AXNT20 KNHC 172356
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
756 PM EDT Thu May 17 2018
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
A central Atlantic tropical wave has an axis that extends from
09N42W to 02S44W, moving W at 10 to 15 kt. This wave appears as
poleward surge in low level moisture and troughing at 700 mb.
Isolated moderate convection and showers are S of 06N between 40W
The monsoon trough passes through the coastal sections of Guinea
near 10N14W to 04N21W. The ITCZ continues from 04N21W to 01N30W
to 01N42W, then resumes W of the tropical wave near 01N45W and
continues to the coast of N Brazil near 00N50W. Besides the
convection associated with the tropical wave, scattered moderate
to isolated strong convection is from 01N-08N between 00W-14W.
Isolated moderate convection is from 02N-06N between 14W-40W.
GULF OF MEXICO…
Scatterometer data as well as buoy data indicate that a surface
trough continues to extend over the eastern Gulf from the Florida
Panhandle near 31N86W to 23N87W. This surface trough is
interacting with an upper trough over the eastern Gulf along 87W
to produce numerous showers and embedded thunderstorms east of 87W
including Florida, the Florida Straits, and western Cuba.
Moderate southerly winds are over the Gulf E of the trough. A
weak 1014 mb high center is over the western Gulf near 26N93W and
is supporting gentle to moderate anticyclonic flow over the
central and western Gulf.
The surface trough over the E Gulf will gradually weaken tonight.
However, the upper trough over the eastern Gulf will remain for
several days, and will continue to be the focus for shower and
thunderstorm activity mainly over the far eastern Gulf, where
deeper moisture and better lift will be present.
An upper trough extends over the Yucatan Peninsula and the NW
Caribbean. Upper level diffluence on the eastern side of this
trough is supporting scattered moderate convection and embedded
thunderstorms across the majority of the western Caribbean W of
75W. Broad high pressure over the subtropical Atlantic supports
moderate to fresh tradewinds over the NW and eastern Caribbean,
and fresh to strong winds over the central Caribbean. Light winds
are occurring over the SW Caribbean near the eastern Pacific
monsoon trough. Wave heights of 8-10 ft are occurring over the S
central Caribbean as confirmed by an afternoon satellite
altimeter pass and current buoy data.
Over the next couple of days the upper trough will remain in
place with an enhancement of shower and thunderstorm activity
over the western Caribbean. The surface ridging pattern over the
Atlantic will persist, keeping a similar wind profile in place
across the Caribbean into the upcoming weekend.
An upper trough and surface trough over the eastern Gulf of Mexico
is supporting scattered showers and thunderstorms over the W
Atlantic W of 76W, including the N Bahamas. A 1029 mb high is
centered over the central Atlantic near 33N55W. Another 1029 mb
high is centered over the E Atlantic near 36N35W. These high
pressure centers anchor a very broad ridge that spans the Atlantic
waters E of 75W to the Africa coast. The pressure gradient
between the central Atlantic high and lower pressures in the
Caribbean and eastern Gulf of Mexico support fresh to locally
strong E to SE winds along the northern coast of Hispaniola, and
fresh SW winds off the north Florida coast. Moderate to fresh
tradewinds are occurring across the central and western Atlantic S
of 27N. Gentle to moderate winds cover the central Atlantic N of
27N. Moderate to occasionally fresh NE winds are occurring over
the eastern Atlantic.
The overall pattern will change little over the next few days,
with ongoing convection possible W of 75W and strong winds
expected to continue along the northern coast of Hispaniola, and
at times eastern Cuba.
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