Caribbean - Central America Weather

[cycloneye]

Hi Luis Glad to see again after a lull. By the way, could you add this precious link about numerous webcams in St Barth: http://chynehome.com/meteo/index.php?page=webcams . Thanks. Your friend Gustywind

Added them.

[Gustywind]

Hi Luis Glad to see again after a lull. By the way, could you add this precious link about numerous webcams in St Barth: http://chynehome.com/meteo/index.php?page=webcams . Thanks. Your friend Gustywind

Added them.

Good boy thanks to you our Superman

[Gustywind]

Hi islanders! Let's see if this twave could bring some benficial rains for most of the EC islands. By the way, Guadeloupe and Martinica are Under an yellow alert for a risk of strong showers and tstorms today and tommorow. We will see what could happen with this moderate active twave...

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
712 AM EDT MON JUL 4 2016


...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 52W/53W, from 18N
southward, moving westward 10 to 15 KNOTS. A 1015 MB low pressure
center is along the tropical wave near 14N. Convective
precipitation: isolated moderate from 14N southward between 50W
and 54W.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
154 PM AST MON JUL 4 2016

.SYNOPSIS...
An upper level ridge will continue to erode as an upper level low
approach from the Northeast. Dry air with Saharan dust particles
still present over the regional mid levels. A tropical wave is
forecast to enter the Eastern Caribbean later this evening. After
the passage of this tropical wave, another dry air mass is
expected across the islands. A surface high pressure across the
North Central Atlantic will continue through the rest of the week.

&&
.DISCUSSION...
A generally fair and mainly stable weather pattern will continue
to prevail through the afternoon hours as an upper level ridge
and mid-upper level dry air mass dominate the weather pattern.
The influence of dry air at mid-upper levels kept the TPW around
around 1.47in, which is below the 25th percentile of July
Sounding Climatology. Still, diurnal instability will be
sufficient to trigger afternoon showers/thunderstorms in West PR.
The latest model guidance suggest a change in the local weather
regime as an approaching tropical wave moves closer to the local
islands late this evening. This feature and the proximity of an
upper level trough will result in squally weather across the USVI
and E PR through Tuesday morning, spreading across W PR in the
afternoon. Although, showers and thunderstorms across W PR could
be suppressed by cloud cover. Weather conditions are expected to
improve by Wednesday morning, as another mass of dry air with
Saharan Dust Particles is expected to reach the local islands.

&&

.AVIATION...
VFR conds expected to prevail at all TAF sites with brief MVFR
conds possible in and around JMZ thru 04/22z. SHRA/TSRA expected
in and around the Leeward terminals as a tropical wave enters the
eastern Caribbean. SHRA/TSRA spreading across USVI terminals and
JSJ aft 05/12z. Winds from the east at around 15-25kt with higher
gusts in SHRA/TSRA.

&&

.MARINE...
Small craft advisories remains in effect across most of the local
waters due to winds around 20 knots and seas up to 7 feet. Marine
conditions are expected to deteriorate this evening through
Tuesday, as a tropical wave enter the Eastern Caribbean and moves
across the local waters. In addition, a surface high pressure
across the North Central Atlantic Ocean will promote a moderate to
fresh easterly winds through mid week. Please refer to the local
marine products for additional information.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 88 79 91 / 50 50 20 20
STT 79 87 80 90 / 50 50 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
557 AM AST WED JUL 6 2016

.SYNOPSIS...
A tutt low now locate north of the islands will continue to move
northwest of the region through late Wednesday. Thereafter, high
pressure aloft will then move across the area from the east and
northeast beginning on Thursday, relaxing the pressure gradients
and somewhat reducing surface wind velocities through Saturday.
Recent aerosol models indicate Saharan Air Layer moving into the
area from the east and persisting through Friday. Surface high
pressure across the Northeast Central Atlantic will continue
through the next several days.

&&

.DISCUSSION...
Fair weather conditions with mostly clear to partly cloudy skies
prevailed across the local islands and coastal waters during the
night and early morning hours. A few light showers were observed
moving quickly northwestward across the nearshore Atlantic
waters. At the moment, little to no shower activity has been
detected inland.The winds were mainly from the east at 5-10 mph
and the minimum temperatures were in the upper 70s to lower 80s
across the coastal areas.

