Severe Thunderstorm Warning 1, NWS JSJ

758 
WWCA52 TJSJ 211525
SVSSJU

Severe Weather Statement
National Weather Service San Juan PR
Issued by National Weather Service Miami FL
1125 AM AST Tue Jul 21 2020

PRC007-211534-
/O.CAN.TJSJ.SV.W.0001.000000T0000Z-200721T1545Z/
Aguas Buenas PR-
1125 AM AST Tue Jul 21 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN AGUAS BUENAS
MUNICIPALITY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning for northern Aguas Buenas 
has been cancelled.

LAT...LON 1835 6605 1830 6608 1828 6610 1828 6616
      1827 6618 1833 6634 1849 6622 1849 6619
TIME...MOT...LOC 1524Z 117DEG 13KT 1836 6619 

$$

PRC021-033-047-051-061-105-127-135-137-211545-
/O.CON.TJSJ.SV.W.0001.000000T0000Z-200721T1545Z/
San Juan PR-Naranjito PR-Guaynabo PR-Bayamon PR-Dorado PR-Corozal PR-
Catano PR-Toa Baja PR-Toa Alta PR-
1125 AM AST Tue Jul 21 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 AM AST
FOR SOUTHWESTERN SAN JUAN...NORTHEASTERN NARANJITO...GUAYNABO...
BAYAMON...EASTERN DORADO...NORTHEASTERN COROZAL...CATANO...TOA BAJA
AND TOA ALTA MUNICIPALITIES...

At 1124 AM AST, a severe thunderstorm was located over Pajaros, or
near Bayamon, moving northwest at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
San Juan, Guaynabo, Toa Alta, Sabana Seca, Corozal, Bayamon,
Naranjito, Toa Baja, Campanilla, Ingenio, Rio Lajas, H. Rivera Colon,
San Jose, Galateo, Pajaros, Candelaria, Levittown, Candelaria Arenas
and Mucarabones.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into a
small central room in a sturdy structure.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in 
San Juan. You can also share your report with NWS San Juan on 
Facebook and Twitter.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 1835 6605 1830 6608 1828 6610 1828 6616
      1827 6618 1833 6634 1849 6622 1849 6619
TIME...MOT...LOC 1524Z 117DEG 13KT 1836 6619 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

RAG

359 
WWCA52 TJSJ 211536
SVSSJU

Severe Weather Statement
National Weather Service San Juan PR
Issued by National Weather Service Miami FL
1136 AM AST Tue Jul 21 2020

PRC033-127-211546-
/O.CAN.TJSJ.SV.W.0001.000000T0000Z-200721T1545Z/
San Juan PR-Catano PR-
1136 AM AST Tue Jul 21 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SAN JUAN AND
CATANO MUNICIPALITIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 1838 6613 1827 6619 1833 6634 1846 6624
TIME...MOT...LOC 1536Z 116DEG 13KT 1836 6624 

$$

PRC021-047-051-061-105-135-137-211545-
/O.CON.TJSJ.SV.W.0001.000000T0000Z-200721T1545Z/
Naranjito PR-Guaynabo PR-Bayamon PR-Dorado PR-Corozal PR-Toa Baja PR-
Toa Alta PR-
1136 AM AST Tue Jul 21 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1145 AM AST
FOR NORTHEASTERN NARANJITO...NORTHWESTERN GUAYNABO...BAYAMON...
SOUTHEASTERN DORADO...NORTHEASTERN COROZAL...TOA BAJA AND TOA ALTA
MUNICIPALITIES...

At 1136 AM AST, a severe thunderstorm was located over Pajaros, or
near Toa Alta, moving northwest at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Toa Alta, Corozal, Bayamon, Naranjito, Toa Baja, Sabana Seca,
Guaynabo, Campanilla, Ingenio, Rio Lajas, H. Rivera Colon, San Jose,
Galateo, Pajaros, Candelaria, Candelaria Arenas and Mucarabones.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 1838 6613 1827 6619 1833 6634 1846 6624
TIME...MOT...LOC 1536Z 116DEG 13KT 1836 6624 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

RAG

Area Forecast Discussion
National Weather Service San Juan PR
1046 AM AST Tue Jul 21 2020

.UPDATE...Minor adjustments to weather grids based on current
weather conditions and recent model guidance. Upper-level trough
will continue to support favorable conditions aloft to enhance
shower and thunderstorm activity today and Wednesday. This
activity will favor eastern Puerto Rico and the US Virgin Islands
throughout the overnight and morning hours. Then, the bulk of the
activity will focus along the interior and over the northwestern
quadrant of the island. Showers and isolated thunderstorms moving
over the San Juan metropolitan area and eastern Puerto Rico in the
afternoon cannot be ruled out. As a result, urban and small stream
flooding can be expected. The entrance of drier air and upper-
level high pressure will lean to a more stable weather pattern on
Thursday and Friday, but the arrival of a two tropical wave will
once again enhance shower and thunderstorm activity by Friday
evening into early next week.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across all
terminals. However, VCSH expected across all terminals through
at least 21/22Z. VCTS/VCSH may affect portions of TJSJ, TJBQ, and
TJPS after 21/16Z, with brief MVFR conditions possible at TJBQ.
Winds will be from the East at 10 to 15 knots with a few gusts and
sea breeze variations.

