Tropical Weather Discussion
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AXNT20 KNHC 180521

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
121 AM EDT Sun Mar 18 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 0000 UTC surface analysis and satellite imagery through
0515 UTC.


The monsoon trough extends from the coast of Africa near 07N11W
to 04N22W. The ITCZ continues from that position to the coast of
Brazil near 02N50W. Scattered moderate convection is within 100 on
either side of the ITCZ between 23W-39W.



A surface ridge extends across the basin anchored by a 1019 mb
high centered east of the northern Bahamas. This pattern continues
to induce gentle to moderate southeast winds across the Gulf
waters, with seas 3 to 4 ft over the western half of the basin
and 3 ft or less in the eastern Gulf. Haze and fog continue to be
reported in the northwest Gulf mainly north of 27N and west of
92W. The ridge will shift east Sunday night ahead of a cold front
that will move off the Texas coast on Monday. The front will
extend from the Florida Big Bend area to Veracruz, Mexico by early
Tuesday. A reinforcing front will overtake the first front by late
Tuesday, accompanied by strong winds and building seas over the
northern Gulf. The merged front sweeps southeast of the Gulf by
early Wednesday. Winds and seas diminish across the Gulf through
mid-week as high pressure builds in the wake of the front across
the northern Gulf.


The undersea volcano Kick `em Jenny, located north of Grenada
near 12.18N 61.38W, is in a state of unrest. The government of
Grenada advises mariners to observe a 5 km / 3.1 nm exclusion
zone around Kick `em Jenny. Please see for further

The pressure gradient generated by a surface ridge anchored by a
1019 mb high centered east of the northern Bahamas and lower
pressures over northern South America is supporting moderate to
fresh trades over the south Caribbean mainly south of 15N and east
of 80W. Seas in this area remain 8 to 10 ft per the latest
observations. Locally strong to near-gale winds are expected to
pulse within 90 nm off the coast of Colombia each night through
the next several days. Gentle to moderate winds prevail across
the remainder of the basin. A weakening cold front will pass
through the Yucatan Basin by late Tuesday. High pressure will
build behind the front. Fresh northerly winds will develop by this
time across the western half of the basin.


A cold front extends from 30N50W to 27N60W to 29N70W. A pre-
frontal trough extends from 31N45W to 26N54W to 23N65W. Scattered
moderate convection prevails within 75 nm on either side of the
trough mainly north of 28N. Fresh to strong winds and 8 to 12 ft
seas will move across the waters north of 28N and east of 70W
through today. A ridge anchored by a 1019 mb high just east of
the northern Bahamas dominates the waters west of 65W and south of
the front and maintains generally light to gentle winds, with
seas ranging between 6-9 ft in open waters primarily due to
northerly swell. Winds will increase mainly north of 28N by late
today as a low pressure moves off the Carolinas coast along with
another cold front, which will reach the west Atlantic by Monday
morning. Southerly winds will increase to fresh to strong off
northeast Florida and north of the Bahamas by late Monday, then
increase to near-gale to gale force north of 28N, with building
seas by late Tuesday through Wednesday as low pressure moves east.
Over the eastern Atlantic, 1023 mb high pressure is centered near
30N28W, and this is maintaining gentle flow over the subtropics
and moderate to fresh winds in the deep tropics.

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