Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
135 PM AST TUE JUN 14 2016

.SYNOPSIS...Low to mid level ridge will continue to produce a
stable atmosphere through at least the end of the work week. In
addition...Saharan Air Layer will keep a dry air mass at mid
levels as well as a strong subsidence that limit the vertical
development of the clouds across the local region. Pattern will
change somewhat during the weekend as a tropical wave enters the
Eastern Caribbean Region...increasing the potential of showers
across the islands.

&&

.DISCUSSION...Fair weather has prevailed across Puerto Rico and
the U.S. Virgin Islands today. Hazy skies have been observed but
visibilities have remained greater than 6 miles across most of
the area. No shower activity have been observed across the islands
so far this afternoon. If any showers form will be short-lived as
very stable conditions prevail across the local area. Similar
pattern expected tonight and overnight...with little or no shower
activity affecting the islands.

Stable pattern will prevail most of the work week as Saharan Air
Layer remains over the area...inhibiting the development of
showers across the local region. Southeasterly flow will keep
warm to hot temperatures across most of the islands. A few bands
of moisture embedded in the trade winds will move at times between
Friday and Saturday...allowing scattered showers to develop across
portions of PR/USVI. The next surge of moisture is associated with
a tropical wave. At this time...operational models suggest that
the moisture associated with the tropical wave will likely reach
the local region on Sunday. Therefore...showers and thunderstorms
are likely as the wave passes by.

&&

.AVIATION...VFR conditions will continue to prevail at all TAF sites
through the forecast cycle with an isolated SHRA possible in and
around JMZ/JBQ through 14/22z. ESE winds will continue 10 to 15
knots becoming light and variable overnight.

&&

.MARINE...Tranquil marine conditions expected over the next few
days. Winds of 10-15 knots and seas of 2-4 feet with occasional
seas of 5 feet will prevail across most of the local waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 91 80 91 / 10 20 20 20
STT 81 86 79 87 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
552 AM AST WED JUN 15 2016

.SYNOPSIS...Shower activity will begin to increase on Thursday as
an upper level low approaches the area and tropical waves move
south of the area Friday through Monday.

At upper levels...Low pressure north of Puerto Rico
will deepen and move south into the Mona Channel by Thursday
evening...displacing the high that is currently ridging over the
forecast area. This low will gradually move to eastern Cuba by
Wednesday of next week as high pressure builds over the area from
the tropical Atlantic.

At mid levels...High pressure in the eastern tropical Atlantic
will drift northwest into the central Atlantic. a ridge from the
high will continue over or just north of the local area through
Tuesday of next week.

At lower levels...High pressure just west of the Azores ridges
across the local Atlantic outer waters. The high will move east
and the ridge will drift into the subtropical Atlantic north of
the area Friday through Sunday. Although low pressure moves into
the west central Atlantic over the weekend, moderate trade winds
will continue over the local area from the east southeast and will
be the strongest on Sunday and Monday. Weak tropical waves will
pass mainly south of the area on Friday through Monday with a
modest increase in shower and thunderstorm activity.

&&

.DISCUSSION...After a few early evening showers that dampened the
coasts of Arroyo and Guayama radar showed few other showers even
over the local waters. Dry air with Saharan dust will continue
today reducing the chance of showers everywhere. Although moisture
increases slightly today and the layer between 850 and 700 mb
remains quite unstable, the atmosphere below 500 mb remains
relatively dry and the GFS sounding suggests that once the surface
moisture is mixed out the buoyancy near the LFC will become
negative. This will greatly limit shower activity even in the
normally shower prone northwest of Puerto Rico. Conditions become
more favorable on Thursday and shower activity is likely in a few
places in western Puerto Rico through at least Monday as tropical
waves and bands of better moisture move south of and brush the
local area. Strong features are not seen in the GFS through the
penultimate week in June.

&&

.AVIATION...VFR conditions will prevail across all terminals during
the next 24 hours. HZ due to Saharan dust is expected but with
P6SM. E-SE winds at 10 to 15 knots with occasional higher gusts.
Sea breeze variations aft 15/14z across NW PR could result in the
development of VCSH at TJMZ late in the afternoon.

&&

.MARINE...Winds will subside somewhat in the Mona channel today
but local maximums are expected for the next several days north of
Puerto Rico. This will bring exercise caution conditions to those
areas today. Conditions are expected to relax until the middle of
the weekend. Small craft advisories may be necessary then for the
area south of the Mona channel for seas up to 7 feet.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 92 79 90 79 / 10 10 10 10
STT 89 78 89 78 / 10 10 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
212 PM AST WED JUN 15 2016

.SYNOPSIS...Low to mid level high pressure will maintain
a stable atmosphere through at least the end of the work
week. In addition...Saharan Air Layer is still present over
the area...keeping a dry air mass and subsidence at mid levels.
This will help to limit the vertical development of the clouds
across the local region. Pattern will change during the weekend
as a tropical wave enters the Eastern Caribbean Region...increasing
somewhat the potential of showers across the islands.

&&

.DISCUSSION...Fair weather has prevailed once again across Puerto
Rico and the U.S. Virgin Islands today. Hazy skies have been
observed but visibilities have remained greater than 6 miles
across most of the area. No shower activity have been observed
across the islands so far this afternoon. If any showers form will
be short-lived as very stable conditions prevail across the local
area. Similar pattern expected tonight and overnight...with little
or no shower activity affecting the islands.

