Strong Wind in Puerto Rico, February 11 to 13, 2018

Area Forecast Discussion
National Weather Service San Juan PR
921 PM AST Sat Feb 10 2018

.UPDATE...Skies became mostly clear across the islands as clouds
and showers over land quickly moved offshore and dissipated during
the early evening hours. Some minor changes made to the inherited
short term forecast packages, as a brief slot of drier air moved
across the region during the evening hours. This will be followed
by another round of quick passing showers of mostly light to moderate
intensity with occasional higher wind gusts during the overnight and
early morning hours. Otherwise, still expecting increasing trade
winds to peak on Sunday as the pressure gradient tightens across
the region, then gradually tapering off and weakening by the latter
part of next week as the Atlantic ridge relaxes its hold across the
region.

&&

.AVIATION UPDATE...No sig change to previous. FEW-SCT cld lyrs nr
FL030...FL050...passing -SHRA/SHRA en route btw islands. Sfc wnds
fm E nr 15 kts...bcmg 20-25 kts aft 11/14z. L/lvl wnds 25-30 kts
fm E blo FL150....then backing and incr w/ht ABV with max wnd
around 70kts fm W nr FL390.

&&

.MARINE UPDATE...Hazardous and increasing seas will continue through
the weekend and into next week as local pressure gradient tightens
across the region, resulting in fresh to strong easterly trade winds.
Small craft advisories will therefore remain in effect for most of
the regional waters.

&&

.PREV DISCUSSION... /issued 324 PM AST Sat Feb 10 2018/

SYNOPSIS...High pressure across the central Atlantic will
continue to drive moderate to strong trade east northeast winds
across the local area for the next several days. Scattered
shallow showers will move from the Atlantic waters across the
windward side of Puerto Rico during the nights and early in the
morning, with afternoon showers in the west and southwest of
Puerto Rico.

SHORT TERM...Tonight through Tuesday...
A mid level ridge will hold across the region for the next
several day, limiting the development of deep convection across
the local islands. Strong high pressure at the surface across the
central Atlantic is expected to merge with another surface high
tonight. This feature will maintain a strong pressure gradient
across the region inducing windy conditions across the local
islands and surrounding waters for the next several days. Model
guidance indicated that local winds will continue to at least 25
knots with higher gusts for the next several days. Low level
perturbations associated with the east northeast trades are
expected to move from time to time across the local islands,
inducing the development of passing showers across the region.
This activity is expected to affect mostly the U.S. Virgin
Islands, Vieques, Culebra as well as the eastern and northern
sections of Puerto Rico during the nights and early in the
mornings. The orographic effects will cause some cloudiness to
develop and move downwind Saturday and Sunday afternoons. These
effects in combination with diurnal heating will cause showers
across the southwestern quadrant of PR each afternoon. The east
northeast trades will also continue to promote pleasant
temperatures across the region for the next several days with
highs around the mid 80s across coastal areas and lows ranging
from the high 50s to low 60s across the higher elevations. Not
significant changes in this weather pattern is expected for the
next several days.

LONG TERM...Wednesday through Monday...from previous discussion...
High pressure stretched across the western and central Atlantic
Wednesday will slowly sag south toward the area and weaken
considerably into the following weekend. This will allow the
gradient to relax somewhat and allow winds to diminish across the
area. The easterly trade winds, however, will still be moderate to
locally fresh across the area and some showers will persist. Even
though the precipitable water will be lower than today or
tomorrow, it will fluctuate more on a daily basis later next week
such that brief shower activity will vary more but still be a
prominent part of the daily pattern. Little change in the pattern
is expected. 1000-850 mb thicknesses will also vary only a little,
but current models suggest that it will be slightly cooler on
Monday and then gradually warm a degree or two the rest of the
week. Upper levels will sport a broad ridge that will be eroded
from the north by an east west trough that will sag toward the
tropical Atlantic during the period and then fade from view.

AVIATION...VFR conds expected across the local terminals with VCSH
expected SCT SHRA through the forecast period. Winds from the E to
ENE 15-20KT with higher gusts and sea breeze variations for TJPS
and TJMZ. Winds decreasing aft 10/23Z, increasing across the USVI
aft 11/06Z then for the terminals in PR increasing after 11/14Z
to 20-25kt and gusty.

