NWS San Juan, PR wrote its last area forecast discussion before the first event at Aug 31, 9:41 PM AST, 2 hours 19 minutes earlier.
Area forecast discussion, Aug 31, 9:41 PM AST, 2 hours 19 minutes before
Area Forecast Discussion
National Weather Service San Juan PR
941 PM AST Wed Aug 31 2022
...New UPDATE, AVIATION, MARINE...
.UPDATE...
Issued at 930 PM AST Wed Aug 31 2022
Calm weather conditions will prevail overnight, with the arrival
of isolated to scattered showers across the north, east and
southeast coast of PR and the USVI late tonight and early
Thursday morning. Tomorrow, a surge of moisture will promote
isolated thunderstorms due to local effects, diurnal heating, and
sea breeze variations across the southwest quadrant in PR during
the afternoon. Winds will persist from the northeast under a land
breeze influence, increasing between 10 and 15 mph with sea
breeze variations and higher gusts tomorrow morning.
&&
.AVIATION...
(00Z TAFS)
Issued at 930 PM AST Wed Aug 31 2022
Generally VFR conditions will prevail thru at least tomorrow
afternoon. JSJ/IST may observe a few VCSH overnight. TSRA/SHRA
will then develop across the the interior, west and southern
slopes of PR btwn 01/16-23z. This activity may result in mtn
obscurations and MVFR/IFR conds at TJPS. Expect calm to light/vrb
winds thru 01/12z, returning from the NE at 10-15 mph with sea
breeze variations and higher gusts, especially near TSRA.
&&
.MARINE...
Issued at 930 PM AST Wed Aug 31 2022
Calm marine conditions will continue with seas of 4 feet or less
and winds around 15 knots. However, mariners are urged to exercise
caution during the afternoon hours, when thunderstorms may develop
across the coastal areas of Puerto Rico.
&&
.SYNOPSIS...
Light to moderate winds will prevail for the next several days.
Active afternoon are expected to persist for the interior, south
and southwest municipalities in Puerto Rico. Temperatures will
remain seasonably warm, with highs in the low 90s and heat indices
around 100 degrees. The low pressure Invest 91L is expected to
mover north of the islands by the weekend and no direct impacts
are anticipated at this time.
&&
.SHORT TERM...Tonight through Friday...
Saharan dust continues to linger across the local islands,
although in lower concentrations. A high pressure north of the
Bahamas and a low pressure (Invest 91L) are maintaining the
steering flow weak, and out of the northeast through at least
Friday. At the upper levels, a weak trough is located just
north of the local islands, providing some instability aloft. Under
this northeast flow, patches of moisture will be advected at
times. Therefore, expect passing showers at times across the
eastern municipalities of Puerto Rico and the U.S. Virgin Islands.
In the afternoon, local effects will combine with the available
moisture to generate showers and thunderstorm activity. In fact,
the National Blend Model shows 1 to 2 inches of accumulation for
the interior, south-central and southwestern Puerto Rico. This
rainfall, along with the amounts received in previous days could
result in urban and small stream flooding, as well as frequent
lightning and gusty winds with the strongest thunderstorms.
On Friday, as the strong tropical wave monitored by the National
Hurricane Center moves east-northeast of the Lesser Antilles, a
slot of drier air is expected to filter in. This should limit the
available moisture for afternoon shower production. However, the
upper level low lingers, and with strong diurnal heating, another
round of showers and thunderstorm is anticipated. Temperatures
will continue to be seasonably warm, with highs reaching the low
90s at coastal and urban areas, and heat indices generally
climbing to around 100 degrees, and isolated areas as high as 105
to 107 degrees.
