[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201707
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sat May 20 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 1200 UTC surface analysis and satellite imagery through
1655 UTC.

...SPECIAL FEATURES...

Excessive Rainfall in W Colombia and E Panama: A deepening
upper-level trough across the Caribbean is interacting with the
Colombian/Panamanian low and the monsoon trough. This results in a
large area of deep convection just south of Panama and also
affecting western Colombia. This pattern will bring enhanced
moisture to western sections of Colombia and eastern Panama over
the weekend. It will also lead to the potential for heavy
rainfall across this area today through early Mon, then will shift
eastward across the remainder of Colombia and across Venezuela
Mon through early Tue. These rains could lead to moderate
flooding. Please refer to the latest forecast products from your
local or national meteorological service for additional
information.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has been introduced along 11W,
south of 14N and moving westward at 5-10 kt. Scattered moderate
convection is observed over the coastal waters of Africa between
07W and 15W.

Another eastern Atlantic tropical wave has its axis along 28W,
south of 13N and moving westward at 10 kt. Scattered moderate
convection is noted south of 08N and between 25W and 31W.


...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic Ocean through the coast
of Guinea near 10N14W and extends to 06N20W then to 04N31W. The
ITCZ is analyzed from 04N31W to the coast of Brazil near 01N50W.
Scattered moderate convection is observed within 90 nm north of
the ITCZ between 33W and 43W.

GULF OF MEXICO...

A weak pressure regime dominates the Gulf of Mexico while a weak
stationary front sags into the offshore waters of the Florida
panhandle. No deep convection is noted across the basin. Light to
gentle winds and 1-3 ft seas prevail.

For the forecast, weak high pressure will dominate the Gulf of
Mexico into early next week, inducing light to gentle winds and
slight seas. A diurnal trough will move offshore each night W of
the Yucatan Peninsula, with moderate N to NE winds ahead of it. A
weak trough will sink into the northern Gulf late Mon, and
gradually produce gentle to moderate N to NE winds across the
entire basin by Wed.

CARIBBEAN SEA...

Divergence aloft over the Bahamas is producing a large area of
showers and thunderstorms and some of these showers are affecting
the waters south of Hispaniola. A few thunderstorms are also
impacting the nearshore waters near the Panama and Colombia
border. A dry airmass is suppressing the storm activity in the
rest of the Caribbean Sea.

The extensive subtropical ridge northeast of the Greater Antilles
supports moderate to locally fresh easterly winds across the
central and eastern Caribbean. Seas in these waters are 5-8 ft,
with the highest seas occurring off NW Colombia. Moderate or
weaker winds and slight seas are prevalent in the remainder of the
basin.

For the forecast, a very modest pressure gradient across the basin
will lead to moderate trades and slight to moderate seas over
the east and central Caribbean, except fresh to locally strong
trades S of 14N today. Winds will then gradually weaken across
the basin Sun through Wed as an inverted surface trough develops N
of the area along about 71W and slowly lifts northward. Showers
and thunderstorms will impact waters near the coasts of South
America and Panama as well as Caribbean waters E of 68W through
early next week.

ATLANTIC OCEAN...

A weak surface trough north of the central Bahamas and divergence
aloft from an upper level trough is producing a large area of
showers and isolated thunderstorms south of 27N and between 66W
and 73W. Farther west, a weak stationary front remains from 31N79W
to NE Florida and a few showers are noted ahead of the boundary.
Another surface trough extends from near Bermuda to 25N63W and
some showers are seen within 120 nm east of the boundary.

The remainder of the tropical Atlantic is dominated by a broad
subtropical ridge that is positioned north of the Azores and
maintains fairly tranquil weather conditions. Moderate to locally
fresh easterly winds are found over the vast majority of the
basin, especially east of 70W. Seas in these waters are 5-8 ft.
Moderate or weaker winds and moderate seas are prevalent west of
70W.

For the forecast west of 55W, the Atlantic high pressure ridge is
centered on the Azores high along 27W and extends SW to near 60W.
An inverted trough is expected to develop along 71W by Sun
afternoon and drift northward through Wed. Scattered to numerous
showers and thunderstorms are expected near and E of the trough
through Wed night.

$$
DELGADO
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