[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 022341
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
805 PM Sun Aug 02 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
2315 UTC.

...SPECIAL FEATURES...

Tropical Storm Isaias is centered near 27.8N 79.8W at 02/2100
UTC, or about 55 miles southeast of Cape Canaveral, Florida and
about 355 nm south of Myrtle Beach, South Carolina moving NNW or
345 degrees at 8 kt. The estimated minimum central pressure is
994 mb. Maximum sustained winds have increased slightly to 60 kt
with gusts to 76 kt. GOES-16 satellite imagery shows a large and
rather symmetrical area numerous moderate to strong type
convection within 180 nm NE of the center. Similar convection is
within 90 NW and 60 nm SE of the center. Scattered moderate to
isolated strong convection to the southeast of the center depicts
a band within 30 nm either side of a line from 26N77W to 27N78W.
Scattered moderate convection is within 30 nm either side of a
line from Miami, Florida to 26N78W and to 26N77W. Fresh to strong
winds on the periphery of Isaias reach northward to near 30N,
eastward to near 75W and westward to near 80W. Peak seas with
Isaias are up to around 22 ft. Isaias is forecast to continue on
a general north to northwest motion through tonight. A turn
toward the north and north-northeast along with an increase in
forward speed is anticipated on Mon and Tue. On the forecast
track, the center of Isaias will pass just to the east of the
Florida east coast through tonight. The center of Isaias will
then move offshore of the coast of Georgia and southern South
Carolina on Mon. It will move inland over eastern North Carolina
Mon night and move along the coast of the mid-Atlantic states on
Tue.

Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT4.shtml, and the
Forecast/Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT4.shtml, for more details.

A tropical wave extends along a position from near 20N60W to
15N62W and to inland Venezuela, moving westward at about 15 kt.
This wave remains within close proximity to an inverted mid to
upper-level trough to its northwest. As a result, scattered
moderate convection has been sustained and is increasing with
time near and across the northern part of this wave. This
activity is evident from 20N to 25N between 58W-63W. Isolated
showers and thunderstorms are from 17N to 20N between 58W-61W.
This system is forecast to move through environmental conditions
that are conducive for additional development during the next
few days, and a tropical depression could form by the middle of
the week. This system is forecast to move northwestward over the
western Atlantic early this week, passing north of the Leeward
Islands. It has a medium chance of becoming a tropical cyclone
during the next 48 hours. Please refer to the latest NHC Tropical
Weather Outlook at www.hurricanes.gov for more details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis from 01N to
across the Cabo Verde Islands and to near 19N, moving westward
near 15 kt. Scattered moderate to isolated strong convection is
within 120 nm west of the wave axis from 06N to 10N and along and
within 30 nm east of the wave axis from 08N to 10N.

A central Atlantic tropical wave has its axis along 43W from
02N to 16N, moving westward at 15 kt. This wave marks the leading
edge of a pool of deep atmospheric moisture. Isolated showers
and thunderstorms are within 180 nm east of the wave axis from
04N to 13N. This activity could increase during the overnight
hours.

A central Caribbean tropical wave has its axis along 75W south of
19N to inland Colombia. It is moving westward at 13 kt. This wave
was introduced on the 18Z per updated guidance and past tracking
history. Only isolated quick westward moving isolated showers and
thunderstorms are noted within 180 nm east of the wave from 14N
to 17N and within 120 nm west of the wave from 14N to 18N. Some
of this activity is approaching the eastern tip of Jamaica.
The northern part of the wave may be assisting to some extent
with the development of scattered showers and thunderstorms over
most of interior Haiti.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coast of Senegal near
14N17W to 11N30W to 10N40W and to 10N50W, where latest
scatterometer data indicates that it transitions to the ITCZ
and continues to 11N60W. Aside from the convection related to
the tropical waves described above, scattered moderate to
isolated strong convection is seen from 08N to 14N between
13W-23W. Scattered moderate convection is within 240 nm south
of the trough between 29W-32W and within 180 nm south of the
trough between 35W-38W. Similar activity is within 60 nm south
of the trough between 53W-59W.