&&
.LONG TERM...Saturday through Wednesday.../from prev discussion/
The general model agreement continues, and also the consistency
from one model run to another. Therefore there seems to be a bit
more confidence in the long term forecast, though still not more
confidence than normal for a long term forecast. The biggest
takeaway from the expected weather in the long term is that it
will be generally due to local effects and diurnal heating. This
means that the afternoon convection is likely to occur in areas of
sea breeze convergence. Also,the winds will be very light, as the
current low pressure (91L) in the central Atlantic will move
north of the local islands, leaving the local area with a very
weak pressure gradient from Saturday onward. That said, the winds
will be generally southerly to southeasterly on Monday and
Tuesday. The available moisture during the long term will be near
normal, but an increase in moisture is forecast for Monday,
possibly lingering into Wednesday. With this light wind pattern,
the areas of sea breeze convergence over PR will likely be mainly
across the interior, with thunderstorms developing later on with
the outflow from the initial thunderstorms that develop in the
afternoon. The USVI will remain mainly with a slight chance of
showers, likely observing little measurable precip for the most
part, with the chances of rain increasing early in the upcoming
workweek.
&&
.AVIATION...Generally VFR conditions will prevail across most
aerodromes for the next 24 hours. Brief MVFR or lower categories are
possible at TJPS due to TSRA/SHRA from afternoon convection between
through 31/21Z and after 01/17Z. Winds will continue from the NE at
10-15 knots with higher gusts and sea breeze variations through
31/21Z. Winds will become light and variable after that, increasing
once again after 01/12Z.
&&
.MARINE...
Light to moderate northeasterly winds will prevail for next
several days. Marine conditions will remain relatively tranquil
with seas up to 4 feet. Across the local beaches, there is a low
rip current risk everywhere.
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...None.
VI...None.
&&
SHORT TERM...CAM
LONG TERM....ERG
PUBLIC DESK...RVT
Hazardous weather outlook, Aug 31, 5:36 AM AST, 18 hours 24 minutes before
Perspectivas sobre las Condiciones Peligrosas del Tiempo
Servicio Nacional de Meteorologia en San Juan PR
436 AM AST miercoles 31 de agosto de 2022
AMZ710>745-PRZ001>013-010845-
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 del Caribe-
436 AM AST miercoles 31 de agosto de 2022
Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Puerto Rico y las aguas costeras adyacentes.
.DIA UNO...Hoy y esta noche
.Rayos...Tronadas de aisladas a dispersas son posibles a traves de
sectores del suroeste e interior de Puerto Rico. Este atento a las
tronadas en su area y preparese para refugiarse.
.Lluvia Excesiva...Acumulacion de agua en carreteras y areas de
drenaje deficiente a traves de sectores del suroeste e interior de
Puerto Rico. Inundaciones, si alguna, seran localizadas en areas que
pudieran experimentar escorrentias rapidas con lluvia fuerte.
.Calor Excesivo...Indices de calor entre 102-107 grados a traves de
areas de poca elevacion cerca de las costas del norte y noroeste. El
agotamiento por calor es posible con una exposicion prolongada.
.DIAS DOS HASTA EL SIETE...jueves a martes
Se esperan indices de calor en exceso de 102 grados para algunas
areas de poca elevacion durante la semana. Independientemente de una
disminucion en la humedad, los efectos locales mantendran el
potencial de lluvia excesiva y tronadas aisladas para sectores de
las islas. Se espera un aumento en la humedad el lunes, lo cual
pudiera aumentar estos riesgos. Se pronostica la llegada de una
marejada este fin de semana, aumentando el riesgo de corrientes
marinas, con riesgo de moderado a alto para la mayoria de las playas
locales para tarde el domingo o lunes.
.Comunicado sobre informacion reportada por observadores...
No sera necesaria la activacion de los observadores.
AMZ715-725-VIZ001-002-010845-
San Tomas, San John e Islas Adyacentes-Santa Cruz-
Aguas cercanas del Atlantico y aguas costeras adyacentes del Caribe-
436 AM AST miercoles 31 de agosto de 2022
Esta perspectiva sobre las condiciones peligrosas del tiempo es para
Islas Virgenes Estadounidenses y las aguas costeras adyacentes.
.DIA UNO...Hoy y esta noche
.DIAS DOS HASTA EL SIETE...jueves a martes
Se pronostica la llegada de una marejada, aumentando el riesgo de
corrientes marinas para algunas playas locales.
.Comunicado sobre informacion reportada por observadores...
No sera necesaria la activacion de los observadores.