Caribbean - Central America Weather

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
159 PM AST FRI SEP 2 2016

.SYNOPSIS...Showers and thunderstorms will diminish tonight as a
weak disturbance moves out of the area. The tropical wave
approaching will remain mostly south of the area but showers and
scattered thunderstorms are expected. After the wave moisture
will return and fuel scattered convection. Saharan dust will
remain visible in the area through at least Tuesday.

At upper levels...A weak trough oriented northeast-
southwest is approaching the area from the east and will cross
through on Saturday. This will be followed by a broad ridge early
next week and another trough of similar orientation the following
weekend.

At mid levels...High pressure will continue in the subtropical
Atlantic just north of the local area through the period. Moisture
at mid levels remains mainly south of Puerto Rico until the
weekend after next.

At lower levels...A weak disturbance has continued to produce
showers and scattered thunderstorms across the area. An area of
dry air will follow tonight, but the increase in moisture begins
Saturday and continues until Monday afternoon. A moderate
tropical wave will pass mainly south of the area Sunday afternoon
through Monday spreading showers and thunderstorms across the
area. There is another brief intermission in the moisture before a
moist regime returns Wednesday through early the following week.
Also Saharan dust will be seen in the air through at least
Tuesday.

&&

.DISCUSSION...Showers formed over the Caribbean and moved rapidly
over Puerto Rico and the U.S. Virgin Islands this morning. Amounts
in the U.S. Virgin Islands were light, but amounts in Puerto Rico
were more substantial. Some areas in the northwest and Luquillo
range received in excess of 1.5 inches. Rio Cauguitas at Rio
Blanca had 0.61 inches since 2 this morning. Saharan dust has
weakened this system considerably. The GFS has slowly pulled the
next tropical wave and its moisture just south of the area. Now
instead of showing 2.4 inches of precipitable water for San Juan
on Monday it is showing less than 1.8 and air with Saharan dust
and winds of 25 to 30 knots at 850 mb are right over the Atlantic
waters in our forecast area with the best moisture south. Although
this could change--and small changes could mean a large
difference in rainfall--it is not expected to be as vigorous a
system as previously indicated by the models. Nevertheless,
showers and scattered thunderstorms are expected Sunday into
Monday over most of the land areas and the Caribbean waters in our
area. Although Tuesday should be drier, showers and isolated
thunderstorms should continue and increase toward the end of next
week. The model is no longer portraying significant systems in the
tropical Atlantic this week or next week.

&&

.AVIATION...SHRA/TSRA expected to diminish across mainland PR
by sunset. This activity should impact mainly TJBQ/TJSJ with MVFR
conditions at times. Across the rest of the terminals, mainly VFR
conditions are expected to prevail through the forecast period.
Light trade wind showers possible overnight across the
leeward/USVI/eastern PR terminals. HZ due to Saharan dust expected
tomorrow across the flying area. Easterly winds at 10-20 kts, light
and variable at the sfc overnight across PR terminals.

&&

.MARINE...Although the forecast has taken the wave and the
moisture south of the area, small craft advisories are still
expected across much of the exposed waters possibly as early as
Saturday night. Lately seas have been running between 5.5 and 6.5
feet at the outer buoy 41043. This will likely hold with light
swell from Gaston until waves from the approaching wave make it
into the area on Sunday.

&&

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

[cycloneye]

8 PM TWO:

Shower activity has increased since yesterday in association with a
tropical wave located about 1000 miles east of the Lesser Antilles.
However, environmental conditions are only marginally conducive, and
any additional development of this system should be slow to occur
while it approaches the Lesser Antilles and continues westward into
the eastern Caribbean Sea early next week.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...20 percent

[cycloneye]

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
510 AM AST SAT SEP 3 2016

.SYNOPSIS...Mid level ridge across the forecast area is expected
to slowly erode during the next few days. A surface high pressure
north of the area will continue to promote easterly winds through
next week with the local pressure gradient tightening between Sun-
Mon. As a result, winds are expected to increase across the
forecast area. A mainly fair weather pattern will continue to
prevail through the next tropical wave passage which is expected
late Sunday into Monday.

