Tropical Weather Discussion
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AXNT20 KNHC 181046

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 AM EDT Sat Mar 18 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
1045 UTC.


A tight surface pressure gradient is generating gale force E-NE
winds along the northern Colombia coast for a few more hours
until 18/1200 UTC. See the latest NWS High Seas Forecast under
WMO/AWIPS headers MIAHSFAT2/FZNT02 KNHC for more details.


The Monsoon Trough extends from the African coast near 06N10W to
00N20W. The Intertropical Convergence Zone axis extends from
00N20W to 02S32W to the South American coast near 05S37W.
Isolated moderate convection is within 180 nm either side of the



As of 0300 UTC, a 1027 mb high is centered over the NE Gulf of
Mexico near 28N85W. 5-20 kt E-SE surface flow is over the Gulf
with lightest winds over the NE Gulf and strongest winds NW of
the Yucatan Peninsula. Fair weather is over the Gulf. In the
upper levels, zonal flow is noted with strong subsidence. Expect
in 24 hours for a 1025 mb surface high to be over the N Gulf
near 28N91W. Also expect the tail end of a cold front to over
the Florida Panhandle with showers.


A quasi-stationary front extends from Haiti near 20N72W to E
Honduras near 16N84W. Scattered showers are within 90 nm of the
front. 15-25 kt NE surface winds are N of the front. A gale is
along the coast of Colombia. See above. 15-30 kt tradewinds are
over the remainder of the Caribbean Sea. Scattered showers are
over the Leeward Islands, Puerto Rico, Hispaniola, Jamaica, E
Cuba, N Nicaragua, Honduras, and Guatemala. More showers are
over W Panama, and Costa Rica. In the upper levels, an upper
level high is centered over the E Caribbean near 15N65W. Strong
subsidence is over the entire Caribbean. Expect little change
over the next 24 hours.


Scattered showers are presently over the island due to the
front. Expect little change over the next 24 hours.


A 1027 mb high is centered over the W Atlantic near 31N72W. A
cold front is over the central Atlantic from 31N50W to 27N59W. A
stationary front continues to Haiti near 20N72W. Scattered
moderate convection is within 60 nm of the cold front. Scattered
showers are within 90 nm of the stationary front. A 1031 mb high
is centered near the Azores at 40N26W with a surface ridge axis
extending SW to 27N50W. A 1012 mb low is centered N of the
Canary Islands near 32N15W. Of note in the upper levels, an
upper level trough is over the W Atlantic N of 20N between 55W-
80W supporting the surface fronts. A large upper level low is
centered over the tropical Atlantic near 18N37W. Upper level
diffluence E of the center is producing scattered showers within
600 nm E of the center. Another upper level low is centered N of
the Canary Islands near 32N15W with scattered showers mostly N
of the center. Expect over the next 24 hours for the cold front
to drift E to 31N48W with convection.

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