Areal Flood Warning 26, NWS JSJ

Area Forecast Discussion
National Weather Service San Juan PR
158 PM AST Sun Nov 13 2016

.SYNOPSIS...easterly trade winds with moisture and troughiness
will continue in the local area with scattered showers. A cold
front is likely to drop into the forecast area next weekend to
increase shower activity and lower temperatures a few degrees.

At upper levels...High pressure will dominate the Caribbean Sea
until Friday night. A moderately strong trough will move off the
Atlantic coast of the United States this Wednesday. A low will
cut-off Thursday night or Friday and drop south causing the sub-
tropical jet to dip within 80-160 miles of Puerto Rico by Sunday.

At mid levels...High pressure over the Caribbean Sea will become
centered over Saint Thomas by Wednesday. A low will form as a
trough leaves the Atlantic coast of the United States near
Washington DC and dip to as close as 31 north Friday through
Sunday. Mid-level moisture is quite limited except for a
boundary-layer passage on Saturday.

At lower levels...A weakening trough/tropical wave near 52 west
will approach the Lesser Antilles early this week causing local
flow to remain mainly easterly. Low pressure just off of the
Florida coast will move quickly north in the western Atlantic.
Moderately strong high pressure will become stalled over the
eastern coast of the Untied States Thursday while that low
pressure returns to the south in the vicinity of 50 west. This and
the mid level low mentioned above will cause a cold front to move
into the forecast area on Saturday with increased moisture and
shower activity.

&&

.DISCUSSION...Moisture continued in easterly flow causing showers
to form from Humacao to Toa Baja. Some areas will receive more
than one inch in a narrow band. Other showers formed along the
Cordillera Central from Mayaguez to Coamo. Up to now thunderstorms
had not been observed.

Easterly flow will continue and prevailing moisture will drive
early morning passing showers as well as more active convection
over higher terrain and areas of local convergence during the
afternoons. A few thunderstorms will also remain possible.
Moisture continues over the area through Monday, decreases
slightly the first half of the work week and then increases
through Saturday with the approach of a cold front. The driest
weather of the next 10 days is promised Monday morning of next
week when precipitable water drops below 1 inch.

This is a likely scenario, but confidence in the models is
medium-low. The GFS has changed from a strong trough deepening
over the western Caribbean to a strong tropical low advancing on
Hispaniola late in the 15 day period to a tropical low moving
into the Pacific (13/06z run) and back to a weak tropical low
that approaches Jamaica. This leads to considerable uncertainty as
to whether the features necessary to bring the cold front this far
south will materialize. That said, although these are considerable
changes for the western Caribbean, they have not been
particularly significant for the local area as moisture and modest
instability will continue to bring scattered showers and warm
temperatures though much of the week.

&&

.AVIATION...SHRA/TSRA will continue to impact the flying area
of TJSJ/TJPS/TJBQ/TJMZ for the rest of the afternoon hours.
Mtn top obscd and tempo MVFR conds possible through 22z. Streamers
off the USVI will continue to create mainly VCSH with possible -RA at
TIST. Mainly VFR conditions expected after 23z through at least
14/16z. ESE low level winds are expected to become ENE after
14/00z around 9-15 kts. However, light and variable winds are
expected at sfc overnight.

&&

.MARINE...Seas will continue to diminish slowly through Monday,
increase slightly and then decrease until Friday. The approach of
a cold front will increase winds and seas, but small craft
advisories are no longer as certain.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  79  87  78  87 /  40  40  40  40
STT  77  86  78  86 /  40  40  40  40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
AM...None.
&&

13/12

PERSPECTIVAS SOBRE CONDICIONES PELIGROSAS DEL TIEMPO...CORRECCION
SERVICIO NACIONAL DE METEOROLOGIA SAN JUAN PR
517 AM AST DOMINGO 13 DE NOVIEMBRE DE 2016