As the tutt low continues to move northwest of the area, a drier
air mass will move in from the east along with suspended Saharan
dust. Thus, mostly fair weather conditions are expected to prevail
today. However, some lingering moisture combined with the local
effects and diurnal heating may still aid in some convective
development during the afternoon hours. A chance of showers and
isolated thunderstorms is possible mainly across the interior and
western portions of Puerto Rico. Hazy conditions and maximum
temperatures between the upper 80s and lower 90s is also expected
for today.

Area of high pressure across the mid and upper levels is expected
to prevail through at least Friday. As a result, a similar weather
pattern with limited shower activity can be expected to continue
through the end of the work week. Also, pressure gradients will
relax a bit over the region, decreasing the surface wind
velocities through at least Saturday.

&&

.AVIATION...VFR conds durg entire prd. Few clds FL020...FL030...
FL050...Isold SHRA en route btw ERN PR and NRN Leeward Islands. Aft
06/16z chance of SHRA/Isold TSRA W/MVFR CIG psbl at TJMZ...and VCSH
TJBQ...Elsewhere VFR. Sfc winds 5-10 kts...BCMG 15-20 kts except
w/local seabreeze variations aft 06/14z. L/lvl winds mainly FM E blo
FL150...BCMG FM SW abv FL300.

&&

.MARINE...Small craft should exercise caution across most of the
local waters due to seas up to 6 feet and winds up to 20 knots.
There is a moderate risk of rip currents across the North, East
and South coasts of Puerto Rico, as well as Vieques, Culebra and
Saint Croix USVI.

&&

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

[msbee]

thanks Luis for the great updates every day.
Unfortunately little to no rain has fallen on St Maarten and we need it badly.

Hi Gusty.. glad to see you here again

and Luis I have some links for you too for some SXM web cams.
PTZtv has some really good SXM cams up now. Be sure to watch them with ad blockers disabled.

http://portstmaartenwebcam.com/
http://mahobeachcam.com/

Beat regards to all
Barbara

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
145 PM AST WED JUL 6 2016

.SYNOPSIS...Ridge pattern aloft will strengthen across the forecast
area as TUTT to our north shifts westward. This feature is expected
to hold through at least early next week. A surface high pressure
northeast of the local islands will continue to promote a moderate
to locally fresh easterly wind flow during the next several days.
Fair weather conditions with hazy skies are expected to prevail
through at least the upcoming weekend.

&&

.DISCUSSION...Mostly sunny to partly cloudy skies were observed
today with a few isolated showers detected across the coastal
waters as well as USVI and E Puerto Rico in the morning hours.
Then, some showers with thunderstorms developed over and west
of the Cordillera Central early in the afternoon. The potential
for shower and thunderstorm development will continue across
central and west Puerto Rico through sunset.

Fair and stable weather conditions with hazy skies and limited
shower activity are expected to prevail through at least the
upcoming weekend, under ridge pattern and precipitable water
below the normal values. There is a tropical wave which is
forecast to cross the region during the day on Saturday, but too
many factors are against significant rainfall accumulations. At
least through the weekend, maximum temperatures will range near
the normal range, in the upper 80s to low 90s at low elevations
to mid 80s at high elevations.

As the ridge aloft weakens during the upcoming weekend, low level
moisture will increase across the eastern Caribbean Sunday and
into early next week, and therefore there is a better chance for
a seasonable weather pattern with locally induced showers and
thunderstorms across central and west Puerto Rico each day.

&&

.AVIATION...VFR will prevail at most of the TAF sites through
the forecast period...except over the TJMZ and TJBQ thru 06/21Z
where MVFR conds are possible at times due to SHRA/ISOLD TSRA.
East Winds of 15-30 kts will prevail below FL100.

&&

.MARINE...Seas will continue at 3-5 feet nearshore while seas
of 4-6 feet can be expected offshore. Winds will continue between
10-20 knots.

&&

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

[cycloneye]

Here comes the dust.

 https://twitter.com/anumetservice/status/750718452181012480

[cycloneye]

thanks Luis for the great updates every day.
Unfortunately little to no rain has fallen on St Maarten and we need it badly.

