Special Weather Statement, NWS JSJ

Area Forecast Discussion
National Weather Service San Juan PR
953 AM AST Sun Feb 28 2021

.UPDATE...

Surface high-pressure north of the islands is tightening the local
pressure gradient resulting in windy easterly trades. These winds
will bring quick passing showers, clouds, and gusty winds across
the region the rest of today. TJSJ 28/12z sounding measured a
Precipitable Water (PW) of 1.42 inches and E-ENE winds between 20
and 30 knots (between the surface and 3 k ft) across Puerto Rico
and the U.S. Virgin Islands. Once again, dry air is observed above
700 MB (above 10.200 k ft). Therefore, expect the advection of
clouds and showers the next few days across most of the islands,
resulting in periods of low to moderate rains at times, especially
across the windward portions.

&&

.AVIATION...

VFR conditions will prevail today. However, easterly winds between
20 and 25 knots with gusts from 25 and 35 knots will affect the
local terminals. Winds will continue around 15 knots after 28/23z.
SHRA/+SHRA will move in the vicinity and across the terminals at
times. This pattern is forecast to continue.

Beachgoers, the risk of rip currents continues high for the north-
facing beaches of Puerto Rico, the southeast and south-central
coast of PR, Culebra, St Croix, the north, east, and south of
Vieques, the western third of St Thomas, and the southern coast of
St John.

&&

.MARINE...

Mariners can expect seas and winds between 6 and 10 feet and out
of the east at 20 to 25 knots with higher gusts, respectively.
Therefore, Small Craft Advisories still in effect for the local
waters and should last through at least Tuesday.

&&

.PREV DISCUSSION... /issued 413 AM AST Sun Feb 28 2021/

SYNOPSIS...
Windy conditions continue across the area, resulting in hazardous
seas through the first half of the workweek. No major rain events
are in the forecast through the next several days, but the trade
winds will carry some areas of showers across the area from time
to time.

SHORT TERM...Today through Tuesday...

A surface high pressure over the southwestern Atlantic will continue
to promote strong east to northeast winds through at least Monday
morning. Sustained winds between 20-25 mph and gusts up to 35 mph
are expected through this period, mainly across the northern and
eastern coastal areas. Moderate trades are expected to return on
Tuesday. These winds will promote an advective pattern across the
region, and shower activity is expected mainly across the northern
and eastern sections of Puerto Rico and across the U.S. Virgin
Islands, mainly during the nights and early morning hours. Low-level
moisture and instability peaks between 03z-09z Monday, as the
remnants of a frontal boundary will move across the area. A drier
air mass will follow during the day on Monday as a mid-level ridge
builds from the west and strengthens the inversion layer, while an
upper-level trough lies northeast of the Leeward Islands. Therefore,
more stable conditions are expected. For Tuesday, fair weather
conditions should continue across the islands, however, another area
of trade wind showers is forecast to move from the northeast during
the overnight/early morning hours.

LONG TERM...Wednesday through Monday...

A relatively dry weather pattern is expected for the middle of the
workweek. At the low to mid-levels, a high pressure will be the
dominant feature. This will maintain a trade wind cap around 800
to 850 mb to at least Friday. The forecast soundings are showing
precipitable waters near 1.0 inch or less, hence very limited
shower activity is expected to prevail through this forecast
period. Some shallow patches of moisture may be advected across
the islands from time to time, resulting in a few passing showers.

At the surface, a high pressure will begin to migrate toward the
eastern Atlantic, while a cold front exists the eastern coast of
the United States. Although the cold front is not expected to
affect the islands, the wind flow is expected to shift from the
southeast by late Thursday and continuing into the weekend. This
will pull some moisture over the area, increasing somewhat the
chances of showers. In general, this shower activity should affect
the local waters, as well as the eastern half of Puerto Rico and
the U.S. Virgin Islands, while enhancing afternoon activity across
western Puerto Rico.

AVIATION...
Mainly VFR conditions are expected to prevail across all
terminals during the next 24 hours. However, quick passing -SHRA may
cause brief MVFR conds at TJSJ/TJBQ/TIST/TISX through the period.
Surface winds from the east-northeast at 15-25 kt with higher gusts.

MARINE...
Fresh to strong winds, 20 to 25 knots, are causing hazardous
marine conditions, with seas up to 10 feet expected. These
conditions are expected to continue through early in the workweek.
As a result, Small Craft Advisories are in effect. For the
beaches, there is a high rip current risk for most of the coastal
areas across the islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  84  73  83  72 /  50  50  40  50
STT  85  73  85  72 /  50  50  40  40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through Tuesday afternoon for Culebra-
     North Central-Northeast-Northwest-San Juan and Vicinity.

