Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
452 AM AST MON AUG 15 2016

.SYNOPSIS...Mid to upper level trough will retrogress across the
Western Atlantic over the next few days. This will keep the atmosphere
somewhat unstable...however moisture will be below normal. As a
result...the shower coverage will be mainly isolated to scattered
through midweek. At low levels...high pressure just northeast of
the region will maintain a moderate easterly flow across the forecast
area. Deeper moisture is expected on Thursday with the next tropical
wave.

&&

.DISCUSSION...Fair weather conditions will prevail across most of
the islands today. A generally dry air mass with Saharan dust
particles will help to inhibit the shower development across most
of the area. However...trough aloft will allow some thunderstorms
to develop across the Western Interior and West portions of Puerto
Rico each afternoon. A few isolated showers expected elsewhere...
including the U.S. Virgin Islands. No significant changes in the
weather pattern is forecast through midweek.

Then...the next tropical wave will cross the local area on Thursday.
Moisture and instability is forecast to increase late Wednesday
night into Thursday as the wave approaches from the east. Shower
and thunderstorm activity will likely increase...especially on
Thursday. Moisture will peak across the area on Thursday morning
when precipitable water values approaches to 2 inches. Drier and
more stable air mass with some Saharan Dust will follow the wave.
As a result...fair weather pattern will likely return to the local
islands on Friday. Limited shower activity will prevail between
Friday and Saturday as drier than normal air mass dominates the
region.

&&

.AVIATION...Mainly VFR conditions expected to prevail at all TAF
sites through the forecast period. However, between 16z-22z
SHRA/TSRA development is expected across the western interior of PR,
impacting mainly TJMZ/TJBQ with MVFR conditions and mtn top obscd.
Low level winds will be from the E-ESE at 10-18 kts with sea breeze
variations after 14z.

&&

.MARINE...Seas of 4-6 feet will continue across the Caribbean
Waters and Mona Passage through Tuesday. Elsewhere...mainly seas
of 3-5 feet will prevail most of the week. Moderate easterly winds
will persist through through the end of the work week. No major
changes to the marine conditions are expected over the next 5-7
days. Small Craft Advisories are not anticipated.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 80 90 81 / 10 10 20 20
STT 90 79 90 79 / 20 20 20 30

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT MON AUG 15 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Disorganized cloudiness and thunderstorms over the far eastern
Atlantic are associated with a tropical wave located a few hundred
miles south-southwest of the Cabo Verde Islands. Environmental
conditions are conducive for gradual development of this disturbance
during the next few days, but could become less favorable later this
week. The system is expected to move west-northwestward to
northwestward at 10 to 15 mph into the central tropical Atlantic
during the next several days.
* Formation chance through 48 hours...medium...40 percent
* Formation chance through 5 days...medium...50 percent

Forecaster Kimberlain

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
136 PM AST MON AUG 15 2016

.SYNOPSIS...An upper level trough just north of Puerto Rico will
continue to move westward and away from the region. An upper
level ridge will build across the region Tuesday and Wednesday.
This will keep the atmosphere relatively stable for the next
couple of days. As a result...the shower coverage will be mainly
isolated to scattered through midweek. An increase in moisture is
expected on Thursday with the next tropical wave.

&&

.DISCUSSION...Showers and a couple of thunderstorms developed
this afternoon across western Puerto Rico. This activity is
expected to diminish rapidly after sunset, leaving the region
under partly cloudy skies. As an upper level trough moves away
from the region, a generally dry air mass with Saharan dust
particles will continue to inhibit the shower development across
most of the area until at least Tuesday. A few isolated showers
expected overnight and early Tuesday morning across the U.S.
Virgin Islands and Eastern Puerto Rico. However...no significant
changes in the weather pattern is forecast through midweek.

