[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 172335
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
735 PM EDT Fri Jul 17 2020

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
2220 UTC.

...TROPICAL WAVES...

The axis of a tropical wave is analyzed along 30W, from 18N
southward, moving westward at 10 knots. Scattered moderate
isolated strong convection is noted from 04N-11N between 24W-39W.

The axis of a tropical wave is analyzed along 45W from 14N
southward, moving westward at 10 knots. Only isolated moderate
convection is noted along the ITCZ between 50W and 51W.

The axis of a tropical wave is analyzed along 61W/62W, from 20N
southward, moving westward at 10 to 15 knots. Widely scattered
showers are moving across the Lesser Antilles and the adjacent
Atlantic waters north through northeast, otherwise no significant
convection is associated with this wave.

The axis of a tropical wave in the Caribbean Sea is analyzed along
79W from 21N southward, moving westward 15 knots. The northern
portion of the wave is interacting with an upper trough shifting
westward across the easterly Gulf of Mexico to produce scattered
moderate isolated strong thunderstorms to the northwest of the
wave, from 20N north and northwest of 80W across western Cuba and
the Yucatan Channel.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends off the coast of Senegal near 13N17W
to 10N27W to 07N42W. The ITCZ continues from 07N43W to 10N60W.
Scattered moderate isolated strong convection is north of the
monsoon trough to 15N east of 22N to the African coast.

GULF OF MEXICO...

Upper level ridging is noted across the western Gulf with an
middle to upper level low centered over the central Gulf along
89W-90W, shifting gradually westward. At the surface, a trough is
analyzed in the eastern Gulf along 85W-86W from 30N-23N. Scattered
showers and isolated thunderstorms are on either side of the
surface trough east of 89W, with thunderstorms more numerous
offshore of SW Florida. Scattered moderate isolated strong
thunderstorms are also across the NW Gulf from 24N to 28N west of
91W. Gentle to moderate easterly winds generally prevail across
the basin. Seas range 2 to 4 ft.

A surface trough across Florida today will move westward and pass
over the eastern Gulf tonight into Sat. Gentle to moderate winds
and slight seas are expected across the region, except for locally
fresh winds near the coast of the Yucatan peninsula due to local
effects.

CARIBBEAN SEA...

Generally dry and stable atmospheric conditions prevail across
much of the Caribbean, except for NW and south central portions.
Scattered moderate to strong afternoon convection is seen over the
Greater Antilles, while other convection across the far northwest
portions are described above with the tropical wave along 79W.
Widely scattered showers and a few moderate thunderstorms extend
from the A-B-C Islands westward to the Colombian coastal waters.
Moderate thunderstorms area also scattered about the Gulf of
Honduras. Fresh winds are north of Colombia with moderate to
fresh trades across the rest of the basin. Seas range 3 to 6 ft
with 8 ft north of Colombia.

The pressure gradient between high pressure north of the area and
climatological low pressure over Colombia will maintain fresh to
strong trade winds over the south-central Caribbean through early
next week. Elsewhere, gentle to moderate trade winds will persist
across the region.

ATLANTIC OCEAN...

Complex middle to upper level troughing meanders across the
Atlantic from the Azores Islands southwest to a small upper low
just north of the Mona Passage. Much of the area is generally
stable east of 67W. Broad upper ridging across Florida and the
adjacent Atlantic west of 67W is acting to enhance afternoon
convection across Florida south of Orlando, as well as the
adjacent waters of the NW Bahamas and Grand Bahama Banks.

At the surface, a 1025 mb high is across the east central Atlantic
near 42N32W and extends a ridge southwest to 28N50W. A lingering
surface trough extends from 31N49W to 28N57W, where scattered
showers and a few moderate thunderstorms are seen within 120 nm
east of the trough. To the west, a weak 1023 mb high is centered
near 33N70W. Easterly winds of 10-18 kt generally prevail south of
28N to the Greater Antilles and are providing ample moisture
across the Bahamas and Florida for the current convection. A band
of fresh easterly winds was depicted by morning scatterometer data
from 20N-24N between 40W and 60W. Elsewhere across the tropical
Atlantic, tradewinds are below normal at 18 kt or less based on
morning scatterometer data. Associated seas are only 4-6 ft.

The high pressure north of the area will support pulses of fresh
to strong winds off Hispaniola and near the entrance to the
Windward Passage for the next couple of nights. Otherwise,
moderate to fresh easterly winds will generally prevail south of
27N and west of 60W through the weekend. A tropical wave will
pass westward across the waters S of 24N Sat through Sun night.
Winds and seas may increase E of 65W Tue night through Wed night
following the passage of another tropical wave.

$$
Stripling
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