[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 090605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 AM EDT Mon Oct 9 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 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

A nearly stationary 1009 mb low pressure is located over the
central subtropical Atlantic Ocean near 30N40W. Scattered showers
and isolated thunderstorms are within 210 nm NE quadrant. Gale-
force winds are to the NNW of the low. The low is being affected
by strong upper-level winds, however shower and thunderstorm
activity has become a little better organized. Upper-level winds
are not expected to become more conducive for development until
mid-week, but a tropical or subtropical cyclone could form at any
time if the shower activity persists near the center. The low is
forecast to drift northward on Monday and then move slowly toward
the east-southeast through the middle of the week. There is a
high chance for tropical cyclone formation within the next 48
hours.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 12N21W
to 01N22W, moving W at 5 kt. Satellite derived data indicate the wave
is in a low to moderate vertical shear region. Both CIRA LPW and
SSMI TPW imagery show patches of dry air in the wave environment,
which is limiting the convection to isolated showers from 02N-13N
E of 23W.

A tropical wave is in the central Atlc associated with a 1010 mb
low located near 13N47W, which is expected to move WNW towards
14N50W within the next 24 hours. The wave axis extends from
18N46W to the low center to 05N48W, and has been moving W at 10
kt. The wave is in a region of mainly strong vertical wind shear N
of 15N and some dry air intrusion to its environment is observed
in both CIRA LPW and SSMI TPW imagery. This is limiting
convection to scattered moderate from 10N-16N between 40W-49W.

A tropical wave is in the central Atlc with axis extending from
19N56W to 09N57W, moving west at 5 kt. The wave is in a region of
mainly moderate to strong vertical wind shear. Shallow moisture
in the wave environment along with upper level diffluence support
scattered moderate convection from 11N-18N between 52W-58W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 15N17W to
06N25W to 05N34W. The ITCZ extends from 05N34W to 05N42W to 08N46W.
Besides the convection mentioned in the tropical wave section,
scattered moderate convection is from 02N-10N between 23W-40W.

...DISCUSSION...

GULF OF MEXICO...

Shallow moisture and upper level diffluent flow support scattered
showers and tstms over the SE Gulf S of 25N between 83W and 90W.
Otherwise, gentle to moderate southerly flow dominates the Gulf
waters ahead of a cold front forecast to come off the coast of
Texas Tuesday evening.

CARIBBEAN SEA...

Isolated showers and tstms are in Central America associated with
the eastern extension of the Pacific monsoon trough. A middle
level trough and upper level diffluent flow support scattered to
isolated showers across Hispaniola and Puerto Rico. Showers over
Hispaniola are being enhanced by a surface trough extending from
the SW N Atlc waters to the central island, which have been
nearly stationary the last 24 hours. A tropical wave is forecast
to move into the E Caribbean later today, thus increasing the
chances for more showers to Puerto Rico. A second wave is forecast
to enter the basin Tuesday night.

...HISPANIOLA...

A middle level trough and upper level diffluent flow support
scattered to isolated showers across Hispaniola. These showers are
being enhanced by a surface trough extending from the SW N Atlc
waters to the central island, which has been nearly stationary
the last 24 hours. Continuation of showers expected through early
Tuesday morning.

ATLANTIC OCEAN...

Three tropical waves are moving across the basin. See the section
above for details. A surface trough, which has been nearly
stationary the last 24 hours, extends from 27N68W to 19N71W with
isolated showers within 15 nm either side of its axis. A low
pressure is over subtropical waters of the central Atlantic with
high chances of development within the next 2 days. Refer to the
special features for details. Surface ridging prevails elsewhere.

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

$$
Ramos
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