Tropical Weather Discussion
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417
AXNT20 KNHC 191717
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
117 PM EDT Wed Apr 19 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
1645 UTC.

...SPECIAL FEATURES...

The center of Subtropical Depression ONE is near 31.9N 40.9W. The
subtropical depression is moving north-northeastward, or 30
degrees, 7 knots. The estimated minimum central pressure is 995
mb. The maximum sustained wind speeds are 30 knots with gusts to
40 knots. Please read the PUBLIC ADVISORIES about Subtropical
Depression ONE, that are issued under the WMO header WTNT31 KNHC
and under the AWIPS header MIATCPAT1. FORECAST/ADVISORIES about
Subtropical Depression ONE are issued under the WMO header WTNT21
KNHC, and under the AWIPS header MIATCMAT1. Convective
precipitation: scattered moderate to isolated strong is from 29N
northward between 30W and 41W. isolated moderate elsewhere from
20N northward between 30W and 53W.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through the coastal sections of Guinea
near 11N15W to 06N17W. The ITCZ continues from 06N17W, to 04N19W
01N32W, and to the Equator along 41W. Convective precipitation:
scattered moderate to strong from 03N to 06N between 15W and 17W.
scattered moderate to isolated strong from 04N southward between
25W and 33W. isolated moderate elsewhere from 07N southward from
44W eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

An upper level cyclonic circulation center is near 24N93W.
Cyclonic wind flow covers the Gulf of Mexico from 27N southward
from 88W westward.

One separate area of upper level anticyclonic wind flow covers the
area that is from 27N northward. A separate and second area of
anticyclonic wind flow covers the area that is from 27N southward
from 88W eastward, on the eastern side of the 24N93W cyclonic
circulation center. One surface trough is along 28N94W 25N95W. A
second surface trough is along 26N94W 23N95W. Convective
precipitation: widely scattered moderate to isolated strong from
24N to 28N between 86W and 90W. Widely scattered moderate is in
the NE part of the Yucatan Peninsula. Isolated moderate, with some
areas of developing and dissipating convective activity, from 29N
southward from 90W westward.

...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: KBBF, KXIH, KHQI, KMDJ, 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 Falfurrias and Galveston, in Beaumont/Port Arthur
and in Jasper. Moderate rain is in Pearland. Rainshowers are near
Ellington Field. Rain has ended for the moment at the Houston
Hobby Airport, and at the Intercontinental Airport. LOUISIANA:
MVFR in the southern sections/the coastal plains, even a bit on
the southern side of Lake Pontchartrain. MISSISSIPPI: MVFR a few
hours ago at the Stennis International Airport. ALABAMA and
FLORIDA: VFR.

...THE CARIBBEAN SEA...

Broad middle level-to-upper level anticyclonic wind flow spans the
Caribbean Sea. The anticyclonic wind flow is related to a
Colombia-to-Eastern Pacific Ocean ridge that extends beyond
08N/09N along 90W.

A weak upper level trough is along the coast of Nicaragua.
Convective precipitation: scattered strong from 11N to 13N between
82W and 83W.

Broad surface cyclonic wind flow, in the isobaric pattern, extends
from Hispaniola into northern Colombia.

Other areas of convective precipitation: widely scattered moderate
from 19N to 20N between 81W and 84W, and in the Windward Passage.
Isolated moderate elsewhere to the west of the line that runs from
south central coastal Hispaniola to the coast of Colombia along
74W, and from 13N to 18N between 60W and 73W.

24-hour rainfall totals that are listed for the period that ended
at 19/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...0.14 in Guadeloupe,
0.04 in Trinidad, and a trace in Freeport in the Bahamas and in
Montego Bay in Jamaica.

...HISPANIOLA...

Middle level-to-upper level SW-to-W wind flow is moving across
the island. Hispaniola is on the eastern side of a ridge that
extends from Colombia to the Eastern Pacific Ocean near 08N/09N
along 90W. Convective precipitation: isolated moderate in the
coastal waters of SW Haiti. Rain is being reported inland.
Rainshowers are possible elsewhere in the coastal waters.

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

The GFS MODEL forecast for 250 mb shows that SW-to-W wind flow
will cover the area during the entire time. A ridge will extend
from Colombia into the Eastern Pacific Ocean near 10N90W, by the
end of the 48-hour forecast period. The GFS MODEL forecast for
500 mb shows that SW wind flow at the start of the 48-hour
forecast period, will become NW, as a ridge will be to the west
of Hispaniola, and eventually on top of Hispaniola, during the
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...

Upper level cyclonic wind flow covers the area from 20N northward
from 50W eastward. This cyclonic wind flow is moving around the
upper level cyclonic circulation center that is associated with
Subtropical Depression ONE.

Upper level NW wind flow is moving through the Atlantic Ocean
trough passes through 32N23W, to a 22N36W cyclonic circulation
center, to 10N41W. A 1015 mb low pressure center is near 22N37W.
Convective precipitation:
isolated moderate from 19N to 25N between 32W and 38W.

A surface ridge passes through 32N27W to 22N28W 14N39W,
and 07N54W.

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

$$
MT



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