&&

.MARINE...No changes from previous forecast.

&&

.PREV DISCUSSION... /issued 456 AM AST Tue Jul 21 2020/

SYNOPSIS...

A typical pattern of isolated to scattered passing showers during
the mornings and nights, and afternoon showers and thunderstorms,
especially in the west, is anticipated today and tomorrow. On
Thursday, drier and more stable conditions are anticipated as a
dry slot ahead of a tropical wave affects the area. The tropical
wave is forecast for Friday, and shower activity will increase.

SHORT TERM...Today through Thursday...

Widely scattered showers are affecting the local waters, USVI and
eastern PR this morning. This is due to near normal moisture and a
weak upper level low and associated trough located north and west of
Puerto Rico will move west through Wednesday. This upper trough will
cause some instability over the local area today and Wednesday.
There is a slightly drier air mass expected to move in for this
afternoon, but the available moisture, diurnal effects and marginal
instability will combine to cause some showers and thunderstorms
this afternoon, especially across the same areas that observed
significant rain yesterday, which are the western sections and some
sections of north and eastern PR as well as portions of the San Juan
Metro. The USVI will remain observing isolated to scattered brief
showers through the day. Slightly higher moisture is expected on
Wednesday, but otherwise the overall pattern is expected to be
similar, so similar rainfall pattern is expected. On Thursday, an
upper level high pressure will move just north of the local area,
stabilizing the atmosphere a little bit. There will also be drier
air moving in, ahead of a Tropical Wave that is expected for Friday.
Therefore the shower activity should be much less for Thursday
compared to Today and Wednesday.

The forecast models continue being somewhat inconsistent, and the hi-
res models are indicating much more rainfall than the global models.
That said, the hi-res models seem to be initializing a bit better
and seem to have a more representative solution, so we leaned a bit
more towards the high res models for todays's and Wednesday's
forecast. In terms of temperatures, the guidance continues
indicating that high temps will be in the upper 80s, although some
areas could easily surpass 90 degrees across south and SW-PR, while
the USVI will also be near 90 degrees.

LONG TERM...Friday through Tuesday...

A tropical wave is forecast to arrive by Friday morning, bringing
increased moisture to the region. An increase in shower activity
is expected, with the typical pattern of showers and isolated
thunderstorms due to local effects and diurnal heating. This
increase will be somewhat subdued, however, as conditions aloft
are expected to be unfavorable for convective development, with a
ridge in the upper levels. The tropical wave's visit will likely
be relatively brief, as it speeds across the region, which could
further limit rainfall amounts seen from it, and conditions will
begin to dry out somewhat late in the day on Friday.

Saturday remains somewhat vexing. The GFS has once again backed
off on moisture reaching the area with the two most recent runs,
which is better supported by foreign guidance. It does still
suggest that southern portions of the forecast region will see
some moisture from this feature on Saturday, largely for the
Caribbean waters, though some southern portions of the islands and
possibly into western Puerto Rico could be impacted. Moisture
levels for the rest of the region will be near normal or possibly
just below normal. As such, the typical pattern of afternoon
showers and isolated thunderstorms and passing showers during the
overnight and morning is anticipated. Whether or not the moisture
makes it across the islands, conditions aloft are forecast to
remain unfavorable for development, which would limit somewhat
any impacts that might be anticipated.

A dry airmass is forecast to enter the region Sunday. As such,
drier, more stable weather is expected for the day. Some patches
of moisture will likely stream across the region embedded in the
trade winds, which could help sustain afternoon showers due to
local effects and diurnal heating.

Another wave is expected for Monday. Moisture associated with this
wave will help to fuel afternoon showers and thunderstorms, which
will likely be relatively widespread. Also helping to sustain this
activity is a more favorable environment aloft for convection. An
upper level low is forecast to push across the area on Sunday,
lingering over or near the area into midweek. Model guidance has
been relatively consistent with this feature and its potential
impact, though timing remains relatively uncertain; any changes to
expected arrival time of this feature over the local islands would
likely be to push it back, possibly even into the day on Tuesday.
Behind the wave, some moisture will linger, keeping precipitable
water values around climatological normal values or higher. As
such, another day of active weather is expected for Tuesday,
though slightly diminished compared to Monday.

AVIATION...

Mainly VFR conditions are expected to prevail across all
terminals. VCSH will be observed through the forecast period for
TIST and TISX, especially in the morning. VCTS/VCSH may affect
portions of TJSJ/TJBQ after 21/16Z, with brief MVFR conditions
possible at TJBQ. Winds will be from the East at 10 to 15 knots
with a few gusts and sea breeze variations.

MARINE...