A tropical wave along 45 West this afternoon, will reach the
local area Wednesday night and Thursday. This feature will produce
an increase in moisture and instability across the region to
induce the development of showers and thunderstorms across the
local islands. Drier and more stable air mass with some Saharan
Dust will follow the wave. As a result...fair weather pattern will
likely return to the local islands on Friday. Limited shower
activity will prevail between Friday and Saturday as drier than
normal air mass dominates the

&&

.AVIATION...SHRA/TSRA will continue over western Puerto Rico and
this may result in periods of MVFR or even IFR conditions at
TJMZ until 15/22z. After 15/22Z mostly VFR conditions expected to
prevail across the local flying area with vicinity -SHRA in and
around TIST and TISX. Low level winds will continue from the E to
SE at around 10-15kts until 15/23Z, diminishing to around 10 knots
after that.

&&

.MARINE...Seas of 4-6 feet will continue across the Caribbean
Waters and Mona Passage through Tuesday. Elsewhere...mainly seas
of 3-5 feet will prevail most of the week. Moderate easterly winds
will persist through the end of the work week. No major changes
to the marine conditions are expected over the next 5-7 days.
Small Craft Advisories are not anticipated.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 90 81 91 / 10 20 20 20
STT 79 90 79 90 / 20 20 30 20

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON AUG 15 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A large area of cloudiness and thunderstorms over the eastern
Atlantic several hundred miles southwest of the Cabo Verde
Islands is associated with a tropical wave. Environmental
conditions are expected to be conducive for development during
the next few days, and a tropical depression is likely to form
while the system moves west-northwestward to northwestward
toward the central tropical Atlantic.
* Formation chance through 48 hours...medium...50 percent
* Formation chance through 5 days...high...70 percent

$$
Forecaster Brown

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
500 AM AST TUE AUG 16 2016

.SYNOPSIS...Upper level ridge will build over the region as the
mid to upper level trough/TUTT will continue to retrogress across
the Western Atlantic. This will lead to stable conditions across
the area through Wednesday. Tropical wave near 50 West this
morning will increase the shower and thunderstorm activity across
the local islands on Thursday. Drier and more stable air mass will
dominate the region Friday and Saturday.

&&

.DISCUSSION...Satellite precipitable water analysis indicated drier
than normal air mass upstream of the forecast area. As a result...
a fair weather pattern is expected to prevail across most of the
islands over the next few days. Brief morning showers will be possible
across local waters and the windward areas at times. Showers and
isolated thunderstorms will develop over Western Puerto Rico during
the afternoon hours. Elsewhere...mostly sunny to partly cloudy
skies with limited shower activity are anticipated for the rest
of the forecast area.

The next tropical wave will cross the local area on Thursday.
Moisture and instability is forecast to increase late Wednesday
night into Thursday as the wave approaches from the east. Moisture
will peak across the area on Thursday morning when precipitable
water values approaches to 2 inches. Therefore...a few rounds of
showers and thunderstorms will affect Puerto Rico and the U.S.
Virgin Islands during the day on Thursday. Drier and more stable
air mass with some Saharan Dust is likely after the wave passage.
As a result...a fair weather pattern will return to the local
islands on Friday and Saturday. A slightly increase in the shower
activity is forecast on Sunday and Monday as a few bands of
moisture embedded in the trade winds will move across the local
region.

&&

.AVIATION...Mainly VFR conditions expected to prevail at all TAF
sites through the forecast period. Low level winds from the east at
10-18 kts except for sea breeze variations AFT 14z. SHRA/ISOLD TSRA
16/18-22Z ovr western PR, impacting mainly JMZ with MVFR conds.