GULF OF MEXICO...

Upper-level anticyclonic flow tied to a small anticyclone that
is located just south of the Yucatan Channel covers just about
the entire basin, except over in the far northwest part where a
mid to upper-level trough is located. At the surface, a 1014 mb
high center is analyzed near 27N93W as of 2100 UTC. A trough is
over the far southwestern Gulf from near 23N97W to just inland
the coast of Mexico at 18N94W. Isolated showers and thunderstorms
are south of 25N between 90W-96W. Broken bands of scattered
showers and isolated thunderstorms rotating around the western
semicircle of Isaias are over the interior sections of the
Florida peninsula, with some of this activity having reached the
far eastern part of the Gulf mainly south of 29N. The activity
over the Gulf waters appears to be diminishing.

Winds throughout the basin are in the light to gentle range,
except for winds of moderate speeds near the coast of Florida.
Seas in the basin are rather low, in the 2-4 ft range.

Moderate winds will continue near the west coast of Florida
through early Mon as Isaias moves north-northwest near the east
coast of Florida. A weak high pressure ridge will persist over
the northern Gulf this week, maintaining gentle flow across much
of the region with moderate winds expected over the southwestern
Gulf.

CARIBBEAN SEA...

A small upper-level anticyclone is just south of the Yucatan
Channel near 21N86W, with associated anticyclonic flow present
to the west of 79W. At the surface a trough extends from just
south of the western tip of Cuba to a 1011 mb low at 18N87W and
to just inland the border between Guatemala and Honduras. Scattered
showers and thunderstorms are along and near the trough from
18N to 20N between 84W-86W. Otherwise west of the tropical wave
along 75W, isolated showers moving quickly westward are over the
central and western Caribbean waters north of about 12N. Similar
showers are over the eastern Caribbean north of 14N.

Winds are light to moderate across the basin, with seas in the
from 3-6 ft.

The northern part of the eastern Caribbean sea tropical wave
will slightly increase winds and seas over the Tropical N
Atlantic waters north of 15N and east of 64W tonight. Fresh
trade winds over the central Caribbean waters are expected to
strengthen by mid-week following the passage of the above
described tropical wave.

ATLANTIC OCEAN

See the Special Features section above for more details on
Tropical Storm Isaias and on a tropical wave near the Leeward
Islands with potential for development.

High pressure is present across most of the Atlantic, anchored
by a 1022 mb high center near 29N47W. A few troughs are analyzed
over the eastern and central sections of the area. The first one
from near 30N42W to 23N42 with no significant convection
associated with it, and the other from 35N31W to 28N36W, also
with no significant convection associated with it. A trough left
over from former Tropical Depression Ten extends from 23N27N to
16N30W. It has no convection. Another trough is ahead of this one
from near 24N32W to 17N36W and it has no convection. The
gradient across the area is allowing for light to moderate winds
throughout, except for fresh winds near the Canary Islands and
fresh to strong winds in the western part of the area on the
periphery of Tropical Storm Isaias. Seas range from 5-8 ft,
except for much higher seas in the range of 8-12 ft within the
area of 20-33 kt winds in the western part of the area outside
the tropical storm force winds related to Isaias.

Tropical Storm Isaias will move near the east coast of Florida
to 29.0N 80.1W Mon morning, 30.9N 79.9W Mon afternoon, then
accelerate N-NE away from the forecast waters to near 33.7N 78.8W
Tue morning. Large seas associated with Isaias will spread
northward across the waters W of 75W through Mon, then gradually
subside late Mon night through Tue night. The special features
system will approach the southeastern waters tonight, with
environmental conditions conducive for development during the
next few days. This system is expected to impact winds and seas
over these waters. For marine information regarding this system,
please read the latest high seas forecasts at website-
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml.

$$ Aguirre
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