Tropical Weather Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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
AXNT20 KNHC 190519 CCA

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
705 PM EST Sun Feb 18 2018

Corrected Monsoon Trough/ITCZ Section

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 1800 UTC surface analysis and satellite imagery through
2345 UTC.


Caribbean Sea Gale Warning: A tight surface pressure gradient
continues between a surface high pressure in the western Atlantic
and lower surface pressures in northern sections of South
America. This pattern supports winds pulsing to minimal gale force
near the coast of Colombia through early next week. Wave heights
within the area of gale force winds will range between 12-17 ft.
Please read the latest NHC High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.


The monsoon trough axis extends from the coast of Africa near
06N10W southwestward to 03N14W and dips below the Equator at 19W
where it transitions to the ITCZ axis to 02S29W and to the coast
of S America at 03S39W.  The ITCZ continues from that point to
03N39W. Scattered moderate convection is within 30 nm N of the
axis between 18W-19W.



A surface ridge extends westward from a 1026 mb high centered
over the Atlantic near 28N64W to 1023 mb high centered over
central Florida, and continues westward to the NW Gulf. The
earlier frontal boundary that was along the coastal plains has N
of the as a warm front, and is over eastern Texas and the southern
portions of Louisiana, Mississippi and Alabama. A rather weak
surface trough is over the NE Gulf from 30N86W to 27N88W. Earlier
related shower activity has dissipated. Another surface trough
has recently emerged off the west coast of the Yucatan Peninsula
to over the far eastern Bay of Campeche. Isolated showers are S
of 21N and E of 94W. Areas of fog are expected over portions of
the northern and central gulf during the overnight hours and
into Mon morning. Both buoy observations and latest
scatterometer data reveal generally light to gentle east to
southeast flow N of of 26N, and gentle to moderate east to
southeast winds S of 26N, except for higher winds in the
moderate to fresh range E of 88W and W of 94W. Expect increasing
winds and building seas by early next week as high pressure
strengthens in the western Atlantic Ocean. The thermal trough
will develop again over the western Yucatan Peninsula each
afternoon, drift westward across the eastern Bay of Campeche
during the overnight hours, and then dissipate in the SW Gulf
waters by the late morning hours.


Please refer to the SPECIAL FEATURES section for details
regarding the Gale Warning near the coast of Colombia.

A tight pressure gradient across the basin created by the
combination of high pressure over the central Atlantic and lower
pressure over NW Colombia is producing strong east winds
throughout. These winds continue to quickly advect patches of
mainly broken low clouds westward along with quick passing
isolated showers, except over the far western Caribbean from
14N-18N W of 83W, including the Gulf of Honduras, where patches
of overcast low clouds contain scattered showers. This same
gradient will continue to support pulsing winds of minimal gale
force near the coast of Colombia through early next week. Fresh to
locally strong trade winds are expected elsewhere across the
Caribbean Sea. The high pressure will be reinforced by a stronger
one system on Mon. This stronger system will bring increasing
winds and building seas across the eastern and central Caribbean,
and the Tropical N Atlantic waters possibly into the middle of
next week.


Broad area of high pressure prevails across the basin, centered by
a 1026 mb high center near 28N64W and a 1024 mb high center near
31N34W. A weakness in the ridge was analyzed as a surface trough,
extending from 28N44W to 19N45W. The tail end of a stationary
front is along 32N from 44W-51W, while a cold front is just along
32N W of 72W. The cold front will drop southward over the NW
waters tonight and dissipate on Mon. The ridge will be reinforced
by a stronger high pressure system through Tuesday.

For additional information please visit

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