&&

.MARINE...Winds of 10-20 knots and seas of 3-5 feet can be
expected across most of the local waters...except the Caribbean
Waters and Mona Passage where seas up to 6 feet are possible
through this evening. No major changes to the marine conditions
are expected over the next 5-7 days. Small Craft Advisories are
not anticipated through the forecast period.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 80 89 80 / 30 40 40 50
STT 90 80 90 80 / 40 40 40 50

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT TUE AUG 16 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Satellite images indicate that the large area of cloudiness and
thunderstorms associated with a tropical wave centered about 500
miles west-southwest of the Cabo Verde Islands is gradually becoming
better organized. Conditions appear to be favorable for a tropical
depression to form during the next couple of days while the system
moves toward the west-northwest and then northwest toward the
open waters of the central Atlantic.
* Formation chance through 48 hours...high...70 percent
* Formation chance through 5 days...high...80 percent

$$
Forecaster Avila

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT TUE AUG 16 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

An area of cloudiness and thunderstorms associated with a tropical
wave centered about 600 miles west-southwest of the Cabo Verde
Islands is beginning to show some signs of organization.
Environmental conditions appear to be favorable for additional
development, and a tropical depression could form on Wednesday.
This system is expected to move toward the west-northwest and then
northwest over the open waters of the central Atlantic during the
next several days.
* Formation chance through 48 hours...high...80 percent
* Formation chance through 5 days...high...90 percent

$$
Forecaster Avila

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
140 PM AST TUE AUG 16 2016

.SYNOPSIS...An upper level ridge will remain as the main weather
feature across the region until Wednesday. This will keep the
atmosphere relatively stable...resulting in mainly isolated to
scattered showers through midweek. An increase in moisture is
expected on Thursday with the next tropical wave. Drier and more
stable air mass will dominate the region Friday and Saturday.

&&

.DISCUSSION...Showers and a couple of thunderstorms developed
this afternoon across northern and southwestern sections of
Puerto Rico. This activity is the result of daytime heating in
combination with local effects and it is expected to diminish
rapidly after sunset, leaving the region under partly cloudy
skies. An upper level ridge will continue as the main weather
feature across the region until Wednesday. This feature is
expected to maintain the region under a relatively stable weather
pattern until midweek. However...the limited moisture in
combination with daytime heating will produce isolated to
scattered showers overnight and early Wednesday morning across the
U.S. Virgin Islands and Eastern Puerto Rico followed by showers
and thunderstorms over western an interior Puerto Rico.

A tropical wave along 50 West this afternoon, will reach the
local area Wednesday night and Thursday. This feature will produce
an increase in moisture and instability to induce the development
of showers and thunderstorms across the local islands. Drier and
more stable air mass with some Saharan Dust will follow the wave.
As a result...fair weather pattern will likely return to the local
islands on Friday. Limited shower activity will prevail Friday
and Saturday as drier than normal air mass dominates the region.

&&

.AVIATION...SHRA/TSRA will continue over western Puerto Rico and
this may result in periods of MVFR or even IFR conditions at
TJMZ/TJBQ until 16/22z. After 16/22Z mostly VFR conditions
expected to prevail across the local flying area with vicinity
-SHRA in and around TIST and TISX. Low level winds will continue
mostly from the East at around 10-15kts until 16/23Z, diminishing
to around 10 knots after that.

&&

.MARINE...Seas up to 6 feet and winds up to 20 knots will
continue across the regional waters. Moderate easterly winds will
persist through the end of the work week. No major changes to the
marine conditions are expected over the next several days. Small
Craft Advisories are not anticipated.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 89 80 91 / 40 40 50 50
STT 80 90 80 89 / 40 40 50 50

&&

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT TUE AUG 16 2016

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Showers and thunderstorms associated with a low pressure area
located about 650 miles west-southwest of the Cabo Verde Islands
have become more concentrated and better organized during the past
several hours. If this development trend continues, advisories
would be initiated on a tropical depression tonight or Wednesday.
This system is expected to move generally northwestward over the
open waters of the central Atlantic during the next several days.
* Formation chance through 48 hours...high...90 percent
* Formation chance through 5 days...high...90 percent

$$
Forecaster Brown

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
534 AM AST WED AUG 17 2016

.SYNOPSIS...Tropical wave will move across the forecast area late
this evening through Thursday. Upper ridge will continue to move
west just over/north of the area through Friday. At the same time
an upper trough moves over the Caribbean waters. Fair weather
expected through the weekend. However, locally induced afternoon
showers are expected each day. Another tropical wave is forecast
to enter the local area by early next week.