&&

.DISCUSSION...Partly cloudy skies prevailed across the local
islands overnight and early this morning. Some passing showers
were noted over the local waters as well as the USVI and NE PR.
Low temperatures ranged from the low to mid 70s in the mountains
to the upper 70s to low 80s elsewhere.

Under the eroding mid level ridge, moderate to locally fresh
easterly winds and near to below normal precipitable water, a
mainly fair weather pattern will prevail through Sunday with
locally induced afternoon showers and thunderstorms across west
Puerto Rico each day.

The local weather pattern is expected to change late Sunday and
into Monday as a tropical wave moves across the eastern Caribbean.
Based on the latest NHC Tropical Weather Outlook, this wave at
2am AST was located about 800 miles east of the Lesser Antilles
and environmental conditions are only marginally conducive to
development. Development, if any, should be slow to occur. The
formation chance through the next 48 hours is low, 20 percent.
And in fact, latest guidance suggested bulk of moisture remaining
over the Caribbean waters and south of PR and the USVI.

However, low level moisture will increase across the area late
Sunday and into Monday with lingering moisture prevailing through
Tuesday. Winds are also expected to increase with the tropical
wave passage. As a result, periods of squally weather could be
expected late Sunday through early Tuesday, and focused across
the east and south sections of forecast area.

&&

.AVIATION...Mostly VFR conditions expected with vicinity SHRA
possible across the USVI, Leeward Islands and Eastern PR terminals.
After 03/17Z, SHRA/TSRA expected to develop across southwestern
Puerto Rico, affecting the vicinity of TJMZ and TJPS through 03/22Z
with mountain top obscuration. In addition, Sfc winds expected
from the E-ENE below 10 kt til 03/13z, increasing to 10-15 kts
with higher gusts after 03/13Z.

&&

.MARINE...Marine conditions will deteriorate between Sunday and
Monday as winds and seas increase due to a tropical wave. Although
the shower activity associated with the wave will remain mostly
over the Caribbean Waters, the seas will build to around 5-7 feet
across most of the waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 80 89 79 / 20 20 20 50
STT 91 81 91 80 / 20 20 20 50

[cycloneye]

Up to 20%-30%

Shower and thunderstorm activity associated with a tropical wave
located about 600 miles east of the Lesser Antilles has increased
since yesterday. However, environmental conditions are only
marginally conducive, and any development of this system should
be slow to occur while it moves westward at 15 to 20 mph. This
disturbance is expected to bring locally heavy rainfall and gusty
winds to portions of the Lesser Antilles beginning later today
through Sunday night.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...low...30 percent

[cycloneye]

2 PM TWO has no change.

A tropical wave located about 450 miles east of the Lesser Antilles
continues to produce a large area of disorganized showers and
thunderstorms. Environmental conditions are only marginally
conducive, and any development of this system should be slow to
occur while it moves westward at 15 to 20 mph. This disturbance is
expected to bring locally heavy rainfall and gusty winds to portions
of the Lesser Antilles beginning later today through Sunday night.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...low...30 percent

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
205 PM AST SAT SEP 3 2016

.SYNOPSIS...A tropical wave will pass mostly south of the area
Monday and Tuesday bringing some additional showers. Saharan dust
will slowly taper off by Tuesday.

At upper levels...A weak low will cross through the
northern U.S. Virgin Islands and Puerto Rico overnight. A broad
high pressure will pass several hundred miles north of the area,
influencing much of the eastern Caribbean on Tuesday, with its
backside affecting the local weather through Saturday of next
week.

At mid levels...High pressure over the sub tropical
Atlantic will move northeast into the mid latitudes on Sunday. A
trough near 36 west will move slowly across the tropical Atlantic
and pass through the local area on friday. Mid level moisture is
best on Tuesday and Saturday.

