Tropical Weather Discussion
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000
AXNT20 KNHC 171801
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
201 PM EDT Mon Jul 17 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.

...SPECIAL FEATURES...

A 1010 mb low pressure center is near 11N51W. Convective
precipitation: Scattered moderate to isolated strong from 10N to
12N between 51W and 53W. Environmental conditions are conducive for
some development before the system reaches the Lesser Antilles late
Tuesday or early Wednesday. Less favorable upper-level winds are
expected to hinder additional development after that time. It is
expected that this system may bring locally heavy rainfall and
gusty winds to parts of the Lesser Antilles beginning on Tuesday.
An Air Force Reserve reconnaissance aircraft is en route in order
to investigate the situation. The chance for formation into a
tropical cyclone during the next 48 hours is medium. Please refer
to the latest Tropical Weather Outlook...MIATWOAT/ABNT20 KNHC...
for more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 33W/34W from 20N
southward. Convective precipitation: widely scattered moderate to
isolated strong from 10N to 14N between 30W and 36W.

An Atlantic Ocean tropical wave is along 55W/56W from 19N
southward. Convective precipitation: isolated moderate from 12N to
24N between 54W and 60W.

A Caribbean Sea tropical wave is along 82W/83W from 23N in NW
Cuba, southward. Convective precipitation: widely scattered to
scattered moderate and isolated strong from 17N southward between
80W and 86W, including interior sections and coastal waters of
Nicaragua and Honduras.

A SW Gulf of Mexico tropical wave is along 95W/96W from 22N
southward. The wave is moving through southern Mexico, just to the
west of the Isthmus of Tehuantepec of southern Mexico. Convective
precipitation: Weakening precipitation and convective debris
clouds are present from 24N southward between 90W and 96W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through coastal sections of Senegal near
14N17W to 14N24W, 09N37W, and 10N51W. Convective precipitation:
scattered to numerous strong is in the coastal plains and coastal
waters of Africa from 10N to 14N between 14W and 17W. Isolated
moderate to locally strong from 08N to 10N between 12W and 14W in
the coastal plains. Widely scattered moderate to isolated strong
from 04N to 11N between 35W and 45W. Scattered moderate to strong
from the Equator to 02S between 35W and 40W.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level cyclonic circulation center is moving inland along
the coast of Mexico near 21N97W. Cyclonic wind flow covers Mexico
and the Gulf of Mexico from 17N to 25N between 89W and 106W. A
weakening cyclonic circulation center is near 23N86W. Weakening
precipitation and convective debris clouds are present from 24N
southward between 90W and 96W.

The surface pressure pattern is weak, with little gradient.

Convective precipitation: rainshowers and thunder are in the
coastal waters, and reaching land in some cases, from 27N
northward between 83W for Florida and 95W for the upper Texas Gulf
coast. rainshowers and thunder also are present in along the SW
coast of Florida from 25N to 27N between 81W and 83W, and in the
coastal plains of Texas from 27N to 28N between the coast and 98W.

...THE CARIBBEAN SEA...

Broad upper level anticyclonic wind flow covers the area that is
from 18N southward, from the Yucatan Peninsula of Mexico and
Guatemala eastward to 70W, and southeastward. Broad and weak
cyclonic wind flow, and comparatively drier air in subsidence that
is evident in water vapor imagery, cover the Caribbean Sea from
70W eastward. Weak upper level cyclonic wind flow also covers the
rest of the area, in the NW corner of the Caribbean Sea.

The monsoon trough is along 09N/10N between 74W/75W in Colombia,
beyond NW Costa Rica, into the eastern Pacific Ocean. Convective
precipitation: isolated moderate from 12N southward between 75W
and 80W.

24-hour rainfall totals in inches, for the period that ended at
17/1200 UTC, according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 1.45 in
Merida in Mexico, 0.17 in Guadeloupe, 0.10 in Bermuda, 0.07 in
San Juan in Puerto Rico and in St. Thomas in the Virgin Islands,
0.03 in Nassau in the Bahamas. a TRACE was reported in Freeport in
the Bahamas, in Montego Bay in Jamaica, and in Trinidad.

...HISPANIOLA...

An upper level trough is in the Atlantic Ocean, to the north of
Hispaniola, between 62W and 75W. Upper level anticyclonic wind
flow, westerly at the moment, is in the Caribbean Sea to the south
of Hispaniola. A surface ridge passes through the Atlantic Ocean
near 28N61W, to 22N71W, to Hispaniola.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR. for the
DOMINICAN REPUBLIC: Barahona: VFR. Santo Domingo: earlier rain has
ended for the moment. few towering cumulus clouds. La Romana: VFR.
Punta Cana: VFR. Santiago: MVFR. ceiling 2200 feet. few
cumulonimbus clouds. Puerto Plata: VFR.

The GFS MODEL forecast for 250 mb shows that broad cyclonic wind
flow will be spanning the area during the next 48 hours. The GFS
MODEL forecast for 500 mb shows that E-to-SE wind flow will be
moving across the area during the next 48 hours. It is possible
that even NE wind flow may be present at the end of the 48-hour
forecast period. The GFS MODEL forecast for 700 mb shows that at
least one inverted trough, and possibly a second one, will be
moving across Hispaniola, during the next 48 hours. Expect
cyclonic wind flow.

...THE ATLANTIC OCEAN...

An upper level cyclonic circulation center is near 30N70W.
Upper level cyclonic wind flow covers the area from 20N between
62W and 75W. Convective precipitation: widely scattered moderate
to isolated strong within 90 nm on either side of the line that
passes through 32N64W, to 29N67W and 23N70W. isolated moderate to
locally strong covers parts of the NW Bahamas from 24N northward
between 77W and 80W.

An upper level cyclonic circulation center is 32N50W. Upper level
cyclonic wind flow covers the area from 23N northward between 40W
and 57W. Convective precipitation: isolated moderate from 31N
northward between 44W and 60W.

Surface anticyclonic wind flow spans the area from 20N northward
between Africa and 80W. A 1031 mb high pressure center is near
34N43W.

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

$$
MT



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