[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191034
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
634 AM EDT FRI AUG 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 0600 UTC surface analysis and satellite imagery through
1030 UTC.

...SPECIAL FEATURES...
Tropical Storm Fiona is centered near 17.6N 42.7W at 19/0900 UTC
or about 1077 nm W of the Cabo Verde Islands, moving WNW at 9 kt.
Estimated minimum central pressure is 1006 mb. Maximum sustained
wind speed is 40 kt with gusts to 50 kt. A cluster of heavy
showers is from 17N-20N between 42W and 44W. See latest NHC
Forecast/Advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC
for more details.

...TROPICAL WAVES...
Tropical wave extends from a 1009 mb low near 10N28W to 18N28W,
moving W at 15-20 kt within the last 24 hours. Intrusion of Saharan
dry air and dust to the wave environment limits the convection to
a cluster of heavy showers in the vicinity of the monsoon trough
W of the low pressure center or from 07N-11N between 32W and 37W. Environmental
conditions are expected to be conducive for gradual development,
and a tropical depression could form early next week while the
system moves westward across the tropical Atlantic Ocean.

Tropical wave extends from 10N to 18N with axis near 60W, moving
W at 20 kt within the last 24 hours. Meteosat enhanced imagery and
TPW imagery show there is dry air in the wave environment. On the
other hand, satellite derived data indicate the wave is in a
region of unfavorable deep layer wind shear. Both the dry air and
strong shear are hindering convection at the time.

Tropical wave in the Caribbean extends from 11N-21N with axis
near 74W, moving W at 20-25 kt within the last 24 hours. Shallow
moisture accompanies this wave, which is in a region of mainly
neutral to unfavorable deep layer wind shear. These factors are
limiting the convection to isolated showers over Haiti and the
Windward Passage.

...ITCZ/MONSOON TROUGH...
The Monsoon Trough extends from the African coast near 16N16W to
12N20W to 10N30W to 10N43W. The Intertropical Convergence Zone
axis extends from 10N43W to Venezuela coastal waters near 09N61W.
Aside from convection associated with the tropical
waves...scattered to isolated showers are from 07N-14N E of 30W.

...DISCUSSION...

GULF OF MEXICO...
Surface ridging continues to extends from the Atlantic across
Florida and the Gulf waters N of 22N. In the Gulf, the ridge is
anchored by a 1018 mb high centered near 29N86W, which provides
gentle variable flow across the NE basin and E-SE gentle to
moderate flow elsewhere N of 22N. Over the Bay of Campeche, a
surface trough extends from 21N89W to 18N92W supporting
occasionally moderate to fresh NE flow within 90 nm off the
Yucatan Peninsula coast. The trough also generates isolated
showers E of 94W and across the Yucatan Peninsula. An elongated
upper level low over the SE basin extending SW to the W Bay of
Campeche fuels isolated heavy showers and tstms S of 20N W of 94W
and across the Florida straits. Dry air subsidence and unfavorable
deep layer wind shear support fair weather elsewhere. Mostly
gentle to moderate E-SE winds persist and are expected through the
weekend ahead.

CARIBBEAN SEA...
Water vapor imagery continue to show mostly dry air and stable
conditions basin-wide. The main feature in the Caribbean is a
tropical wave moving across the central basin supporting shower
activity over portions of Hispaniola and Windward Passage. See
the tropical waves sections for further details. The E pacific
monsoon trough support scattered showers in the SW basin S of 11N.
Isolated showers are in the Yucatan Channel and in the NW basin
waters W of 80W associated with a diffluence zone between an
elongated upper level low centered over the SE Gulf of Mexico and
an upper ridge over the W Caribbean. Otherwise...fresh to strong
trades prevail between 68W-80W. A new tropical wave is forecast
to enter the E Caribbean later this morning, however no
significant convection is expected to develop for the Lesser
Antilles.

...HISPANIOLA...
A tropical wave moving across the central Caribbean with axis
near 74W is accompanied with shallow moisture. The wave is also
in a region of mainly neutral to unfavorable deep layer wind
shear. These factors are limiting the convection to isolated
showers over portions of Haiti and the Windward Passage. This
shower activity is forecast to cease later this morning.

ATLANTIC OCEAN...
The main feature in the basin is T.S. Fiona discussed in the
special features section. Over the SW North Atlc, an upper level
anticyclonic circulation centered near 21N67W is generating
diffluent flow on the northern periphery of the ridge to support
scattered to isolated showers from 22N-29N between 60W-68W.
Remnant moisture associated with a former surface trough supports
isolated showers across the northern Bahamas. Otherwise...the
remainder of the SW North Atlc is under the influence of weak
surface ridging. Farther east...the central and eastern Atlc are
influenced by a surface ridge anchored by a 1019 mb high centered
near 29N58W.

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

$$
RAMOS
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