&&

.DISCUSSION...Light trade wind showers were observed across the
forecast area during the overnight hours. A few reached the USVI
and coastal areas of eastern PR, leaving minor rainfall
accumulations. Mostly clear skies prevailed across the western
half of PR. For Today, drier air ahead of the tropical wave will
limit shower activity across the islands. However, diurnally
induced afternoon convection can`t be ruled out across western
PR. For tonight into Thursday, cloudiness and shower activity will
increase as the weak tropical wave moves across the islands.

PWAT drops once again after the passage of the wave and fair
weather conditions are expected across the islands through early
in the weekend. However, typical trade wind showers during the
night/early morning hours and diurnally induced afternoon convection
over the islands is expected each day. A surge in moisture is
expected by early/mid next week due to a tropical wave.


&&

.AVIATION...VFR conds expected at most of the TAF sites thru the
forecast period. Some SHRA and ISOLD TSRA possible near TJMZ and
TJBQ between 17/17Z-21Z. This may lead to brief MVFR conds at times
during the afternoon hours. Mountain Obscurations are also possible
over the western interior of PR. East to East-Southeast winds of 10-
20 kts will prevail below FL120.


&&

.MARINE...Seas should continue under 5 feet for the next several
days. Easterlies will continue at 10-15 knots, and up to 20 knots
at times across the near shore Atlantic/Caribbean waters and Mona
passage where small crafts should continue to exercise caution.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 81 91 81 / 20 50 50 10
STT 90 81 90 81 / 20 50 50 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
157 PM AST WED AUG 17 2016

.SYNOPSIS...Tropical wave will move across the forecast area late
this evening through Thursday. Upper ridge will continue to move
west just over/north of the area through Friday. At the same time
an upper trough moves over the Caribbean waters. Fair weather
expected through the weekend. However, locally induced afternoon
showers are expected each day. Another tropical wave is forecast
to enter the local area by early next week.

&&

.DISCUSSION...Very dry weather conditions prevailed across Puerto
Rico and the U.S. Virgin Islands today. Some showers developed
over the western interior and west sections of Puerto Rico.
Satellite images are showing a slot of drier air across the U.S.
Virgin Islands and will move across Puerto Rico the rest of this
afternoon and tonight. Therefore...shower activity will be limited
to the western interior and west sections of Puerto Rico.

A Tropical Wave will move across the forecast area late this
evening through Thursday. Therefore...an increase in low level
moisture is expected. After the passage of this wave...upper level
ridge and a dry airmass will encompass the region.

Tropical Depression six continues across the far eastern Atlantic.
This system is expected to become a Tropical Storm later today or
tonight. At this time...the tropical cyclone it is expected to
pass away from the local area without any significant impact
across the region.

&&

.AVIATION...VFR conditions still expected at most of the TAF sites.
SHRA/TSRA are possible near TJMZ/TJBQ between 17/18z-22z. Mountain
obsc is expected over the west and interior portions of PR. SHRA
will diminish aft 17/23z, however a tropical wave is expected to
reach the area around 18/06z, to increase SHRA/TSRA from the east,
and some will likely affect the USVI and the surrounding waters.
TJSJ 17/12z sounding indicated NE winds up to 2kft, expect E-NE
winds at 10-20 kts and sea breeze variations.

&&

.MARINE...Mariners can expect winds at 15 to 20 knots in the
Coastal Water of Northern Puerto Rico, therefore they should
exercise caution. Seas up to 5 feet are expected.



&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 81 91 81 90 / 50 50 10 20
STT 81 90 81 90 / 50 50 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
529 AM AST THU AUG 18 2016

.SYNOPSIS...Weak tropical wave and associated shower activity will
continue to move across the local area through this evening. SAL
follows the wave lingering through the weekend. Upper ridge will
continue to move west through the weekend as another ridge builds
from the east by early next week. Another tropical wave is
forecast to enter the local area by early next week.

