Tropical Weather Discussion
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AXNT20 KNHC 271001

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
601 AM EDT Tue Jun 27 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
1000 UTC.


A tropical wave extends its axis over Africa from 20N15W to
11N15W, moving west at 10-15 kt. This wave was found using
satellite imagery and model diagnostics. Scattered moderate
convection prevails along the northern portion of the wave mainly
north of 14N between 13W-18W.

A tropical wave extends its axis from 10N30W to 02N30W, moving
westward at 15 kt. The wave is embedded within a moist environment,
however Saharan dry air and dust is intruding some around the
northern segment of the wave. Isolated showers are observed within
150 nm west of the wave`s axis mostly along 06N.

A tropical wave extends over the central Atlantic with axis from
12N52W to 04N54W, moving westward at 10-15 kt. The wave is in an
area of moderate moisture and a diffluent flow aloft. These
features are supporting scattered showers and thunderstorms north
of 08N between 50W-58W.

A tropical wave is over the central-west Caribbean with axis from
19N76W to 11N76W, moving westward at 15-20 kt. The wave is in a
region of limited moisture at low to mid-levels. Isolated showers
are north of 16N between 71W-77W.

A tropical wave is over the Yucatan Peninsula and Central America
with axis from 21N88W to 10N88W, moving westward at about 10-15
kt. The southern portion of the wave is very near to the eastern
Pacific monsoon trough. The wave marks the leading edge of deep
tropical moisture that trails the wave east to near 89W. Isolated
moderate convection are observed across portions of Central
America between 88W-92W.


The monsoon trough extends from the coast of Africa near 21N17W
southwest to near 11N27W. The Intertropical Convergence Zone is
from 06N34W to 09N50W. Isolated showers are within 180 nm on
either side of the ITCZ.



A broad upper-level trough extends from eastern United States
to the extreme northeast portion of the Gulf waters, then becomes
a narrow trough south to near 25N84W. This feature supports a
stationary front that is analyzed from 30N84W to 29N90W. Isolated
showers are noted along the portion of the front near Louisiana
affecting the adjacent waters north of 28N between 89W-96W. This
frontal boundary is forecast to gradually become diffuse through
the afternoon hours, with the remnants possibly lifting back
north. The portion of the front along the Florida coast may sag
some to the south today as a high pressure to its north builds in
from the northwest. To the west, a surface trough extends across
the Bay of Campeche from 22N89W to 18N92W. Isolated showers are
observed along this trough.


The main features in the basin are two tropical waves already
discussed in the section above. Latest scatterometer data depicts
fresh to strong winds in the vicinity of the wave over the central
Caribbean mainly south of 17N. These winds are expected to
increase to near gale across the Gulf of Venezuela by tonight.
Scattered showers and thunderstorms are developing over the
Windward Passage, Jamaica, and eastern Cuba mostly related to the
tropical wave. Another tropical wave currently over the central
tropical Atlantic is expected to enter the eastern Caribbean on
Tuesday night, and reach the central Caribbean late on Wednesday.
This wave will be accompanied by scattered showers and thunderstorms,
some of which may contain gusty winds.


Upper-level moderate to strong southwest to west winds continue
to advect deep level moisture over the island and surrounding
waters as the northern portion of a tropical wave moves across
west away from the area. Expect scattered showers and thunderstorms
to continue through the next 24 hours.


Two tropical waves are moving across the basin. Please refer to
the section above for details. A surface high pressure covers the
basin, with the parent 1025 mb anticyclonic center located just
north of the area at 34N44W. A broad upper-level trough along the
United Stated eastern seaboard supports a stationary front that
extends from a 1015 mb low pressure center near 33N76W southwest
to inland northeast Florida. Isolated showers are observed along
the front. This activity is expected to continue through today as
the surface boundary begins to drift southward, and upper-level
dynamics provide further support to maintain it active.

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