Area Forecast Discussion
National Weather Service San Juan PR
544 AM AST MON JUL 4 2016
.SYNOPSIS...Ridge aloft will continue to gradually erode over the
next few days, as a tutt low located just northeast of the northern
Leeward islands, shifts westward and relocates north of the forecast
area by Wednesday. This feature is to then hold north of the area through
the remainder of the week. Surface high pressure will continue to prevail
and remain the dominant feature across the north central Atlantic during
the next several days. A tropical wave with axis just east of the Lesser
Antilles is forecast to enter the eastern caribbean later this evening,
then move across the forecast area Tuesday through early
Wednesday.
&&
.DISCUSSION...Mostly clear to partly cloudy skies prevailed across
the islands during the overnight hours. A few clouds and quick
passing showers moved across the regional waters and briefly
affected parts of the north and east coastal sections of some of
the islands. However so far no significant rainfall accumulations
were observed or reported. Early morning low temperatures across
coastal areas were high 70s to low 80s, and the wind over land
was mainly from the east at 5-10 mph.
For the rest of the day,mostly sunny skies and fair weather conditions
is forecast for most areas, under the present high pressure ridge pattern
and limited low level moisture advection. Except for local sea breeze
variations winds will be generally from the east at 15-20 mph with
occasionally higher gusts along the coastal areas. The local weather
pattern is however expected to change later tonight through early Tuesday
as the tropical wave enters and moves across the eastern caribbean.
The axis of the previously mentioned tropical wave was now located
near 54W, and is forecast to cross the Lesser Antilles later tonight.
This approaching feature along with the proximity of the upper level
trough moving north of the region will bring an increase in tropical
moisture and instability to the region. As a result deteriorating
weather conditions and isolated areas of squally weather conditions
will be possible across parts of the coastal waters, the U.S Virgin
Islands and eastern Puerto Rico by early Tuesday. These conditions
will later spread to the west portions of Puerto Rico during the
rest of the day on Tuesday. So far latest model guidance and recent
satellite imagery all suggest Tuesday as the most active weather
day. Widespread rainfall accumulations are not anticipated at this
time, however urban and small stream flooding will be possible in
isolated areas across the islands.
Weather conditions are then expected to improve by Wednesday, but locally
induced showers and isolated thunderstorms can still be expected mainly
across parts of the interior and west sections of Puerto Rico due to
the lingering moisture trailing the wave. A much drier air mass is then
expected by Thursday and through the upcoming weekend.
&&
.AVIATION...VFR conds are expected to continue at all TAF sites
through the forecast period. VCSH expected for TJSJ, TIST,TISX with
some directly affecting the terminals on occasion. SHRA/VCTS
activity expected after 04/17Z at TJMZ and pos TJBQ, causing brief
MVFR conds. Winds from the east at around 15-20kt with higher gusts
after 04/13Z.
&&
.MARINE...Winds and seas will increase during the next 48 hours as
a tropical wave moves across the regional waters. As a result small
craft advisories can be expected for some of the coastal waters from
now through Tuesday. Elsewhere small craft should continue to exercise
caution. Please refer to the latest Coastal Waters forecast and Marine
Weather Message issued by WFO San Juan PR, for additional information.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 88 79 / 20 50 50 20
STT 91 79 87 80 / 20 50 50 30
National Weather Service San Juan PR
544 AM AST MON JUL 4 2016
.SYNOPSIS...Ridge aloft will continue to gradually erode over the
next few days, as a tutt low located just northeast of the northern
Leeward islands, shifts westward and relocates north of the forecast
area by Wednesday. This feature is to then hold north of the area through
the remainder of the week. Surface high pressure will continue to prevail
and remain the dominant feature across the north central Atlantic during
the next several days. A tropical wave with axis just east of the Lesser
Antilles is forecast to enter the eastern caribbean later this evening,
then move across the forecast area Tuesday through early
Wednesday.
&&
.DISCUSSION...Mostly clear to partly cloudy skies prevailed across
the islands during the overnight hours. A few clouds and quick
passing showers moved across the regional waters and briefly
affected parts of the north and east coastal sections of some of
the islands. However so far no significant rainfall accumulations
were observed or reported. Early morning low temperatures across
coastal areas were high 70s to low 80s, and the wind over land
was mainly from the east at 5-10 mph.
For the rest of the day,mostly sunny skies and fair weather conditions
is forecast for most areas, under the present high pressure ridge pattern
and limited low level moisture advection. Except for local sea breeze
variations winds will be generally from the east at 15-20 mph with
occasionally higher gusts along the coastal areas. The local weather
pattern is however expected to change later tonight through early Tuesday
as the tropical wave enters and moves across the eastern caribbean.
The axis of the previously mentioned tropical wave was now located
near 54W, and is forecast to cross the Lesser Antilles later tonight.
This approaching feature along with the proximity of the upper level
trough moving north of the region will bring an increase in tropical
moisture and instability to the region. As a result deteriorating
weather conditions and isolated areas of squally weather conditions
will be possible across parts of the coastal waters, the U.S Virgin
Islands and eastern Puerto Rico by early Tuesday. These conditions
will later spread to the west portions of Puerto Rico during the
rest of the day on Tuesday. So far latest model guidance and recent
satellite imagery all suggest Tuesday as the most active weather
day. Widespread rainfall accumulations are not anticipated at this
time, however urban and small stream flooding will be possible in
isolated areas across the islands.
Weather conditions are then expected to improve by Wednesday, but locally
induced showers and isolated thunderstorms can still be expected mainly
across parts of the interior and west sections of Puerto Rico due to
the lingering moisture trailing the wave. A much drier air mass is then
expected by Thursday and through the upcoming weekend.
&&
.AVIATION...VFR conds are expected to continue at all TAF sites
through the forecast period. VCSH expected for TJSJ, TIST,TISX with
some directly affecting the terminals on occasion. SHRA/VCTS
activity expected after 04/17Z at TJMZ and pos TJBQ, causing brief
MVFR conds. Winds from the east at around 15-20kt with higher gusts
after 04/13Z.
&&
.MARINE...Winds and seas will increase during the next 48 hours as
a tropical wave moves across the regional waters. As a result small
craft advisories can be expected for some of the coastal waters from
now through Tuesday. Elsewhere small craft should continue to exercise
caution. Please refer to the latest Coastal Waters forecast and Marine
Weather Message issued by WFO San Juan PR, for additional information.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 88 79 / 20 50 50 20
STT 91 79 87 80 / 20 50 50 30
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