AXNT20 KNHC 191006
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Apr 19 2021
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
Eastern Caribbean Ashfall Advisory: An Ashfall Advisory is in
effect for La Soufriere Volcano on St. Vincent near 13.3N 61.2W.
A new eruption occurred Sunday, and a plume of ash spread over the
eastern Caribbean from 13N to 14N between 61W and 63W. The
volcano remains in a very active state, and additional eruptions
and ash plumes are possible at any time. Mariners transiting the
nearby waters should exercise caution and are encouraged to report
volcanic ash to the National Hurricane Center by calling
The monsoon trough extends from the coast of West Africa near
12N16W and continues southwestward to 04N23W. The ITCZ continues
from 04N23W to 02N30W to 00N40W. Scattered moderate convection is
from 02S-04N between 08W-14W.
GULF OF MEXICO...
A nearly stationary cold front stretches from near Tampa Bay,
Florida, to 26N90W, to the western Bay of Campeche. Scattered
moderate to isolated strong convection is noted across a fairly
broad area of the eastern Gulf, from 23N to 28N, E of 89W. Fresh
NE winds are occurring to the NW of this boundary, with an area of
strong NW winds offshore Veracruz, Mexico. Seas in this region
are 6-10 ft. Ahead of the front and within the Florida Straits,
winds are SE moderate to fresh, while within the Yucatan Channel
winds are fresh from the south. Seas ahead of the front and within
the far northeast Gulf are 2-4 ft.
A nearly stationary front is noted from near Tampa Bay,
Florida, to 25N92W, to the western Bay of Campeche. Fresh to
strong winds occurring west of this boundary across the southwest
Gulf will continue to diminish today. This front will remain
nearly stationary into mid week, before reinforcing cool and dry
air pushes the front into the far southeast Gulf from mid to late
An Ashfall Advisory is in effect for La Soufriere volcano on the
island of St. Vincent. See the special features section above
Scattered moderate convection remains in the Gulf of Honduras,
otherwise dry air is supporting fair weather conditions over the
basin. A pressure gradient between lower pressure over Colombia
and a surface high pressure over the central Atlantic extending
into the northern Caribbean continues to support fresh to strong
winds over the south-central basin with seas to 9 ft and moderate
to locally fresh SE winds in the Gulf of Honduras. Moderate trade
winds with seas to 7 ft are elsewhere.
The ridge N of the area will shift east ahead of a weak front
moving through the Gulf allowing trade winds to increase over
mainly the south central Caribbean through mid week. Looking
ahead, the trade winds will diminish by late week as the high
pressure shifts eastward, although fresh to strong winds will
persist off Colombia.
A weak frontal boundary will remain nearly stationary off the
coast of northeast Florida through the early part of the week, as a
ridge extends westward from the central Atlantic through the central
Bahamas. Broad gentle to moderate anticyclonic flow extends over the
Atlantic north of 20N. South of 20N trades are moderate to fresh.
Looking ahead, as the ridge shifts east by Wed, a slightly stronger
frontal boundary will move off the southeast U.S. coast by Thu. This
front will reach from near Bermuda to the Straits of Florida by Thu
night, then start to stall along 25N through Fri night as high
pressure builds between northeast Florida and Bermuda.