Hi Gusty.. glad to see you here again

and Luis I have some links for you too for some SXM web cams.
PTZtv has some really good SXM cams up now. Be sure to watch them with ad blockers disabled.

http://portstmaartenwebcam.com/
http://mahobeachcam.com/

Beat regards to all
Barbara

Added both cams,Thanks for posting them and let's see if it rains a lot soon.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
546 AM AST THU JUL 7 2016

.SYNOPSIS...
Ridge pattern aloft will continue across the forecast area and
persist through the weekend. Saharan dust particles are expected
to prevail today and decreasing gradually on Friday. Surface high
pressure northeast of the local islands will continue to maintain
a light to moderate easterly wind flow today and tonight.

&&

.DISCUSSION...
Mostly clear to partly cloudy skies and little shower activity
was observed over the local waters with a few light passing
showers affecting the eastern coasts of Puerto Rico as well Saint
Thomas USVI during the overnight and early morning hours. The
winds remained from the east at 5-10 mph and the minimum
temperatures were in the upper 70s to lower 80s across the
coastal areas.

Suspended Saharan dust particles will continue over the area
today. As a result, hazy skies are once again expected across the
forecast area. A fair weather pattern will prevail during the
morning hours with a slight chance of brief showers mostly across
the eastern half of Puerto Rico and possibly the US Virgin
Islands. During the afternoon hours, local effects and diurnal
heating will combine to produce some showers with possible
thunderstorms over and west of the Cordillera Central. Mostly
clear to partly cloudy skies with limited shower activity is
expected after sunset.

Latest models continue to indicate drier air prevailing over the
region through at least early weekend. Ridge aloft located
northeast of the region will be the main feature through early
weekend. Thereafter, it is expected to weaken and shift north as
a tropical wave approaches the region from the east. As a result,
low level moisture will increase across the eastern Caribbean on
Sunday and Monday, increasing the shower activity across the
waters and local islands.

&&

.AVIATION...
VFR will prevail at most of the TAF sites through the
forecast period...except over the TJMZ and TJBQ thru 06/21Z where
MVFR conds are possible at times due to SHRA/ISOLD TSRA.
East Winds of 15-30 kts will prevail below FL100.

&&

.MARINE...
Small craft operators should exercise caution across the Caribbean
waters and Mona Passage for seas up to 6 feet. Elsewhere, seas of
3 to 5 feet and up to 15 knots are expected today. There is a
moderate risk of rip currents for the East, North and South coasts
of Puerto Rico as well as Culebra, Vieques and Saint Croix USVI.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 78 91 77 / 10 10 10 20
STT 90 80 89 80 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
136 PM AST THU JUL 7 2016

.SYNOPSIS...Building mid to upper level high pressure will
maintain a stable atmosphere over the next few days. Saharan Air
Layer is still present over the area...resulting in hazy skies
and somewhat reduced visibilities. Pattern will change slightly
during the weekend as a weak tropical wave moves across the
region...increasing somewhat the potential of showers across the
islands. Stable pattern with another pulse of Saharan dust is
forecast for early next week.

&&

.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. Diurnal induced showers have been developing over the
southwest quadrant of Puerto Rico this afternoon. The coverage and
intensity of the afternoon showers have been less than yesterday
due to the subsidence cap and drier air mass over the area today.
Tranquil pattern expected tonight and overnight...only light
showers possible at times across the U.S. Virgin Islands and
eastern Puerto Rico. activity affecting the islands.

Stable pattern will prevail across the local islands on Friday. A
relatively dry and subsidence air mass will limit the development
of showers across the local region. Although...diurnal induced
showers can not ruled out...the coverage over western PR will be
mainly isolated. The next surge of moisture is associated with a
weak tropical wave. At this time...operational models suggest that
the moisture associated with the wave will likely reach the local
region on Saturday morning and persist through Sunday. Therefore...
showers and thunderstorms are likely as the wave passes by.

Generally dry and stable conditions will return to the area next
week as mid level ridge will dominate the region. Another pulse
of Saharan Dust will reach the local islands Monday and Tuesday.

