Tropical Weather Discussion
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000
AXNT20 KNHC 221804
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
204 PM EDT Sat Apr 22 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
1715 UTC.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through the coastal sections of Guinea-
Bissau near 12N16W to 06N18W and 04N20W. The ITCZ is along 04N20W
02N26W 02N30W, crossing the Equator along 31W, to 02S34W. Convective
precipitation: scattered strong from 04N southward between 01W and
04W, and from 02N southward between 21W and 23W. Widely scattered
to scattered moderate and isolated strong from 04N to 05N within
30 nm on either side of 15W, from 02N southward between 28W and
29W, from 02N southward between 32W and 35W, and from 01N to 03N
between 48W and 52W. isolated moderate elsewhere from 07N
southward between Africa and 60W.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level trough extends from an east central Gulf of Mexico
cyclonic circulation center, that is near 24N86W, into the SW
corner of the Gulf of Mexico beyond 19N96W at the coast of Mexico.
A second upper level trough is moving through Alabama,
Mississippi, and Louisiana, into the north central Gulf of Mexico,
and 25N91W, before blending with the cyclonic wind flow that
corresponds to the 24N86W cyclonic circulation center and its
trough. A surface trough is along 24N86W, through the NE corner of
the Yucatan Peninsula, into southern Belize. Convective
precipitation: isolated moderate from 21N to 27N from 90W
eastward.

A surface ridge passes through SE Louisiana, into the north
central Gulf of Mexico, into the SW corner of the Gulf of Mexico.

...LOW LEVEL CLOUD CEILINGS AND WEATHER FOR THE OFFSHORE OIL
PLATFORM SITES THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N
NORTHWARD AND FROM 88W WESTWARD...

LIFR: none.

IFR: none.

MVFR: KHQI and KVOA.

LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF
THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

TEXAS: MVFR in Laredo, Victoria, and Galveston. light rain is
at the Houston Intercontinental Airport. IFR in Tomball. MVFR in
Conroe and Huntsville. Heavy rain and MVFR in Jasper. LOUISIANA:
MVFR in parts of the Lake Charles metropolitan area, and in Port
Fourchon. MISSISSIPPI: MVFR in Natchez. ALABAMA: MVFR in Gulf
Shores. FLORIDA: MVFR in Pensacola metropolitan area. light rain
Milton. smoke in parts of Ft. Myers and Naples. MVFR in Marathon
Key. light rain at the Key West NAS. moderate rain at the Key West
International Airport.

...THE CARIBBEAN SEA...

Broad middle level-to-upper level westerly wind flow spans the
Caribbean Sea. An upper level ridge extends from Colombia to the
Eastern Pacific Ocean near 08N90W.

An east-to-west surface trough extends from SW Haiti to 18N80W,
just to the west of Jamaica.

Convective precipitation: widely scattered moderate to isolated
strong from 15N to 18N between 73W and 76W. Broken to overcast
multilayered clouds and other possible rainshowers cover the
Caribbean Sea, the islands, and parts of the Atlantic Ocean from
15N to 27N between 66W and 80W.

24-hour rainfall totals that are listed for the period that ended
at 22/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...1.67 in Kingston in
Jamaica, 0.37 in Montego Bay in Jamaica, 0.12 in Guadeloupe, 0.01
in Nassau in the Bahamas, and a trace in Freeport in the Bahamas.

...HISPANIOLA...

Middle level-to-upper level westerly wind flow, slightly
anticyclonic, is moving across the island. Hispaniola is on the
eastern side of a ridge that extends from Colombia to the Eastern
Pacific Ocean near 08N90W. An east-to-west surface trough extends
from SW Haiti to 18N80W, just to the west of Jamaica. Convective
precipitation: rain inland and in the coastal waters.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR. the
earlier light rain has ended for the moment. for the DOMINICAN
REPUBLIC: Barahona: light rain. MVFR. ceiling 1600 feet. few
cumulonimbus clouds. Santo Domingo: nearby rainshowers. MVFR.
ceiling 1600 feet. few cumulonimbus clouds. La Romana: VFR. Punta
Cana: VFR. Santiago: MVFR. ceiling 2000 feet. earlier nearby
rainshowers have ended for the moment. Puerto Plata: light rain.
MVFR. ceiling 1800 feet.

The GFS MODEL forecast for 250 mb shows that westerly wind flow
will prevail, until the last 6 hours to 12 hours, with SW wind
flow during that time period. The GFS MODEL forecast for 500 mb
shows that SW wind flow, with a trough, will move across
Hispaniola during the next 48-hour forecast period. The GFS MODEL
forecast for 700 mb shows that broad anticyclonic wind flow, with
a ridge, will span the area.

...THE REST OF THE ATLANTIC OCEAN...

A large-scale cyclonic circulation center is near 38N44W,
associated with the remnant of ARLENE. Upper level cyclonic
wind flow covers the area from 20N northward between 30W and 63W.
A dissipating stationary front curves through 32N36W to 26N40W
and 21N46W. A cold front passes through 32N42W to 29N46W and
28N50W. Convective precipitation: isolated moderate to locally
strong from 26N to 29N between 22W and 26W, and from 28N
northward between 25W and 43W. Rainshowers are possible elsewhere
in areas of scattered-to-broken low level clouds, that are from
20N northward between 30W and 70W.

A surface ridge extends from a 1021 mb high pressure center that
is near 32N18W , to 26N24W, and 19N32W.

A 1020 mb high pressure center is near 28N65W. A surface ridge
extends from the high center beyond 30N80W.

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

$$
MT



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