Sunrise 6:08 AM   Sunset 7:13 PM Moonrise 5:36 AM   Moonset 7:01 PM

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AMZ085 Atlantic S Of 22n W Of 70w Including Approaches To The Windward Passage- 1026 Am Edt Tue Mar 26 2024
Today - NE to E winds 10 kt in the afternoon. Seas 9 ft. Tonight - NE to E winds 10 to 15 kt. Seas 4 to 6 ft. Wed - NE to E winds 10 kt. Seas 5 to 7 ft. Wed night - NE winds 10 to 15 kt. Seas 4 to 6 ft. Thu - NW to N winds 10 kt. Seas 3 to 5 ft. Thu night - NW winds 10 kt. Seas 3 to 5 ft. Fri - NW winds 15 to 20 kt. Seas 2 to 4 ft. Fri night - N to ne winds 15 to 20 kt. Seas 4 to 6 ft. Sat - NE winds 15 to 20 kt. Seas 5 to 7 ft. Sat night - NE to E winds 15 kt. Seas 5 to 7 ft.

FXCA62 TJSJ 072050 AFDSJU

Area Forecast Discussion National Weather Service San Juan PR 450 PM AST Tue May 7 2024

SYNOPSIS
Abundant moisture and increasing instability from an approaching mid-to-upper-level trough will maintain a wet and unstable weather pattern during the next few days. Due to the soil saturation and the much above-normal streamflows, any period of moderate to heavy rains may result in sudden urban and small stream flooding to localized flash floods and mudslides near areas of steep terrain. Severe thunderstorms may produce wind impacts, including waterspouts, and in rare instances, weak isolated tornadoes. Residents and visitors alike are advised to stay weather-aware and informed about these potential hazards and closely monitor the forecast for any updates.



SHORT TERM
Today through Thursday...

Doppler radar indicated showers with isolated thunderstorms affecting eastern Puerto Rico early this morning, and around 9-10 AM AST, convective development began over central Puerto Rico. By noon, shower activity intensified and spread across most of Puerto Rico. So far, radar-estimated rainfall accumulations have exceeded 5 inches in an area centered around Ponce, Adjuntas, Jayuya, Ciales, Orocovis, and Barranquitas. Various Flood Advisories, Flash Flood Warnings, and River Flood Warnings were issued during this period. Most coastal sites have had high temperatures in the mid 80s to lower 90s. Winds were generally easterly with sea breeze variations at 10-15 mph, but gusty of up to 20-30 mph near the shower and thunderstorm activity.

The wet and unstable weather pattern is forecasted to persist until Wednesday evening due to above-normal precipitable water values, ranging from 2.0 to 2.2 inches, coupled with an advancing upper-level trough from the west and below-normal mid-level temperatures, around -8 degrees Celsius. While a weak surface-induced trough over the northeastern Caribbean and eastward-moving high pressure across the Atlantic will sustain light to moderate easterly winds of 5-15 mph at lower levels, winds from the west to southwest will dominate around the 700 mbar layer.

Anticipate a showery weather scenario tonight into Wednesday, characterized by slow-moving showers and a likelihood of severe thunderstorms, which could exacerbate flooding and lightning risks. According to the latest model guidance, the activity will likely concentrate primarily across the local waters into eastern Puerto Rico, Vieques, Culebra, and the U.S. Virgin Islands during nighttime, shifting to inland and downwind regions from mountainous areas during the day. However, rainfall could affect most land areas at any given time.

Given the saturated soils and significantly elevated river streamflows, any additional moderate to locally heavy rain poses a risk of dangerous flooding, including sudden mudslides and landslides in steep terrain areas. Additionally, thunderstorms may produce strong winds capable of causing tree falls, power line disruptions, and movement of unsecured objects. Waterspouts, and in rare instances, weak isolated tornadoes, could also occur with the most intense storms. Therefore, residents and visitors alike are advised to stay weather-aware and informed about these potential hazards and closely monitor the forecast for any updates.

Temperature-wise, a warm trend will continue, with daytime high temperatures ranging between the upper 80s to lower 90s along the coastal/urban areas and in the upper 70s to low 80s along the higher Terrains. With abundant moisture across the region, heat indices may exceed 102 degrees Fahrenheit, primarily across coastal areas of Puerto Rico, the local islands, and other urban areas.

