Tropical Weather Discussion
Issued by NWS
AXNT20 KNHC 161409 RRA
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
637 AM EST Mon Jan 16 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
...THE MONSOON TROUGH/THE ITCZ...
The Monsoon Trough passes through Liberia near 06N10W to 05N14W.
The ITCZ continues from 05N14W to 02N29W and 01N35W. Convective
precipitation: Widely scattered moderate to strong from 06N
from 37W eastward. Scattered strong from 02N southward between
01W and 07W. Numerous strong from 02N southward between 47W and
51W in NE Brazil. Isolated moderate elsewhere from 10N southward
between 50W and 58W.
...THE GULF OF MEXICO...
An NE-to-SW oriented upper level ridge passes through Florida, to
the Yucatan Peninsula of Mexico. The upper level winds are
pushing high level moisture across the Gulf of Mexico.
Comparatively drier air in subsidenc is apparent in water vapor
imagery in the NW corner of the area. A deep-layer trough is
moving through Texas, with the upper level cyclonic circulation
center moving through the Texas Panhandle. The deep-layer trough
is supporting a developing cyclone and frontal boundary that are
moving through central Texas and northern sections of Mexico.
A surface ridge passes through NE Florida, into the SE corner of
the Gulf of Mexico, to the Yucatan Peninsula of Mexico.
...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...
MVFR: KHHV, KVAF, KGUL, KVQT, KGHB, KEIR, and KATP.
LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF
THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...
TEXAS: changing conditions from MVFR to VFR in Brownsville and
Harlingen. MVFR in Weslaco and Edinburg. MVFR in Hebbronville
and Laredo. MVFR in Kingsville and Alice, at the NAS Corpus
Christi, and Rockport. light rain in Port Lavaca. MVFR in
Angleton/Lake Jackson. moderate rain in Sugar Land. MVFR in the
southern part of the Houston metropolitan area and surrounding
smaller communities. light rain in Tomball, at the Houston IAH,
and in Conroe. heavy rain in Huntsville. LOUISIANA: LIFR in parts
of the Lake Charles metropolitan area. IFR in New Iberia. LIFR in
Baton Rouge, and around the NW part of Lake Pontchartrain.
MISSISSIPPI: MVFR from Natchez to McComb. LIFR in parts of the
Hattiesburg metropolitan area. ALABAMA: light rain in parts of
the Mobile metropolitan area. FLORIDA: VFR.
...THE CARIBBEAN SEA...
Upper level SW wind flow curves anticyclonically, from Nicaragua
eastward, into the Caribbean Sea, from 15N southward. High level
clouds cover the Caribbean Sea from 16N southward. Other high
level clouds are moving through the NE corner of the Caribbean
Sea, from the Atlantic Ocean, with the NE wind flow from 350 mb
to 800 mb.
NE wind flow, from 350 mb to 800 mb, covers the Caribbean Sea
from 14N northward from 72W eastward.
Middle level-to-upper level cyclonic wind flow covers the area
that is from 16N northward from 70W westward. A cyclonic
circulation center is near 19N80W.
NE wind flow, from 600 mb to 800 mb, is from 18N southward from
Comparatively drier air in subsidence, that is apparent in water
vapor imagery, spans the Caribbean Sea.
24-HOUR rainfall amounts in inches for the period ending at
16/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...0.31 in Curacao,
and 0.15 in Guadeloupe.
The wind flow from 350 mb to 800 mb is from the NE to E,
across Hispaniola. Comparatively drier air in subsidence is
apparent in water vapor imagery, across the entire area.
SURFACE OBSERVATIONS...for the DOMINICAN REPUBLIC: Santo
Domingo/La Romana/Punta Cana: VFR. Santiago: VFR. Puerto Plata:
light rain. MVFR. ceiling 1600 feet.
The GFS MODEL forecast for 250 MB shows that SW wind flow will
move across the area at the start of the 48-hour forecast period.
The trough will move into the Windward Passage after 6 to 12
hours, followed by nothing but NW wind flow for the rest of the
time. The GFS MODEL forecast for 500 MB shows that NE wind flow,
and then N wind flow, will move across the area. An east-to-west
oriented trough will be to the east of Hispaniola. A ridge will
be to the NW and W of Hispaniola. The GFS MODEL forecast for 700
mb shows that NE wind flow will move across Hispaniola, with a
...THE ATLANTIC OCEAN...
An upper level trough passes through 32N32W 27N34W 21N36W 19N44W
and 18N57W. A cold front passes through 32N30W to 27N32W and
22N35W. A surface trough continues from 22N35W to 19N40W 16N45W
13N45W. Convective precipitation: isolated moderate to locally
strong from 21N northward between 20W and 33W. Rainshowers are
possible also from 10N to 20N between 20W and 57W.
A shallow cold front passes through 32N57W to 29N70W, beyond
32N79W. Convective precipitation: widely scattered moderate to
isolated strong from 31N northward between 48W and 54W.
Multilayered clouds and other possible rainshowers are elsewhere
from 28N northward from 50W westward.
A surface ridge is to the east of the cold front, along 11N34W
22N28W beyond 32N22W.
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