[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 050559
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
159 AM EDT Sun Aug 5 2018

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 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 06N-
17N along 23W, moving W at 10 kt. Both water vapor and CIRA LPW
imagery at the lower levels show abundant moisture in the wave
environment that along upper level diffluent flow support
scattered moderate convection from 09N-15N between 21W-26W.

A tropical wave is in the E Atlc with axis extending from 08N-19N
along 30W, moving W at 10-15 kt. The wave continues to be
affected by intrusion of Saharan dry air and dust as indicated by
GOES-16 RGB and water vapor imagery as well as CIRA LPW imagery.
No convection is associated with this wave at this time.

A tropical wave is in the E Caribbean with axis extending from
09N-19N along 63W, moving W at 10-15 kt. The wave is in a very
moist environment at the lower levels as indicated by CIRA LPW
and water vapor imagery. The wave is being supported by an
inverted trough in the middle levels and is underneath an upper
level low that supports scattered showers and tstms from 12N-18N
between 58W and 65W.

A tropical wave is in the central Caribbean with axis S of 21N
along 74W, moving W at 15-20 kt. CIRA LPW imagery show abundant
shallow moisture associated with the wave. However, GOES-16 low
level moisture imagery show very dry air in the central Caribbean.
GOES-16 RGBs also show Saharan dust moving across the central
basin. These last two factors and strong deep layer wind shear
hinder the development of convection at the time.

A tropical wave is moving across the Yucatan Peninsula and
Guatemala. Its axis is S of 21N along 90W, moving W at 10-15 kt.
Shallow moisture support scattered showers and tstms ahead of the
wave in the eastern Bay of Campeche.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from 16N16W to 11N24W to 09N38W. The
ITCZ begins near 09N38W and continues along 08N48W to 10N58W.
Numerous moderate convection is moving off the coast of Africa
from 09N-13N E of 18W. Scattered moderate convection is from
07N-10N between 34W-39W. Please refer to the TROPICAL WAVES
section for more information about precipitation.

...DISCUSSION...

GULF OF MEXICO...

The Bermuda high extends a ridge axis SW across the Florida
Peninsula to the NW Gulf of Mexico providing light to locally
moderate SE to E winds. CIRA LPW imagery show abundant shallow
moisture across the basin while the low level water vapor imagery
show dry conditions across most of the eastern half of the Gulf.
The western half of the Gulf is under a diffluent environment
which along the moisture support isolated showers and tstms W of
90W while a tropical wave moving across the Yucatan Peninsula
support scattered showers and tstms in the E Bay of Campeche. Over
the far E gulf, middle-level diffluence support heavy showers and
tstms from 25N-28N E of 85W. Otherwise, a weak surface trough is
across the central basin along 27N88W to 21N94W. Showers in the
western Gulf will continue through Monday morning. Otherwise,
surface ridging will prevail through early next week.

CARIBBEAN SEA...

Mostly low level dry air is across the basin as shown by GOES-16
water vapor imagery. GOES-16 RGBs also indicate that a thin layer
of Saharan dust moves across the basin. This along with strong
deep layer wind shear keep the Caribbean mostly convection free.
Shallow moisture associated with the passage of a tropical wave
that currently moves across the Yucatan Peninsula support
scattered to isolated showers within 90 nm off the coast of Cuba
and within 150 nm of the coast of Honduras and Nicaragua. A second
tropical waves moves over the E Caribbean waters supporting
scattered showers and tstms from 13N-17N E of 71W. Otherwise,
strong high pressure N of the area supports fresh to near gale
force winds along the coast of Colombia and Gulf of Venezuela. No
major changes expected through Monday. See the tropical waves
section for further details on the waves and the Atlantic high
seas forecast for possible developing gale in the south-central
Caribbean early in the week.

ATLANTIC OCEAN...

A well-defined, non-tropical low pressure system centered about
1000 miles west-southwest of the Azores continues to produce limited
shower activity. However, environmental conditions are expected
to become marginally conducive for the low to acquire subtropical
or tropical characteristics while it moves southwestward over the
next day or two, and then lifts back to the northeast while
remaining over warm water through Tuesday. See the National
Hurricane Center Atlantic Tropical Weather Outlook for more
information on this system. To the SE of this low a 1013 mb low is
centered near 32N44W generating heavy showers and tstms from
29N-35N between 39W-49W. A cold front extends from this low along
30N47W to 26N57W to 30N69W generating scattered showers and tstms
within 150 nm ahead of the front N of 25N. Aside from the tropical
waves, the remainder W and E Atlc are under the influence of a
surface ridge that supports fair weather. The front is forecast to
dissipate Sunday night, leaving a remnant surface trough over the
SW N Atlc waters Monday.

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

$$
Ramos
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