&&

.DISCUSSION...Band of moisture associated to a tropical wave
reached the local area during the overnight hours. Scattered to
locally numerous light showers were observed mainly over both
Atlantic and Caribbean waters and sections of eastern PR. For this
afternoon, showers and thunderstorms are expected mainly over the
western sections of Puerto Rico and over San Juan and vicinity.
Partly cloudy skies and isolated showers are expected across the
U.S. Virgin Islands.

Moisture decreases quickly after the passage of the wave as a more
stable and drier air mas with Saharan dust filters through the
weekend. Fair weather conditions are expected across the islands
for the next few days. However, typical trade wind showers during
the night/early morning hours and diurnally induced afternoon
convection over the islands is expected each day. A small surge
in moisture from the northeast is expected on Sunday/Monday. Next
tropical wave is forecast to reach the local area by Wednesday.


&&

.AVIATION...VFR conditions still expected at most of the TAF sites
through 18/12Z. Approaching tropical wave will bring some SHRA to
the local area after 18/04Z or so causing VCSH at the
TNCM/TKPK/TIST/TISX/TJSJ terminals overnight. Easterly winds at 5-
10kt expected overnight. SHRA/TSRA developing affecting PR after
18/12Z with SHRA likely at TJSJ thereafter. SHRA/TSRA in and around
TJMZ and TJBQ after 18/17Z.


&&

.MARINE...Seas between 3-5 feet are expected through the rest of
the work week, decreasing to 2-4 feet during the weekend.
Easterlies will continue a 10-15 knots and up to 20 across the
coastal Atlantic waters. Moderate risk of rip currents expected
mainly across the Atlantic coastline.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 80 91 80 / 60 0 10 10
STT 91 81 91 80 / 40 20 20 20

[cycloneye]

A tropical wave located about 300 miles southwest of Cabo Verde
Islands is producing widespread cloudiness and disorganized shower
activity. Environmental conditions are expected to be conducive for
gradual development of this disturbance over the next several days
while the system moves westward at about 15 mph.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...20 percent

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
146 PM AST THU AUG 18 2016

.SYNOPSIS...A ridge pattern aloft will prevail across the forecast
area through early next week. At low levels, a surface high north
of the area will continue to promote moderate to locally fresh
easterly winds. A weak tropical wave will continue to move away
from the local islands this afternoon.

&&

.DISCUSSION...A generally fair and mainly stable weather pattern
will prevail across the local islands through at least the upcoming
weekend under upper level ridge pattern and limited low level moisture.
However, locally induced afternoon showers/Tstorms still possible
across W PR each afternoon. Intensity and areal coverage of afternoon
convection may increase somewhat Sun-Tue as the ridge aloft
weakens and low level moisture increases across the area. As the
ridge aloft collapses early next week, an upper level low will
establish north of the area by Thu. This feature will promote
moisture advection across the eastern Caribbean in addition to a
tropical wave passage which is expected on Wed. Under this
pattern, there is a better chance for showers and Tstorms across
the forecast area Wed and into the end of the week.

&&

.AVIATION...VFR conditions still expected at most of the TAF sites.
Dry air intrusion is over the area but the available moisture will
enhance the formation of SHRA/TSRA across the TJMZ/TJBQ between
18/18-23z. SHRA should diminish aft 18/23z. Easterly winds at 10-20
kt with sea breeze variations and gusty winds expected til 18/21z,
dropping at around 10kt overnight.