Seas of up to 5 feet continue across the local waters for the
first half of the week. Associated with a ridge to the north,
moderate to locally fresh winds persist across the area as well.
Locally stronger winds are also possible with showers. Seas are
forecast to build to around 6 to 8 feet late this week due to a
wind surge associated with a tropical wave, due to arrive on
Friday. There is a moderate risk of rip currents today at beaches
along the north coast of Puerto Rico, as well as eastern beaches
of St. Croix, Vieques, and Culebra.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  90  79  88  78 /  40  40  40  40
STT  89  78  89  78 /  30  30  30  40

&&

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

SHORT TERM...ICP
LONG TERM....ICP
PUBLIC DESK...RVT

Perspectivas sobre Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorologia San Juan PR
534 AM AST martes 21 de julio de 2020

AMZ710>745-PRZ001>013-220945-
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 mar afuera del Atlantico y Caribe-
534 AM AST martes 21 de julio de 2020

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 lluvia fuertes y
vientos en rafagas breves esta tarde a traves de sectores del
interior, oeste y noroeste de Puerto Rico. Ademas, tronadas aisladas
son posibles a traves de sectores del area metropolitana de San Juan.

.Inundaciones...Lluvias moderadas pudieran resultar en acumulacion
de agua en carreteras y areas de pobre drenaje, mientras que lluvias
fuertes pudieran resultar en inundaciones urbanas y de riachuelos.

.Vientos...Vientos sostenidos de 20 MPH (17 nudos) son anticipados a
traves de las aguas costeras del Atlantico de Puerto Rico.

.Oleaje...Oleaje picado de hasta 5 pies es anticipado a traves de
las aguas del Atlantico.

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

.Dias dos hasta el siete...miercoles hasta lunes

Riesgo moderado de corrientes marinas continuara para playas del
norte de Puerto Rico esta semana. Una vaguada en los niveles altos
aumentara el potencial de tronadas y lluvias el martes y
potencialmente el miercoles, especialmente durante las horas de la
tarde. Se pronostica que una onda tropical se acercara al area local
el viernes y el sabado, trayendo humedad amplia y posible aumento
significativo en la actividad de aguaceros.

.Comunicado sobre informacion reportada por observadores...

No se anticipa activacion de observadores, sin embargo, se
recomienda a los observadores individuales que reporten 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-VIZ001-002-220945-
San Tomas, San John y Islas Adyacentes-Santa Cruz-
Aguas cercanas del Atlantico y aguas costeras adyacentes del Caribe-
534 AM AST martes 21 de julio de 2020

Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Islas Virgenes Estadounidenses y las aguas costeras adyacentes.

.Dia Uno...Hoy y esta noche

.Inundaciones...Lluvias de moderadas a fuertes pudieran resultar en
acumulacion de agua en carreteras y areas de poco drenaje.

.Oleaje...Oleaje picado de hasta 5 pies es anticipado a traves de
las aguas alrededor de las Islas Virgenes Estadounidenses.

.Corrientes Marinas...Existe un riesgo moderado de corrientes
marinas para el norte y este de Santa Cruz.

.Dias dos hasta el siete...miercoles a lunes

Se espera riesgo moderado de corrientes marinas para las playas del
norte y este de Santa Cruz esta semana. Una vaguada en los niveles
altos aumentara el potencial de aguaceros y tronadas el martes. La
actividad de aguaceros pudiera causar acumulacion de agua en
carreteras y areas de pobre drenaje. Se pronostica que una onda
tropical se acercara al area local el viernes y sabado, resultando
en humedad abundante y posible aumento significativo en la actividad
de aguaceros.

.Comunicado sobre informacion reportada por observadores...

No se anticipa activacion de observadores, sin embargo, se
recomienda a los observadores individuales que reporten vientos,
oleaje y corrientes marinas al Servicio Nacional de Meteorologia en
San Juan mientras siguen las indicaciones de las autoridades locales
y estatales.

Special Weather Statement
National Weather Service San Juan PR
Issued by National Weather Service Miami FL
1100 AM AST Tue Jul 21 2020

PRZ001-004>006-211530-
San Juan and Vicinity-North Central-Central Interior-Eastern
Interior-
1100 AM AST Tue Jul 21 2020

...A STRONG THUNDERSTORM WILL AFFECT AGUAS BUENAS...CENTRAL
CAROLINA...NORTHERN CAGUAS...NARANJITO...BAYAMON...TOA BAJA...
TRUJILLO ALTO...NORTHEASTERN COMERIO...SAN JUAN...NORTHWESTERN
GURABO...GUAYNABO...SOUTHEASTERN DORADO...NORTHERN CIDRA...EAST
CENTRAL COROZAL...CATANO AND TOA ALTA MUNICIPALITIES...

At 1100 AM AST, a strong thunderstorm was located near Bairoa, or
near Aguas Buenas, moving northwest at 15 mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
San Juan, Aguas Buenas, Caguas, Trujillo Alto, Guaynabo, Toa Alta,
Sabana Seca, Catano, Bayamon, Naranjito, Corozal, Carolina,
Campanilla, Ingenio, H. Rivera Colon, San Jose, Galateo, Pajaros,
Bairoa and Candelaria.

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 1849 6618 1847 6616 1848 6614 1836 6595
      1820 6605 1828 6633 1849 6621
TIME...MOT...LOC 1500Z 116DEG 13KT 1832 6608

RAG