MARINE...
Seas will continue as the main weather concern for the next
several days. Seas up to 12 feet are expected, especially in the
outer Atlantic waters. Showers will also contain strong gusts,
possibly up to 32 kt. A gradual improvement is not expected until
after Tuesday. The high risk of rip currents will remain in effect
for the northwest to northeast, southeast and southwest beaches of
Puerto Rico, Vieques, Culebra and for the U.S. Virgin Islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  73  82  73  84 /  50  50  50  50
STT  73  84  72  84 /  50  50  40  40

&&

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

     Small Craft Advisory from 6 AM Tuesday to 6 PM AST Wednesday for
     Southeast.

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

     Small Craft Advisory until 6 PM AST Wednesday for
     St.Thomas...St. John...and Adjacent Islands.

AM...High Rip Current Risk through late Monday night for Coastal
     Waters OF Southwestern Puerto Rico out 10 NM-Coastal Waters
     of Northern USVI and Culebra out 10 NM-Coastal Waters of
     Southern Puerto Rico out 10 NM-Coastal Waters of Southern
     USVI Vieques and Eastern Puerto Rico out 10 NM.

     Small Craft Advisory until 6 PM AST Wednesday 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-
     Coastal Waters of Southern Puerto Rico out 10 NM-Coastal
     Waters of Southern USVI Vieques and Eastern Puerto Rico out
     10 NM-Mona Passage Southward to 17N.

&&

SHORT TERM...RAM
LONG TERM....RAM

Perspectivas sobre Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorologia San Juan PR
555 AM AST sabado 10 de febrero de 2018

AMZ710>745-PRZ001>013-111000-
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 lejanas a la costa del Atlantico y Caribe-
555 AM AST sabado 10 de febrero de 2018

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

.Vientos...Se esperan vientos sostenidos en exceso de 25 MPH a
traves de las aguas del Atlantico y la mayoria de las localidades
costeras locales.

.Olas...Se espera oleaje picado/peligroso de hasta 12 pies a traves
de las aguas del norte del Atlantico y algunos de los pasajes
locales.

.Corrientes Marinas...Existe un riesgo alto de corrientes marinas
desde la costa noroeste a noreste de Puerto Rico, algunas playas del
sureste de Puerto Rico, Culebra y Vieques.

.Dias dos a siete...domingo a viernes

El viento y oleaje permaneceran elevados hasta el martes debido a
una fuerte alta presion en el norte y este del Atlantico. Corrientes
marinas tambien permaneceran altos a lo largo de la mayoria de las
costas expuestas a las marejadas del este noreste.

.Comunicado sobre informacion reportada por observadores...

No se anticipa activacion amplia de observadores, sin embargo, se le
exhorta a los observadores que reporten vientos fuertes, trombas
marinas o corrientes marinas al Servicio Nacional de Meteorologia en
San Juan.

AMZ715-725-VIZ001-002-111000-
San Tomas, San John e Islas Adyacentes-
Santa Cruz-Aguas cercanas del Atlantico y aguas costeras adyacentes
del Caribe-
555 AM AST sabado 10 de febrero de 2018

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...Vientos sostenidos en exceso de 25 MPH se esperan a
traves de la mayoria de las aguas locales y localidades costeros.

.Olas...Se espera oleaje picado/peligroso de hasta 10 pies a traves
de las aguas locales.

.Corrientes Marinas...Existe un riesgo alto de corrientes marinas
para las playas del norte y este de Santa Cruz.

.Dias Dos a Siete...domingo a viernes

El viento y oleaje permaneceran elevados hasta el martes debido a
una fuerte alta presion en el norte y este del Atlantico. Corrientes
marinas tambien permaneceran altos a lo largo de la mayoria de las
costas expuestas a las marejadas del este noreste.

.Comunicado sobre informacion reportada por observadores...

No se anticipa activacion amplia de observadores, sin embargo, se le
exhorta a los observadores que reporten vientos fuertes o corrientes
marinas al Servicio Nacional de Meteorologia en San Juan.