Stable pattern will prevail most of the work week as Saharan Air
Layer remains over the area...limiting the development of showers
across the local region. Southeasterly flow will keep warm to hot
temperatures across most of the islands over the next few days.
Moisture bands embedded in the trade winds will move at times
between Friday and Saturday...allowing scattered showers to develop
across portions of PR/USVI. The next surge of moisture is associated
with a tropical wave. At this time...operational models suggest that
the moisture associated with the tropical wave will likely reach
the local region on Sunday. Therefore...showers and thunderstorms
will likely affect the local islands as the wave passes by.

&&

.AVIATION...VFR conds will continue through the forecast period.
Winds will continue through the

&&

.MARINE...Tranquil marine conditions expected over the next few
days. Winds of 10-15 knots and seas of 2-4 feet with occasional
seas of 5 feet will prevail across most of the local waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 79 90 / 10 10 10 30
STT 78 89 78 88 / 10 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
352 AM AST THU JUN 16 2016

.SYNOPSIS...Increasing moisture today and over the weekend will
generate better shower and thunderstorm activity with a threat of
urban and small stream flooding mainly in the interior western
portion of Puerto Rico.

At upper levels...A weak upper level low will drop south southwest
over the eastern tip of the Dominican Republic today and will
aid thunderstorm development over Puerto Rico. As the low drifts
slowly west northwest over the weekend and into next week, high
pressure will ridge over the area. A TUTT Low will deepen
northeast of the Windward Islands next week.

At mid levels...The focus of the high pressure stretched east to
west across the Atlantic Ocean north of the local area will shift
into the central Atlantic. Weak troughiness will move into the
eastern Caribbean mid week next week. Moisture north of the area
today moves southwest and fades. Better moisture associated with
a tropical wave moves past the area to the southwest.

At lower levels...High pressure over the Azores forms a ridge to
the north of the area and drives the current trade winds. It will
recede to the east. High pressure over Pennsylvania and New York
will move into the central Atlantic Saturday through Tuesday and
become the dominant feature that continues to drive the east
southeast trade winds over the local area through the end of next
week. A weak tropical wave will pass mainly south of the area
Friday night and Tuesday. A minor disturbance will also cross
through this Sunday before dawn.

&&

.DISCUSSION...Moisture is forming a band over the Leeward Islands
that was pulled in from the northeast from an old frontal
boundary. It will be the first moisture to cross the local area
tonight through Friday. Then moisture from weak tropical waves
will move into the area Sunday through Monday night. Although
drier Saharan air is crossing the tropical Atlantic at mid and
lower levels, it is mixing a little more deeply which is bringing
bands of better moisture there. Nevertheless mid layers remain
quite dry through the next 10 days and will limit the extent of
showers and thunderstorms that can form. Yesterday`s thunderstorms
did bring very heavy rain to a few local area in Maricao, Las
Marias and Utuado. Small hail also fell in Utuado due to the
intensity of the heating and convergence in the area. An inversion
also capped the activity early in the afternoon that caused the
storms to be stronger when they broke through. This cap is nearly
gone now.

Today precipitable water has spiked upward nearly an inch over
Bayamon to reach 2.5 inches and should cause much more extensive
showers even if they are a little weaker when they begin to block
the near-solstice heating. Such a high reading from the sounder is
unusual and we cannot be entirely confident of its accuracy until
the morning sounding is seen, so will be somewhat conservative
with POPs in all but western Puerto Rico today. Moisture and trade
wind flow is expected to continue through the weekend and into
Monday with showers, isolated thunderstorms and possible urban and
small stream flooding each day until then. Although moisture
moderates Tuesday and Wednesday it increases again toward the end
of next week with similar low-level flow. An upper level low will
also enhance shower and thunderstorm activity today through
Monday. A passing ridge will cause an ebb in the activity Tuesday
followed by northwest flow around the subsident side of a TUTT low
to the east northeast that consolidates early next week.

&&

.AVIATION...VFR conditions will prevail across all terminals during
the next 24 hours. HZ due to Saharan dust expected but with P6SM.
Low level winds expected to continue from the east at 10 to 15
knots. Sea breeze variations after 16/14z across northern PR
terminals...leading to development of shra/tsra across the western
interior...impacting mainly TJMZ btwn 16/18z-23z with MVFR conds
likely and mtn obscurations.


&&

.MARINE...Winds and seas remain relatively tranquil through
Saturday evening but winds at 850 mb will ramp up to almost 30
knots by early Monday morning. This will cause seas to increase
Sunday into Monday. Small Craft Advisory conditions are possible
on Monday...mainly in the Caribbean outer waters, but also in the
northeast portion of the Atlantic.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 79 90 79 / 10 10 30 40
STT 89 78 88 79 / 20 20 20 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
158 PM AST THU JUN 16 2016

.SYNOPSIS...Surface high pressure across the northeastern Atlantic
will continue to promote an East to E-SE wind for the next several
days. Upper low to the west of the local area will remain nearly
stationary for the next several days, however the presence of
Saharan dust and relatively dry air is expected to limit the
shower development over the local islands. Tropical wave to bring
an increase in moisture and instability on Sunday. Saharan dust
concentrations will gradually decrease tonight and Friday.

