Puerto Rico Caribbean Waters from 10nm to 17N Marine Forecast
|Rest Of Tonight...East Winds Around 20 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet. Dominant Period 8 Seconds. Isolated Showers.|
|Monday...East Winds Around 20 Knots. Seas 4 To 6 Feet With Occasional Seas Up To 8 Feet. Dominant Period 8 Seconds. Isolated Showers.|
|Monday Night...East Winds Around 20 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 8 Seconds. Scattered Showers.|
|Tuesday...East Winds Around 20 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 8 Seconds. Scattered Showers.|
|Tuesday Night...East Winds Around 15 Knots. Seas 3 To 5 Feet With Occasional Seas Up To 6 Feet. Dominant Period 8 Seconds. Isolated Showers.|
|Wednesday...East Winds Around 15 Knots. Seas 2 To 4 Feet With Occasional Seas Up To 5 Feet. Dominant Period 8 Seconds. Scattered Showers.|
|Thursday...East Winds Around 15 Knots. Seas 2 To 4 Feet With Occasional Seas Up To 5 Feet. Dominant Period 10 Seconds. Isolated Showers.|
|Friday...East Winds Around 20 Knots. Seas 2 To 4 Feet With Occasional Seas Up To 5 Feet. Dominant Period 8 Seconds. Isolated Showers.|
| Area Forecast Discussion|
National Weather Service San Juan PR
850pm AST Sunday May 15 2022
Cloud cover and shower activity over the west sections of Puerto Rico continued to diminish during the evening hours while few showers of light to moderate intensity were noted moving over the coastal waters between eastern Puerto Rico and the U.S. Virgin Islands. Some of these shower affected the islands of St Croix and Vieques but so far rainfall accumulation were a tenth of an inch or less. During the rest of the overnight and early morning hours,expect additional tradewind showers to reach portions of east and southeast coasts of Puerto Rico as well as the USVI from time to time. Rainfall accumulations are expected to be a tenth of an inch or less, as the showers should continue to be fast moving and of short duration steered by the moderate east southeast trade winds. Recent TJSJ 16/00Z upper air sounding suggests low level winds continued from east southeast between 15-20 kts with most of moisture trapped below 700 millibars, as mid to upper level ridge remained in place. Otherwise no change to the inherited short term forecast grids and reasoning at this time.
change to the previous marine discussion at this time. Small craft operators should continue to exercise caution through at least Monday due to the choppy wind driven seas.
/issued 503pm AST Sunday May 15 2022/
SYNOPSIS...Mainly fair weather conditions with limited shower activity will prevail through at least Monday until increased tropical moisture leads to an increased chance of shower activity by midweek. Slightly drier and hazy conditions will return by the latter part of the week, with the entrance of a drier air mass accompanied by small concentrations of Saharan Dust particulate. Breezy conditions will maintain choppy seas and life-threatening rip currents during the next few days.
SHORT TERM...Tonight through Tuesday... A mid-to-upper high pressure over the northeastern Caribbean and a surface high pressure over the western Atlantic will remain the dominant features. The first feature will maintain unfavorable conditions for deep convective development with a strong trade wind cap, drier air entrainment, and warmer mid-level temperatures of around -4 and -5 degrees Celsius. The surface feature will support east to east-southeast winds at 10-20 mph tonight but diminishing to 10-15 mph and veering to the south-southeast from Monday onwards as tropical wave streams across the eastern Caribbean. Across coastal areas, the sea breeze will cause winds to peak higher, at about 15-25 mph with higher gusts, by the late morning and early afternoon. Southeasterly trade winds will also lead to warmer than average temperatures, mainly across northern sections of the islands, where daytime highs can reach the lower 90s. Intermittent patches of moist and relatively drier air will affect the forecast area through Monday, with model-estimated precipitable water values ranging from 1.7 inches tonight to 1.3 inches by Monday afternoon. After that, increased tropical moisture from the south with the passage of a tropical wave will cause precipitable water values to exceed 2 inches by Tuesday evening.
