[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041759
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
159 PM EDT Mon Sep 4 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
1715 UTC.

...SPECIAL FEATURES...

Hurricane Irma is centered near 16.7N 53.8W at 04/1800 UTC or
about 460 nm E of the Leeward Islands moving WSW at 12 kt.
Estimated minimum central pressure is 944 mb. Maximum sustained
wind speed is 105 kt with gusts to 130 kt. Numerous strong
convection is within 90 nm of the center. Scattered moderate
convection is elsewhere from 14N-19N between 49W-56W. Warnings and
watches have been issued for the Leeward Islands. Some
strengthening is forecast during the next 48 hours. See the latest
NHC Intermediate Public Advisory under AWIPS/WMO headers
MIATCPAT1/WTNT31 KNHC and the full Forecast/ Advisory under
AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details.

A tropical wave is in the central Atlc associated with a 1010 mb
low located near 10N35W. The wave axis extends from 14N35W to the
low to 05N35W, moving W at 10 kt. The wave is a low amplitude wave.
SSMI TPW imagery shows the wave is in a very moist area. The wave
is also within a distinct 700 mb trough. Widely scattered
moderate convection is over a large area from 06N-13N between
32W-42W. Environmental conditions are expected to be conducive
for gradual development, and there is a medium chance for tropical
cyclone formation within the next 48 hours.

Two surface troughs are presently over the the SW Gulf of Mexico.
Models indicate a surface low is forecast to form off the coast of
Tampico Mexico. There is a medium chance for tropical cyclone
formation within the next 48 hours.

...TROPICAL WAVES...

A tropical wave is along the coast of W Africa. Its axis extends
from 18N16W to 06N17W, moving W at 10 kt. SSMI TPW imagery shows
the wave is in a very moist area. The wave is also within a
distinct 700 mb trough. Scattered moderate convection is from
04N-12N between 13W-19W.

A tropical wave is in the central Caribbean with axis extending
from 22N74W to 06N79W, moving W at 10-15 kt. SSMI TPW imagery
shows the wave is in a moderately moist area. The wave is also
within a distinct surface and 700 mb trough. Scattered showers are
over Hispaniola and Jamaica. Scattered moderate convection is
over the SW Caribbean, Costa Rica, and Panama, S of 12N between
76W-83W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 13N16W to
10N20W to 13N28W to 10N35W to 12N44W. Aside from the convection
associated with the tropical waves, scattered moderate convection
is from 07N-10N between 21W-27W.

...DISCUSSION...

GULF OF MEXICO...

A surface trough is over the SW Gulf of Mexico from 24N97W to
19N95W. Another surface trough is over the Bay of Campeche from
21N93W to 18N92W. Scattered moderate convection is from 19N-26N
between 91W-98W. The remainder of the Gulf of Mexico has scattered
showers and isolated thunderstorms, as noted on radar and
satellite imagery. In the upper levels, an upper level low is
centered over S Texas near 29N100W. Upper level diffluence is over
the W Gulf enhancing the showers and convection. Expect the
convection over the SW Caribbean to persist. Also expect increased
convection over S Florida and the Straits of Florida over the next
24 hours.

CARIBBEAN SEA...

Hurricane Irma is a major hurricane approaching the Leeward
Islands. See Above. A tropical wave is also over the central
Caribbean. See above. In addition, the eastern extent of the E
Pacific monsoon trough traverses Costa Rica and Panama
intersecting with the tropical wave. 10-15 kt tradewinds are over
the remainder of the Caribbean Sea. In the upper levels, an upper
ridge is over the Caribbean Sea with axis along 78W. Expect the
Leeward Islands to be under the influence of Hurricane Irma over
the next 36-60 hours.

...HISPANIOLA...

Isolated showers are across the island as a tropical wave
continues to move W over the central Caribbean. Upper level
diffluence also supports scattered showers over the island.
Looking ahead, Hurricane Irma is forecast to approach the Island
early Thursday. See Special Feature for further details.

ATLANTIC OCEAN...

Major Hurricane Irma continue to represent a threat for the
Leeward Islands. See special features for further details. The
tail end of a cold front is over the W Atlantic from 31N74W to
29N77W. Scattered showers are within 90 nm of the front. Scattered
showers are also over the W Atlantic W of 77W to include the N
Bahamas. A Surface trough is also over the W Atlantic from 29N67W
to 24N71W. Scattered showers are within 90 nm of the trough. A
1022 mb high is centered over the central Atlantic near 32N44W.
Another 1024 mb high is centered over the E Atlantic near 35N20W.
Of note in the upper levels, an upper level low is centered over
the W Atlantic near 27N62W. Another upper level low is centered
over the E Atlantic near 28N32W.


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

$$
Formosa
This weather bulletin was brought to you by:
www.nashvilleweather.net