&&

.AVIATION...VFR conditions should be expected at all TAFs through
08/12Z. Mostly east to southeast winds at 12-15 kts should prevail
through 22z...decreasing to 5 to 10 kts overnight.

&&

.MARINE...Seas will continue at 3-5 feet nearshore while seas of
4-6 feet can be expected offshore. Winds will continue between
10-15 knots. Surface winds will increase up to 20 knots during
the weekend as the wave passes by.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 91 77 89 / 10 10 20 30
STT 80 89 80 88 / 20 20 20 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
530 AM AST FRI JUL 8 2016

.SYNOPSIS...A weak tropical wave will pass on Saturday with a
slight increase in shower activity. A second will pass on Sunday
with a better increase. Then showers will be limited until the
following weekend.

At upper levels...Weak high pressure will give way to weak passing
lows...but most features are very weak and transient.

At mid levels...High pressure will continue across the Atlantic
in the sub tropical latitudes. Weak troughs are seen to pass
Saturday night and Wednesday. Moisture is quite limited at mid
levels through at least Friday of next week.

At lower levels...High pressure extends from south of the Azores
to the central Atlantic and then west to Florida. High pressure
coming out of the northeast United States on Tuesday will settle
into the central Atlantic by late next week to reinforce the east
northeast to easterly trade wind flow. Tropical waves will pass
through on Saturday and Sunday with limited effect. Another wave
is expected the following weekend.


&&

.DISCUSSION...Spotty showers were observed in the pre-dawn hours
across the Caribbean and Atlantic waters...but few have been
coming onshore up to now and rainfall over the islands has been
negligeable. Precipitable water was 1.5 inches in the 08/00z
sounding and is expected to drop below 1.2 inches, according to
the GFS, at both 08/18z and 09/06z. Stability increases
considerably today and will recover somewhat tomorrow. Therefore
do not expect thunderstorms today or early next week, though
cannot rule them out entirely. Conditions will become more
favorable later next week but no significant features are foreseen
through Friday of next week. A weak tropical wave is expected
during the following weekend.

&&

.AVIATION...Mainly VFR conditions will prevail across all
terminals during the next 24 hours. Expect -SHRA over eastern PR
and the USVI during the morning hrs. Then, SHRA may form across
western PR to affect the vicinity of TJBQ/TJMZ during the
afternoon. Elsewhere it will be partly cloudy with trade wind
showers en route between USVI and the Leeward islands. Surface
winds are from the east-northeast at 7-19 kts becoming gusty btwn
08/13z-20z.

&&

.MARINE...Winds around Puerto Rico in the near shore waters and a
little beyond will become fresh during the next several
afternoons and small craft will need to exercise caution. Small
craft advisories are not expected for the next 10 days.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 79 90 79 / 20 30 30 30
STT 89 80 87 80 / 10 10 20 30

[Gustywind]

thanks Luis for the great updates every day.
Unfortunately little to no rain has fallen on St Maarten and we need it badly.

Hi Gusty.. glad to see you here again

and Luis I have some links for you too for some SXM web cams.
PTZtv has some really good SXM cams up now. Be sure to watch them with ad blockers disabled.

http://portstmaartenwebcam.com/
http://mahobeachcam.com/

Beat regards to all
Barbara

Added both cams,Thanks for posting them and let's see if it rains a lot soon.

Hi my little dear Barbara very glad to see you back in the action here

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
203 PM AST FRI JUL 8 2016

.SYNOPSIS...Mid to upper level high pressure is dominating the
local area...maintain a fair weather pattern. Conditions will
change slightly during the weekend as a weak tropical wave moves
across the region...increasing somewhat the potential of showers
across the islands. Stable pattern with another pulse of Saharan
dust is forecast for early next week.

&&

.DISCUSSION...Fair weather has prevailed across Puerto Rico and
the U.S. Virgin Islands today. Some afternoon showers are still
possible across western Puerto Rico later this afternoon. Isolated
to scattered showers could affect the Anegada Passage and portions
of the the U.S. Virgin Islands during the overnight as the tropical
wave approaches to the local area.

Moisture associated with the wave will spread over the region early
Saturday Morning. The best moisture convergence and instability
will likely remain over the Caribbean Waters. However...expect
rounds of scattered showers affecting the islands at times during
the weekend. The heaviest showers are likely over the north and
west portions of Puerto Rico each afternoon.