Overall, limited shower activity is expected through Monday, with overnight/early morning trade wind passing showers affecting windward areas and isolated to scattered afternoon convective development over the far northwestern corner of Puerto Rico. Streamer-like showers could also affect eastern sections in the afternoon. The lack of significant wetting rains will further deteriorate soils and fuel conditions across fire-prone areas of southern Puerto Rico. As moisture increases, expect an increase in shower activity, clustering over southeastern and northwestern sections of the island, where ponding of water on roadways and poorly drained areas to localized urban flooding is likely. There is a slight risk of excessive heat, wind, and fire weather during the short-term forecast cycle for land areas. The risk of flooding remains low but may elevate to slight or moderate with the increasing chance for showers.
Long TermWednesday through Sunday... FROM /issued 508am AST Sunday May 15 2022/
High pressure at upper levels will be found in the southern and central Caribbean. It will drift slowly westward during the period. At mid levels high pressure also dominates the tropical Atlantic and the local area through Friday. Then a wide, but weak trough will invade the western tropical Atlantic, divide and push the high over us to the west. The trough will rotate west to over the local area by Sunday. At lower levels, the tropical wave that moved into the area on Tuesday will move into Hispaniola on Wednesday and begin an overall drying trend that should last through Sunday. Showers during the long term period will follow the usual diurnal pattern for winds out of the east southeast. Meaning scattered showers with modest accumulations on the east southeast side of Puerto Rico during the overnight and early morning hours, followed by showers over central and western Puerto Rico during the afternoon. Shower activity over the U.S. Virgin Islands will generally be sparse. Beginning Friday winds will gradually back to the east and the shower pattern--considerably diminished-- will follow. As the mid and upper level trough gains more influence over the area over the weekend, showers will increase somewhat. By Saturday, mid level temperatures at 500 mb will drop to between minus 8 and 9 to renew the chances of afternoon thunderstorms, mainly over western Puerto Rico during Saturday and Sunday afternoons.
And finally, the Goes GEOS model from NASA indicates that dust from the Sahara will begin to be seen in trace amounts on Tuesday and increase each day through Sunday until a noticeable reduction in visibilities will be noticed by the weekend. This will also have a dampening effect on showers and convective activity.
AVIATION...VFR conditions expected to prevail across all terminals during the next 24 hours. VCSH expected during the evening and overnight hours for the eastern PR and USVI terminals. Low level winds from the ESE at 10 kts or less expected overnight, increasing from 15 to 20 kts, with ocnl gusts after 16/13Z.
Moderate to fresh winds of around 20 knots will maintain choppy seas of 6 feet through at least Monday night. These conditions will require small craft operators to exercise caution, mainly across the offshore Atlantic waters. There is a high risk of rip currents for beaches across the northwest to northeast coasts of Puerto Rico and the eastern coast of Culebra and St Croix.
.The lack of significant wetting rains will continue to support the further drying of soils and fuels across fire-prone areas of southern Puerto Rico. While fuels have remained relatively moist recently, KBDI values support elevated fire danger risk conditions across these areas, with 551 in Cabo Rojo, 585 in Guanica, 665 in Camp Santiago, and 716 in Maricao. Although the prevailing winds will subside during the next few days, the sea breeze could generate locally higher winds reaching the 15-25 mph range during the late morning and early afternoon hours. Moisture levels or relative humidity may remain relatively high, yet, elevated fire danger conditions are likely on Monday and by the latter part of the workweek.
.SJU WATCHES/WARNINGS/ADVISORIES... PR...High Rip Current Risk until 6am AST Monday for Northeast- Northwest-San Juan and Vicinity.
High Rip Current Risk through Monday afternoon for Culebra-North Central.
VI...High Rip Current Risk through Monday afternoon for St Croix.