AXNT20 KNHC 130917
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sun Jun 13 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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.
Based on 0600 UTC surface analysis and satellite imagery through
The axis of a tropical wave is near 27W from just west of the
Cabo Verde Islands southward, moving W at 10 to 15 kt. Scattered
moderate convection is noted from 05N to 10N between 27W and 30W.
The axis a tropical wave is near 36W from 15N southward, moving W
at 10 to 15 kt. Scattered moderate and isolated strong convection
is noted from 02N to 07N between 31W and 41W.
The axis of a tropical wave is near 55W from 15N southward,
moving W at 10 to 15 kt. Scattered moderate convection is noted
from 08N to 10N between 54W and 56W. This tropical wave is
forecasted to reach near the Windward Islands late tonight,
increasing the likelihood of showers and thunderstorms there.
The axis of a tropical wave is along 80W from 18N southward,
moving W at 10 to 15 kt. No significant convection is noted with
this wave over the Caribbean waters.
The monsoon trough passes through the coast of Africa near
11N15W and continues through 09N20W to 06N34W to end near 07N37W.
The ITCZ then continues from 07N37W to end near 07N53W. Aside
from the convection described in the tropical waves section above,
scattered to numerous moderate and isolated strong convection is
noted SW of the coast of Africa from 02N to 08N between 10W and
GULF OF MEXICO...
A broad 1008 mb surface low is centered over the Bay of Campeche
near 20N95W. A surface trough extends from 20N97W to the low to
18N92W. Scattered moderate and isolated strong convection is noted
from 18N to 23N between 94W and 98W. A 1015 mb high center is
analyzed near 26N90W with a ridge axis extending to the central
Texas coast and through the Straits of Florida. A complex of
scattered thunderstorms has moved from the lower Mississippi
Valley into the N central Gulf north of 27N between 85W and 90W.
Moderate anticyclonic winds are noted south of 23N and north of
27N, with light to gentle anticyclonic winds elsewhere. Seas are
3 ft or less across the basin, except higher in and near any
For the forecast, weak high pressure ridging will remain over the
central Gulf of Mexico through the early part of the week
supporting mainly gentle to moderate anticyclonic winds across the
basin. A trough of low pressure that has formed over the Bay of
Campeche. Slow development is possible over the next several days
while the broad disturbance moves little, and a tropical
depression could form in this area by Thu or Fri. Regardless of
development, heavy rainfall will be possible over portions of
southern Mexico during the next several days. Please consult
products from your local meteorological service for more
Earlier scatterometer data showed fresh to strong winds in the S
central Caribbean and just offshore of the central coast of
Honduras. Gentle to moderate trades prevail elsewhere. Seas are
4 to 7 ft in the S central Caribbean, 4 to 6 ft elsewhere in the
central and eastern Caribbean, and 2-4 ft in the western
Caribbean. Scattered showers and thunderstorms are noted over the
Gulf of Honduras extending inland across NW Honduras, far eastern
Guatemala, Belize, and the far southern portion of the Mayan coast
of Mexico. Isolated showers and thunderstorms are noted in the lee
of Cuba likely due to upper level divergence.
For the forecast, a ridge of high pressure north of the basin
combined with lower pressure over Central America and Colombia
will support fresh to strong trades over the S central Caribbean
and Gulf of Honduras through Thu. Moderate to fresh trades will
prevail elsewhere, except light to gentle south of 11N. A tropical
wave will move into the E Caribbean Mon.
A stationary front is analyzed north of the area along 32N to
across the southeast U.S. An associated pre-frontal trough
extends from 31N78W to near Cape Canaveral, Florida. Isolated
showers and thunderstorms are possible north of 29N near the
trough. Elsewhere, high pressure ridging dominates the basin
anchored by a 1029 mb high center just northeast of the Azores at
41N24W, extending west-southwest through 31N47W to the central
Bahamas. Gentle to moderate winds are found under the ridge axis,
with moderate to fresh winds north of 27N and west of 60W, as
well as south of 20N and west of 45W, and east of 45W. An
exception is fresh to strong northeast winds south of 30N and east
of 20W across the Canary Islands to the coast of Africa. Seas are
mainly 4 to 7 ft east of the Bahamas across the open waters of
the tropical Atlantic, except 5-8 ft near the fresh to strong
A large area of Sahara dust covers the tropical Atlantic westward
to near the Windward Islands. Both the GOES Geocolor imagery and
Sahara Dust imagery from CIMSS indicate this feature.
For the forecast west of 65W, a ridge of high pressure along 28N
will sink southward today. Winds will be moderate to fresh north
of 28N through the early part of the week as pair of cold fronts
move by north of the area, except fresh to strong Tue through Wed.