Generally dry and stable conditions will return to the area next
week as mid level ridge will dominate the region. Another pulse
of Saharan Dust will reach the local islands Monday and Tuesday.

&&

.AVIATION...Mostly VFR cond expected through the rest of the
period. SHRA may develop across western portions of PR, possibly
affecting TJMZ during the afternoon hours. Based on the 08/12Z
TJSJ sounding, low level winds prevail from the east at 5-15 kts
with higher gusts and sea breeze variations.

&&

.MARINE...Winds will increase to 15-20 knots and seas to 4-6 feet
during the weekend as the wave passes by. The main hazard is the
possible thunderstorms moving across the local waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 79 90 79 89 / 30 30 30 30
STT 80 87 80 89 / 10 20 30 30

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
455 AM AST SAT JUL 9 2016

.SYNOPSIS...A weak tropical wave will pass through the area today.
A second wave will move through on Sunday. The rest of the week
will be dominated by locally driven processes with scattered
afternoon showers and isolated thunderstorms.

At upper levels...A weak high pressure to the north will be
replaced by a weak low over the area by mid-week. High pressure
will move into position to our northeast later next week, but
features and gradients are very weak.

At mid levels...High pressure will continue to dominate the sub-
tropical Atlantic through the next 7 to 10 days. An approaching
trough will weaken as it passes by on Sunday. A second trough will
move through mid week and the Monday after next, according to the
GFS.

At lower levels...High pressure just south of the Azores stretches
across the Atlantic to Florida. High pressure moves off the New
England coast to re-generate the Atlantic high and will dominate
the Atlantic again by next Friday. Several tropical waves move
through the local area this weekend. A weak wave is also expected
next weekend. Some Saharan dust will continue with the highest
concentrations beginning late on the tenth and lasting through the
twelfth of July.

&&

.DISCUSSION...Showers have been increasing in the local area as a
tropical wave approaches. The latest NEXRAD scans have shown tops
of 47 kft half way between the east end of Saint Croix and the
southern boundary of our forecast area at 17 north. Lightning has
not yet been detected, but isolated thunderstorms are expected to
begin this morning. Otherwise shower tops have been below 20 kft. East
southeast flow will continue to bring in better showers and
coverage for the U.S. Virgin Islands and Puerto Rico. Localized
areas of urban and small stream flooding are possible later today where
showers persist for more than a few hours, but winds in the lower
atmosphere are expected to continue to run 15 to 25 knots and most
cells should move along.

The second round of showers appears set to commence around midday
on Sunday when heating is best. A similar situation to today is
expected, although moisture appears a little more diffuse
tomorrow. Immediately after this wave another episode of Saharan
dust will lower visibilities to 10 to 15 miles and reduce
convection and showers in the area to a minimum. This will be
remedied by mid-week, but features are weak and so expect shower
generation processes to be limited mostly to local effects in
moderate trade wind flow. The next tropical wave to appear over
the following weekend does not even look as strong as the one-two
punch we are to have this weekend, but showers will increase
then.

&&

.AVIATION...A tropical wave will increase the chance for
SHRA/TSRA across the forecast area today. -SHRA from time to time
are expected across all TAF sites this morning...then SHRA/TSRA
expected to increase in intensity/coverage mainly over the Interior
and Northern sections of PR. Therefore brief MVFR with BKN-OVC
ceiling at FL025-FL080 are likely at TJBQ/TJSJ/TJMZ btwn 09/15-23z,
elsewhere VCTS or VCSH. Surface winds from the E-ENE at 7-15 kt
increasing at 10-20 with higher gusts aft 09/13z.


&&

.MARINE...Seas have generally subsided over the last 24 to 36
hours, but will begin to rise as the winds in the tropical wave
begin to be felt. At this time small craft advisory conditions are
not anticipated over the weekend or next week except perhaps near
particularly strong thunderstorms for very brief periods where
gusty downdrafts may be encountered during the tropical wave
passages.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 78 89 77 / 90 30 40 50
STT 88 79 89 78 / 50 30 70 50

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
153 PM AST SAT JUL 9 2016

.SYNOPSIS...Tropical wave is moving across the area producing
showers and thunderstorms across the local region. A second
tropical wave will cross the area on Sunday...keeping the
potential for showers and thunderstorms high the rest of the
weekend. Stable pattern with a pulse of Saharan dust is forecast
for early next week.

