[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 312346
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
746 PM EDT Thu Aug 31 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 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...SPECIAL FEATURES...

Hurricane Irma is centered near 17.3N 34.8W at 31/2100 UTC or
about 617 nm west of the Cabo Verde Islands, moving west-
northwest at 10 kt. Estimated minimum central pressure is 967 mb.
Maximum sustained wind speed is 100 kt with gusts to 120 kt.
Scattered moderate to isolated strong convection is from 14N-19N
between 32W-38W. Irma is a category 3 hurricane on the
Saffir-Simpson Hurricane Wind Scale. 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 extends from 22N53W to
09N53W, moving west at 15 kt. The wave coincides with an
amplified 700 mb trough in model wind fields. The SSMI TPW
satellite imagery shows an area of modest deep layer moisture.
Satellite imagery also shows an area of Saharan dust to the west
of the wave. No convection is observed within this wave at this
time.

A tropical wave over the central Caribbean extends from 22N80W to
08N81W, moving west at 15 kt. The wave coincides with modest 700
mb troughing in model wind fields, and with curvature of low-
level winds in scatterometer data. SSMI TPW imagery shows this
wave is embedded in an area of modest deep layer moisture.
Scattered moderate to isolated strong convection is over E Cuba
and Jamaica. Scattered moderate to isolated strong convection is
over the SW Caribbean, Honduras,and Nicaragua from 10N- 17N
between 81W- 88W.

A tropical wave over the Bay of Campeche extends from 22N94W to
09N95W, moving west at 15-20 kt. The wave coincides with subtle
700 mb troughing in initial model wind fields. SSMI TPW satellite
imagery shows this wave is embedded in an area of modest deep
layer moisture. Scattered moderate to isolated strong convection
is inland over the Yucatan Peninsula and S Mexico.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from 13N17W to 14N26W then resumes
from 13N37W to 10N52W. The ITCZ is from 10N52W to 10N61W.
Scattered moderate isolated strong convection is off the coast of
W Africa from 06N-15N between 20W-24W. Similar convection is from
10N-14N between 37W-43W.

...DISCUSSION...

GULF OF MEXICO...

Tropical Depression Harvey is centered over N Mississippi, moving
NE at 17 kt and weakening. Further S, a surface trough is over the
N Gulf of Mexico from 30N88W to 26N93W. Isolated moderate
convection is within 120 nm E of the trough axis over the NE Gulf
and the Florida Panhandle. Scattered moderate convection is also
over the Florida Peninsula, and W Cuba. A tropical wave is over
the Bay of Campeche. See above. In the upper levels, an upper
level trough is over the NW Gulf and Texas with strong subsidence.
The remainder of the Gulf has a large amount of upper level
moisture. Expect the upper level trough to move E over the next 24
hours.

CARIBBEAN SEA...

A tropical wave is over the central Caribbean. See above. Further
S, the eastern portion of the E Pacific monsoon trough passes
over the SW Caribbean along 10N with scattered showers. Recently,
widely scattered moderate convection has developed over
Hispaniola, the central Caribbean, N Venezuela, and N Colombia.
Satellite derived wind data depicts moderate to fresh trades
covering the basin. An upper level low is centered over the SW
Caribbean near 13N79W. Expect additional convection over the W
Caribbean over the next 24 hours.

...HISPANIOLA...

Presently widely scattered moderate convection is over the
island. Expect a dry weather pattern to prevail across the island
during the next couple of days.

ATLANTIC OCEAN...

Hurricane Irma is over the eastern Atlantic, and a tropical wave
is is over the central Atlantic. Please see above. A frontal
boundary extends across the W Atlantic, analyzed as a cold front
from 30N55W to 27N64W, then as a stationary front from that point
to 27N70W to 30N80W. Scattered showers and thunderstorms are
observed along the cold front. A 1019 mb surface high is centered
N of the front near 33N73W. A surface trough extend from 28N47W
to 24N50W. Isolated moderate convection is within 90 nm of the
trough. The remainder of the basin is dominated by a 1027 mb high
centered over the Azores near 38N27W.

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

$$
Formosa
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