Tropical Weather Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

AXNT20 KNHC 191741

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
141 PM EDT Mon Mar 19 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
1500 UTC.


Atlantic Gale Warning: Southerly flow will increase off northeast
Florida late tonight and Tue ahead of a cold front moving into
the region late Tue. SW to W winds will reach gale force north of
29N E of front to 76W late Tue through Wed as the front moves


The monsoon trough extends from the coast of Africa near 07N12W
to 04N20W. The intertropical convergence zone continues from that
point to 02N30W to 03N51W. A few showers are noted within 150 nm
on either side of the ITCZ between 20W and 32W.



As of 1500 UTC, a prefrontal trough has entered the NW Gulf of
Mexico. A cold front is just inland over Texas. Scattered showers
are along the front. Weak ridging extends from southeast Florida
to the north central Gulf, supporting light to gentle southeast
winds over most of the region. Radar imagery shows scattered
moderate convection over the NE Gulf and Florida N of 28N between
81W and 87W.

The front will extend from the Florida Big Bend area to Veracruz
Mexico tonight, just as a reinforcing push of cold air moves off
the Texas coast. The reinforcing front overtakes the first front
late Tue, accompanied by strong winds and building seas over the
northern Gulf. The merged front sweeps southeast of the Gulf by
early Wed. Winds and seas diminish across the Gulf through Thu as
high pressure follows the front across the northern Gulf.


A pair of scatterometer passes confirmed a large area of fresh to
strong trade winds off Colombia, and a smaller area of strong
winds south of the Bay Islands off central Honduras. Seas are
reaching 8 ft off Colombia, but are generally 4 to 6 ft in the
eastern and central Caribbean and tropical north Atlantic, and 2
to 4 ft in the northwest Caribbean. No significant convection is

Building high pressure north of the region will support fresh to
locally strong trades across the south central Caribbean the
next several days, except increasing to near gale force along the
northwest coast of Colombia during the overnight hours. A cold
front will pass through the Yucatan Basin by early Wed, then
drift south and stall from the Windward Passage to central
Honduras Fri, followed by fresh northerly flow and seas building
to 7 ft.

Undersea volcano Kick`em Jenny, 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 or 3.1 nm exclusion zone around Kick`em
Jenny. Please see for additional information.


Please see Special Features section for information on the
developing gale warning in the Atlantic.

A cold front is over the W Atlantic from 31N57W to 27N70W.
Scattered moderate convection is within 60 nm of the front. The
front will shift eastward and weaken through Tue. Farther south,
weak ridging is supporting gentle breezes west of 60W, with 4 to 6
ft seas in open waters east of 75W, due mainly to residual
northerly swell.

The next cold front will move off the coast late Tue, associated
with a deep surface low moving off the mid-Atlantic coast. The
supporting upper trough will become negatively tilted as it
emerges off the coast. This will interact with the Gulf Stream to
support scattered thunderstorms Tue night off the northeast coast
of Florida. In addition to the gales, strong westerly winds and
seas ranging from 8 ft to as high as 17 ft will prevail north of
27N and west of 60W into Wed night.

Winds and seas will diminish Thu as the front reaches from
Bermuda to the Windward Passage, before stalling and weakening
through late week. A weaker front will move eastward north of 28N
Thu night into Fri.

Over the eastern Atlantic, 1028 mb high pressure is centered near
31N27W, supporting gentle to moderate NE to E winds over the
subtropics and moderate to fresh trades in the deep tropics. An
upper trough is noted along 28W north of 05N, supporting a few
small areas of modest convection along the monsoon trough and
ITCZ. Recent altimeter satellite passes indicate seas are still 8
to 12 ft north of 05N, likely in persistent long period NW swell.

For additional information please visit

Formosa is the U.S. government's official web portal to all federal, state and local government web resources and services.