[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 030602
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
202 AM EDT Mon Jul 3 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 0000 UTC surface analysis and satellite imagery through
0500 UTC.

...TROPICAL WAVES...

A tropical wave is in the Eastern Atlantic with axis near 20W
extending from 07N to 15N, moving west at 5 to 10 kt within the
last 24 hours. No significant deep convection is occurring near
the wave, though there are scattered showers within 120 nm of the
wave axis. The wave is embedded in a moist monsoonal flow, as seen
in the Total Precipitable Water imagery, and extends across the
monsoon trough. Little to no surface signature of the wave is
apparent from satellite imagery and limited surface observations,
though the SUNY-Albany Trough Diagnostics well depict the wave at
700 mb.

A tropical wave is in the central Atlantic with axis near 32W
extending from 05N to 16N, moving west at about 5 kt within the
last 24 hours. A broad 1011 mb surface low is embedded on the wave
axis near 10N, as suggested by low-level cloud motions. The wave
also is quite apparent at 700 mb in the Trough Diagnostics. Quite
dry conditions are occurring north of about 12N in the vicinity
of the wave, as seen in the Saharan Air Layer imagery from
Meteosat 9. Scattered moderate and isolated strong convection is
occurring from 05N and 10N between 26W and 32W, while scattered
showers are seen within 120 nm of the wave axis south of 12N.

A tropical wave is in the Eastern Caribbean with axis near 68W
extending 08N to 18N. The wave is not apparent in either the
surface observations, nor in the Trough Diagnostics. However, it
remains detectable in the Total Precipitable Water imagery as a
maximum east of the wave axis. No significant convection or shower
activity are currently noted with this wave.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough axis extends from the west coast of Africa
near 13N17W to 08N40W. The Intertropical Convergence Zone extends
from 08N40W to 08N59W along northeastern South America. Convection
observed near the Monsoon Trough and ITCZ is mainly related to
tropical waves. Refer to the section above for details. Otherwise,
scattered moderate convection is observed from 05N to 10N between
18W and the West African coast.

...DISCUSSION...

GULF OF MEXICO...

A 1020 mb surface high is over the northeastern Gulf near 28N86W.
A weak surface trough exists in the southwestern Gulf from 24N94W
to 18N95W. Scattered moderate convection is observed within 120 nm
of the trough axis south of 20N. Isolated moderate convection is
occurring in the eastern Gulf within 120 nm of the southwest
Florida coast. Winds throughout the Gulf are fairly tranquil,
generally 5 to 15 kt. The piece of Saharan Air Layer that had
moved across the Gulf during the last couple of days and reached
Texas, Louisiana, and Mississippi appears to still be in place.
This should gradually moisten up, though the overall synoptic
pattern should not change during the next two days.

CARIBBEAN SEA...

The moderate pressure gradient across the Caribbean between the
Bermuda high to the north and the Colombia low to the south is
generally producing 10 to 20 kt tradewind easterlies. The
exception is the 25 kt east to northeasterlies just north of
Colombia. Scattered moderate and isolated strong convection is
located in the southwesternmost Caribbean, south of 11N,
associated with the eastern extension of the Northeast Pacific's
monsoon trough. An upper low is centered over central Cuba, as
seen in both the water vapor imagery as well as the rawindsondes
from Key West, Nassau, Grand Cayman, and Kingston. It is helping
to promote isolated moderate convection over the northwestern
Caribbean including Cuba and the central and southeastern Bahamas.
As the tropical wave along 68W this evening is relatively weak,
this will have little impact on the winds/convection. The upper
low should drift slowly westward during the next couple of days,
enhancing scattered moderate convection from Cuba to the Yucatan
of Mexico.

...HISPANIOLA...

During late afternoon and early evening, scattered moderate
convection occurred over central Haiti and Dominican Republic.
This has since dissipated. With some increased moisture from a
weak tropical wave over the eastern Caribbean, more moderate
convection and showers may occur during the next couple of days.

ATLANTIC OCEAN...

Two tropical waves are analyzed over the basin. Refer to the
Tropical Waves section above for details. The only other area with
significant convection is the scattered moderate convection
occurring over the central Bahamas in association with a vigorous
upper-level low over Cuba. This will likely diminish during the
next day as the upper-level low pushes slowly westward. A large
surface trough over the central Atlantic is analyzed from near
29N48W to 12N54W moving steadily westward at 10 to 15 kt. It is
possible that this trough is associated with an undiagnosed
tropical wave. The trough has scattered showers occurring within
180 nm of the axis south of 20N. The remainder of the basin
remains under the influence of a broad Bermuda/Azores high along
35N. This synoptic pattern will change little through Tuesday.

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

$$
Landsea
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