Rip Current in Puerto Rico, April 18, 2017

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
1109 AM AST Tue Apr 18 2017

.UPDATE...Light moderate showers prevailed during the morning
hours across eastern PR. Additional showers are expected to
develop later during the early afternoon hours across the mountain
ranges of the island. Periods of heavy showers are expected with
thunderstorms across the interior and southwestern sections of PR.
Due to yesterdays rains across much of PR, major rivers and
tributaries can reach quickly with any additional rainfall this
afternoon. Also, as soils are already saturated, mudslides can be
triggered even without heavy rainfall periods across areas of
steep terrain. For these reason the Flash Flood Watch remains in
effect for mainland PR through this evening. Although afternoon
convection can be delayed due to high clouds streaming from the
Caribbean waters due to thunderstorms south of the Dominican
Republic. Latest model guidance continues to indicate a high
chance for showers to develop across the west/southwestern
sections of the island. Elsewhere across the rest of the islands,
isolated to scattered shower activity is expected.

&&

.AVIATION...BKN cigs around FL030 and mtn top obscd are expected
to continue through at least the early evening hours. MVFR conds
possible at TJMZ. SHRA/TSRA across the interior/west areas of PR
will impact mainly the vcnty of TJPS/TJBQ. Showers around El
Yunque area can impact briefly with RA/-SHRA periods the flying
area of TJSJ. Streamers are expected to create mainly VCSH/-RA
periods across the USVI/Leeward terminals. The 18/12z TJSJ upper
air sounding indicated E winds at 7-24 kts below FL060...light NE
thru FL130 and westerlies above and increasing w/height.

&&

.MARINE...Long period northerly swell will continue to create
small craft advisory conditions through late Wednesday night and
life threatening rip currents across the surf zone of the northern
beaches of all islands. Seas are currently between 6-8 feet
nearshore and up to 10 feet across the offshore Atlantic waters.
East to northeast winds are prevailing between 15-20 knots.
Breaking waves between 8 to 13 feet and at times higher are
expected across the Atlantic coastline of the islands. Swell will
subside by early Thursday.

&&

.PREV DISCUSSION... /issued 523 AM AST Tue Apr 18 2017/

SYNOPSIS...Residual moisture and favorable upper level dynamics
will contribute to another round of showers and isolated
thunderstorms that will likely lead to local flooding and rapid
rises on area rivers in Puerto Rico. The remnant of a frontal boundary will
shift south today through Friday then gradually return to the area
with another plume of moisture from South America that will last
into mid-week next week. Moisture increasing over the weekend
will be accompanied widespread shower activities which may lead to
flooding that could extend through the first half of next week.

SHORT TERM...Today through Thursday...
The Flash Flood Watch for Puerto Rico and the the U.S. Virgin
Islands has been extended through this afternoon. For today, the
lingering moisture across the region is expected to combine with
daytime heating and local effects to produce another round of
showers and thunderstorms across the region. A slight shift to an
ENE wind is expected today, which will cause the convection to
develop across the interior and the southwest quadrant of PR this
afternoon. Due to saturated soils from previous rainfall across
most of Puerto Rico, urban and small stream flooding and river
flooding are possible again this afternoon. Drying should spread
across the area later tonight from the northeast.

Drier weather conditions are expected to encompass the region
Wednesday and Thursday as a high pressure system builds across the
region and precipitable waters values decrease to near 1.5
inches. However, some afternoon showers and thunderstorms are
expected both Wednesday and Thursday afternoon as lingering
moisture combines with diurnal heating and local effects that
could lead to very localized urban and small stream flooding.

LONG TERM...Friday through Thursday...
The boundary that has plagued Puerto Rico and the U.S. Vrigin
Islands with record rainfall in some areas will move into the
central Caribbean. The upper level ridge that will be found over
the central Caribbean Wednesday will diminish in intensity and
move over the local area Friday. The passage of the ridge followed
immediately by a moderately strong jet segment over the local
outer Atlantic waters of up to 90 knots will again set in motion a
trend toward wetter weather. By Saturday local urban and small
stream flooding will return and by next week the plume of moisture
out of South America will likely be sufficient to generate more
widespread flooding.

AVIATION...Mostly VFR conditions expected across the local flying
area through 18/16Z. After 18/13Z the winds will increase to about
15-20 kt with occasional higher gusts as high as 30 kt. SHRA and
isolated TSRA expected across interior and western PR after 18/17Z
causing VCSH/VCTS across TJBQ and TEMPO SHRA/TSRA across TJMZ
with VCSH expected across the rest of the TAF sites. Hir trrn
will be obscured. Weather conditions are expected to improve after
19/00Z, leaving Partly cloudy skies with ISOLD/SCT SHRA across
the local flying area. Maximum winds will decrease from WSW at 85
knots around FL440.