&&

.DISCUSSION...High clouds have moved into the local area, mainly
over Puerto Rico today. The local effects in Puerto Rico have
caused some low level cloudiness to develop across the interior
portions of PR while some clouds are currently starting to develop
in the early afternoon hours. The rest of the outlying islands
have some clouds streaming off them. There has been no showers
detected across over the local islands. The Saharan dust is still
over the local area, causing haze. The warm temperatures and local
effects may help in the development of showers and thunderstorms
across the western portions of PR with only a slight chance of
showers elsewhere.

The overall pattern is not expected to change much until Sunday.
We have a weak upper low to the west of the forecast area but we
are in the subsident side of the low, plus there is limited
moisture. This means that any showers or thunderstorms that
develop is expected to be in a limited area, mainly across western
PR, fair weather elsewhere.

Tropical wave is expected to move in on Sunday, which will cause a
slight increase in moisture and instability. This means that there
is an increased chance of showers and thunderstorms on Sunday,
however there is the possibility of Saharan dust over the area.
Lingering moisture is expected through Monday. Drier air to move
in once again on Tuesday.


&&

.AVIATION...VFR conditions will prevail across all terminals during
the next 24 hours. Saharan Dust will continue to diminish across the
flying area through Friday. Low level winds expected to continue
from the east-southeast at 10 to 15 knots.


&&

.MARINE...Seas of 2 to 4 feet and winds of 10 to 15 knots are
expected through the local waters. Portions of the nearshore
Atlantic waters may experience winds of up to 20 knots on Friday
and Saturday.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 91 79 90 / 30 20 40 30
STT 77 89 79 89 / 50 20 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
509 AM AST FRI JUN 17 2016

.SYNOPSIS...Some showers will enter Puerto Rico this morning, but
main activity continues to be the formation of mid afternoon
showers and thunderstorms each day through Wednesday in western
Puerto Rico. Tropical waves will pass through Sunday night and
Tuesday night.

At upper levels...Low pressure on the eastern tip of the Dominican Republic
will drift northwest today and tonight and then northeast until it
is well north of the Mona channel by Tuesday and nearly
dissipated. High pressure will move into the eastern Caribbean
from the east and pass south of Puerto Rico by Wednesday.

At mid levels...Broad high pressure over the tropics will become
focused in the Atlantic stretching southwest of the Azores. It
will drift into the central Atlantic by Tuesday. A weak trough is
seen over the lesser Antilles next week.

At lower levels...High pressure over the Azores stretches
southwest and then west over the sub tropical Atlantic to Cuba.
High pressure over the eastern United States will move into the
central Atlantic by Tuesday and the ridge will shift farther
north. Tropical waves will cross through or just south of the area
both Sunday and Tuesday nights with an increase in showers both
times.

&&

.DISCUSSION...Showers and thunderstorms developed over the western
interior of Puerto Rico yesterday in much the same area as the day
before. Overnight isolated showers moved across the waters from
saint Croix to east through south of Puerto Rico. Some of these
dampened the eastern coast of Puerto Rico. A similar situation is
expected again to day. With the wind turning slightly more
easterly, moisture increasing slightly but stability increasing as
well, should see another round of showers and thunderstorms
starting in or around Utuado in the early afternoon and moving
westward across Mayaguez during the late afternoon. Saturday will
also be similar and slightly drier but moisture increases with the
passage of a tropical wave and shower activity could be scattered
over more of the area. An upper level low should help conditions a
little today through Sunday. Presently the most favorable
conditions for showers and thunderstorms is Sunday and Wednesday,
(after the wave has passed). Urban and small stream flooding will
be possible in localized areas of western Puerto Rico each day.

Saharan dust will continue although there will be some let up
today, tonight and Sunday. Dust is expected to continue after
Sunday. Visibilities will dip to as low as 10 miles during these
episodes.

&&

.AVIATION...VFR conds will prevail this morning. -SHRA expected
across TNCM/TKPK this morning, also can affect TJSJ/TIST/TISX.
Cloudiness will increase across the Cordillera Central of PR and
downwind from the USVI aft 17/16z. As a result, expect SCT-BKN
ceiling btwn FL025-FL050 and SHRA/TSRA over the interior/western
PR causing mtn obscurations. Some of them are possible over/near
TJMZ/TJBQ, so brief MVFR conditions are possible. Sfc winds from
the east-southeast at 10-15 kt and gusty in/near SHRA/TSRA with
sea breeze variations aft 17/13z.

&&

.MARINE...Winds and seas have been relatively tranquil but are
expected to increase Sunday and Monday. Small craft advisories may
be necessary Monday and Tuesday for 7 foot seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 79 91 79 / 10 10 10 20
STT 89 79 89 80 / 10 10 10 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
349 PM AST FRI JUN 17 2016

.SYNOPSIS...Upper low over The Dominican Republic will continue
for the next day or so as it moves to the northeast over the
Atlantic waters...becoming a trof later on Sunday. Upper ridge
builds from the eastern Caribbean by early next week. A tropical
wave will enter the local area on Sunday...followed by another one
on Tuesday.


&&

.DISCUSSION...Showers and thunderstorms developed across the
interior and western sections of PR early in the afternoon hours.
As of 3:30 pm ast...the doppler radar estimated 2-3 inches of rain with
the heaviest showers across Lares...Las Marias and Utuado.
Also...showers affected San Juan and vicinity just around
noon...with the doppler radar estimating 1-2 inches of rain over
Guaynabo. Max temperatures were in the high 80s to low 90s across
the coastal areas of the islands. Across the USVI showers
developed off streamers and affected mainly the coastal waters
west of the islands.

