Tropical Weather Discussion
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000
AXNT20 KNHC 180604
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
204 AM EDT Sun Jun 18 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
0515 UTC.

...SPECIAL FEATURE...

A tropical wave is along 42W/43W from 11N southward. The wave is
moving westward 10 to 15 knots. A 1008 mb low pressure is along
the tropical wave near 06N. Widely scattered moderate to isolated
strong rainshowers are from 06N to 09N between 42W and 48W.
Isolated moderate rainshowers are elsewhere from 03N to 10N
between 38W and 50W. The chance of formation into a tropical
cyclone during the next two days is medium. Please read the
latest NHC Tropical Weather Outlook under AWIPS/WMO headers
MIATWOAT/ABNT20 KNHC for more details.

A 1007 mb low pressure center is about 60 nm to the east of the
northern half of the coast of Belize, near 17N87W. Numerous strong
rainshowers cover the area that is from 15N in Honduras to 18N
between 83W and 86W. Numerous strong rainshowers also are to the
SW of Jamaica from 14N to 18N between 78W and 81W. Numerous strong
rainshowers are to the south of Cuba from 18N to 22N between 80W
and 82W. This low pressure center is forecast to move slowly
northwestward across the Yucatan Peninsula on Sunday, and into the
southern or central Gulf of Mexico early next week. It is likely
that a subtropical or tropical cyclone may form. Heavy rains are
expected in parts of Central America, the Yucatan Peninsula,
Jamaica, the Cayman Islands, and western Cuba during the next
several days. An Air Force Reserve Hurricane Hunter aircraft is
scheduled to investigate this system on Sunday, if necessary.
The chance of formation into a tropical cyclone during the next
two days is medium. Please read the latest NHC Tropical Weather
Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more
details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 19W/20W from 13N
southward. Isolated moderate to locally strong rainshowers are
from 05N to 12N between 10W and 20W.

An Atlantic Ocean tropical wave is along 31W/32W from 11N
southward, moving westward 10 to 15 knots. Isolated moderate
from 02N to 09N between 30W and 40W.

An Atlantic Ocean tropical wave is along 51W/53W from 18N
southward moving westward 10 knots. Scattered moderate to
isolated strong rainshowers are from 06N to 09N between 51W
and 54W.

A Caribbean Sea tropical wave is along 80W/81W, from 20N
southward. This wave is moving into the area of weather that is
being influenced by the 1007 mb low pressure center that is just
to the east of Belize, from the Special Features section.

...MONSOON TROUGH/ITCZ...

The Monsoon Trough passes through the coastal border sections of
Senegal and Mauritania near 16N16W, to 08N23W, 06N40W, and
06N43W. The ITCZ continues from 06N43W to 07N52W, to the border of
Guyana and Suriname near 06N57W. Convective precipitation:
scattered to numerous strong from 06N to 09N between 23W and 27W.
Isolated moderate to locally strong elsewhere from 10N southward
from 60W eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

A NE-to-SW oriented upper level trough cuts through the Florida
Panhandle, to 19N98W in southern Mexico, just to the west of the
Isthmus of Tehuantepec. A surface ridge passes through 27N/28N in
Florida, into the central Gulf of Mexico, to the coast of Mexico
near 22N98W. Comparatively drier air in subsidence is apparent in
water vapor imagery, within 180 nm on either side of the line that
passes through the Florida Big Bend, into the central Gulf of
Mexico, to the Mexico coast near 21N/22N.

...CURRENT CONDITIONS AND WEATHER, FOR THE OFFSHORE OIL
PLATFORM SITES, FROM 27N NORTHWARD AND FROM 88W WESTWARD...

LIFR: none.

IFR: none.

MVFR: KHHV and KGBK.

CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE
U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

Texas: MVFR in interior sections of the Lower Valley. LOUISIANA:
MVFR in parts of the SW and S central coastal plains.

...THE REST OF THE CARIBBEAN SEA...

Upper level anticyclonic wind flow covers the area from 66W
westward. The rest of the Caribbean Sea is just to the west of the
Atlantic Ocean 26N55W-to-09N61W trough.

The Monsoon Trough is along 08N74W in Colombia, through 09N80W in
Panama, beyond NE Costa Rica, and beyone western Nicaragua. Widely
scattered moderate to isolated strong rainshowers from the
northern half of Costa Rica into NE Nicaragua.

24-hour rainfall totals that are listed for the period that ended
at 18/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.04 in
Guadeloupe, and a trace in Tegucigalpa in Honduras.

...HISPANIOLA...

Upper level NW wind flow is moving across Hispaniola.

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

The GFS MODEL forecast for 250 mb shows that NW wind flow will
move across the area during the first 24 hours of the 48-hour
forecast. N wind flow will continue for the next 24 hours. A
N-to-S oriented ridge develops directly on top of Hispaniola at
the end of the forecast period, for the start of day three.
The GFS MODEL forecast for 500 mb shows that anticyclonic wind
flow, with a N-to-S oriented ridge, will move across Hispaniola
during much of the first 24 hours of the forecast. The ridge will
be followed by an inverted trough at the end of day one. The
inverted trough remains across Hispaniola during the first two-
thirds of day two. The ridge slides westward during the rest of
the time of the day two forecast period. The GFS MODEL forecast
for 700 mb shows that SE wind flow will move across the area
during the next 48 hours, with Hispaniola being on the southern
side of an E-to-W oriented Atlantic Ocean ridge.

...THE ATLANTIC OCEAN...

An upper level central Atlantic Ocean trough is anchored by a
cyclonic circulation center that is about 760 nm to the NE of
Puerto Rico, and that ends near NE coastal Venezuela near 09N61W.
A cold front/stationary front is along 32N/33N between 40W and
55W. Broken to overcast multilayered clouds and possible
rainshowers cover the area from 30N northward between 34W and 70W.
A 1020 mb low pressure center is near 30N62W. Isolated moderate
rainshowers cover the Atlantic Ocean from 10N northward between
45W and 70W.

A NE-to-SW oriented upper level trough, from 20N northeastward,
is within 300 nm to 600 nm to the west of Africa. No significant
deep convective precipitation is apparent in satellite imagery.

Surface anticyclonic wind flow covers the Atlantic Ocean from 20N
northward from 58W eastward. A 1025 mb high pressure center is
near 30N42W.

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

$$
MT



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