MARINE...Seas have proven to be higher than model forecast with
the outer buoy showing 10 to 12 feet and the inner buoy near San
Juan showing 6.5 to 8.0 feet. Maximum wave height recorded at the
San Juan buoy was over 15 feet overnight. A high risk of rip
currents exist for almost all beaches with northern exposures. A
high surf advisory is also in effect. Mariners will find seas
growing up to 10 feet in the local Atlantic outer waters with some
action extending into the passages. Winds will increase today to
15 to 20 knots making the Caribbean rough as well. Conditions are
expected to begin improving by later today with more tranquil
condtions by Thursday. Weaker, but still significant northeast
swell, will return to the area Saturday evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  84  76  86  76 /  40  10  20  20
STT  86  76  86  73 /  40  10  10  20

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through late Wednesday night for Culebra-
     Mayaguez and Vicinity-North Central-Northeast-Northwest-San
     Juan and Vicinity-Southeast-Vieques-Western Interior.

     Flash Flood Watch until 8 PM AST this evening for Central
     Interior-Eastern Interior-Mayaguez and Vicinity-North
     Central-Northeast-Northwest-Ponce and Vicinity-San Juan and
     Vicinity-Southeast-Southwest-Western Interior.

     High Surf Advisory until 6 AM AST Thursday for North Central-
     Northeast-Northwest-San Juan and Vicinity-Southeast-Western
     Interior.

     High Surf Advisory until 6 PM AST Wednesday for Culebra-Mayaguez
     and Vicinity.

VI...High Rip Current Risk through late Wednesday night for St Croix-
     St.Thomas...St. John...and Adjacent Islands.

     High Surf Advisory until 6 PM AST Wednesday for St Croix-
     St.Thomas...St. John...and Adjacent Islands.

AM...Small Craft Advisory until 2 AM AST Thursday for Anegada
Passage Southward to 17N-Atlantic Waters of Puerto Rico and USVI
from 10 NM to 19.5N-Caribbean Waters of Puerto Rico from 10 NM to
17N-Coastal Waters OF Northwestern Puerto Rico out 10 NM-Coastal
Waters of Northern Puerto Rico out 10 NM-Coastal Waters of
Northern USVI and Culebra out 10 NM-Mona Passage Southward to 17N.
Small Craft Advisory until 2 PM AST Wednesday for Coastal Waters
of Southern USVI Vieques and Eastern Puerto Rico out 10 NM.

&&

DS

Perspectivas sobre condiciones peligrosas del tiempo
Servicio Nacional de Meteorologia San Juan PR
524 AM AST martes 18 de abril de 2017

AMZ710>745-PRZ001>013-190930-
San Juan y Vecindad-Noreste-Sureste-Este Interior-Norte Central-
Interior Central-Ponce y Vecindad-Noroeste-Oeste Interior-
Mayaguez y Vecindad-Suroeste-Culebra-Vieques-Aguas cercanas y
aguas mar afuera del Atlantico y aguas costeras del Caribe-
524 AM AST martes 18 de abril de 2017

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

.Dia uno...Hoy y esta noche

.Tronadas...Existe probabilidad de tronadas con lluvia fuerte y
rafagas de vientos esta tarde a traves del interior, oeste y
suroeste de Puerto Rico.

.Inundaciones...Lluvias fuertes pudieran resultar en inundaciones
urbanas y de riachuelos y y posibles rios a traves del interior,
oeste y suroeste de Puerto Rico. Una vigilancia de inundaciones
repentinas esta en efecto.

.Vientos...Se esperan vientos sostenidos de alrededor de 20 mph (17
nudos) a traves de la mayor parte de las aguas costeras locales.

.Olas...Se espera oleaje picado y borrascoso de hasta 10 pies a
traves de las aguas del Atlantico y el Pasaje de Anegada.

.Corrientes marinas...Existe un riesgo alto de corrientes marinas
para las playas del noroeste a noreste de Puerto Rico al igual que
sobre las playas del norte de Culebra y Vieques.

.Dias dos a siete...miercoles a lunes

Riesgo de corrientes marinas permanecera moderado a alto durante los
proximos dias y las condiciones maritimas se esperan que permanezcan
peligrosas durante los proximos dias tambien. Tambien existira la
probabilidad de inundaciones urbanas y de riachuelos durante el
proximo fin de semana.

.Comunicado sobre informacion reportada por observadores...

Algun reporte de inundaciones y fuertes lluvias sera agradecido.

AMZ715-725-VIZ001-002-190930-
San Tomas, San John e islas adyacentes-Santa Cruz-
Aguas cercanas del Atlantico y aguas costeras adyacentes del Caribe-
524 AM AST martes 18 de abril de 2017

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

.Dia uno...Hoy y esta noche

.Vientos...Se esperan vientos sostenidos de alrededor de 20 mph (17
nudos) a traves de la mayor parte de las aguas costeras locales.

.Olas...Se espera oleaje picado y borrascoso de hasta 10 pies a
traves de las aguas del Atlantico y el Pasaje de Anegada.

.Corrientes marinas...Existe un riesgo alto de corrientes marinas
para el norte de San Tomas y Santa Cruz.

.Dias dos a siete...miercoles a lunes

Riesgo de corrientes marinas permanecera moderado a alto durante los
proximos dias y las condiciones martimas se esperan que permanezcan
peligrosas durante los proximos dias.

.Comunicado sobre informacion reportada por observadores...

No se anticipa activacion amplia de observadores, sin embargo se les
exhorta a observadores a reportar inundaciones, trombas marinas, y
corrientes marinas al Servicio Nacional de Meteorologia en San Juan.