Showers are expected to focus over the interior/western areas of
PR...with some streamers forming off the islands each day. As
tropical wave enters the eastern Caribbean on Sunday...moisture
will increase and with the possible combination of the upper
low/trof more favorable upper level conditions could lead to more
cloudiness...shower and thunderstorm activity across the forecast
area. Saharan dust returns after the passage of the wave.


&&

.AVIATION...Mainly VFR thru the fcst period. SHRA across western
PR should end by 23z. Light trade wind showers could reach
portions of the USVI/Eastern PR terminals thru the overnight
hours. Low level winds will continue E-ESE at 10-15 knots.


&&

.MARINE...Tranquil seas expected to continue through the
weekend...increasing by early next week across the Caribbean
waters. East winds will continue at 10-15 knots.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 91 79 89 / 10 10 20 20
STT 79 89 80 88 / 10 10 30 40

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
524 AM AST SAT JUN 18 2016

.SYNOPSIS...
At upper levels...a low aloft will continue over Dominican
Republic today, then it will moves northeastward to the Atlantic
Ocean. This low will become a trough Sunday into Monday. An upper
level ridge is expected to build from the Eastern Caribbean by
early next week. At the surface...a tropical wave, off to the east
of the Windward Islands, is forecast to enter the local region
late tonight or Sunday, followed by another one by late Monday
and into Tuesday.

&&

.DISCUSSION...
Clouds with embedded showers moved across the local waters
overnight, some moved inland across the windward sections, but
were brief and light. For the rest of this morning, expect mostly
sunny to partly cloudy skies with passing showers from time to
time across Eastern Puerto Rico and the U.S. Virgin Islands. The
instability created by the low aloft will combined with the
available moisture to produce another round of showers and
thunderstorms across the interior and western sections of Puerto
Rico during the afternoon hours. In addition, under the
prevailing southerly wind flow, some streamers are possible off
from El Yunque, to result in showers and thunderstorms across the
San Juan Metropolitan area, as well as off from the USVI.

Satellite imagery showed a tropical wave off to the East of the
Windward Islands, however is surrounded of Saharan Dust, which is
weakening this system. As this tropical wave enters the local
region on Sunday, moisture is forecast to increase and as it
interacts with the upper trof could lead to the enhancement of
shower and thunderstorm activity across the forecast area.
However, the amount of Saharan dust and dry air will be a limiting
factor to this activity. Another tropical wave is expected to
move across the local region late Monday or Tuesday.

&&

.AVIATION...VFR conditions will prevail across all terminals during
through arnd 18/17z. Some passing showers are expected VCNTY TKPK
TISX...TIST TJSJ during the morning hours. Periods of MVFR
conditions with and mtn obscurations from SHRA/TSRA expected over
TJMZ and TJBQ from 18/18z through 18/22z. Low level winds expected
to continue from the east-southeast at 10 to 15 knots up thru FL190.
Abv FL200 wind bcm SW up to 35 kt at FL400.

&&

.MARINE...
Latest coastal buoy observation indicated seas below 4 feet and
east winds up to 14 knots. An increase in seas and winds is
expected across the Caribbean waters through late Sunday and into
Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 80 89 80 / 40 40 40 20
STT 90 80 88 79 / 20 40 40 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
122 PM AST SAT JUN 18 2016

.SYNOPSIS...Tutt low across Hispaniola will continue to fill and
lift northwards overnight through Sunday...as high pressure builds
across the region through the early part of next week. Strong
surface high pressure centered across the east and northeastern
Atlantic will maintain light to moderate east southeast winds
overnight through Sunday. The easterly trade winds are to however
gradually increase later on Sunday into early next week as the
surface high repositions north of the region. A tropical wave will
cross The Lesser Antilles on Sunday then move across the Eastern
Caribbean during the early part of The upcoming week.

&&

.DISCUSSION...Local and diurnal effects along with the proximity
of the upper tutt low aided in the development of afternoon showers
and isolated thunderstorm across parts of the west interior and
the San Juan metro area. Some showers also formed over the west
coasts of the U.S Virgin Islands...but quickly streamed northwest
over the coastal waters. So far no significant rainfall amounts
were reported. Expect the activity to taper off and dissipated
after sunset leaving mostly clear to partly cloudy skies overnight.

On Sunday ...Few early morning passing showers can be expected
across the east sections of the islands...followed by mostly sunny
conditions during the rest of the morning. Expect afternoon showers
and isolated thunderstorms once again on Sunday with increasing low
level moisture and better chance for showers and possibly enhanced
isolated thunderstorms development at least through Monday. By Tuesday
another surge of drier air and Saharan dust will move across the region
and high pressure will build aloft and limiting daytime convection
across the region.

&&

.AVIATION...VFR conds through 18/18Z with possible MVFR at TJMZ and
TJBQ thereafter as SHRA and TSRA develop across NW-PR. VCSH at TJSJ,
TISX and TIST through 18/22Z. Winds from the ESE at 15KT or so with
sea breeze variations until 18/22Z, weakening thereafter to about 5-
10KT from the east. VCSH overnight across the USVI and Leewards with
gradually increasing clouds as a tropical wave approaches.

