Rip Current in Puerto Rico, January 28, 2023

Area Forecast Discussion
National Weather Service San Juan PR
951 PM AST Sat Jan 28 2023

.UPDATE...
Variably cloudy skies and periods of passing showers continued to
affect the region this evening, steered by the brisk northeast
wind flow. Expect this pattern to continue overnight into the
morning hours as both satellite imagery and the doppler weather
radar continue to show patches of trade wind moisture propagating
southwards across the islands and coastal waters. Estimated rainfall
accumulations so far ranged between a quarter to half an inch with
the heaviest downpours. The recent TJSJ 29/00Z upper air sounding
continued to suggest dry and stable conditions above 700 millibars
with strong cap inversion and brisk northeast steering winds between
15-25 knots. No changes made to the inherited short term forecast
grids and reasoning at this time.

&&
.AVIATION UPDATE...
No change to the previous AVN discussion. Prevailing VFR conds
durg prd. SCT-BKN lyrs nr FL025...FL050. Passing SHRA over the
regional waters and en route btw the islands will continue til at
least 29/13Z with VCSH at TJSJ/TIST/TIST/TJBQ. SFC wnds will cont
fm NE btw 8-11 kts but hir gusts accompanying the passing SHRA...
then bcmg fm NE 15 to 20 kts and ocnly hir gusts aft 29/14Z. Brief
MTN top obscr psbl with passing SHRA/Low cld lyrs ovr east interior
PR and vcty of TJNR.

&&

.MARINE UPDATE...
Recent data from the surrounding buoys suggests choppy wind driven
seas and a small northeasterly swell continued to affect much of
the local Atlantic waters and passages as well as portions of the
offshore Caribbean waters. These conditions will persist into the
upcoming workweek. Small craft advisories and precautionary statements
will therefore continue for most of the regional waters and local
passages. Please refer to the latest Coastal Waters Forecast (CWFSJU)
and Marine Weather Message (MWWSJU) issued by WFO San Juan for the
most up to date info.

&&

From previous discussion issued at 401 PM AST Sat Jan 28 2023

.SYNOPSIS...Variable weather conditions will prevail during the
next few days, influenced by intermittent patches of moist and
relatively dry air. A higher frequency of passing showers may lead
to limited flooding impacts, mainly across northeastern Puerto Rico.
Slightly below seasonal temperatures are likely due to persistent
northeasterly winds. Breezy conditions and small northeasterly swells
will maintain choppy to hazardous marine conditions for small craft
and life-threatening rip currents for beachgoers.

&&

.SHORT TERM...Tonight through Monday...

Potential hazards during the short-term forecast period remain the
same, with rip currents at moderate to high risk levels, and
flooding rains, marine, and winds at limited to elevated risk
levels. A meandering mid-level high pressure centered over  the
Bahamas and Cuba region and a surface high pressure stretching
northeastward from the Bahamas into the north Atlantic will remain
the dominant features through the cycle. The latter will continue
to promote moderate to fresh northeasterly winds, steering
patches of low-level moisture into the region and leading to
choppy to hazardous seas for small craft into early next week.

The local weather conditions will be influenced by occasional
moist and drier air patches steered by a persistent northeasterly
wind flow, with satellite- and model-estimated precipitable water
vapor values ranging from 1.4 inches by Sunday evening to 0.9
inches by late Monday night. The timing of each patch will be
critical, especially for periods with normal to near-normal
seasonal moisture levels during increased cooling advective
influences at nighttime. Following these patches' potential arrival
time, expect an increase in cloud cover and shower activity by
this evening and Sunday evening, when precipitable water vapor
values could peak around 1.3-1.4 inches. Rainfall accumulations
of around 0.5-1.0 inches during these periods, generated by a
higher frequency of showers moving inland over northern and
eastern Puerto Rico and the U.S. Virgin Islands, may lead to
limited flooding impacts. Ponding of water on roadways and poorly
drained areas is likely, with possible localized urban and small
stream flooding. Afternoon convective development is also possible
across western to southwestern sections of Puerto Rico, but any
effect will be limited and short-lived. Drier conditions are
expected on Monday.

Normal to slightly below-normal seasonal temperatures will
continue, ranging from the lower to mid 80s across coastal and
other urban areas during the daytime to around 50 degrees across
higher elevations at nighttime. Surface winds will remain out of
the northeast, varying from 5-10 mph with land breeze variations
at night to 10-20 mph with higher gusts and sea breeze variations
during the daytime.

&&

.LONG TERM...Tuesday through Saturday...