&&

.MARINE...Surface high pressure will continue north of the islands
generating moderate to locally fresh easterly winds through friday.
Winds are expected to decrease during the weekend and become moderate
once again by early next week. Weak tropical wave will continue to
move west and away from the forecast area throughout the day. Seas
3-5 feet expected during the next few days.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 79 90 / 0 0 20 20
STT 80 91 80 91 / 20 20 20 20

[cycloneye]

A tropical wave located about 300 miles southwest of the Cabo Verde
Islands is producing an elongated area of cloudiness and
disorganized shower activity. Environmental conditions are expected
to be conducive for gradual development of this disturbance through
early next week while it moves westward at about 15 mph across the
tropical Atlantic Ocean.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...medium...40 percent

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
446 AM AST FRI AUG 19 2016

.SYNOPSIS...Surface high pressure ridge will hold across the West
and Central Atlantic today and into the weekend. The prevailing
easterly trade winds are to become slightly more northeasterly by
late Saturday, as Tropical Storm Fiona rides the southern periphery
of the ridge across the Atlantic and induces the northeasterly
flow across the region. Recent model guidance continue to suggest
a surge of moisture to arrive across the area from the northeast
by early Sunday into Monday. This will be fragments of moisture
from the distant Tropical Storm which is still forecast to track
Northwest then well north of the forecast area.

In the meantime mid to upper level ridge will remain in place to
maintain subsidence and a strong cap inversion across the region
through the upcoming weekend. A weakly induced easterly wave now
near 57 west this morning is expected to cross into the southeastern
Caribbean and continue westward through Saturday. However, this
feature will move well south of the area having no effect on the
region.

&&

.DISCUSSION...Mostly fair and stable weather conditions expected
to prevail across the region today, as strong ridging aloft and
subsidence along with fairly dry airmass will limit any convective
development today and into the weekend. No significant change is
expected in this weather pattern at least until Sunday into Monday
as the previously mentioned surge of moisture will move across the
Atlantic and arrive across the forecast area. This will bring a
brief increase in moisture which will aid in periods of early
morning showers followed by a slightly better chance for afternoon
convection over parts of the islands at least until late Monday.
Drier condition once again by Tuesday with increasing moisture
during the latter part of next week as a strong tropical wave is
forecast to approach the Lesser Antilles and a Tutt low and
associated trough shift will westward across the region
destabilizing the mid to upper levels and providing support for
the approaching wave. More on this feature to come as will see how
this unfolds with time and models become more consistent.

&&

.AVIATION....Mostly VFR conditions are expected across the local
flying area as drier air continues to move across the region. Winds
will continue from the East Northeast increasing to around 15 knots
after 19/14Z. Chance of rain in the vicinity of TJMZ/TJBQ after
19/18Z.

&&

.MARINE...Marine conditions continue to be just under small craft exercise
caution criteria, except for brief periods of winds up to 20 knots just
off the north and south coasts of Puerto Rico. Condtions are expected
to diminish over the weekend. Small craft advisories are not expected
through Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 79 90 81 / 10 20 20 10
STT 91 80 91 79 / 10 20 20 20

[cycloneye]

A tropical wave located about 600 miles southwest of the Cabo Verde
Islands is producing a disorganized area of cloudiness and shower
activity. Development, if any, during the next couple of days
should be slow to occur as the system encounters a dry and stable
air mass. After that time, environmental conditions are expected to
become more conducive for development, and a tropical depression
could form early next week while the system moves westward at about
15 mph across the tropical Atlantic Ocean.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...medium...50 percent

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
206 PM AST FRI AUG 19 2016

.SYNOPSIS...
A mid to upper level ridge will continue over the region during
the weekend. A dry air mass with Saharan Dust Particles will
continue to move across the islands through at least late Monday.
Surface high pressure ridge will hold across the West and Central
Atlantic today and into the weekend.

&&

.DISCUSSION...
A generally fair and mainly stable weather pattern will prevail
across the local islands through the upcoming weekend, as a mid to
upper level ridge with a dry air mass is expected to prevail
across the region. However, early morning showers across the
windward sections of PR and the USVI followed by locally induced
afternoon showers/Tstorms across West PR sill possible each day.
Warm and hot temperatures are likely this weekend too. Model
guidance indicated the arrival of a surge of moisture between late
Sunday and Monday. As a result the intensity and areal coverage of
afternoon convection may increase somewhat by early next week as
the ridge aloft weakens too.