&&

.MARINE...Overall tranquil Seas will persist in most of the regional
waters overnight except for slight chop over the offshore Caribbean
waters due to winds of 15 to 20 knots. Expect Seas of 4 feet or less
and winds 10 to 15 knots over the remainder of the local waters overnight.
Seas are forecast to gradually increase up to 5 feet on Sunday across
the local offshore waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 89 80 90 / 40 40 20 20
STT 80 88 79 90 / 40 40 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
535 AM AST SUN JUN 19 2016

.SYNOPSIS...
At upper level...A TUTT Low, to the northwest of PR, weakens as
an upper level ridge builds from the East into the Eastern
Caribbean. This ridge will holds at least until mid week. At low
levels...a weak tropical wave will moves across the region today,
followed by another easterly wave by Monday. Both waves are
surrounded with dry air and Saharan Dust Particles. A strong
surface high pressure will persist across the Atlantic waters
throughout the week.

&&

.DISCUSSION...
Subsidence ahead of the tropical wave produced mostly clear skies
with little or no shower activity across the region last night.
However, the tropical wave has being felt in St Croix and its
surrounding waters with showers and thunderstorms early this
morning. This activity is moving toward eastern Puerto Rico,
therefore, expect increasing shower activity with isolated
thunderstorms across the Caribbean waters, the U.S. Virgin
Islands and the East half of PR this morning. Saharan Dust to the
North of the tropical wave will limit shower and thunderstorm
activity. During the afternoon, once again the available moisture,
the orographic effect and diurnal heating will trigger showers and
thunderstorms mainly over the interior and west PR. Urban and
small stream flooding will be possible with this activity. The
maximum temperatures will be in the lower 90s mainly across the
west coastal sections of PR and in the San Juan Metropolitan.

The best chance of shower and thunderstorm activity should remain
at least until early Tuesday morning. Then, another dry air mass
with Saharan Dust particulate is forecast to reach the islands
through most of the upcoming work week.

&&

.AVIATION...
A tropical wave is moving into the area and the first
bands of SHRA/TSRA passed through TISX at 19/08Z. Tops were up to 45
kft. SHRA will arrive in PR arnd 19/12z and spread west during the
day bringing MVFR conds to TJMZ and TJBQ by 19/17Z. Mtn obscurations
will increase aft 19/12Z. Winds are ESE 10 to 20 kt with gusts near
thunderstorms to 30 knots. Winds will shift to SW abv FL200 and
increase to 40 knots by FL400. For the leeward islands periods of
MVFR conds will occur with SHRA and ISOLD TSRA through at least
20/02Z. A second tropical wave will move through late today with
another increase in moisture.

&&

.MARINE...
Expect east to southeast winds up to 20 knots and seas up to 5
feet with occasional seas up to 6 feet. Small craft operators are
urged to exercise caution across the nearshore Atlantic waters.
Showers and thunderstorms are likely at least until early Tuesday
morning as a series of tropical waves moves across the eastern
Caribbean.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 81 88 80 / 20 20 30 20
STT 89 82 89 81 / 40 30 30 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
204 PM AST SUN JUN 19 2016

.SYNOPSIS...TUTT Low, just to the northwest of PR, will continue
to lift northwards and weaken...as the upper level ridge builds
over the Eastern Caribbean. The ridge aloft is to then remain in
place at least until Wednesday or Thursday of the upcoming week.
At low levels...a tutt induced tropical wave will continue to move
across the region today. This will be followed by yet another tropical
wave on Monday. Strong surface high pressure will persist across the
East and Central Atlantic throughout the week but will shift slightly
to just north of the forecast area by Wednesday.

&&

.DISCUSSION...Approaching tropical wave with axis now south of
Puerto Rico brought an increase in moisture as well as an increase
in showers and thunderstorms across the forecast area. Isolated
thunderstorms with occasional wind gusts and lightning was observed
across the local Caribbean waters and parts of Puerto Rico. Due
to the fast movement of the storms...so far rainfall accumulations
have been generally less than an inch across the islands. During
the rest of the afternoon...increasing moisture and instability
combined with diurnal and local effects will lead to additional
enhanced convection and better chance for significant rainfall
accumulations. Activity should then be focused across the interior
and western sections of PR. For the U.S Virgin Islands during the
rest of the afternoon...only isolated showers are expected for
now.

Overnight through Monday still looks like the best chance is
for increased convection as decent amounts of tropical moisture
will be transported across the area. Satellite imagery as well
as the latest model guidance both suggest increasing PWAT values
to around two inches or more during the period. Moderate upper
level instability/diffluence and low level moisture will increase
the chances for showers and thunderstorms across the islands and
coastal waters overnight through Monday. Some of the activity may
again be enhanced over the coastal waters and near the east
coastal sections of the islands during the overnight and early
morning hours. During the afternoon...additional showers may form
and spread to the interior and west sections of Puerto rico.

On another note...aerosol products and guidance continue to suggest
both waves continue to be surrounded by traces of Saharan Dust
Particulates. However expect drier air and a higher concentration
of dust trailing the wave on Tuesday and Wednesday. Expect a gradual
improvement in the weather conditions by Tuesday and the rest of the
week.


.AVIATION...Mainly VFR conds expected across most of the local
terminals. However, MVFR conds and gusty winds possible for TJBQ and
TJMZ after 19/18Z as SHRA/TSRA may re-develop over the area. E-ESE
winds at around 15KT and gusty with sea breeze variations for the
rest of today, decreasing after 19/23Z. VCSH across the local
terminals tonight as tropical wave moves in. SHRA/TSRA expected
tomorrow over the local islands, which will affect most of the local
terminals possibly causing MVFR or even brief IFR conds.