&&

.DISCUSSION...Active weather has been observed across the islands
today. Showers and thunderstorms moved inland over the eastern
half of Puerto Rico since early this morning. Afternoon showers
will continue to affect the central and western Puerto Rico.
Conditions will improve somewhat tonight and overnight as the
tropical wave moves away from the area.

The second tropical wave is moving fairly quickly across the
Tropical Atlantic...and it is forecast to reach the Eastern
Caribbean by early Sunday. Deep moisture associated with this
wave will surge over the area around mid-morning on Sunday.
Therefore...expect additional rounds of showers and thunderstorms
affecting the islands at times. The rapid movement of the wave
will result squally weather...locally heavy rainfall and gusty
winds with the strongest storms.

Generally dry and stable conditions will return to the area next
week as mid level ridge will dominate the region. Another pulse
of Saharan Dust will reach the local islands Monday and Tuesday.
No significant weather feature is foreseen the rest of the work
week.

&&

.AVIATION...SHRA/TSRA expected to continue over the interior...
northern and western sections of PR. Therefore, brief MVFR with BKN-
OVC cigs btw FL025-FL080 are likely at TJBQ/TJSJ/TJMZ thru at least
23z. -SHRA will continue across the waters with a few of them
creating mainly VCSH across the rest of the terminals during the
overnight hours. Low level winds from the E-ESE at 10-23 kt.

&&

.MARINE...Winds of 15-20 knots and seas to 4-6 feet the rest of
the weekend as the waves pass by. The main hazard for mariners is
the thunderstorms associated with the tropical waves. Winds and
seas will gradually subside through midweek next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 89 77 89 / 30 40 50 20
STT 79 89 78 90 / 40 40 50 20

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
601 AM AST SUN JUL 10 2016

.SYNOPSIS...A tropical wave moving through the windward islands
will move through the forecast area today and early tonight. High
pressure in the Atlantic will continue to drive trade wind flow
through the next 10 days. But any waves moving through the area
mid week or over the next weekend will be weak and weather
processes will be dominated by local and diurnal heating.

At upper levels...A weak upper level low northeast of the area
will dig southwest across Puerto Rico early this week followed by
higher pressure that will persist into the weekend.

At mid levels...High pressure will continue across the sub-
tropical Atlantic. A weak trough just west of the Cape Verde
Islands will move across the local area mid week. A second trough
over the Cape Verde Islands at mid week is expected to move
across the local area early next week. Mid levels are mostly dry
this week.

At lower levels...High pressure in the central Atlantic will be
joined by another high out of the New England states mid week this
week. That high will strengthen as it moves into the north central
Atlantic late this week and next weekend. This will maintain
moderate to fresh trade wind flow over the local area. A tropical
wave over the windward islands early this morning will move
through the local area today and early tonight accompanied by
showers and isolated thunderstorms.

&&

.DISCUSSION...The tropical wave that has been followed across the
Atlantic this past week is now appearing as an arch of showers:
the left side moving into the eastern Caribbean and the right side
moving through the Windward and Leeward Islands. Currently
earthworks is showing lightning activity along the south coast of
the Dominican Republic--likely associated with the wave that
recently passed through here--but no lightning activity is noted
with the wave moving through the lesser Antilles, although some
higher tops are noted in the infra-red satellite imagery. The GFS
models appears to be bringing in the wave faster than the MIMIC
imagery shows the wave to be moving, but the difference is only on
the order of several hours rather than half a day. Also the MIMIC
imagery shows moisture extending well north of the area as the arc
of highest moisture--rather like a shark`s fin--even though the
best convective activity in the satellite imagery is confined to
latitudes south of our area. The GFS does not show humidities as
high over the area today as for yesterday and with the center of
the best activity farther south, am limiting POPs for all but the
northwest section of Puerto Rico. Again it appears that the south
coast of Puerto Rico will be the area least likely to receive
rain.

