AXNT20 KNHC 171643
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1243 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 1200 UTC surface analysis and satellite imagery through
A central Atlantic tropical wave has an axis that extends from
10N41W to 02S42W, 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 is from 03S-05N between 38W-45W.
The monsoon trough passes through the coastal sections of Guinea
near 10N14W to 04N20W. The ITCZ continues from 04N20W to 01N30W
to 01N41W, then resumes W of the tropical wave near 01N44W 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-07N between 00W-05W.
Isolated moderate convection is within 120 nm of the ITCZ between
GULF OF MEXICO…
A surface trough extends from the Florida Panhandle near 31N87W
to 25N90W. This surface trough is interacting with an upper
trough over the eastern Gulf along 87W to produce numerous
showers and embedded thunderstorms east of 88W including Florida,
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
25N93W 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 surface trough over the NE Gulf will gradually weaken tonight.
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 13N 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 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 13N between 77W-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 thunderstormsover the W
Atlantic W of 76W, including the N Bahamas. a 1029 mb high is
centered over the central Atlantic near 33N52W. Another 1030 mb
high is centered over the E Atlantic near 36N33W. The pressure
gradient between the central Atlantic 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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