&&

MARINE...Small craft should exercise caution due to winds up to 20
kts and Seas increasing up to 6 feet. Shower and isolated
thunderstorms activity will continue to affect the regional
waters through Monday as a tropical wave will move across the
eastern caribbean. Please refer to the latest Coastal Waters
Forecast and Marine weather statements issued by the WFO San Juan
PR.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 81 88 80 90 / 20 30 20 20
STT 82 89 81 90 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
528 AM AST MON JUN 20 2016

.SYNOPSIS...A tropical wave will continue to move across the area
through this afternoon. A drier airmass behind the wave will
encompass the local region late tonight into Tuesday.

&&

.DISCUSSION...Scattered to numerous showers were seen across the
Caribbean coastal waters overnight. This activity was associated
with a Tropical Wave...which is moving across the local area.
Better moisture of the wave will remain south of the local islands
the rest of the day. However...abundant moisture will combine with
daytime heating and local effect to produce showers and
thunderstorms this afternoon mainly over western interior Puerto
Rico.

After the passage of this wave...a drier airmass will encompass
the local region from the east. In addition...some Saharan air
particles are expected to affect the region later today and
tonight. For the rest of the work week...stable atmospheric
conditions are expected to prevail...as upper level ridge
dominates the region.


&&

.AVIATION...As tropical wave continues to exit the local area
Today...periods of MVFR conds are possible mainly across the
USVI/eastern PR terminals thru late in the morning hours...spreading
to the western terminals during the afternoon. Afternoon TSRA can
affect TJSJ. SHRA/TSRA is expected to continue thru the fcst period
across both Atlantic and Caribbean waters. E-ESE winds at 15-25 kts
will continue blo FL120.

&&

.MARINE...Due to the passage of the tropical wave...winds and seas
have increased. As a result...small craft should exercise caution
across most coastal waters due to winds up to 20 knots and seas up
to 6 feet.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 79 85 77 / 40 20 20 30
STT 88 80 82 79 / 60 20 20 30

[cycloneye]

DISCUSSION...Scattered to numerous showers and thunderstorms
associated to a tropical wave continued to affect the eastern and
southern portions of Puerto Rico. These showers and thunderstorms will
move out of the local area as the wave moves away from the local
area tonight.

A tropical wave now located south of puerto rico will continue to
move west and away through tonight. A much drier airmass will
begin to dominate the local forecast area on Tuesday. This airmass
will also bring Saharan particles across the region. For the rest
of the work week...stable atmospheric conditions are expected to
prevail...as upper level ridge dominates the region.

AVIATION...As the tropical wave continues to move across the
local area...periods of SHRA are expected across the USVI/eastern
PR terminals thru early evening hours. Afternoon TSRA can affect
TJSJ, TJBQ, TJMZ in the afternoon. SHRA/TSRA is expected to
continue thru the fcst period across both Atlantic and Caribbean
waters. Low level winds mainly from the E-ESE at 15-20 kts.

MARINE...Choppy marine conditions will prevail this afternoon and
tonight therefore Small craft should exercise caution across most
coastal waters due to winds up to 20 knots and seas up to 6 feet.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 89 77 88 / 30 20 30 30
STT 80 89 79 88 / 40 20 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
521 AM AST TUE JUN 21 2016

.SYNOPSIS...High pressure will continue to dominates the local
region through the end of the work week. an area of moisture will
move across the region wednesday.

&&

.DISCUSSION...Some showers were seen across the Caribbean coastal
waters south of the local area. These showers are the result of
lingering moisture from the tropical wave which affected the local
area yesterday. very little shower activity was observed over land
areas. Local area continues under the influence of a High pressure
system. This feature will continue to suppress the development of
showers across the region. However...available moisture will
combine with daytime heating and local effects to produce
scattered showers with thunderstorms across the western interior
section of Puerto Rico this afternoon.

An area of moisture ahead of a weak tropical wave will move across
the region late tonight into Wednesday. this area of moisture
will bring an increase in shower activity across the region by
Wednesday morning. After this feature...a drier airmass will move
across the region. At this time...no significant weather events
are forecast to affect the local area in the long term.

&&

.AVIATION...Mainly VFR conditions expected across all terminals.
However...after 16Z SHRA/TSRA will develop across the interior and
western sections of PR...impacting mainly TJBQ/TJMZ. Low level winds
will continue from the east at 10-20 knots with sea breeze
variations and higher gusts at the sfc after 13Z.

&&

.MARINE...Choppy marine conditions will prevail today. Small
craft should exercise caution across most coastal waters due to
winds up to 20 knots and seas up to 6 feet.



&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 88 79 / 20 30 30 20
STT 89 79 89 78 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
159 PM AST TUE JUN 21 2016

.SYNOPSIS...East to ESE surface winds are expected to continue for
the next few days as a surface high pressure over the north
central Atlantic dominates the region. High pressure in the upper
levels will continue to dominate over the local area with an
upper low to the ENE of the leewards. Relatively drier air
expected the rest of today but a patch of moisture is expected to
move in late tonight into wednesday, which will cause isolated to
scattered showers in the morning across the local area and a few
thunderstorms in the afternoon across western PR.

