Tropical Weather Discussion
Issued by NWS
AXNT20 KNHC 230001
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
801 PM EDT Sat Apr 22 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 1800 UTC surface analysis and satellite imagery through
The Monsoon Trough extends across the western Africa coast from
11N16W to 05N18W to 03N21W. The Intertropical Convergence Zone
continues from 03N21W to 01N28W to 01S33W to the coast of Brazil near
02S41W. Scattered moderate convection and isolated tstms are from
03N to 07N E of 21W and from 07S to 03N W of 20W.
GULF OF MEXICO...
Broad surface low pressure is across the basin ahead of a cold
front to enter the NW Gulf waters tonight. In the middle levels, a
cyclonic circulation centered N of the Yucatan Peninsula near
24N87W reflects at the surface as a 1010 mb center of low
pressure near 24N86W from which a surface trough extends from
28N84W to the low to 21N84W. A middle to upper level diffluent
environment just east of the low along with moisture inflow from
the Caribbean to the SE basin support scattered heavy showers and
tstms S of 27N E of 86W, including the Florida Straits. Water
vapor and CIRA LPW imagery show dry air across the remainder
basin, which is favoring fair weather conditions. Gentle to light
variable winds cover the Gulf, however building high pressure
behind the cold front will support fresh to strong N winds NW of
the front starting near 0600 UTC Sunday. These winds are forecast
to increase to near gale force on Sunday afternoon while the front
moves across the Florida Panhandle SW to the NE coast of Mexico.
Scattered to isolated showers are expected in the vicinity of the
front as it crosses the basin through Monday night. The low in the
SE basin will move E-NE in the next 24 hours, thus allowing the
continuation of showers across S Florida and the Straits.
A middle level diffluent environment across the NW Caribbean along
with abundant low level moisture across the basin support
scattered heavy showers and tstms along northern Cuba and isolated
showers across the Island coastal waters. To the SE of this area
of diffluence, a middle level short-wave trough support showers
across Hispaniola and adjacent waters, including the Windward and
the Mona Passage as well as Jamaica. Scattered heavy showers and
isolated tstms are in the central basin from 14N to 17N between
70W and 76W. Water vapor imagery show very dry air aloft, which in
part supports fair weather across the remainder Caribbean. Latest
scatterometer data show fresh winds N and S of Jamaica while
gentle to moderate winds dominate elsewhere...strongest being
along the northern Caribbean. Showers across the NW and north-
central Caribbean will continue through Monday, extending to
Puerto Rico Sunday night through Tuesday. Otherwise, the tail of
a cold front is forecast to reach NW Caribbean waters Monday
Abundant low level moisture across the northern Caribbean and a
middle level short-wave trough support showers across Hispaniola
and adjacent waters, including the Windward and the Mona Passage.
Heavy showers will continue over the remainder weekend through
Scattered showers and isolated tstms are across the Straits of
Florida and the Grand Bahama Bank ahead of a middle area of
diffluent flow over the NW Caribbean. Over the central basin, the
tail of a dissipating cold front extends from 30N41W to 27N48W.
Ahead of it, the remnants of a dissipating stationary front are
analyzed as a surface trough from 31N36W to 26N40W to 23N43W.
Isolated showers are within 60 nm either side of these boundaries.
Surface high pressure dominate the remainder basin W and E of the
cold front. A cold front will move across Florida Monday and into
the SW Atlc waters Mon night where it will dissipate Tue.
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