[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 311059
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Jul 31 2023

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
1040 UTC.

...SPECIAL FEATURES...

Central Tropical Atlantic Gale Warning (Invest AL96): A 1011 mb
low pressure is centered near 22N52.5W. Numerous moderate isolated
strong convection is noted within 270 nm in the eastern
semicircle. Earlier ASCAT passes from late Sunday evening showed
gale force winds to 35 kt in the eastern semicircle, within the
convection. Peak seas are estimated at 13 ft. Environmental
conditions are forecast to be marginally favorable for development
over the next few days, and a tropical depression or tropical
storm is likely to form during the next day or so. The system is
expected to move northwestward at about 10 to 15 kt today, and
then turn northward over the central subtropical Atlantic by late
tonight or Tuesday. There is a high chance of tropical cyclone
development of this system through the next 48 hours. During the
next 48 hours, this system is forecast to produce winds of 35 to
40 kt and seas of 12 to 16 ft. Please read the latest High Seas
Forecast issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC
Tropical Weather Outlook at www.hurricanes.gov for more details.

...TROPICAL WAVES...

A tropical wave is analyzed in the eastern Atlantic with its axis
near 30W from 04N to 20N, moving westward at around 15 kt.
Scattered moderate convection is within 360 nm E of the wave axis
from 07.5N to 12N.

An eastern Caribbean tropical wave extends from St. Kitts and
Nevis to Venezuela near 10N64W and inland to 03N64W, moving W at
10 to 15 kt. Scattered moderate isolated strong convection is
noted within 60 nm either side of a line from 18N57W to 15N67W,
including Guadeloupe, Antigua, Montserrat and St. Kitts and Nevis.
Scattered moderate convection is also affecting portions of the
ABC Islands.

A western Caribbean tropical wave is located along 82W from 22N
southward to western Panama, moving W at around 15 kt. Isolated
showers and tstorms are noted near the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near 19N16W
to 08N41W. Aside from the convection described above, isolated
moderate convection is noted along and within 120 nm S of the
monsoon trough between 33W and 41W.

GULF OF MEXICO...

Scattered showers and thunderstorms are noted over portions of the
northeastern Gulf of Mexico. Similar activity is seen over the
western Straits of Florida to north of the Yucatan Channel.
Moderate convection also covers a small area in the southern Bay
of Campeche, south of 19.5N between 95W and 96W. Otherwise, high
pressure ridging prevails across the northern Gulf, anchored by a
1018 mb high pressure near 28N89W. This is leading to light to
gentle winds across the basin with seas 1 to 3 ft.

For the forecast, the surface ridge will remain the dominant
feature across the basin through early this week. This will
support gentle to moderate winds, except over the eastern Bay of
Campeche during the middle to latter part of the week, where winds
will be enhanced by a thermal trough that will emerge off the
Yucatan Peninsula each night. High pressure will shift SE into the
east Gulf Tue and Wed and allow for moderate return flow to
develop across the W Gulf Wed through Fri.

CARIBBEAN SEA...

Please refer to the Tropical Waves section above for information
on the waves moving across the Caribbean.

The east Pacific monsoon trough is inducing scattered strong
convection across eastern Panama, NW Colombia, and the waters
south of 11.5N between 75W and 80W. Fresh to strong trade winds
continue across the central Caribbean with seas 7 to 8 ft. Mainly
moderate winds prevail elsewhere with 3-6 ft seas.

For the forecast, the pressure gradient between high pressure
ridging north of the area and lower pressure over Colombia will
maintain fresh to strong trades across the central Caribbean
through this morning. A 1011 mb low pressure near 22N52.5W is
expected to move NW into the open Atlantic through Wed, disrupting
the ridging N of the area. As this occurs, winds will diminish
slightly across the Caribbean, and the fresh to locally strong
winds will be confined to the south-central Caribbean.

ATLANTIC OCEAN...

Please refer to the Special Features section for details on low
pressure well NE of the Leeward Islands that has potential for
tropical development. Elsewhere, scattered showers and isolated
thunderstorms prevail across the western Atlantic, west of 67W
through the northwest Bahamas area. A surface ridge extends from
31N57W to 26N66W to the southern tip of Florida. To the north of
the ridge, moderate to fresh SW winds are present north of 30N
between 65W and 75W, where seas are 4 to 6 ft. Fresh trades and
4-5 ft seas are also present north of Hispaniola and within the
Windward Passage. Mainly gentle winds and 3-4 ft seas prevail
elsewhere over the western Atlantic.

East of 60W, AL96 is affecting waters from 20N to 27N between 46W
and 55W. A 1027 mb high pressure centered near 34.5N37W dominates
the remainder of the waters. Fresh trades are in the E Atlantic
from 16N to 27N with seas 5 to 7 ft. Fresh to strong NE winds
extend from the coast of Morocco through the Canary Islands with
seas 6 to 8 ft.

For the forecast west of 55W, the aforementioned high pressure
centered SW of the Azores will gradually shift E-NE through the
week. Moderate to locally fresh trade winds will continue S of 23N
through early Tue before diminishing. Fresh trades will pulse
during the afternoon through early evening today and Tue N of
Hispaniola and over the Windward Passage. A gale force 1011 mb low
pressure across the central Atlantic near 22N52.5W will move NW
then N and brush the NE offshore zones tonight through early Wed,
likely as a tropical cyclone, before exiting the region to the N,
which will act to disrupt the Atlantic ridge. A weak frontal
trough will sink S into the waters offshore of NE Florida Tue
night and move SE and reach from near Bermuda to the northwest
Bahamas by Thu.

$$
Hagen
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