Tropical Weather Discussion
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000
AXNT20 KNHC 251120
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
720 AM EDT Sat Mar 25 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 0600 UTC surface analysis and satellite imagery through
1115 UTC.

...SPECIAL FEATURES...

The 12-hour forecast, starting at 25/0600 UTC, consists of: a
cold front along 31N41W 26N51W, and then stationary to 24N69W. A
1014 mb low pressure center will be near 21N68W, with a surface
trough extending from the low center to 19N70W. Expect gale-force
winds, and sea heights ranging from 11 feet to 15 feet, between
180 nm and 270 nm in the NE quadrant of the low pressure center.
Please read the latest High Seas Forecast product under AWIPS/WMO
headers HSFAT2/FZNT02 KNHC for more details.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through the coastal sections of Guinea
near 09N13W, curving to the Equator along 21W. The ITCZ continues
from the Equator along 21W, to 01S30W, and to 03S39W off the
coast of Brazil. Convective precipitation: scattered to numerous
strong from 05N to 07N between 13W and 16W, in the coastal waters
of Sierra Leone. Scattered strong from 02N to 03N between 23W and
27W. Isolated moderate elsewhere from 08N southward from 47W
eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

A deep layer trough is digging through the central sections of the
U.S.A. A north-to-south oriented cold front cuts through Texas.
Middle level-to-upper level anticyclonic wind flow spans the Gulf
of Mexico. Comparatively drier air in subsidence is apparent in
water vapor imagery, in the NW corner of the Gulf of Mexico.
Convective precipitation: scattered moderate to strong has been
moving through east Texas into Louisiana.

A surface ridge passes through the Florida Panhandle, into the
north central Gulf of Mexico, to 27N94W to 23N98W along the coast
of Mexico.

Rainshowers are possible, in areas of scattered to broken low
level clouds in SE return flow, from 90W eastward.

...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: KBBF.

MVFR: KMZG, KBQX, KXIH, KVBS, KHHV, KEHC, KVQT, KEIR, KSPR,
KGRY, KMDJ, KIKT, KMIS, and KDLP.

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

TEXAS: Mostly MVFR/some IFR from the Lower Valley northward to
the Houston metropolitan area and smaller surrounding communities
and to Conroe, to Beaumont/Port Arthur and Jasper. rainshowers and
thunder in Tomball and Conroe. LOUISIANA: rainshowers and thunder
in Lafayette and New Iberia. MVFR from Lafayette and New Iberia
eastward, from Baton Rouge southward and southeastward.
MISSISSIPPI: rain and MVFR ceilings are moving eastward with time,
from Natchez eastward and southeastward. ALABAMA and FLORIDA: VFR.

...FROM THE CENTRAL ATLANTIC OCEAN, ACROSS THE BAHAMAS AND CUBA,
AND INTO THE SW CORNER OF THE CARIBBEAN SEA, INCLUDING THE REST
OF THE CARIBBEAN SEA...

An upper level trough passes through 32N47W to 30N52W, along a
shear axis to 29N70W, to 27N74W. The trough continues from 27N74W,
across SE Cuba, into the Windward Passage, to 14N79W, and to the
border of Nicaragua and Costa Rica. A cold front passes through
32N44W to 27N50W and 25N56W. A shear line is along 26N55W 24N60W
22N66W 21N72W 21N76W with comparatively faster surface winds to
the north of it. Convective precipitation: broken to overcast
multilayered clouds and possible rainshowers are within 240 nm to
360 nm on either side of 32N38W, 27N42W, 25N55W, 25N65W, and
19N66W.

...FROM THE ATLANTIC OCEAN INTO THE CARIBBEAN SEA...

A cold front passes through 32N44W to 27N50W and 25N56W. A shear
line is along 26N55W 24N60W 22N66W 21N72W 21N76W with
comparatively faster surface winds to the north of it.  The
surface trough continues from 21N63W, through the Mona Passage,
into the Caribbean Sea near 13N70W. Convective precipitation:
broken to overcast multilayered clouds and possible rainshowers
are within 240 nm to 360 nm on either side of 32N38W, 27N42W,
25N55W, 25N65W, and 11N69W at the coast of Venezuela. Upper level
SW wind flow is moving on top of the area of clouds and possible
precipitation in the Caribbean Sea. Upper level anticyclonic wind
flow is moving on top of the area of clouds and possible
precipitation in the Atlantic Ocean.

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

The dividing line of wind flow regimes extends from the southern
border of Haiti and the Dominican Republic to the coast of Costa
Rica near 10N83W. The upper level wind flow that is to the west of
that line is cyclonic. The upper level wind flow that is to the
east of that line is from the SW.

Rainshowers are comparatively more possible to the east of the
dividing line of upper level cyclonic wind flow and upper level SW
wind flow. Comparatively drier air in subsidence is evident in
water vapor imagery to the west of the dividing line.

The 24-hour rainfall total in inches for the period ending at
25/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...is 0.16 in Curacao.

...HISPANIOLA...

SW wind flow at all levels is moving across the island.
Rainshowers are possible inland, and in the coastal waters.

SURFACE OBSERVATIONS...for the DOMINICAN REPUBLIC: Santo
Domingo/La Romana: VFR. Punta Cana: MVFR. ceiling 1600 feet.
Santiago: MVFR. ceiling 1400 feet. earlier rain has ended for the
moment. Puerto Plata: heavy rain 4 to 5 hours ago. IFR. ceiling
1200 feet.

The GFS MODEL forecasts, for 250 mb and for 500 mb, show that SW
wind flow will move across the area during the next 48 hours. A
trough will remain to the west of Hispaniola during the next 48
hours. The GFS MODEL forecast for 700 mb shows that cyclonic wind
flow with a trough will cover the area for the first 30 hours.
Expect SW and W wind flow during the rest of the 48-hour forecast
period.

THE REST OF THE ATLANTIC OCEAN...

An upper level trough passes through Morocco, across the Canary
Islands, to 24N19W, to 15N26W and to 09N30W. No significant deep
convective precipitation is apparent in satellite imagery.

Surface anticyclonic wind flow is to the east, and to the northwest
of, the 32N44W-to-25N56W cold front. A surface ridge passes
through 32N33W 23N45W to 17N55W to 11N60W, on the eastern side of
the surface trough. A 1034 mb high pressure center is near
35N61W, to the northwest of the front. A surface ridge extends
from the 1034 mb high pressure center to South Carolina and
Georgia.

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

$$
MT



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