[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 060604
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
204 AM EDT Mon Aug 6 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.

...SPECIAL FEATURES...

Gale warning in the south-central Caribbean...
A strong ridge over the E CONUS extending E to Atlc adjacent waters
W of 60W will tighten the pressure gradient in the south-central
Caribbean early this week as a tropical wave moves W of
Hispaniola. Gale force winds are forecast for the Gulf of
Venezuela Tue night and along the coast of Colombia Wed night.
Please see the National Hurricane Center Atlantic High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for
further details.

...TROPICAL WAVES...

A tropical wave is in the central Atlc with axis extending from
07N-18N along 32W, moving W at 10 kt. CIRA LPW imagery show
abundant shallow moisture in the wave environment. However, the
wave continues to be affected by Saharan dry air and dust
intrusion, which is limiting convection to isolated showers from
09N-15N between 29W-34W.

A tropical wave is in the central Atlc with axis extending from
05N-18N along 45W, moving W at 15 kt. The wave continues to be
severely affected by intrusion of Saharan dry air and dust as
indicated by GOES-16 RGBs, water vapor and CIRA LPW imagery at
the lower levels. Shallow moisture in the vicinity of the ITCZ
support scattered moderate convection from 06N-11N between 44W-
48W.

A tropical wave is in the E Caribbean with axis S of 20N along
69W, moving W at 10-15 kt. The wave is in a very moist
environment at the lower levels as indicated by CIRA LPW and
GOES-16 water vapor imagery. The wave is underneath a diffluent
environment between an elongated upper level low over the central
basin and S-SW flow to the E, which is supporting scattered
showers and tstms N of 14N between 64W and 71W.

A tropical wave is in the W Caribbean with axis S of 20N along
78W, moving W at 15 kt. CIRA LPW imagery shows shallow moisture
associated with the wave. However, strong deep layer wind shear
and a thin layer of Saharan dust hinder convection at the time.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from 13N17W to 11N28W to 09N35W to
09N41W. The ITCZ begins W of a tropical wave near 08N48W and
continues to 08N55W to 10N59W. For information about convection,
see the tropical waves section.

...DISCUSSION...

GULF OF MEXICO...

The Bermuda high extends a ridge axis SW across the Florida
Peninsula to the SW Gulf of Mexico where a weakness in the ridge
is analyzed as a surface trough from 28N95W to the Bay of Campeche
near 18N94W. Return flow provided by the ridge continue to advect
shallow moisture from the Caribbean and SW N Atlc waters into the
Gulf, which is supporting scattered showers and tstms within 150
nm either side of the trough axis. Another surface trough is in
the far E Gulf from the Florida Big Bend to 24N82W generating
isolated showers and tstms E of 85W. Showers and tstms in the W
Gulf are forecast to continue through Mon night. However, isolated
showers are forecast in the Bay of Campeche through the middle of
the week associated with a surface trough that will come off the
Yucatan Peninsula at night. This trough will also enhance the
winds to fresh off the W Yucatan Peninsula. Otherwise, surface
ridging is forecast to prevail through early in the weekend.

CARIBBEAN SEA...

GOES-16 RGBs continue to show a thin layer of Saharan dust moving
across most of the basin where strong deep layer wind shear
prevails. This environment continue to suppress the development
of significant convection in the region. However, abundant shallow
moisture is across the basin supporting isolated showers and
tstms within 90 nm off the S coast of Cuba. The monsoon trough
supports similar convection within 120 nm off southern Panama. A
tropical wave is in the W Caribbean lacking convection while an
upper level low over the central basin support scattered to
isolated showers in the vicinity of a tropical wave just W of the
Mona Passage. See the tropical waves section for further details.
Otherwise, fresh to near gale force winds in the south-central
Caribbean are forecast to increase to gale force in the Gulf of
Venezuela and off the coast of Colombia Wed and Thu, respectively.
See the special features section for further details.

ATLANTIC OCEAN...

A non-tropical, surface low pressure system centered near 31N50W
is interacting with a broad upper-level low. Although thunderstorm
activity has increased near and to the east of the low-level
center, environmental conditions are expected to be only
marginally conducive for the low to acquire subtropical or
tropical characteristics while it moves little over the next day
or so. By this afternoon, the low is expected to move toward the
north or north-northeast and continue that motion through Tuesday.
SE of this low, a surface trough extends from 30N44W to 25N50W to
26N57W supporting heavy showers and tstms N of 29N between 44W and
46W. Aside from the tropical waves, the remainder of the Atlc is
under the influence of surface high pressure that supports fair
weather.

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

$$
Ramos
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