Tropical Weather Discussion
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AXNT20 KNHC 041040

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
640 AM EDT Tue Aug 4 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 0600 UTC surface analysis and satellite imagery through
0920 UTC.


Doppler radar imagery and surface observations indicate that
center of Tropical Storm Isaias is inland across northeastern
North Carolina, near 36.3N 77.5W at 5 am EDT, moving quickly NNE
at 28 mph. Maximum sustained winds are near 60 kt, 70 mph. or 110
km/h with higher gusts. The strongest winds are occurring across
the eastern side of Isaias, and were impacting the coastal waters
of the Outer Banks of North Carolina, as well as Pamlico and
Albemarle Sounds. Scattered showers and small isolated clusters of
moderate thunderstorms extend from offshore of the Outer Banks
southwestward to the waters N of 28N, and also southward into the
central Bahamas between 74W and 77W.

Isaias will continue to accelerate north northeastward and race
along the eastern seaboard and the I-95 corridor today, producing
sustained tropical storm force winds and wind gusts to hurricane
force. Heavy rainfall along its path will also produce flash

Please read the latest NHC Public Advisory at and
Forecast/Advisory at for more details.


A far eastern Atlantic tropical wave has its axis along 22-23W
from 03N-18N, moving westward at 10-15 kt. The wave is embedded
within deep tropical moisture south of 13N. Scattered moderate
Isolated strong convection is seen about the African monsoon
trough from 04.5N to 12.5N between 20W and 28W.

An eastern Atlantic tropical wave has its axis along 35W
from 02N-18N, moving westward at about 10-15 kt. This wave is
embedded within deep tropical moisture south of 16N. Scattered
moderate convection is seen about the monsoon trough in that area
of the Atlantic, from 03N to 09N between 28W and 40W.

A central Atlantic tropical wave has its axis along 45W-46W,
from 02N to 15N, moving westward at 15 kt. Scattered moderate
isolated strong convection is noted ahead of the wave, from 07N to
13N between 45W and 54W.

A central Caribbean tropical wave has its axis along 77W from
00N-18N, moving westward at 15-20 kt. Scattered moderate
convection is seen north of the wave to the east and north of
Jamaica, while scattered moderate to strong convection is along
the monsoon trough between Colombia and 81W.


The monsoon trough axis extends from the coast Africa near
20N16W to 10N37W to 10N45W. The ITCZ extends west of a tropical
wave from 07N59W to 06N58W. No significant convection is noted
aside from the convection described in the Tropical Waves section


Surface ridging prevails across the basin, anchored by a 1016 mb
high entered near 28N93W. Overnight scatterometer data depicted
light to gentle anticyclonic winds across the whole area, with
seas ranging between 2-4 ft. Scattered strong convection occurring
over land also extends northward across the central Bay of
Campeche south of 20N.

The weak high pressure ridge will persist over the N Gulf this
week, maintaining gentle flow across much of the region, while
moderate winds across the eastern Bay of Campeche pulse to fresh
each late afternoon through night.


Refer to the section above for details on the tropical wave over
the central part of the basin.

Scattered moderate to strong convection persists across the waters
from 18N-20N from north of Jamaica to 82W. To the south, the EPAC
monsoon trough extends along 10N between 75W-83W where active
convection prevails. Overnight scatterometer data depicted gentle
to moderate trades across the basin except south of 15N between
66W-72W, where moderate to fresh easterly winds were noted.

The Bermuda High north of the area along with the typical
eastward extension of the NE Pacific monsoon trough to Colombia
will contribute toward fresh to strong E trades over the central
Caribbean from today through Fri. Elsewhere winds and seas are
at or below normal. No tropical cyclone formation is expected in
these waters for the next several days.


Refer to the sections above for details on Tropical Storm Isaias
and the tropical waves moving across the basin.

Scattered moderate convection continues over the northwest
waters W of 74W, extending from the southern periphery of Isaias.
To the east, a surface trough extends from 29N65W to 24N71W will move
NW across the area waters today then weaken tonight and Wed.
Associated convection has become scattered across the north end of
the trough from 27N-29N between 65W and 86W. Surface ridging
extends from the NE Atlantic southwestward and south of the front
to 60W, anchored by a 1023 mb high centered near 37N21W.

High seas north of 29N associated with Tropical Storm Isaias will
shift northward and exit the waters west of 75W, allowing seas to
gradually subside there today through tonight. Weak troughing
will linger across the waters north of 25N and west of 50W through
Fri, leading to gentle to moderate winds across most of the area
waters. Meanwhile moderate to fresh trades will prevail across the
tropical Atlantic south of 20N, with seas 4-7 ft.

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