[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111006
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Jul 11 2022

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
1000 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 34W from 07N
to 20N. It is moving westward at 10-15 kt. Convection with this
wave remains suppressed as African dust surrounds this wave.
Scattered moderate convection is limited to within 120 nm east of
the wave from 07N-10N and within 60 nm east of the wave from 07N-
09N.

An eastern Caribbean tropical wave has its axis along 66W south
of 19N, moving westward at 15-20 kt. No significant deep
convection is noted with this tropical wave.

A western Caribbean tropical wave has its axis along 82W south
of 21N to northern Panama. It is moving westward at 10-15 kt. This
wave is situated to the southeast of an upper-level low that is
near the western tip of Cuba. Divergence aloft between this low
and the tropical wave is helping to sustain scattered moderate to
isolated strong convection that is west of the wave axis from 12N
to 14N west of the wave to just inland Nicaragua. Similar
convection is along the coast of Honduras, north to near 18N.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Guinea near 11N15W
just east of a a tropical wave axis near 10N34W. The ITCZ begins
just west of the same tropical waves axis near 10N35W to 09N48W
and to along the coast of Guyana at 09N60W. In addition to
convection associated with the Atlantic tropical wave, scattered
moderate to isolated strong is within 120 nm south of the ITCZ
between 37W-49W. Scattered moderate convection is within 300 nm
south of the trough between 20W-25W and within 180 nm south of the
trough between 25W-28W.

GULF OF MEXICO...

A weak ridge continues to dominate the Gulf waters supporting
mainly light and gentle winds, except moderate to locally fresh
southerly winds over the far NW Gulf. A surface trough is analyzed
from inland the Florida panhandle, south-southwest to Apalachicola
and out over the Gulf to near 29N87W. Scattered showers and
isolated thunderstorms are seen within 120 nm either side of the
trough north of 28N. Isolated showers and thunderstorms are from
25N to 28N between 85W-89W. Areas of rain, with embedded scattered
showers and isolated thunderstorms are from 21N to 25N between
87W-90W.

Moderate to fresh northeast to east winds are just west of the
Yucatan peninsula due to the an enhanced gradient related to the
Yucatan Peninsula trough that has shifted to offshore the Yucatan
Peninsula. Buoy observations along with recent altimeter data
indicate seas of 3 ft or less throughout, except for higher seas
of 3-5 ft in the central Bay of Campeche.

For the forecast, surface ridging extending across the basin will
maintain light to gentle return flow east of 90W through the
forecast period, except over the far northeast part of the basin
where a slighter tighter gradient near the aforementioned surface
trough will support moderate to fresh southwest winds. Gentle to
moderate southerly winds west of 94W will increase to moderate to
fresh speeds at night through Thu, while diminishing back to
gentle to moderate speeds by early in the afternoons as broad low
pressure develops over Texas and northeastern Mexico. Light to
gentle winds are expected across the Gulf on Fri, except over the
eastern Bay of Campeche where winds will be enhanced by a thermal
trough coming off the Yucatan peninsula at night. Southerly winds
may be enhanced over sections of the north-central and NE Gulf
from Wed through Fri night associated to the surface trough or
to low pressure that may form from the trough.

CARIBBEAN SEA...

The pressure gradient between the Bermuda-Azores High located
well northeast of the area and the Colombian Low supports fresh to
strong northeast to east trade winds across much of the central
Caribbean. A 1017 mb high is along the western tip of Cuba.

Seas are in the 8-9 ft range with these winds based on overnight
altimeter data passes. Mainly moderate trade winds along with seas
of 5-7 ft are in the eastern Caribbean, while gentle northeast to
east winds are over the northwestern Caribbean along with seas of
3-5 ft.

An elongated upper-level low is identified on water vapor imagery
to be over the northwestern Caribbean near 21N86W. It continues
to support the development of showers and thunderstorms across
parts of Cuba and the NW Bahamas and convection associated to
the tropical wave along 82W as described above. This feature will
also continue to aid in the development of showers and thunderstorms
over South Florida today. The upper-level low will move into the
far south-central Gulf of Mexico by early this evening.

For the forecast, strong high pressure centered over the north-
central Atlantic extending a ridge to the northern Caribbean will
maintain moderate to fresh trade winds across the E basin, and
fresh to strong winds in the central and portions of the SW basin
through Fri night. These winds will be modulated by a pair of
tropical waves moving across the area. Gentle to moderate winds in
the northwestern Caribbean will increase to moderate to fresh on
Tue, and reach strong speeds in the Gulf of Honduras on Tue night,
continuing through Fri night.

ATLANTIC OCEAN...

The subtropical Bermuda-Azores High continues to dominate the
Atlantic forecast waters, with the associated ridge extending
toward the Bahamas and Florida. Moderate to locally fresh
northeast to east trade winds are present between the ridge and
the ITCZ. Seas are 6-8 ft south of 22N and 4-5 ft north of 22N.
Strong to locally near gale force northerly winds are between the
Canary Islands with moderate or rough seas. An altimeter pass
across this area shows seas of 8 to 9 ft. CIMSS Saharan Air Layer
(SAL) GOES-E images and the GOES16 RGB dust imagery indicate
substantial amount of African dust east of 62W covering the
majority of the tropical North Atlantic.

For the forecast west of 55W, the Bermuda-Azores High will continue
to extend a ridge southwestward across the region, which will
maintain moderate to fresh easterly winds mainly south of 25N
during the forecast period. Moderate to fresh southwest winds
north of 29N associated with the passage of a frontal boundary
north of the area will diminish slightly on Tue and continue
through Thu. Afterwards, these winds become mainly gentle
southeast to south through Fri night.

$$
Aguirre
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