LONG TERM
Friday through Tuesday

FROM PREVIOUS DISCUSSION...446 AM AST Tue May 7 2024

Model guidance suggests a mid- to upper-level ridge is trying to build over the Northeast Caribbean Friday into the weekend, promoting stable conditions and potentially bringing relief from the current weather conditions.

Once again, GFS Total Precipitable Water guidance suggests returning the climatological values for this time of year, with the advection of occasional patches of increased moisture.
Combining high moisture content with the typical upper 80s to low 90s maximum air temperatures will result in heat indices between 100-107 Fahrenheit or even higher, especially during the daily maximum heating, across the USVI and PR's urban and coastal areas where no significant rain is observed. 

Although we expect variable weather conditions with a mixture of sunshine/clear skies and clouds each day, local effects and sea breeze fluctuations may promote strong afternoon convection each day. Furthermore, the advection of a cooler air mass across the above-normal warmer sea surface temperature may result in frequent nighttime showers, affecting the windward sections and local waters each night.

The NASA aerosol optical thickness (AOT) guidance suggests the arrival of an air mass with possible African Dust Particles by the upcoming weekend, which may extend into next week.



AVIATION
(18Z TAFS)

Mostly VFR conditions expected for the USVI and TJPS terminals this afternoon, but SHRA and TSRA expected to linger through 22Z around the Cordillera Central and near TJSJ and TJBQ. Periods of reduced VIS and low ceilings are expected through this time. SHRA are expected to decrease aft 22Z across land areas, but will continue across Atlantic waters. Some may reach the USVI and TJSJ terminals at times. Winds will be light, shifting from the ESE east aft 06Z at 5-10 kts.



MARINE

The surface high-pressure building north of the islands from the Western to Central Atlantic will maintain light to moderate trade winds. Pulses of northeasterly swell will spread across the regional waters later tonight onward. Unsettled weather conditions due to strong thunderstorms are likely, especially during the afternoon and evening, today and tomorrow.



BEACH FORECAST

FROM PREVIOUS DISCUSSION...446 AM AST Tue May 7 2024

Expect increasing seas of 3 to 4 feet across most of the local beaches in the Atlantic, mainly from the northeast, at 6 to 8 seconds. Across the Caribbean, seas will range around 2 feet from the east to southeast at 6 to 8 seconds. Therefore, we expect the risk of rip currents to increase to moderate today.

Pulses of northeast swells, with wave periods of 10 to 13 seconds, will increase the risk of rip currents to moderate from late tonight into next weekend across the north and east-facing beaches of PR and the USVI. There is still a possibility of a high risk of rip currents during that period; it's crucial to monitor the beach forecast for possible updates to the expected conditions as the coastal hazards can change rapidly.



SJU WATCHES/WARNINGS/ADVISORIES
PR...None.
VI...None.
AM...None.

Abrahams Bay
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Tue -- 02:02 AM EDT     0.47 feet Low Tide
Tue -- 05:40 AM EDT     Moonrise
Tue -- 06:15 AM EDT     Sunrise
Tue -- 08:01 AM EDT     2.97 feet High Tide
Tue -- 01:54 PM EDT     0.52 feet Low Tide
Tue -- 07:07 PM EDT     Moonset
Tue -- 07:21 PM EDT     Sunset
Tue -- 08:23 PM EDT     3.64 feet High Tide
Tue -- 11:24 PM EDT     New Moon
Tide / Current data from XTide NOT FOR NAVIGATION

Abrahams Bay, Mayaguana Island, Bahamas, Tide feet

Hawks Nest Anchorage
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Tue -- 01:36 AM EDT     -0.25 feet Low Tide
Tue -- 05:33 AM EDT     Moonrise
Tue -- 06:09 AM EDT     Sunrise
Tue -- 07:38 AM EDT     2.38 feet High Tide
Tue -- 01:39 PM EDT     -0.26 feet Low Tide
Tue -- 06:58 PM EDT     Moonset
Tue -- 07:12 PM EDT     Sunset
Tue -- 08:04 PM EDT     2.95 feet High Tide
Tue -- 11:24 PM EDT     New Moon
Tide / Current data from XTide NOT FOR NAVIGATION

Hawks Nest Anchorage, Turks Islands, Tide feet

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