Marine Weather Net

Puerto Rico Caribbean Waters from 10nm to 17N Marine Forecast


REST OF TODAY

S
WINDS
5 - 10
KNOTS

TONIGHT

W
WINDS
5 - 10
KNOTS

THURSDAY

W
WINDS
5 - 10
KNOTS

THURSDAY NIGHT

N
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
AMZ732 Forecast Issued: 929 AM AST Wed Mar 08 2023

Rest Of Today...South Winds 5 To 10 Knots. Seas Around 2 Feet Or Less. Dominant Period 11 Seconds. Isolated Showers.
Tonight...West Winds 5 To 10 Knots, Becoming Northwest After Midnight. Seas Around 2 Feet Or Less. Dominant Period 11 Seconds. Isolated Showers.
Thursday...West Winds 5 To 10 Knots. Seas 1 To 3 Feet. Dominant Period 11 Seconds. Isolated Showers.
Thursday Night...North Winds 10 To 15 Knots. Gusts Up To 25 Knots In The Evening. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 11 Seconds. Scattered Showers.
Friday...Northeast Winds 10 To 15 Knots With Gusts Up To 25 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 11 Seconds. Isolated Showers.
Saturday...Southeast Winds 5 To 10 Knots. Seas 2 To 4 Feet With Occasional Seas Around 5 Feet. Dominant Period 12 Seconds. Isolated Showers.
Sunday...Southeast Winds 5 To 10 Knots, Becoming East. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 12 Seconds.
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Area Forecast Discussion
National Weather Service San Juan PR
517am AST Fri Jun 14 2024

Synopsis
An induced surface trough passing through the region will promote passing showers and afternoon convection, mainly across western Puerto Rico. Isolated areas may experience heavy rainfall at times, however mid to upper-level ridging will limit widespread rainfall. A Heat Advisory will be in effect from 10am to 6pm for the metro area, north- central, northwestern and western PR. A limited heat risk will still be present along the rest of the lower elevation and coastal areas of the islands. Please continue to monitor the latest forecast for possible updates. By tomorrow, a plume of Saharan dust of moderare to high concentration is forecast to spread across the region, causing hot and hazy conditions that last through the second half of the weekend into the next workweek. An Excessive Heat Watch is in effect for tomorrow.

.SHORT TERM...Today through Sunday... A mid to upper ridge will remain anchored across Hispaniola and the Mona passage through the weekend while an upper trough will continue to extend southward across the northern Leeward Islands into the eastern Caribbean. The dominant surface high pressure will continue across the west and central Atlantic while an induced surface trough is forecast to cross the region today through Saturday. This will maintain a light to moderate east northeast wind flow this morning then become east southeast later this afternoon then more southeasterly throughout the weekend.

Fragmented low level moisture accompanying the trough and carried by the present wind flow will bring periods of light to moderate showers to the local waters and mainly the windward side of the islands during the rest of the early morning. No significant rains are anticipated. However this slight increase in moisture along with good daytime heating will be sufficient to increase instability across the region resulting in afternoon convection particularly across the central interior and west sections of Puerto Rico. Isolated areas may experience periods of locally heavy rains with the afternoon thunderstorms, however the mid to upper-level ridging will continue to limit widespread rainfall. Hot and humid conditions are expected to persist today with maximum heat indices to reach the 100 degrees along some coastal and urban areas resulting in excessive heat impacts.

By late Saturday and through Sunday, a plume of Saharan dust of moderare to high concentration is forecast to spread across the region while the low level winds becomes southeasterly. With this expected warm and humid southerly flow, expect continued hot and hazy conditions. The combination of suspended Saharan dust particulates and the mid to upper level ridging will favor subsidence and good compression of the warm air in the low layer. Daytime high temperatures will be in the low 90s especially along the north and west coastal areas with maximum heat indices expected to again exceed 100 degrees, resulting in excessive heat impacts particularly along the west north and east coastal and urban areas. Late afternoon convection will be likely each day but excessive and widespread rainfall is not forecast for the period.

Long Term
Monday through Thursday... Although a decrease in saharan dust is forecast to start the workweek, another pulse will continue to promote hazy conditions through most of the long term period. Current model guidance suggest Precipitable Water (PWAT) values at generally normal values to start the period with a patch of below normal PWAT values reaching the area on Tuesday. For Wednesday and Thursday, columnar moisture will increase once again to normal to above normal values as moisture related to a surface trough and a possible wave, although uncertainty remains. A developing upper level trough near the area will also increase instability. Although model guidance suggest moisture over the mid levels, a more notable increase is suggested by Wednesday. Most available moisture to start the workweek will remain below 850 mb, however. East to east- southeast surface winds should affect the islands through Thursday, when they become more easterly and increase. This will steer warmer tropical air towards the islands, promoting overall warm to hot conditions. Heat related products will possibly be issued for the islands to start the period. 925 mb temperatures are forecast to be above normal to start the workweek.

Marine
Surface high pressure over the Atlantic and an induced trough now just east of the area will promote light to moderate east northeast winds this morning then become more southeasterly later this afternoon. Moisture remnants steered by the northeast windflow and enhanced by an upper level trough just east of the area will increase the potential for showers and isolated thunderstorms development over portions of the local waters the rest of today. Winds will continue to diminish and veer, becoming east southeast then southeast through the weekend with increasing Saharan dust expected across the region through Sunday.

Beach Forecast

The risk for rip currents is low, however, life-threatening rip currents often occur in the vicinity of groins, jetties, reefs, and piers.

.SJU WATCHES/WARNINGS/ADVISORIES... PR...
Heat Advisory from 10am this morning to 6pm AST this evening for PRZ001-005-008-010.

Excessive Heat Watch from Saturday morning through Saturday afternoon for PRZ001-002-005-008-010-012-013.

VI...Excessive Heat Watch from Saturday morning through Saturday afternoon for VIZ001-002.

AM...None.