&&

.DISCUSSION...Slightly drier air moved in today across the local
islands. However there is enough moisture to cause showers moving
in with the trades and some development across the west and
southwestern sections of PR in the afternoon. Some showers
affected the eastern sections of PR as they streamed off the
USVI. We expect the shower and possible thunderstorm development
across the SW quadrant of PR to continue into the late afternoon
hours. For tonight we expect passing showers across the local area
as an area of moisture moves in overnight into Wednesday. This
moisture could be enough to cause brief showers through the day
across the local area, then thunderstorm development across
the NW quadrant of PR is possible. Precipitable water values could
reach to as much as 2 inches by Wednesday afternoon according to
the GFS model. Which will be enough for some decent showers and
possible thunderstorms.

The rest of the week looks pretty normal with some locally induced
showers and thunderstorms as the available moisture combines with
the local effects and diurnal heating. Saharan dust seems to take
a break until Friday into Saturday.


&&

.AVIATION...VFR conds expected across the local terminals with
brief moments of SHRA across TJSJ and the potential for TSRA/SHRA
at TJMZ after 21/17Z until about 21/21Z. Winds will continue from
the East to ENE with sea breeze variations at about 10-15KT with
higher gusts. Winds will decrease after 21/23Z leaving light
easterly winds and VRB winds across the terminals in PR. VCSH
expected overnight across the local terminals except TJMZ and
TJBQ.


&&

.MARINE...Small craft should exercise caution as seas will
continue up to 6 feet through tonight and winds up to 20 knots.
Therefore small craft should exercise caution across the local
waters. There is also a moderate risk of rip currents across many
of our local beaches.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 88 79 89 / 10 20 20 20
STT 79 89 78 89 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
537 AM AST WED JUN 22 2016

.SYNOPSIS...An area of moisture will continue to move across the
area today. a drier air mass will encompass the region late
tonight. upper level ridge will continue to dominates until
Friday. Upper level trough will move northeast of the area
Saturday.

&&

.DISCUSSION...Scattered showers were observed across the local
area overnight. Shower activity affected mainly the eastern half
of Puerto Rico including the San Juan metro area. This area of
moisture embedded in the trade winds will continue to affect the
local region today. Therefore...showers and thunderstorms are
expected to develop this afternoon over western interior section
of Puerto Rico.

For the rest of the work week...a drier airmass will encompass the
region from the east...limiting somewhat the development of
showers and thunderstorms across the area. However...local area
will remain under a moist wind flow...which will aid in the
development of some isolated showers over the mountains. Upper
level trough (TUTT) will dig south north of the islands...but will
remain to the east of the local islands. At this time...no
significant weather events are forecast to affect the local region
next several days.

&&

.AVIATION...Trade wind shra will continue across the forecast area
through the fcst period. SCT-BKN layers btw FL030-FL050 and -RA
expected to affect the USVI and the east/south PR terminals with the
passing showers. Mountain top obscd across east PR. Afternoon
TSRA/SHRA expected across the western sections of PR...impacting
mainly JBQ/JMZ. Low level winds will be from the E-ESE at 10-20
knots.

&&

.MARINE...Small craft should are urged to exercise caution across as
seas will continue up to 6 feet through tonight and winds up to 20
knots. There is a moderate risk of rip currents across many of
our local beaches.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 89 78 / 30 20 20 20
STT 88 79 89 79 / 50 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
214 PM AST WED JUN 22 2016

.SYNOPSIS...Ridge aloft will continue to hold through at least Thursday.
The ridge is to erode by Friday as a Tutt low now across the Tropical
Atlantic shifts W across the Northeastern Caribbean. The Tutt will
then linger aloft through the upcoming weekend. Strong surface high
pressure ridge will remain anchored across the Central Atlantic
through Thursday to maintain moderate easterly trade wind flow
across the region. A Tutt induced low level trough extending
across the Tropical Atlantic will shift westward across the region
by Friday through the weekend.

&&

.DISCUSSION...An easterly perturbation moving across the region
during the afternoon and was now approaching the Mona Passage with
trailing moisture and areas of scattered to numerous showers moving
across Puerto Rico and the surrounding coastal waters. Shower
activity in and around the U.S Virgin Islands continued to
diminish during the afternoon as drier air filtered in from the
west. For the rest of the afternoon local terrain and mountain
effects will aid in continued afternoon convection across parts of
the interior and west sections of Puerto Rico at least until
sunset. Thereafter activity should diminish leaving mostly clear
to partly cloudy skies overland during the evening and overnight
hours.

By early morning expect passing trade wind showers to affect portions
of eastern Puerto Rico...the Virgin Islands as well as the coastal
waters. For the rest of the day on Thursday...lesser moisture transport
is expected. However there will still be sufficient lingering moisture
to combine with local and diurnal effects to allow for showers and
isolated thunderstorm development mainly over the west interior sections
of Puerto Rico. Mostly isolated showers expected elsewhere. On Friday
and into Saturday low to mid level induced trough will reposition across
the region as well as the tutt now east of the region. This will again
allow for a better chance of enhanced convection across portions
of the islands once again.

&&

.AVIATION... Afternoon TSRA/SHRA expected across the W and NW PR
impacting mainly TJBQ/TJMZ til 22/22z. Low level winds will be
from the E-ESE at 10-20 knots. Prevailing VFR conds expected
elsewhere.

