AXNT20 KNHC 171155
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
754 AM 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 0600 UTC surface analysis and satellite imagery through
A central Atlantic tropical wave has an axis that extends from
12N40W to 02S41W, moving W at 10 to 15 kt. This wave appears as
poleward surge in mid level moisture and troughing at 700 mb.
Isolated moderate convection is from 03S-05N between 37W-43W.
The monsoon trough passes through the coastal sections of Guinea
near 10N14W to 05N20W. The ITCZ continues from 05N20W to 02N30W to
02N39W, then resumes W of the tropical wave near 02N42W and
continues to the coast of N Brazil near 00N50W. Besides the
convection associated with the tropical wave, widely scattered
moderate convection is from 01N-04N between 07W-30W.
GULF OF MEXICO…
A surface trough extends from a 1010 mb low over the Florida
Panhandle near 31N84W to 24N87W. This surface feature is
interacting with an upper trough with an axis over the eastern
Gulf to produce scattered to numerous showers and embedded
thunderstorms east of 85W including the Florida Peninsula,
Florida Straits, and western Cuba. Moderate to fresh SW winds are
over the NE Gulf, N of 27N and to the east of the surface trough.
Gentle to moderate southerly winds are S of 27N over the eastern
Gulf. A weak 1014 mb high center is over the western Gulf near
26N94W and is supporting gentle to moderate anticyclonic flow over
the central and western Gulf, except moderate to fresh winds near
the Texas coast, where a tighter pressure gradient exists due to
a cold front over interior east Texas.
The low over the Florida panhandle will move NE of the region
today with the trailing surface trough gradually weakening. 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 N of 11N between 75W-85W. Broad high pressure over
the subtropical Atlantic supports moderate to fresh tradewinds
over the majority of the Caribbean basin, except for light winds
over the SW Caribbean, and strong winds over the S Central
Caribbean. Wave heights near 10 ft are occurring under the
stronger winds as confirmed by a recent satellite altimeter pass.
The eastern extent of the Eastern Pacific monsoon trough extends
along 09N between Costa Rica and N Colombia. Scattered moderate
to strong convection is S of 11N between 75W-84W.
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 W of 76W,
including the central and NW Bahamas. An expansive area of high
pressure centered from just E of Bermuda to the Azores spans the
remainder of the western, central, and eastern Atlantic. The
pressure gradient between this high and lower pressures in the
Caribbean and eastern Gulf of Mexico supports fresh to locally
strong E to SE winds along the northern coast of Hispaniola and E
of the the northern Florida coast. Moderate to fresh tradewinds
are occurring across the central Atlantic S of 27N. Gentle to
moderate winds cover the central Atlantic N of 27N. Moderate 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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