     High Rip Current Risk through Monday afternoon for Central
     Interior-Southeast.

     High Rip Current Risk through late tonight for Mayaguez and
     Vicinity-Ponce and Vicinity-Vieques-Western Interior.

VI...High Rip Current Risk through Tuesday afternoon for St Croix.

     High Rip Current Risk through Monday afternoon for
     St.Thomas...St. John...and Adjacent Islands.

AM...Small Craft Advisory until 2 PM AST Monday for Coastal Waters of
     Southern Puerto Rico out 10 NM.

     Small Craft Advisory until 8 AM AST Tuesday for Caribbean Waters
     of Puerto Rico from 10 NM to 17N-Anegada Passage Southward
     to 17N-Atlantic Waters of Puerto Rico and USVI from 10 NM
     to 19.5N-Coastal Waters of Northern Puerto Rico out 10 NM-
     Coastal Waters of Northern USVI and Culebra out 10 NM-
     Coastal Waters of Southern USVI Vieques and Eastern Puerto
     Rico out 10 NM-Mona Passage Southward to 17N.

     Small Craft Advisory until 2 AM AST Tuesday for Coastal Waters
     of Northwestern Puerto Rico out 10 NM.

&&

SHORT TERM...CAM
LONG TERM....LIS
PUBLIC DESK...99

Perspectivas sobre Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorologia en San Juan PR
423 AM AST domingo 28 de febrero de 2021

AMZ710>745-PRZ001>013-010830-
San Juan y Vecindad-Noreste-Sureste-Este Interior-Norte Central-
Interior Central-Ponce y Vecindad-Noroeste-Oeste Interior-
Mayaguez y Vecindad-Suroeste-Culebra-Vieques-Las aguas costeras
cercanas y lejanas a la costa del Atlantico y Caribe-
423 AM AST domingo 28 de febrero de 2021

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Puerto Rico y las aguas costeras del Atlantico.

.Dia Uno...Hoy y esta noche

.Viento...Se esperan vientos sostenidos entre 20 a 30 mph on rafagas
mas altas a traves de las aguas locales y gran parte de las areas
costeras.

.Oleaje...Se espera oleaje peligroso de 6 a 10 pies hoy, con el
oleaje mas alto a traves de las aguas mar afuera y los pasajes.

.Corrientes Marinas...Existe un riesgo alto de corrientes marinas
para todas las islas.

.Fuegos...Se espera peligro elevado de fuegos forestales a traves de
la costa sur y oeste de Puerto Rico.

.Dias dos hasta el siete...lunes a sabado

El riesgo alto de corrientes marinas para las costas expuestas hacia
el norte continuara hasta el martes. Oleaje peligroso continuara
hasta el martes en la manana. Se espera que los vientos sobre 20
mph/17 nudos terminen el lunes. Una marejada del norte aumentara el
oleaje y riesgo de corrientes marinas nuevamente para finales de la
semana laboral.

.Comunicado sobre informacion reportada por observadores...

No se espera activacion amplia de observadores. Favor de reportar
cualquier informacion sobre vientos, oleaje y corrientes marinas al
Servicio Nacional de Meteorologia en San Juan mientras siguen las
indicaciones de las autoridades locales y estatales.

AMZ715-725-VIZ001-002-010830-
San Tomas, San John e Islas Adyacentes-
Santa Cruz-Aguas cercanas del Atlantico y aguas
costeras adyacentes del Caribe-
423 AM AST domingo 28 de febrero de 2021

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Islas Virgenes Estadounidenses y las aguas costeras adyacentes.

.Dia Uno...Hoy y esta noche

.Viento...Se esperan vientos sostenidos entre 20 a 30 mph on rafagas
mas altas a traves de las aguas locales y gran parte de las areas
costeras.

.Oleaje...Se espera oleaje peligroso de 6 a 10 pies hoy, con el
oleaje mas alto a traves de las aguas mar afuera y los pasajes.

.Corrientes Marinas...Existe un riesgo alto de corrientes marinas
para todas las islas.

.Dias dos hasta el siete...lunes a sabado

El riesgo alto de corrientes marinas continuara para las playas del
noroeste de San Tomas y algunas playas del sur de San John hasta el
lunes. Un riesgo alto de corrientes marinas continuara para Santa
Cruz hasta por lo menos el martes. Una marejada del norte aumentara
el oleaje y riesgo de corrientes marinas nuevamente para finales de
la semana laboral.

.Comunicado sobre informacion reportada por observadores...

No se espera activacion amplia de observadores. Sin embargo, favor
de reportar cualquier informacion sobre vientos, oleaje y corrientes
marinas al Servicio Nacional de Meteorologia en San Juan mientras
siguen las indicaciones de las autoridades locales y estatales.