A weakly induced easterly wave is expected to cross into the
southeastern Caribbean and continue westward through Saturday.
However, this feature will move well south of the area having no
effect on the region.

A tropical wave located about 600 miles southwest of Cabo Verde
it is being followed by the National Hurricane Center. For
additional information please refer to the Tropical Weather
Outlook and the National Hurricane Center products.

&&

.AVIATION...
VFR conds expected at all TAF sites through the
forecast cycle. SHRA development still possible in and around
JMZ. Winds will continue easterly at around 15 knots...becoming
light and variable overnight.

&&

.MARINE...Mariners can expect seas below 5 feet and winds up to 18
knots. Small craft operators should exercise caution across the
Northern and Southern Coastal waters of Puerto Rico due to winds
around 20 knots. Condtions are expected to diminish over the
weekend. Small craft advisories are not expected through at least
Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 81 91 80 90 / 20 20 10 20
STT 80 90 79 89 / 20 20 20 20

[cycloneye]

A broad area of low pressure, associated with a tropical wave, is
located about 600 miles southwest of the Cabo Verde Islands. This
disturbance is producing a large area of cloudiness but only a few
showers and thunderstorms, and any development of this system during
the next couple of days should be slow to occur due to its proximity
to dry air. Environmental conditions are forecast to be more
conducive for development after that time, and a tropical depression
could form by the middle of next week while the system moves
westward at 15 to 20 mph across the tropical Atlantic Ocean and into
the eastern Caribbean Sea.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...medium...50 percent

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
447 AM AST SAT AUG 20 2016

.SYNOPSIS...A surface high pressure ridge will lift farther north
of the region through Sunday to maintain light to moderate easterly
trade winds across the region. Winds are to gradually increase once
again by the middle of next week as the local pressure gradient
tightens in advance of a tropical wave forecast to move across
the eastern Caribbean. A mid to upper level ridge will continue to
hold over the region during the rest of the weekend. Therefore a
relatively dry and stable air mass will continue across much of
the region through at least Sunday.

&&

.DISCUSSION... Generally fair and stable weather pattern will
prevail across the entire region during the rest of the weekend,
as the mid to upper level ridge with a dry air mass will dominate
the local weather conditions and limit convective activity.
However, expect a few early morning showers across the windward
sections of PR and the coastal waters surrounding the other
islands. This will be followed by locally induced afternoon
showers/ or an isolated thunderstorms mainly across West PR. Warm
and hot temperatures are likely for the rest of the weekend.

Recent model guidance continue to suggest the arrival of a surge
of moisture in the northeasterly trade winds by late Sunday or
early monday. As a result expect a slight increase in low level
moisture which will allow for a better chance for increased
cloudiness and afternoon convection by early next week.

A broad area of low pressure and associated tropical wave now
located some 700 miles southwest of Cabo Verde is being followed
by the National Hurricane Center Miami Fl. For additional information
please refer to the Tropical Weather Outlook and the tropical
products issued by the National Hurricane Center. In the meantime...
recent models guidance continued to suggest this feature as a tropical
wave which should enter the eastern caribbean during the latter part
of next week. Models guidance also suggest a significant increase
in moisture and instability with PWAT values to increase to near
2.5 inches with this approaching wave. Stay tuned for more on this.

&&

.AVIATION...Mostly VFR conditions expected across the local flying
area during the forecast period. Winds will become from the east
increasing to around 15KT after 20/14Z with sea breeze variations.
SHRA/TSRA in the vicinity of TJMZ and TJBQ after 20/18Z.

&&

.MARINE...Mariners can expect seas below 5 feet and winds below
17 knots with fairly tranquil seas for the rest of the weekend.
For now precautionary statements and small craft advisories are
not expected through at least Tuesday of next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 79 89 80 / 10 20 20 40
STT 91 79 89 78 / 10 30 30 40