From previous discussion...432 AM AST Sat Jan 28 2023

A surface high pressure building in the western to central
Atlantic will maintain east to northeasterly winds across the
local area. This pattern is expected to bring patchy moisture to
support the development of passing showers across the eastern
portions of Puerto Rico and the US Virgin Islands. Scattered
showers, although limited, are forecasted to develop across the
western and southwestern municipalities of Puerto Rico. A mass of
drier air is expected to prevail across the islands. Therefore,
shower activity across the islands will not be significant for the
first half of the long period. The Precipitable Water content
(PWAT) between 1.02 to 1.39 inches indicates a period of low
chances of precipitation, and dry conditions are forecasted for
most of the workweek. By late Thursday into early Friday, a
perturbation moving with the trades will result in a slight
increase in shower activity, mainly for the eastern and northern
portions of Puerto Rico, including Vieques, Culebra and the US
Virgin islands. Continuous showers could lead to minor ponding of
water in roads and poor drainage areas. Temperatures across the
islands are expected to be lower than normal due to the northeast
winds. Expect cooler temperatures, especially over the Central
Cordillera during the overnight hours.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across
all terminals during the next 24 hours. Trade wind showers will
arrive at times, and may impact JSJ/JBQ/USVI terminals. SHRA
activity will diminish overnight into tomorrow morning
(28/18z-29/00z). SHRA will develop near/over JPS btwn 28/18-22z.
Expect northeast winds up to 20 kt with higher gusts and sea
breeze variations, becoming calm to light and vrb aft 29/13z.
Winds will return from the NE at 15-20 kt with higher gusts aft
29/13z.

&&

.MARINE...Moderate to locally fresh northeast winds and small
northeasterly swells will maintain hazardous marine conditions,
mainly across the Atlantic waters and Anegada Passage, where Small
Craft Advisories are now in effect. Advisories will expand to the
Caribbean waters, Mona Passage, and northwestern Puerto Rico
coastal waters by Sunday morning when seas peak around 7 feet.
Seas up to 6 feet and northeasterly winds up to 20 knots with
gusts up to 30 knots will maintain choppy marine conditions across
most remaining local waters, where small craft operators should
continue to exercise caution.

For beachgoers, a high risk of rip currents remains in effect for
most north-facing beaches of Puerto Rico, Culebra, and Saint
Croix, where life-threatening rip currents are likely. Saint
Thomas and Saint John will be under high risk by Monday morning.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Monday night for PRZ001-002-
     005-008-012.

VI...High Rip Current Risk through late Monday night for VIZ002.

     High Rip Current Risk from Monday morning through late Monday
     night for VIZ001.

AM...Small Craft Advisory until 2 AM AST Tuesday for AMZ710-712-715-
     722.

     Small Craft Advisory from 8 AM Sunday to 2 AM AST Tuesday for
     AMZ732-741-742.

&&

SHORT TERM...RAM
LONG TERM....CVB
AVIATION...RAM

Perspectivas sobre las Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorologia en San Juan PR
431 AM AST sabado 28 de enero de 2023

AMZ710>745-PRZ001>013-290845-
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 cercanas y lejanas a la
costa del Atlantico y del Caribe-
431 AM AST sabado 28 de enero de 2023

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Puerto Rico.

.DIA UNO...Hoy y esta noche

.Lluvia Excesiva...Acumulaciones de agua en carreteras y areas de
poco drenaje a traves de sectores del noreste.

.Viento...Se esperan condiciones ventosas a traves de la costa
noroeste y sur de Puerto Rico, y a traves de Culebra y Vieques.
Objetos que no sean asegurados podran salir volando.

.Condiciones Maritimas...Se espera oleaje igual o mayor de 7 pies
a traves de las aguas del Atlantico y pasajes. Condiciones
peligrosas para operadores de embarcaciones pequenas.

.Corrientes Marinas...Corrientes marinas amenazantes a la vida son
posibles en la zona de oleaje rompiente particularmente a traves de
las playas del norte y este de Puerto Rico, y Culebra.

.DIAS DOS A SIETE...Domingo a viernes

Oleaje picado a peligroso continuara durante la semana laboral,
mayormente a traves de las aguas del Atlantico, y porciones de los
pasajes locales. Se esperan condiciones ventosas que continuen a
traves de los sectores del sur y noroeste de Puerto Rico durante la
mayoria del periodo. Corrientes marinas amenazantes a la vida
continuaran hasta al menos el jueves a lo largo de las playas del
norte y este.

.Comunicado sobre informacion reportada por observadores...

No se necesita la activacion de los observadores.

AMZ715-725-VIZ001-002-290845-
San Tomas, San John e Islas Adyacentes-Santa Cruz-Las aguas cercanas a
la costa del Atlantico y las aguas costeras adyacentes del Caribe-
431 AM AST sabado 28 de enero de 2023

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
las Islas Virgenes Estadounidenses.

.DIA UNO...Hoy y esta noche

.Viento...Se esperan condiciones ventosas a traves de las Islas
Virgenes Americanas. Objetos que no asegurados pudieran salir
volando.

.Condiciones Maritimas...Oleaje igual o mayor de 7 pies a traves de
las aguas locales del Atlantico y pasajes. Condiciones peligrosas
para operadores de embarcaciones pequenas.

.Corrientes Marinas...Corrientes marinas amenazantes a la vida son
posibles en la zona de oleaje rompiente particularmente a traves de
las playas de Santa Cruz. Existe un riesgo moderado de corrientes
marinas a traves del resto de las islas.

.DIAS DOS A SIETE...Domingo a viernes.

Oleaje picado a peligroso continuara durante la semana laboral,
mayormente a traves de las aguas del Atlantico, y porciones de los
pasajes locales. Se esperan condiciones ventosas que continuen a
traves de las Islas Virgenes Americanas hasta el lunes. Corrientes
marinas amenazantes a la vida continuaran hasta al menos el jueves a
lo largo de las playas del norte y este de las islas.

.Comunicado sobre informacion reportada por observadores...

No se necesita la activacion de los observadores.