[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 051208
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
808 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 0600 UTC surface analysis and satellite imagery through
1115 UTC.

...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 06N-
17N along 25W, moving W at 15 kt. Both water vapor and CIRA LPW
imagery at the lower levels show abundant moisture in the wave
environment. Upper level diffluent flow is also enhancing
convection. Scattered moderate convection is along the coast of W
Africa from 09N-12N between 13W-19W. Widely scattered moderate
convection is from 07N-12N between 23W-30W.

A tropical wave is in the E Atlc with axis extending from 08N-19N
along 32W, 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.
Isolated moderate convection is from 07N-10N between 30W-33W.

A tropical wave is in the E Caribbean with axis extending from
09N-19N along 65W, 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.
Scattered showers and tstms are from 13N-18N between 58W-68W.

A tropical wave is in the central Caribbean with axis S of 21N
along 75W, moving W at 15-20 kt. CIRA LPW imagery shows shallow
moisture associated with the wave. GOES-16 RGBs shows Saharan
dust moving across the central basin. Scattered showers are within
90 nm of the wave axis. Scattered moderate to isolated strong
convection is inland over N Colombia from 06N-10N between 72W-77W.

A tropical wave is moving across the Bay of Campeche S of 21N
along 93W, moving W at 15 kt. Shallow moisture supports scattered
showers within 90 nm of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from 14N16W to 09N30W to 09N40W. The
ITCZ begins near 09N40W and continues to 06N50W to 06N57W.
Besides the convection mentioned in the tropical wave section,
isolated moderate convection is from 07N-10N between 33W-41W.

...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 shows shallow moisture
across the basin. The western half of the Gulf is under a
diffluent environment enhancing showers and tstms W of 90W. A
tropical wave is moving across the southern Bay of Campeche. See
above. Elsewhere, over the far E gulf, middle-level diffluence
supports heavy showers and tstms from 23N-27N E of 85W. In
addition, a weak surface trough is across the central basin from
27N89W to 22N94W. 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 indicates a thin layer of
Saharan dust is over the basin. This along with strong deep layer
wind shear is suppressing most convection over the Caribbean.
Shallow moisture is associated with the passage of two tropical
waves, however. See above. Scattered to isolated showers are within
90 nm of W Cuba, and within 150 nm of the coasts of Honduras and
Nicaragua. 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.

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. See the National Hurricane Center Atlantic
Tropical Weather Outlook for more information on this system. To
the SE of this low a 1014 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

$$
Formosa
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