NHC Atlantic Tropical Weather Discussion

By | May 21, 2019

AXNT20 KNHC 211804

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
204 PM EDT Tue May 21 2019

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
1745 UTC.


…Subtropical Depression Andrea…

As of 1500 UTC, Subtropical Depression Andrea is centered near
30.8N69.2W, or about 243 nm WSW of Bermuda, moving N at 7 kt.
Estimated minimum central pressure is 1009 mb. Maximum sustained
winds are 30 kt with higher gust. Scattered moderate convection
extends outward to 350 nm in the SE quadrant. Satellite imagery
indicates Andrea is very poorly organized and is interacting with
an upper low that is very near the cyclone. Andrea is forecast to
turn towards the northeast and east tonight, then continued to
weaken and degenerate into a remnant low by this evening. See the
latest NHC forecast/advisory under AWIPS/WMO headers
MIATCPAT1/WTNT31 KNHC for more details.


A tropical wave is along 21W from 10N southward, moving W around
10-15 kt. Scattered showers and isolated thunderstorms are within
100 nm on either side of the wave axis mainly from 02N-07N.


The monsoon trough emerges off the coast of Sierra Leone near
08N13W and extends to 06N19W. The ITCZ begins west of a tropical
wave near 04N23W and extends to 03N39W to 02N50W. Scattered
moderate convection is near and within 100 nm north of the ITCZ
between 25W-37W and near the coast of Brazil between 46W-52W.


A 1017 mb high centered in the western Atlantic extends westward
into the eastern portion of basin, where gentle winds prevail.
Tighter pressure gradient between the 1017 mb high and the 998 mb
low centered in northern Mexico are keeping fresh to strong south
to southeast flow across the western Gulf. Gale force winds have
diminished but coastal advisories continue for most of the Texas
and Louisiana coastline. Refer to the local National Weather
Service office for further details. Smoke from fires across Mexico
continues to be noted in satellite data and observations over the
western Gulf. Although the smoke is not as dense as previous days,
it is still noticeable with hazy conditions mainly west of 93W and
south of 27N.

Deepening low pres across the Central Plains continues to drive
strong SE to S winds and high seas across the NW Gulf today, but
will gradually diminish this afternoon through tonight. Otherwise,
high pres across the W Atlc will maintain fresh to strong return
flow across the W half of the Gulf through Sat. Smoke from fires
across southern Mexico will maintain hazy skies and reduce
visibilities over the western Gulf and the Bay of Campeche the
next several days.


Upper level diffluence is maintaining broad area of cloudiness
with scattered moderate convection across the southwest Caribbean
south of 15N between 75W-83W. Isolated showers are also noted to
the north over the Windward Passage and Hispaniola. Moderate
trades cover much of the basin with moderate to fresh winds in
the south-central Caribbean. Strong winds are seen in recent ASCAT
data near the coasts of NW Venezuela.

High pres across the W Atlc will maintain fresh to occasionally
strong trades across most of the central Caribbean and the Gulf of
Honduras through Thu night, before weakening modestly into the
weekend. A tropical wave will reach the Tropical Atlc waters early


Refer to section above for details on Subtopical Depression Andrea.

Surface ridging is producing mostly fair weather in between
Andrea and Florida. Isolated showers and thunderstorms are
located between N coast of Hispaniola and Puerto Rico and the
convection associated with Andrea. Surface ridging prevails
across the remainder of the basin, anchored by a 1022 mb high
near 32N51W and a 1024 mb high near 32N21W. A cold front is
analyzed between these two highs from 31N36W to 25N45W. Isolated
showers are possible along the front. North to northeast near gale
conditions are forecast to persist off the coast of Morocco in
the marine zone of Agadir through Wednesday.

Subtropical Depression Andrea near 30.8N69.2W 1009 mb at 1500 UTC
moving N at 7 kt. Maximum sustained winds 30 kt gusts 40 kt.
Andrea will move E-NE today, then is expected to weaken tonight
through Wed as it begins to interact with a cold front sinking S
into the region. The cold front will sink S across the northern
waters Wed and Wed night and stall E to W along 24N-25N Fri.
Elsewhere moderate winds will generally prevail across the region
through Sat.

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


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