[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301110
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon May 30 2022

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
1045 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 36W from 02N
to 14N, moving westward around 15 kt. Increasing scattered
moderate to isolated strong convection is noted where the wave
interrupts the ITCZ from 03N to 08N between 33W-36W.

A central Atlantic tropical wave has its axis along 60W from 02N
to 14N. It is moving westward at 13 kt. Isolated showers are possible
near the wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Guinea-Bissau near 11N16W and extends to 09N17W, where overnight
scatterometer data indicates that it transitions to the ITCZ
and continues to 06N33W. It resumes to the west of the eastern
Atlantic tropical from 05N36W to 03N43W and to 00N50W. Aside from
convection associated to the eastern Atlantic tropical wave,
numerous moderate to isolated strong convection is emerging off
Africa within 180 nm south of the trough between 14W-16W.
Similar activity is within 120 nm south of the ITCZ between
24W-29W, and within 60 nm either side of the ITCZ between 36W-41W.
Scattered moderate convection is within 60 nm north of the ITCZ
between 41W-45W.

...GULF OF MEXICO...

Abundant rich deep tropical mid to upper-level moisture in the
form of broken to overcast multilayer clouds is streaming eastward
from the eastern Pacific Ocean to across the southern sections of
the Gulf. This moisture coupled with diffluent flow aloft along
with instability initiated by an upper-level low, and a rather
pronounced jet stream that runs along the southern part of the
upper-level low are all interacting with a couple of surface troughs
leading to scattered to numerous showers and thunderstorms over
the southeastern Gulf. One of the troughs extends from near 27N86W
to 24N89W, while the other one extends from near 23N91W to 19N93W.
Scattered showers and isolated thunderstorms are over the Bay of
Campeche. Isolated showers and thunderstorms are over the west-
central Gulf from 22N to 26N west of 94W. The weather pattern over
the remainder of the Gulf is being influenced by the western
periphery of Atlantic high pressure that reaches the central
Gulf. The pressure gradient between this feature and lower
pressure over Mexico is supporting moderate to locally fresh
southeast winds across the western Gulf waters, especially to the
west of 93W. A light to gentle anticyclonic wind flow is present
elsewhere. Seas of 3-5 ft are present in the western, south-
central and southeastern Gulf, seas of 4-6 ft are in the
southwestern and NW Gulf, while lower seas of 1-3 ft seas are in
the remainder of the basin.

For the forecast, high pressure extending from the western Atlantic
to across the central Gulf will maintain moderate to fresh SE winds
over the western Gulf and mainly gentle southeast winds elsewhere
through the period. Winds may increase to locally strong off the
Texas coast tonight. A large area of low pressure may impact the
southern Gulf by around mid-week.

...CARIBBEAN SEA...

Abundant rich tropical moisture covers the western section of the
Caribbean. This moisture is being transported from the eastern
Pacific Ocean via a rather strong upper subtropical jet stream
branch that stretches eastward to far northwestern Caribbean.
Resultant atmospheric instability in this part of the basin is
resulting scattered showers and thunderstorms mainly from 16N to
19N west of 83W, and south of 16N west of 81W to just inland
Nicaragua and northern Costa Rica. Similar convection is just
inland and along the coast of northwestern Colombia.

Fairly tranquil weather conditions are over the rest of the
Caribbean Sea, with the exception of a pocket of scattered
showers and thunderstorms that is located from along the southwest
part of Haiti, south to 15N and between 71W-74W. The pressure
gradient between subtropical high pressure and lower pressure over
Colombia is producing fresh to strong trades across the central
Caribbean and Gulf of Honduras, with the strongest winds occurring
offshore Colombia and the Gulf of Venezuela. Moderate to locally
fresh trades are noted in the eastern Caribbean, while lighter
winds are present over the northwestern southwestern Caribbean as
detected by overnight ASCAT data. Seas are 5-8 ft in the central
part of the sea, except for slighter higher seas of 6-9 ft in the
Colombian basin and 3-5 ft elsewhere, except for 4-6 ft seas south
of 15N between 64W-68W.

For the forecast, the subtropical ridge north of the area will
support fresh to strong winds and seas to 8 ft off the coasts of
Colombia and Venezuela into mid-week. Moderate to fresh trades
will prevail across much of the remainder of the Caribbean into
mid- week. A large area of low pressure may form in the far NW
Caribbean late this week.

...ATLANTIC OCEAN...

Divergence aloft provided by an upper-level trough that extends
from offshore the southeastern U.S. to an upper-level low just
off the northeast Florida coast and to another one over the
eastern Gulf of Mexico support a surface trough off Florida is
helping to sustain scattered to numerous shower and thunderstorm
activity that covers most of the waters west of about 72W,
including the Bahamas, Florida and surrounding waters. Colder air
aloft along with favorable dynamics in play may allow for some of
the shower and thunderstorm activity to attain strong to possibly
severe status. Mariners should exercise caution while navigating
these waters today and into this evening as showers and
thunderstorms may be accompanied by strong wind gusts and frequent
lightning.

The subtropical high over the central Atlantic dominates the rest
of the tropical Atlantic, permitting fairly tranquil weather
conditions. Overnight ASCAT data highlighted moderate to fresh
trades off northern Hispaniola and the southeastern Bahamas,
including the entrance of the Windward Passage. Seas of 3-6 ft are
noted W of 55W. Farther east, a cold front enters the basin near
31N17W and continues southwestward to 23N29W, where it
transitions into a stationary front that reaches to near 22N42W.
No deep convection is present near this frontal boundary. Isolated
shower and/or small patches of light rain are possible along and
near this frontal boundary. Another cold front has just entered
the area from near 31N27W to 29N33W. It continues northwestward
to 32N39W. Fresh northwest winds follow this front, along with
seas of 8-9 ft due to a north swell that follows the front west
of 30W, but exceeds the front by about 180 nm east of 30W.

Farther south, moderate to fresh trades are over the waters
south of 20N and between 35W and the Lesser Antilles. The
combination of wind generated wave mixed with northeast to east
swell is generating seas of 5-7 ft over these waters. Winds are
in the gentle to moderate range along with 3-6 ft seas across the
remainder of the basin.

For the forecast west of 55W, the subtropical ridge will change
little over the western Atlantic through the next few days. A
weak trough is expected to form near the NW and central Bahamas by
mid-week, then lift northeastward Thu and Thu night. Winds will
pulse moderate to fresh north of Hispaniola and the southern
Bahamas into Tue. Gentle to moderate winds will continue over the
remainder of the region into mid-week. Active weather is expected
over most of the western half of the forecast waters through the
next few days.

$$
Aguirre
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