
tstms from 06N-16N between 30W and 40W. Any development of this
system during the next couple of days should be slow to occur due
to its proximity to dry air. Environmental conditions are forecast
to be more conducive for development after that time, and a tropical
depression could form by the middle of next week while the system
moves westward across the tropical Atlantic Ocean and into the
eastern Caribbean Sea.

Tropical wave in the eastern Caribbean extends from 11N-18N with axis
near 66W, moving W at 20 kt within the last 24 hours. Even though
the wave is in a region of favorable deep layer wind shear, strong
dry air subsidence from aloft and Saharan dry air in the wave
environment hinder convection at the time.

Tropical wave in the western Caribbean extends from 09N-19N with
axis near 82W, moving W at 20-25 kt within the last 24 hours. CIRA
LPW imagery from surface to 850 mb show the wave is associated
with moderate moisture. However, strong dry air subsidence from
aloft and mainly unfavorable deep layer wind shear limits the
convection to isolated showers and tstms S of 17N W of 80W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends across Africa into the east Tropical
Atlantic near 16N16W through the 1009 mb low to near 12N39W. The
ITCZ begins near 11N45W and continues along 10N56W to 10N62W. The
monsoon trough/ITCZ is disrupted by Tropical Storm Fiona. Aside
from the convection associated with the tropical wave, scattered
heavy showers and isolated tstms are from 08N-14N E of 20W.

...DISCUSSION...

GULF OF MEXICO...

Weak surface ridging prevails across the Gulf waters N of 22N,
being anchored by a 1017 mb high near 27N84W. The ridge continue
to provide gentle variable flow across the NE basin and E-SE gentle
to moderate flow elsewhere. A heat surface trough extending along
the western Yucatan Peninsula provide NE moderate wind to the
central and eastern Bay of Campeche. The trough also generates
scattered to isolated showers S of 21N E of 94W and across the
Yucatan Peninsula. An elongated upper level low centered N of the
Yucatan Peninsula support isolated showers and tstms across the
Florida straits. Dry air subsidence and unfavorable deep layer
wind shear support fair weather elsewhere. Mostly gentle to
moderate E-SE winds are expected through the weekend. The diurnal
surface trough will form each evening over the Yucatan peninsula
supporting fresh winds along the northwest coast of the Yucatan.

CARIBBEAN SEA...

Water vapor imagery continue to show mostly dry air and stable
conditions in the central and eastern Caribbean. Two tropical
waves are the main features in the basin. However, none represent
a threat in terms of winds and precipitation. Due to the presence
of divergent flow aloft, low level moisture and favorable deep
layer wind shear the westernmost wave is associated with isolated
showers and tstms S of 17N W of 80W. For more details about the
waves see the tropical waves section. The E pacific monsoon
trough support scattered showers in the SW basin S of 10N E of 80W.
Otherwise...fresh to strong trades prevail between 69W-81W with near
gale force trades along the coast of Colombia.

...HISPANIOLA...

Remnant moisture associated with the passage of a tropical wave
and divergent flow aloft support cloudiness and isolated showers
along Haiti and the Windward Passage. Model guidance indicate
these showers will cease before the sunrise today and will resume
Saturday night. Fair weather for the entire Island is expected
Sunday.

ATLANTIC OCEAN...

The primary concern in the Atlantic waters S of 30N continue to be
Tropical Storm Fiona. Please see the Special Features section
above for more details. Over the SW N Atlantic, an elongated area
of low pressure is centered by a 1015 mb low near 28N70W. Farther
east, scattered showers and isolated thunderstorms are N of 28N
between 47W-52W. The remainder of the basin is dominated by a
surface ridge.

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

$$
RAMOS
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