Tropical Weather Discussion
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514
AXNT20 KNHC 201802
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
205 PM EDT TUE SEP 20 2016

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...

The center of Tropical Storm Karl at 20/1500 UTC is near 20.0N
54.3W. Karl is moving westward, or 275 degrees, 15 knots. The
estimated minimum central pressure is 1006 mb. The maximum
sustained wind speeds are 35 knots with gusts to 45 knots.
Convective precipitation: scattered moderate to isolated strong
within 315 nm of the center in the NE semicircle. Please read
the latest NHC Intermediate Public Advisory under AWIPS/WMO
headers MIATCPAT2/WTNT32 KNHC and the Forecast/Advisory under
the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details.

Tropical Depression THIRTEEN was upgraded to TROPICAL STORM LISA
at 20/1500 UTC. The center of Tropical Storm Lisa at 20/1500 UTC
is near 15.3N 30.4W. Lisa is moving northwestward, or 305
degrees, 10 knots. The estimated minimum central pressure is
1007 mb. The maximum sustained wind speeds are 35 knots with
gusts to 45 knots. Convective precipitation: scattered moderate
to isolated strong within 360 nm of the center of Lisa in the NE
semicircle. Please read the latest NHC Intermediate Public
Advisory under AWIPS/WMO headers MIATCPAT3/WTNT33 KNHC and the
Forecast/Advisory under the AWIPS/WMO headers MIATCMAT3/WTNT23
KNHC for more details. The METEO-FRANCE High Seas Forecast
consists of a gale warning for the area that is called: CAPE
VERDE. The OUTLOOK, for the 24 hours that follow the forecast
that is valid until 21/1200 UTC, consists of: the threat of a
cyclonic near gale to severe gale in the southwestern part of
CAPE VERDE.

...TROPICAL WAVES...

A Caribbean Sea tropical wave is along 72W/73W from 18N
southward, moving westward 10 to 15 knots. Convective
precipitation: isolated moderate from 15N to 23N between 67W and
80W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through coastal sections of Mauritania
near 18N16W to 16N20W, and along 08N33W 07N40W 06N45W.
Convective precipitation: rainshowers are possible from 12N to
16N between Africa and 20W. isolated moderate from 03N to 09N
between 30W and 45W. scattered moderate to isolated strong from
07N to 09N between 22W and 24W.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level cyclonic circulation center is in the Isthmus of
Tehuantepec of southern Mexico near 17N95W. Cyclonic wind flow
covers the area from 20N southward between Guatemala and 100W.
Convective precipitation: rainshowers are possible from 20N
southward in the SW corner of the Gulf of Mexico. Comparatively
drier air in subsidence covers the area from 24N northward from
90W westward. The drier air is moving southward.
Convective precipitation: scattered moderate to isolated strong
from 21N to 24N between 91W and 98W.

A NE-to-SW oriented shear axis is along 30N85W 27N90W 24N92W
24N98w. A surface trough extends from 30N81W off the Florida
coast, to a 1013 mb low pressure center that is near 27N88W,
to 24N90W. Convective precipitation: isolated moderate from 90W
eastward, to the north of 22N90W 26N86W 27N83W.

A 1015 mb high pressure center is in the eastern part of the
area, near 27N84W.

...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: KBQX.

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

TEXAS: light rain was occurring in Sugar Land during the last
few observations. from LOUISIANA to ALABAMA: VFR/no ceilings.
FLORIDA: rainshowers, some heavy, were occurring during the last
few observations at the Tampa Executive Airport. rain and
thunder have been reported in the Tampa/St. Petersburg
metropolitan area during the last few observations.
MVFR at the Key West International Airport.

...THE CARIBBEAN SEA...

An upper level cyclonic circulation center is just off the SE
coast of Jamaica. Upper level cyclonic wind flow spans the
Caribbean Sea. Convective precipitation: isolated moderate
elsewhere from 15N northward from 80W westward.

24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT
20/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...0.04 in Acapulco,
and 0.02 in Bermuda and St.Thomas in the Virgin Islands.

The monsoon trough is along 09N/10N from 74W beyond 86W, into
the eastern Pacific Ocean. Convective precipitation: scattered
to numerous strong from 10N to 12N between 80W and 85W.
Numerous strong was apparent from 09N to 12N between 79W and 85W
at 20/1315 UTC.

...HISPANIOLA...

An upper level cyclonic circulation center is just off the SE
coast of Jamaica. Upper level SE wind flow is moving across
Hispaniola.

A surface trough is along 73W/74W, from 19N to 23N, cutting
across the SE Bahamas and into the Windward Passage. A tropical
wave also is along 72W/73W from 18N southward, moving westward
10 to 15 knots. Convective precipitation: isolated moderate from
15N to 23N between 67W and 80W.

SURFACE OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI: VFR/no
ceilings. FOR THE DOMINICAN REPUBLIC...Barahona: VFR/no
ceilings: few cumulonimbus clouds. Santo Domingo: VFR/no
ceilings: few cumulonimbus clouds. La Romana/Punta Cana: VFR/no
ceilings. Santiago: VFR/no ceilings; few cumulonimbus clouds
during the last few observations. Puerto Plata: VFR/no ceilings.

The GFS MODEL forecast for 250 MB shows that cyclonic
circulation centers will be to the south of Hispaniola during
the next 48 hours. SE wind flow will be moving across the area
during the next 48 hours. The GFS MODEL forecast for 500 MB
shows SE wind flow for much of day one will be followed by
anticyclonic wind flow with a ridge at the end of day one.
Expect anticyclonic wind flow also for day two. The GFS MODEL
forecast for 700 MB shows that anticyclonic wind flow with a
ridge will cover the area at the start of the 48-hour forecast
period, giving way to NE wind flow as the ridge moves westward.
The ridge will move to Cuba. Expect more NE wind flow during day
two.

...THE ATLANTIC OCEAN...

A cold front passes through 32N72W to 31N78W. A surface trough
continues from 30N78W to the SE coast of Florida near 25N80W.
Convective precipitation: widely scattered moderate to isolated
strong from 28N to 31N between 76W and 80W. Rainshowers are
possible elsewhere from 20N and Cuba northward from 70W westward.

An upper level cyclonic circulation center is near 36N57W, to
the north of the area. Cyclonic wind flow that is moving around
this center reaches 32N. A surface trough is along 32N62W
29N67W. Convective precipitation: isolated to widely scattered
moderate and locally strong within 60 nm to 75 nm on either side
of the line from 32N62W 27N66W 23N67W.

An upper level cyclonic circulation center is near 22N59W.
Cyclonic wind flow covers the area from 18N to 29N between 56W
and 66W. Convective precipitation: isolated to widely scattered
moderate in the area of cyclonic wind flow from 21N northward.
Tropical Storm Karl is about 310 nm to the ESE of this feature.

Broad surface anticyclonic wind flow covers the Atlantic Ocean
from 24N northward between Africa and 50W.

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

$$

MT



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