[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301723
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
123 PM EDT Wed Aug 30 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...

Tropical Storm Harvey is centered near 30.5N 93.3W at 30/1500 UTC
or about 26 nm NNW of Lake Charles Louisiana, Texas moving NNE at
7 kt. Estimated minimum central pressure is 993 mb. Maximum
sustained wind speed is 40 kt with gusts to 50 kt. Scattered
moderate convection is observed north of 29N between 87W-95W.
Catastrophic flooding is still expected over southeast Texas and
southwest Louisiana. See the latest Intermediate Public Advisory
under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full
Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC
for more details.

As of 30/1500 UTC, the previously low pressure located within 300
nm west of the Cabo Verde Islands is now T.S. Irma. Irma is
centered near 16.4N 30.3W, moving west at 11 kt. Estimated minimum
central pressure is 1004 mb. Maximum sustained wind speed is 45
kt with gusts to 55 kt. Numerous moderate convection is found
from 11N-19N between 28W-35W. A recent scatterometer pass
indicated 30-40 kt winds within 360 nm in the north semicircle of
the cyclonic circulation. See the latest 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.

...TROPICAL WAVES...

A tropical wave over the central Atlantic with an axis extending
from 24N46W to 09N47W, moving west around 15 kt. The wave
coincides with an amplified 700 mb trough in initial model wind
fields. TPW satellite imagery shows an area of modest deep layer
moisture located on the east side of the wave. Satellite imagery
also shows an area of Saharan dust to the east and west of the
wave. No convection is observed within this wave at this time.

A tropical wave over the central Caribbean with axis extending
from 22N72W to 09N74W, moving west at around 10 kt. The wave
coincides with modest 700 mb troughing in initial model wind
fields and curvature of low-level winds in scatterometer data.
SSMI TPW imagery shows this wave is embedded in an area of modest
deep layer moisture. This wave is triggering scattered showers and
thunderstorms south of 18N between 71W-80W.

A tropical wave over the west Caribbean with axis that extends
from 21N86W to 09N86W, moving west at 10 to 15 kt. The wave
coincides with subtle 700 mb troughing in initial model wind
fields. TPW satellite imagery shows this wave is embedded in an
area of modest deep layer moisture. This wave is producing
isolated showers from 17N-22N between 85W-88W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from 20N16W to 16N30W to 09N50W. The
ITCZ continues from 09N50W to 10N62W. Besides the convection
associated with Irma, scattered moderate convection prevails
within 100 nm north of the ITCZ affecting portions of the
Windward Islands.

...DISCUSSION...

GULF OF MEXICO...

Tropical Storm Harvey is centered over southwest Louisiana near
30.5N93.3W. Please refer tot he section above for more details. To
the east, a surface trough extends across the Florida Peninsula
and adjacent waters from 30N86W to 30N83W to 30N79W. No convection
is related to this feature at this time. An area of scattered
showers has developed over the Bay of Campeche south of 23N and
west of 93W. Harvey is expected to slowly weaken and reach
northeast Louisiana by Thursday morning. Little change is expected
across the remainder of the basin.

CARIBBEAN SEA...

Two tropical waves are moving across the Caribbean waters. See
the Tropical Waves section above for additional details. The
eastern portion of the E Pacific monsoon trough passes over the
southwest Caribbean along 10N. Low-level convergence near the
trough is producing scattered moderate and isolated strong
convection along the coasts of Colombia and Panama south of 10N
between 75W-80W. An area of scattered moderate convection is
moving across the Windward Islands. This activity will continue
moving west affecting the southeast Caribbean waters through the
next 24 hours. Scatterometer data depicts moderate to fresh trades
across the basin.

...HISPANIOLA...

Isolated showers and thunderstorms are occurring over the island
due to a passing tropical wave. Expect similar conditions during
the next day or so until the wave moves farther west.

ATLANTIC OCEAN...

T.S. Irma has developed in the eastern Atlantic, while a tropical
wave is moving over the central Atlantic. Refer to the sections
above for details about these features. A surface trough extends
from 31N43W to 26N44W with scattered moderate convection. The
remainder of the basin is under the influence of a surface ridge
anchored by a 1029 mb high centered near 38N27W and a 1019 mb high
centered near 26N58W.

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

$$

ERA
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