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Atlantic Tropical Weather Discussion

AXNT20 KNHC 241055

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sat Jul 24 2021

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 
0950 UTC.


A 1015 mb low pressure centered over the waters east of 
Jacksonville, Florida, near 29.5N77.5W, and has a trough that 
extends W to near Daytona Beach, Florida and across the peninsula.
This low continues to produce an area of showers and 
thunderstorms to the south and and east of the low, extending 
from NW Bahamas northeastward to beyond 31N74W. This system has 
become better organized since yesterday, and a tropical depression
could Form over the weekend while the low meanders offshore or 
near the Florida peninsula. Interest in Florida should monitor the
progress of this system. There is a medium chance for development
in the next 5 days. Please read the latest Tropical Weather 
Outlook at, for more information.

Heavy Rainfall in Southern Central America: High moisture content,
persistent strong trade wind flow, and favorable conditions aloft
will continue to support heavy rainfall for much of southern 
Central America through early next week. The heaviest rain is 
expected over the Caribbean coast of Costa Rica and southeast 
Nicaragua. These rains could cause significant flooding and 
mudslides in some areas. Currently, scattered moderate to strong 
convection is noted along the Caribbean coast from southern 
Nicaragua through western Panama.


A Caribbean tropical wave extends from the Atlantic waters north 
of Puerto Rico near 22N66W to 10N63W, moving W near 20 kt.
Overnight scatterometer data and recent surface observations
indicate a sharp surface trough associated with this wave and have
required a repositioning farther to the W. A broad area of Saharan
Air and a low level wind surge accompany this wave. Scattered
squalls and thunderstorms have developed overnight between the
islands of the NE Caribbean and 23N as the wave has interacted
with an upper level low center to the north of Hispaniola. Other
scattered showers and squalls extend south and southeastward
across the Lesser Antilles and across the tropical Atlantic to

A Caribbean tropical wave is along 75W, from the eastern end of
Cuba to northwest Colombia, moving W at 15 to 20 kt. A few small 
clusters of showers are seen across the Windward Passage and 
the waters of the southeast Bahamas.

Another Caribbean tropical wave is analyzed along 83W, north of 
14N through western Cuba. No significant convection is associated
with this wave.


The monsoon trough enters the Atlantic Ocean near Guinea-Bissau 
near 12N16W to 10N21W to 11.5N30W. The ITCZ continues from 11.5N30W
to 10N46W to 11N54W. Scattered moderate convection is noted over 
the eastern Atlantic within 210 nm south of the trough between 29W
and Africa, and from 06N to 14N between 48W and 58W.


Scattered moderate convection extends from the coastal waters of
SE Louisiana to near the Tampa Bay, Florida area, and are
associated with a surface trough that has moved southward into the
NE Gulf. Across the northwest Gulf, a 1020 mb high pressure is 
centered near 27N92W, which is dominating the wind flow across 
much of the Gulf. To the southeast, a surface trough is analyzed 
along the west coast of the Yucatan Peninsula. Scattered moderate
convection is noted west of the trough to 93W and south of 22N. 
Moderate S winds are noted along the Texas coast, west of the 
high pressure. Elsewhere, the high pressure is supporting light 
to gentle breezes and mostly 1 to 3 ft seas across the basin. 

The high pressure in the northwest Gulf of Mexico will meander 
and weaken through Mon as low pressure meanders offshore of the 
Atlantic waters of central Florida, and an associated trough
across the NE Gulf drifts SW across the eastern Gulf. This is 
expected to produce tranquil marine conditions across the Gulf 
through early next week. 


A nearly stationary middle to upper low center remains north of 
Hispaniola near 21N79W and continues to interacting with the 
tropical wave moving across the E Caribbean to produce scattered
squalls and a few thunderstorms across the waters of the NE
Caribbean, from the Mona Passage southeastward to the waters of
Guadeloupe and Dominica. Expect this activity to shift westward
across the eastern Caribbean today. Overnight scatterometer data
indicated a large area of fresh to strong trades winds over the 
south-central and southwest Caribbean, with the strongest winds 
off northeast Colombia. Seas are 5 to 9 ft in this area. These 
enhanced winds are occurring between the Atlantic high pressure 
ridge extending W-SW to the NW Bahamas, and low pressure over 
northern Colombia. Fresh winds are also noted just west of the 
Leeward Islands, south of Cabo Beata on the south coast of 
Hispaniola, and over the northern part of the Windward Passage. 
Elsewhere, generally moderate E winds and 3 to 5 ft seas are 

This Atlantic ridge will weaken through early next week as the 
high shifts slowly NE and low pressure persists offshore of the 
Florida coast. This will lead to a gradual diminishing in the 
strength of tradewinds across the basin through tonight that will 
persist through early Wed. Look for scattered squalls and tstms 
across the NE Caribbean today and tonight associated with the 
fast moving tropical wave. 


Please see the Special Features section above for information
related to the area of low pressure off northeast Florida. 

A nearly stationary middle to upper low center remains north of 
Hispaniola near 21N79W and continues to interacting with the 
tropical wave moving across the E Caribbean, and is supporting
scattered squalls and strong thunderstorms between 23N and Puerto
Rico and the Virgin Island. Expect this activity to continue today
east of 68W as the tropical wave moves across the eastern 
Caribbean and adjacent Atlantic waters to the north. Fresh to
strong ESE winds and seas of 6-8 ft will prevail across the
southeast waters today.

Elsewhere, 1026 mb high pressure near 34N42W extends W-SW to the
NW Bahamas and is supporting moderate to fresh tradewinds south 
of 25N, and mainly dry weather conditions across the remainder of 
the basin. Seas within this region are 6-8 ft. Fresh to locally 
strong E winds are active off the north coast of Hispaniola, 
reaching westward to the approaches of the Windward Passage, with 
5 to 6 ft seas. Another area of fresh to strong NE winds surrounds
the Canary Islands east of 25W, with winds reaching near gale 
force between the islands. Seas are 5-7 ft east of 25W. Elsewhere,
gentle to moderate flow prevails and seas of 4-6 ft.

Moderate to fresh trades will prevail south of 25N through Sun. 
Low pressure near 29.5N77.5W 1015 mb has a trough that extends SW
to central Florida. Environmental conditions are forecast to be 
marginally conducive for additional development of this low, with 
potential for it to become a tropical cyclone over the weekend 
while it meanders near or just offshore of Florida, then drifts W 
across Florida early next week. Scattered squalls and tstms 
associated with the fast moving tropical wave will move across the
SE waters and north of the Greater Antilles through tonight.