Tropical Weather Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
230
AXNT20 KNHC 291719
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
119 PM EDT Mon May 29 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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...TROPICAL WAVES...

A tropical wave is located over the eastern Atlc off the coast of
W Africa. The axis of the wave extends from 16N20W to 05N22W. The
wave is moving W at 20 kt. TPW satellite imagery shows the wave
is embedded in moderately moist environment near the ITCZ. This
wave possesses a good signature in the 700 mb wind flow field.
There is no significant convection currently associated with this
wave.

A tropical wave located over the eastern Atlc has an axis
extending from 11N34W to 02N36W. The wave is moving W at 10 to 15
kt. TPW satellite imagery shows the wave is embedded in a
moderately moist environment near the ITCZ. The wave lies just to
the SE of large area of dry air associated with the Saharan Air
Layer to the N of 10N. This wave possesses a weak signature in the
700 mb wind flow field. Scattered moderate convection is seen
from 08N to 10N between 29W and 32W.

A tropical wave over the western Atlc and Suriname has an axis
extending from 12N56W to 03N55W. The wave is moving W at 15 to 20
kt. TPW satellite imagery shows the wave is embedded a moderately
moist environment. Dry air associated with the Saharan Air Layer N
of 10N is impinging on the wave from the NE. This wave possesses
a weak signature in the 700 mb wind flow field. Scattered moderate
and isolated strong convection is seen from 06N to 10N between
54W and 59W.

A tropical wave over the eastern Caribbean and Venezuela has an
axis extending from 15N66W to 02N67W. The wave is moving W at 15
to 20 kt. TPW satellite imagery shows the wave is embedded in a
moderately moist environment. This wave possesses a good signature
in the 700 mb wind flow field. Scattered moderate and isolated
strong convection is sheared NE of the wave from 19N to 22N
between 61W and 66W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough extends SW into the tropical Atlc from the
coast of Senegal in West Africa near 12N16W to 09N18W. The ITCZ
continues near 07N24W to 06N33W...then resumes W of a tropical
wave near 05N37W and continues to the coast of South America near
02N49W. Scattered moderate and isolated moderate convection is
found within 90 nm either side of a line from 03N40W to 07N54W.

...DISCUSSION...

GULF OF MEXICO...

A frontal boundary stalling along the Rio Grande and SE Texas has
served as the primary focus for the development of showers and
thunderstorms this morning. A squall line moved SE into the NW
Gulf from Deep South Texas earlier this morning, but it has begun
to weaken. Satellite imagery and lightning detection data show
more showers and thunderstorms are pushing eastward S of Louisiana
in the vicinity of 26N. Elsewhere, a 1018 mb high is centered
over the NE Gulf near 27N85W. 5-10 kt anticyclonic winds revolve
around the high over the NE Gulf. N of 23N and W of 90W 10-20 kt
SE surface winds are over the W Gulf. Scattered showers and
isolated thunderstorms occurring over the Bay of Campeche and S
Mexico S of 23N. In the upper levels, a ridge is over the eastern
Gulf adjacent to Florida. A sharp mid to upper-level trough is
pushing eastward toward the NW Gulf from Northern Mexico. Abundant
deep layer moisture is pooling to the east of the upper-level
trough over most of the Gulf, except over S Florida and the SE
Gulf where subsidence associated with the ridge is noted. Expect
convection to persist over the NW Gulf as the stalled frontal
boundary remains inland just to the NW. Also expect showers to
persist over the Bay of Campeche during the next 24 hours as
upper-level divergence associated with the upper-level trough
serves as a catalyst for deep convection.

CARIBBEAN SEA...

A tropical wave is passing over the E Caribbean. See the tropical
waves section for more details. The monsoon trough extends over
Costa Rica, Panama and Northern Colombia. Scattered moderate and
isolated strong convection associated with the trough is taking
place over the SW Caribbean S of 11N. A broad upper-level ridge
extends N over the Caribbean from Central and South America. An
upper level trough passes just N of the Caribbean from the Bahamas
to just n of Puerto Rico. Subsident flow between the ridge and
trough will generally inhibit convection, except for in the
vicinity of the tropical wave, which will produce some showers and
thunderstorms over the the next 24 hours as it moves from the
Eastern Caribbean into the Central Caribbean. Also expect
continuing convection over the SW Caribbean, and Central America.

HISPANIOLA...

Water vapor imagery shows strong subsidence over the Island,
hindering convection. However, patches of low level moisture,
embedded in the trade wind flow, will maintain isolated showers
today. The approaching tropical wave will bring increasing shower
coverage to Hispaniola by Tuesday.

ATLANTIC OCEAN...

A large 1027 mb high is centered over the central Atlc near
33N29W. Light showers are over the Canary Islands. Three tropical
waves are over the tropical Atlantic. Please refer to the Tropical
Waves section for more details. Saharan dry air and dust is noted
across much of the Atlantic Ocean N of 10N and E of 50W. Of note
in the upper levels, an elongated upper-level trough that curves
from N of Puerto Rico toward the Central Atlc is producing upper-
level divergence over Puerto Rico and the Virgin Islands. The
trough is influence a tropical wave that is currently passing S of
Puerto Rico. Expect during the next 24 hours for more showers to
form in this favorable environment over the Atlc in the vicinity
of the Leeward and Windward Islands.

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

$$
McElroy



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.