Tropical Weather Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | 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 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
AXNT20 KNHC 250509

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1209 AM EST Sun Feb 25 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
0500 UTC.


A system of low pressure over the northeast Atlantic will support
a cold front forecast to extend from 31N35W to 28N48W by early
Monday. A strong pressure gradient between this low and surface
ridging west of it will lead to the development of gale-force
winds mainly north of 30N and east of 42W. Gale conditions are
forecast to prevail through the next day or so. For more details,
refer to the NHC High Seas Forecast under AWIPS/WMO Headers


The monsoon trough enters the eastern Atlantic near 08N13W and
continues to 02N22W. The ITCZ extends from that point to the coast
of Brazil near 02S40W. Scattered moderate convection is noted in
the vicinity of the monsoon trough mainly from 00N-05N and east
of 23W.



Fair weather prevails across the basin due to a very dry airmass
at low and middle levels of the atmosphere, as indicated by
GOES-16 water vapor imagery. CIRA microwave imagery at the lower
levels show patches of shallow moisture advecting to the northwest
Gulf, which is supporting dense fog north of 27N and west of 91W.
A broad area of high pressure over the western Atlantic extends
across the basin supporting moderate to fresh southeast flow
across the basin. By early Monday, a cold front is forecast to
move over the northwestern waters from Louisiana to Brownsville,
Texas to inland northeast Mexico. By Monday afternoon, the front
is forecast to extend from the Florida Panhandle to 27N94W to
inland NE Mexico and then it will stall before it lifts northward
along the Gulf coast through Tuesday night. Scattered showers
will accompany this boundary.


Water vapor imagery from GOES-16 show deep layer dry air across
the Caribbean, which is supporting fair weather across most of
the basin. Scattered showers are noted across the Greater
Antilles generated by shallow moisture transported by moderate to
fresh trades. Latest scatterometer data depicts locally strong
winds within 90 nm of the coast of Colombia increasing to near-gale
force at night. Sea heights are highest near the coast of
Colombia, reaching 12 ft at times. Looking ahead, winds and seas
are expected to gradually lessen by this morning as the high
pressure system north of the area weakens.


Gale-force winds are forecast to develop over northeast Atlantic
waters by Sunday night/Monday morning. See the Special Features
section above for further details. A broad surface ridge prevails
across the west and central Atlantic anchored by a 1026 mb high
near 31N69W and a 1025 mb high near 31N57W. Fresh to locally
strong east winds are noted in the approaches of the Windward
Passage and the eastern Great Bahama Bank. To the east, a low
pressure system over the northeast Atlantic continues to support
a cold front that enters the area of discussion near 31N22W to
22N30W to 19N40W then weakens to 19N45W. Another piece of it was
analyzed as a surface trough that extends from 22N51W to 26N56W.
Little change is expected over the remainder of the basin during
the next day or two as the high pressure system remains nearly-
stationary and weakens.

For additional information please visit


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