000
AXNT20 KNHC 281033
TWDAT
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
633 AM EDT Wed Jun 28 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
1030 UTC.
...TROPICAL WAVES...
A tropical wave has its axis just off the coast of Africa along
19W from 12N to 20N, moving westward at around 10 kt. Low-level
moisture is limited within this wave, therefore, no convection is
associated with this feature at this time.
A tropical wave has its axis from 11N36W to 02N37W, moving
westward at 10-15 kt. Satellite imagery and TPW data reveals that
the wave remains embedded within a very moist environment, except
for over its eastern region where Saharan dry air and dust is
present. Isolated moderate convection is noted north of 06N
between 34W-40W.
A broad tropical wave has its axis tilted from 15N56W to 05N61W,
moving westward 15-20 kt. This wave continues to be easily
identifiable on satellite imagery as having the typical
configuration of waves observed later during the season. It is
detected in the model fields, and is further supported by the
latest diagnostic model analysis. Scattered moderate convection is
observed from 11N-16N between 54W-65W. The wave is forecast to
continue moving west affecting the eastern and central Caribbean
waters through Thursday.
A tropical wave is moving across the western Caribbean with its
axis along 82W from 08N to 21N, moving westward at 10-15 kt. This
wave is also evident in satellite imagery, and continues to mark
the leading surge of very deep atmospheric moisture, as seen in
TPW data. Isolated moderate convection is observed in the vicinity
of this wave between 80W-84W. The wave will move across the
remainder of the western Caribbean Sea through today, and inland
Central America by tonight.
...MONSOON TROUGH/ITCZ...
The Monsoon Trough extends from the coast of Africa near 20N16W,
and continues southwest to 10N30W. The Intertropical Convergence
Zone then extends from 06N39W to 09N56W. Isolated moderate
convection is within 100 nm on either side of the ITCZ axis.
...DISCUSSION...
GULF OF MEXICO...
A mid to upper-level trough axis is over the far northwest Gulf,
while a surface trough is along the Texas coast. The combination
of these features along with the presence of diffluent flow aloft
east of the mid-upper level trough continues to support isolated
showers and thunderstorms mainly north of 24N and west of 90W. A
stationary front is analyzed from northeast Florida to near Cross
City, Florida and to 29N86W where it becomes diffuse from there
to 29N88W. The shower and thunderstorm activity over the western
Gulf is forecast to remain active through today, then shift
northeast by tonight and Thursday as the mid/upper level trough
slides eastward. The stationary frontal boundary is forecast to
gradually become diffuse through the morning hours, with the
remnants lifting back to the north through tonight.
CARIBBEAN SEA...
The main feature presently in the basin is a tropical wave
currently over the western Caribbean, and the near-future arrival
of another tropical wave which is approaching the Lesser Antilles
at this time. These features are discussed in the section above.
Aside from the convection related to the tropical waves, fair
weather prevails elsewhere. Scatterometer data depicts moderate to
fresh trades across the basin. The pressure gradient is forecast
to tighten over portions of the far south-central Caribbean
beginning tonight and continuing through Thursday night inducing
strong to near-gale force east winds over this area, with the
near-gale force winds expected across and near the Gulf of
Venezuela.
...HISPANIOLA...
Fair weather prevails across the island at this time. Little
change is expected in the present weather pattern through the next
24 hours. Convection is expected once again by the end of the week
as a tropical wave approaches.
ATLANTIC OCEAN...
Three tropical waves are moving across the tropical Atlantic.
Refer to the section above for details. A broad mid to upper-level
trough extends southwestward from along the eastern seaboard to
the far northwest portion of the basin. It supports a stationary
front that extends through 33N74W to 30N81W. Scattered showers
and thunderstorms are noted north of the Bahamas and west of about
75W. This activity will continue through much of today and
tonight as the surface boundary weakens, and the mid to upper
trough slides eastward while it broadens out further. A surface
trough extends from 32N56W to 24N57W with isolated showers. This
trough is a reflection of an upper-level low centered in the same
area. A broad high pressure prevails across the remainder of the
basin, anchored by a 1028 mb surface high centered near 36N40W.
For additional information please visit
http://www.hurricanes.gov/marine
$$
ERA
