Rip Current in Puerto Rico, July 24, 2021

Area Forecast Discussion
National Weather Service San Juan PR
417 AM AST Sat Jul 24 2021

.SYNOPSIS...Unstable weather conditions through the weekend due
to a tropical wave passage and the proximity of a trough aloft.
As a result, there is an increasing risk for urban and small
stream flooding as well as localized flash flooding. Weather
conditions are expected to improve early the next workweek.

&&

.SHORT TERM...Today through Monday...

Weather conditions are evolving as expected, and an unsettled
pattern will hold across the islands through at least Sunday. It is
due to the interaction of a meandering TUTT-Low and a tropical wave,
which will enhance shower and thunderstorm formation. GOES-East-
derived products are indicating Total Precipitable Water (TPW)
around 2 inches approaching the U.S. Virgin Islands. Therefore,
abundant tropical moisture will pool over the islands, promoting
widespread showers and scattered thunderstorms across the region
of USVI/PR today and tomorrow. The best round of organized
convection is expected this afternoon as TPW peaks and the TUTT-
low approaches the Hispanola. As a result, widespread showers and
scattered thunderstorms will develop across the region, especially
this afternoon into the evening and early Sunday morning. The
conditions mentioned above could trigger urban and small-stream
flooding, with localized flash flooding and mudslides. The second
round of showers and thunderstorms will develop by Sunday as the
wave's axis moves closer, and the U.S. Virgin Islands would
possibly observe heavy showers and thunderstorms.

GFS-Galvez and Davidson Index suggest favorable atmospheric
conditions for the development of thunderstorms. Therefore scattered
thunderstorms were introduced for this afternoon and Sunday.

Moisture and rain activity will diminish somewhat by Monday as the
lingering moisture of the wave is replaced by dry air with African
dust suspended particulate. However, the typical weather pattern
will persist, with passing showers across the windward sections
during the morning and afternoon convection across the western
portions. Hazy skies will return by late Monday afternoon into the
evening.

.LONG TERM...Tuesday through Sunday...

Long term forecast is still on track. A ridge pattern aloft will
erode as a retrogressing TUTT moves closer to the forecast area.
This feature with its associated upper level low is expected to
cross the local islands Wed-Thu enhancing moisture advection and
instability. As the aforementioned TUTT low moves away, a mid level
ridge will build once again across the area, bringing drier and
stable weather conditions Friday through the end of the forecast
cycle. At lower levels, surface high pressure across the north
central Atlantic will continue to yield moderate to fresh easterly
winds.

Therefore, expect fair weather conditions with afternoon convection
focused across western areas of Puerto Rico much of the next
week, except for Wednesday and Thursday. The intensity and areal
coverage of the afternoon showers and thunderstorms likely to
increase those days due to the proximity of the upper trough and
precipitable water values near 2.0 inches. Some haziness on
Tuesday due to African dust particles as well. Maximum
temperatures continue to range in the upper 80s to low 90s.

&&

.AVIATION...A tropical wave will bring showers and thunderstorms
across the islands through the forecast period. TEMPOs are in
place for JSJ/IST/ISX/NCM/KPK and could be needed later this
afternoon. Therefore, expect MVFR or IFR conditions due to
TSRA/+SHRA. SHRA/TSRA will spread across most of the islands after
24/15z. Winds will continue calm-light/VRB but gusty near
TSRA/SHRA, increasing from the east at 10-20 kt with higher gusts
and sea breeze variations after 24/12Z.

&&

.MARINE...Moderate to fresh easterly winds will continue to
prevail during the next several days with seas expected to mostly
range between 3 and 6 feet. However, across the northeastern
portion of the offshore Atlantic waters, seas of up to 7 feet are
possible through early Sunday morning. For beachgoers, a moderate
risk of rip currents is expected to continue across most of the
beaches of north and southeast Puerto Rico as well as Culebra,
Vieques, and the US Virgin Islands through the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  87  79  88  79 /  80  50  70  50
STT  88  78  88  80 /  60  60  70  50

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...Small Craft Advisory until 8 AM AST Sunday for Atlantic Waters
     of Puerto Rico and USVI from 10 NM to 19.5N.

&&

SHORT TERM...CAM
LONG TERM....OM
MARINE...TW

Perspectivas sobre Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorologia en San Juan PR
343 AM AST sabado 24 de julio de 2021

AMZ710>745-PRZ001>013-250745-
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-
343 AM AST sabado 24 de julio 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

.Tronadas...Existe el potencial de tronadas con lluvias y rafagas
fuertes a traves de gran parte de Puerto Rico durante el transcurso
del dia.

.Inundaciones...Lluvias de moderadas a fuertes podrian
ocasionar inundaciones urbanas y de riachuelos a traves de Puerto
Rico e inundaciones repentinas localizadas a traves de porciones del
noreste de Puerto Rico.

.Viento...Se esperan vientos sostenidos en exceso de 20 mph (17
nudos) a traves de la mayoria de las aguas locales, al igual que
para sectores costeros del norte de Puerto Rico, Vieques y Culebra.

.Oleaje...Se espera oleaje picado de hasta 7 pies a traves
de las aguas mar afuera del Atlantico. Oleaje de hasta 6 pies se
espera a traves de las aguas mar afuera del Caribe y el Pasaje de
Anegada.

.Corrientes Marinas...Existe un riesgo moderado de corrientes
marinas para las playas del norte, suroeste y sureste de Puerto
Rico, al igual que para la mayoria de las playas de Vieques y
Culebra.

.Dias dos hasta el siete...domingo a viernes

Los efectos locales y diurnos junto a la humedad de una onda
tropical van a causar tiempo inestable el domingo. Una masa de aire
Sahariano se movera sobre el area temprano la proxima semana
causando condiciones secas y cielos brumosos.

.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-VIZ001-002-250745-
San Tomas, San John e Islas Adyacentes-Santa Cruz-Aguas cercanas
del Atlantico y aguas costeras adyacentes del Caribe-
343 AM AST sabado 24 de julio 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

.Tronadas...Existe el potencial de tronadas con lluvias y rafagas
fuertes a traves de las Islas Virgenes Americanas.

.Inundaciones...Lluvias fuertes podrian ocasionar inundaciones
urbanas.

.Viento...Se esperan vientos sostenidos en exceso de 20 mph (17
nudos) a traves de la mayoria de las aguas locales y en porciones de
las islas.

.Oleaje...Se espera oleaje picado de hasta 7 pies a traves
de las aguas mar afuera del Atlantico. Oleaje de hasta 6 pies se
espera a traves de las aguas mar afuera del Caribe y el Pasaje de
Anegada.

.Corrientes Marinas...Existe un riesgo moderado de corrientes
marinas para la mayoria de las playas de las islas.

.Dias dos hasta el siete...domingo a viernes

Los efectos locales y diurnos junto a la humedad de una onda
tropical van a causar tiempo inestable el domingo. Una masa de aire
Sahariano se movera sobre el area temprano la proxima semana
causando condiciones secas y cielos brumosos.

.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.