AMZ710>745-PRZ001>013-141000-
SAN JUAN Y VECINDAD-NORESTE-SURESTE-
ESTE INTERIOR-NORTE CENTRAL-CENTRAL INTERIOR-PONCE Y VECINDAD-
NOROESTE-OESTE INTERIOR-MAYAGUEZ Y VECINDAD-SUROESTE-CULEBRA-VIEQUES-
AGUAS COSTERAS Y MAR AFUERA DEL ATLANTICO Y DEL CARIBE-
517 AM AST DOMINGO 13 DE NOVIEMBRE DE 2016

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

.TRONADAS...EXISTE UN POTENCIAL DE TRONADAS CON LLUVIAS
FUERTES Y VIENTOS EN RAFAGAS BREVES ESTA TARDE PARTICULARMENTE A
TRAVES DEL INTERIOR Y OESTE DE PUERTO RICO. SIN EMBARGO...SE
PRONOSTICAN TRONADAS AISLAADS PARA PORCIONES DEL AREA METROPOLITANA
DE SAN JUAN.

.INUNDACIONES...LLUVIAS FUERTES PODRIAN RESULTAR EN INUNDACIONES
URBANAS Y DE RIACHUELO.

.OLEAJE...OLEAJE PICADO Y PELIGROSO HASTA 5 PIES SE ESPERA A TRAVES
DE LAS AGUAS MAR AFUERA DEL ATLANTICO.

.CORRIENTES SUBMARINAS...EXISTE UN RIESGO MODERADO DE CORRIENTES
SUBMARINAS PARA LAS PLAYAS ORIENTADAS HACIA EL NORTE DE PUERTO RICO.

.DIAS DOS HASTA SIETE...LUNES A SABADO

AGUACEROS Y TRONADAS SE ESPERAN CADA TARDE A TRAVES DE PORCIONES DE
PUERTO RICO DURANTE LOS PROXIMOS DIAS. ESTOS AGUACEROS Y TRONADAS
PODRAN CAUSAR INUNDACIONES URBANAS Y DE RIACHUELOS ASI COMO UN
AUMENTO RAPIDO EN LOS NIVELES DE LOS RIOS. EN ADICION...UN RIESGO
MODERADO DE CORRIENTES SUBMARINAS SE ESPERA QUE CONTINUE DURANTE LOS
PROXIMOS DIAS.

.COMUNICADO SOBRE INFORMACION REPORTADA POR OBSERVADORES...

NO SE ANTICIPA ACTIVACION AMPLIA DE OBSERVADORES, SIN EMBARGO SE
INVITA A LOS OBSERVADORES A REPORTAR INUNDACIONES Y CORRIENTES
SUBMARINAS AL SERVICIO NACIONAL DE METEOROLOGIA EN SAN JUAN.

AMZ715-725-VIZ001-002-141000-
SAN TOMAS SAN JOHN E ISLAS ADYACENTES-SANTA CRUZ-
AGUAS CERCA DE LA COSTA DEL ATLANTICO Y AGUAS COSTERAS ADYACENTES
DEL CARIBE-
517 AM AST DOMINGO 13 DE NOVIEMBRE DE 2016

ESTA PERSPECTIVA SOBRE LAS CONDICIONES PELIGROSAS DEL TIEMPO ES PARA
LAS ISLAS VIRGENES AMERICANAS Y LAS AGUAS COSTERAS ADYACENTES.

.DIA UNO...HOY Y ESTA NOCHE

.CORRIENTES SUBMARINAS...EXISTE UN RIESGO MODERADO DE CORRIENTES
SUBMARINAS PARA LAS PLAYAS ORIENTADAS HACIA EL NORTE Y OESTE DE
SANTA CRUZ Y SAN THOMAS.

.DIAS DOS HASTA SIETE...LUNES A SABADO

UN RIESGO MODERADO DE CORRIENTES SUBMARINAS SE ESPERA QUE CONTINUE
PARA SAN THOMAS Y SANTA CRUZ HASTA TEMPRANO EL LUNES EN LA MANANA.

.COMUNICADO SOBRE INFORMACION REPORTADA POR OBSERVADORES...

NO SE ANTICIPA ACTIVACION AMPLIA DE OBSERVADORES, SIN EMBARGO SE
INVITA A LOS OBSERVADORES A CORRIENTES SUBMARINAS AL SERVICIO
NACIONAL DE METEOROLOGIA EN SAN JUAN.