&&

.MARINE...Small craft should are urged to exercise caution across as
seas will continue up to 6 feet overnight and winds up to 20 knots.
There is a moderate risk of rip currents across many of our local
beaches.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 78 90 / 30 30 20 20
STT 79 89 79 89 / 30 30 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
535 AM AST THU JUN 23 2016

.SYNOPSIS...Upper level ridge will erode by Friday as a Tutt low
now across the Tropical Atlantic shifts west across the
Northeastern Caribbean. The Tutt will then linger aloft through
the upcoming weekend. A Tutt induced low level trough extending
across the Tropical Atlantic will shift westward across the region
by Friday through the weekend.


&&

.DISCUSSION...Local area continues under the influence of a
surface high pressure area which is maintaining relatively stable
atmospheric conditions across the region. Passing showers embedded
in the trade winds will continue to affect the local area from
time to time. In the afternoon hours...scattered showers with
thunderstorms are expected to develop over the western interior
and northwest sections of Puerto Rico.

For the next few days...no changes in this weather pattern is
expected. Although an upper level trough will dig south from the
tropical Atlantic and will approach the local area...but will
remain to the east of the local islands. At this time...no
significant weather events are forecast to affect the local region
next several days.

&&

.AVIATION...Brief trade wind shra will continue to affect the
Leeward Islands, USVI and Eastern Puerto Rico taf sites until at
least 23/15Z producing mostly vicinity showers. Mostly VFR
conditions expected across the rest of the local flying area.
Afternoon TSRA/SHRA expected across the western sections of
PR...impacting mainly TJBQ/TJMZ. Low level winds will be from the E-
ESE at around 10 knots, increasing to 10-20 knots after 23/13Z.

&&

.MARINE...Small craft should exercise caution across most of the
local coastal areas as seas will continue up to 6 feet through
Wednesday and winds up to 20 knots. There is a moderate risk of
rip currents across many of our local beaches.



&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 78 90 80 / 30 20 20 30
STT 89 80 90 80 / 30 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
500 AM AST FRI JUN 24 2016

.SYNOPSIS...TUTT will amplify into the eastern Caribbean today.
At lower levels, a high pressure across the north central
Atlantic will continue to promote an easterly wind flow during
the next several days. Tropical wave will remain well south of
the area today and into Saturday.

&&

.DISCUSSION...Partly to variably cloudy skies were observed
during the overnight and early morning hours across the local
islands. Doppler weather radar indicated trade wind showers
affecting USVI and the eastern sections of Puerto Rico as well
as the surrounding coastal waters. Temperatures across coastal
areas were in the mid to upper 70s and the wind was easterly
at 10 mph or less.

Although TUTT across the central Atlantic will amplify into
the eastern Caribbean today and hold through early next week,
precipitable water will remain near normal values through Monday.
Tropical wave will move across the eastern Caribbean and well
south of the local islands today and into Saturday. In addition,
SAL is expected to reach the eastern Caribbean later today and
continue to prevail during the upcoming weekend. This pattern
will result in seasonable weather conditions today through Monday
with locally induced showers and thunderstorms across west Puerto
Rico in the afternoon hours each day.

Precipitable water values will increase Tuesday and Wednesday,
however the best moisture advection is expected on Friday as a
tropical wave with plenty of moisture moves across the eastern
Caribbean.

&&

.AVIATION...Brief trade wind -shra will continue to affect the
local flying area through 24/12Z producing brief VCSH. VFR
conditions expected across the local terminals through 24/16Z.
After 16Z, SHRA/TSRA may develop in the vicinity of TJMZ and TJBQ
which may affect the terminals and cause brief MVFR conditions.
Low level winds will be light and easterly through 24/13Z,
thereafter from the E-ESE at around 10-15KT with sea breeze
variations and occasional gusts.

&&

.MARINE...Tranquil marine conditions are expected during the next
few days with seas up to 5 feet and winds 15 knots or less.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 87 77 / 20 10 20 20
STT 89 80 88 79 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
102 PM AST FRI JUN 24 2016

.SYNOPSIS...Broad surface high pressure will continue across the
north central Atlantic for the next several days. SAL and mid
level ridge across the eastern Caribbean will continue to move
west across the forecast area. Upper level TUTT will move over the
Mona Passage and move east by Monday to the northeast of the area
as an upper level short wave takes it place just north of the
area. Moderate trade winds will continue through the forecast
period.

&&

.DISCUSSION...It was mostly sunny during the day with a few clouds
developing over the mountains and from streamers. However, showers
and isolated thunderstorms are expected this afternoon across the
western interior and NW quadrant of PR. Similar conditions are
expected during the weekend as mid level ridge and upper tutt
continues over the forecast area. Suspended Saharan dust is
expected later tonight through the weekend as SAL moves with mid
ridge. Therefore, light trade wind showers will continue across
the local waters with a few if any reaching parts of the islands
during the night and early morning hours. Wind direction and local
effects will favor limited afternoon convection across the
western sections of PR. Left chance of thunderstorms due to day
time heating and the proximity of the upper tutt.

&&

.AVIATION...VFR conditions should be expected over most terminals
through 25/18z. Isold shwrs/tstms could develop over west-interior
Puerto Rico between 24/18z and 24/23z so will indicate vcts for
tjbq and tjmz...however will not expect significant impact on
operations. Sfc winds should prevail from e-se 10-15 kts daytime
and less than 10 kt nighttime...except for local variations due to
sea breezes.

&&

.MARINE...Dominant short period wind waves will continue across
the waters through the forecast period. Seas will generally be
between 2-5 feet with higher seas across the Caribbean waters and
Mona Passage.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 89 / 10 20 20 20
STT 80 88 79 88 / 20 20 20 20