Divergence aloft at 250 mb does not extend north into our area,
but there is a very weak area northeast of us during the day.
Strong divergence is also seen in the model following the wave at
upper levels.

Synoptic features during the rest of the week are weak and mid-
level moisture is mostly lacking. Although a weak trough moves
through at 500 mb mid week it is not clear there will be much
effect. Another trough moving through early next week may be a
little stronger, but again all features are very weak and the
upper level pattern is rather chaotic. Most convection will be due
to local effects and the diurnal heating pattern. The clearest
feature is the Saharan dust forecast by the NASA GEOS 5 model
that shows dust moving in behind this wave and lasting through at
least Tuesday. This should limit visibilities to 10 to 15 miles
Monday and Tuesday and limit convection to mainly western Puerto
Rico.

&&

.AVIATION...VFR conditions expected early this morning. However,
the moisture associated with tropical wave is forecast to enter the
forecast area late this morning, to increase the potential for
SHRA/TSRA late this afternoon into the afternoon hours. Therefore,
SHRA will affect the leeward/USVI/Eastern PR terminals thru the
morning hours. Followed by brief MVFR conds with BKN-OVC cigs btw
FL025-FL070 at TJBQ/TJSJ/TJMZ thru at least 10/23z. Sfc winds at 10-
20 kt with sea breeze variations/higher gusts in/near SHRA/TSRA.


&&

.MARINE...Most of our local waters will feel the effects of the
passing tropical wave with seas of 3 to 6 feet and winds up to 20
knots and higher gusts near thunderstorms. Conditions will relax
slightly but high pressure will continue to drive moderate to
locally fresh trade winds through the week, with the quietest
period around mid-week. Small Craft Advisories are not expected
for the next 10 days.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 77 90 78 / 60 50 10 20
STT 90 78 91 79 / 40 30 20 30

[cycloneye]

 https://twitter.com/anumetservice/status/752171816274108416

[cycloneye]

 https://twitter.com/anumetservice/status/752173747260432385

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
120 PM AST SUN JUL 10 2016

.SYNOPSIS...Tropical wave is moving across the Eastern Caribbean
today. Although showers and thunderstorms will affect the islands
this afternoon and evening...the bulk of the convection will remain
over the Caribbean Waters. Stable pattern with a pulse of Saharan
dust is forecast in the wake of the tropical wave. No significant
changes in the weather pattern is expected the rest of the work week.

&&

.DISCUSSION...Satellite loops show the best convection associated
with the tropical wave well south of the local area. Moisture in
the northern periphery of the wave is inducing the development of
scattered showers across the local area. Later this afternoon...
stronger showers and a few strong thunderstorms are still possible
over the northern half of Puerto Rico due to the interaction of
the wave and the orographic effects. Conditions will gradually
improve late tonight as the tropical wave moves away from the
forecast area.

Mid level high pressure will maintain a stable pattern across the
local islands most of the work week. Early in the week...Aerosol
models...NASA GEOS-5 and NAAPS indicate a pulse of Saharan Dust
moving across the region. This dusty air mass will produce hazy
skies and somewhat reduced visibilities. The relatively dry and
subsidence air mass at mid levels of the atmosphere will also
limit the development of showers across the local region through
midweek. Although...afternoon showers can not ruled out the
coverage over western PR will be mainly isolated or locally
scattered. No significant weather feature is foreseen the rest of
the work week. Synoptic models suggest better moisture the next
weekend when a tropical wave moves across the local region.

&&

.AVIATION...SHRA/TSRA possible later this afternoon with brief
MVFR conds and BKN-OVC cigs btw FL025-FL070 at TJBQ/TJSJ/TJMZ thru
at least 10/23z. Sfc winds from the east at 10-20 kt with sea
breeze variations and higher gusts in/near SHRA/TSRA.

&&

.MARINE...Winds of 15-20 knots and seas to 4-6 feet expected
through late tonight. Winds and seas will gradually subside
through midweek. Overall seas of 3-5 feet and winds of 10-15
knots can be expected most of the week. No Small Craft Advisories
anticipated this week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 90 78 89 / 50 10 20 20
STT 78 91 79 90 / 30 20 30 20