[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 061114
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
713 AM EDT Thu Jul 6 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 0600 UTC surface analysis and satellite imagery through
1100 UTC.

...SPECIAL FEATURES...

Tropical Depression Four is centered near 13.2N 40.0W at 06/0900
UTC or about 1250 nm east of the Lesser Antilles moving WNW at 15
kt. Estimated minimum central pressure is 1008 mb. Maximum
sustained wind speed is 25 kt with gusts to 35 kt. Scattered
moderate and isolated strong convection is located within 120 nm
of the center of the depression, primarily in the western
semicircle. Please see the latest NHC Public Advisory under
AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full
Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/WTNT24
KNHC for more details.

...TROPICAL WAVES...

A new tropical wave was introduced on the 06 UTC map, just exiting
the west African coast. This was evident from the SUNY-Albany
Trough Diagnostics at 700 mb as well as conventional satellite
imagery. No significant deep convection is currently associated
with the wave.

A tropical wave over the central Atlantic has an axis near 58W
extending from 07N to 20N, moving west at about 15 kt during the
last 24 hours. The wave is easily identifiable both at 700 mb
through the Trough Diagnostics and the Lesser Antilles
rawindsondes and observations at the surface. However, the wave
is in a region of abundant Saharan dry air and dust that is
currently hindering convection. Isolated moderate convection and
scattered showers are present within 120 nm of the wave axis south
of 13N.

A tropical wave located over the central Caribbean has an axis
near 78W extending from 10N to 22N, moving west at around 15 kt
during the past 24 hours. The wave is easily identifiable both at
700 mb from the Kingston and San Andres rawindsondes and at the
surface. Abundant moisture is associated with this wave as seen in
the Total Precipitable Water imagery. However, no deep convection
is currently associated with this wave.

A tropical wave is moving across the Yucatan Peninsula with axis
near 94W extending from 12N to 22N, moving westward at about 15
kt. The wave is easily identifiable both at 700 mb from the Mexico
and Belize rawindsondes and at the surface. Scattered moderate
and isolated strong convection is occurring over portions of the
Yucatan and southeastern Mexico, due to the interaction of the
wave with a tropical upper tropospheric trough over the Gulf of
Mexico.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends from 14N17W to 13N37W. The
Intertropical Convergence Zone extends from 12N41W to 10N53W.
Aside from the convection related to Tropical Depression Four,
widely scattered showers are observed in the vicinity of the ITCZ
mainly south of 08N between 40W-50W.

...DISCUSSION...

GULF OF MEXICO...

A weak surface ridge extends across the northern Gulf of Mexico.
A tropical wave extends across eastern Mexico into the
southwestern Gulf of Mexico enhancing showers and convection in
this area. Refer to the Special Features section above for
details. A light to moderate anticyclonic breeze prevails across
the Gulf. Little change in this pattern is expected during the
next couple of days.

CARIBBEAN SEA...

A tropical wave is moving across the Caribbean. Refer to the
section above for details. The moderate pressure gradient over the
Caribbean between the Bermuda high to the north and the Colombian
low to the south is maintaining moderate to fresh tradewinds over
the basin, except over the waters north of Colombia and Venezuela
where strong breeze easterlies are pulsing every night lasting
through the early morning hours. The ASCAT scatterometer data at
0246 UTC showed a widespread area of 25 kt winds. Little change is
expected through Friday morning, but with diminishing winds
Friday night.

...HISPANIOLA...

A tropical wave is located to the west of Hispaniola enhancing
scattered showers over portions of the island this evening.
Additional moderate convection over the island is possible later
today especially with the diurnal heating in the afternoon,
before some drying occurs on Friday as the wave continues moving
west.

ATLANTIC OCEAN...

Tropical Depression Four and two tropical waves were analyzed
over the tropical North Atlantic. Refer to the Special Features
and Tropical Waves sections above for details. Aside from the
convection associated with Tropical Depression Four and the ITCZ
previously mentioned, no other significant convection is
occurring. A broad 1029 mb surface high is centered north of our
area near 36N35W. This high continues to dominate the weather
across the area. To the south of the high and away from Tropical
Depression Four described above, moderate to fresh trade winds
prevail across the basin. This synoptic pattern will change little
through the next couple of days.

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

$$
Landsea
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