At lower levels...High pressure continues north of the area while
low pressure dominates the southern Caribbean. A tropical wave is
being pressed southeast and is now expected to pass mostly south
of Puerto Rico and the U.S. Virgin Islands. Some increase in
showers is expected Monday and Tuesday. High pressure moves into
the north central Atlantic mid-week next week and weakens only
slowly as it sags southeast to generate moderate to locally fresh
trade winds.

&&

.DISCUSSION...A few showers crossed northeast Puerto Rico during
the morning. In the early afternoon a few streamers were seen off
of Vieques and Saint Croix. Other showers were seen on the
western end of the Cordillera Central. These showers will not
generate as much rain as yesterday and should die off shortly
after sunset, possibly sooner over land. Current GFS run is not
much different from the last several runs and all show drier air
at 850 and 700 mb holding the moisture from the approaching
tropical wave south of the area This moisture is now stretched
from the Windward Islands to 600 miles east of the Windward
Islands. It will begin moving through the Caribbean Sea south of
the local area around 04/06z and now looks like it will not even
enter the forecast area`s southeast corner until 05/12z. Have
lowered some POP expectations for this period, but some local air
mass showers are still possible--though they will be isolated for
the most part. Moisture surges into the area on Monday night and
should continue through Tuesday. It is at this time that we should
have the best showers and thunderstorms, but urban and small
stream flooding--if any---should be very localized.

Moisture patches move through the rest of the week, but better
moisture is not expected until the following weekend. Any
depressions that develop are now expected to remain well south of
the area during the next 10 days.

&&

.AVIATION...Mainly VFR conditions expected across most of the
terminals through much of the forecast period. SHRA/TSRA associated
to a tropical wave is expected to increase late in the fcst period
across the leeward terminals. HZ due to Saharan dust will continue
for the next day or so. Low level winds will continue ENE at 15-
30 kts.

&&

.MARINE...Small craft advisories may still be possible beginning
Sunday night. Although moisture may not be so far north winds in
the 850-700 mb level will be a little higher than usual. Seas may
not be as high as expected over some waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 80 89 79 87 / 10 10 30 30
STT 81 91 80 88 / 20 20 30 30

[cycloneye]

8 PM TWO:

A tropical wave accompanied by a broad area of low pressure located
about 300 miles east of the Lesser Antilles continues to produce a
large area of disorganized showers and thunderstorms. While a
recent buoy observation east of the islands indicates that the wave
is producing winds just below tropical storm force, environmental
conditions are only marginally conducive for any additional
development of this system while it moves westward at 15 to 20 mph.
Regardless of development, locally heavy rainfall and gusty winds,
possibly to tropical storm force, are expected over portions of the
Lesser Antilles overnight and continuing through Sunday night.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...low...30 percent

[Gustywind]

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
805 PM EDT SAT SEP 3 2016


A tropical wave is moving across the central Atlc with an axis
extending from 20N54W to a 1009 mb low near 14N54W to 07N54W,
moving W at 15-20 kt. This wave is embedded in a broad area of
high TPW. Divergent upper-level winds are supporting numerous
moderate and isolated strong convection from 13N to 17N between
51W to 58W. Satellite-derived wind data show the pres gradient
on the N side of the wave is also generating a broad area of
fresh to strong NE to E winds from 13N to 20N between 45W and
60W.

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
502 AM AST SUN SEP 4 2016

.SYNOPSIS...Ridge aloft will continue to slowly erode during the
next few days. A surface high pressure across the north central
Atlantic will promote easterly winds during the next several days.
Fair weather will prevail through the next tropical wave passage
which is expected to reach the eastern Caribbean later today and
move south of the local islands Mon into early Tue. Hazy skies
will prevail across the local islands today.

&&

.DISCUSSION...Clear to partly cloudy skies prevailed across the
local islands overnight and early this morning. Some light passing
showers were noted over the local waters. Low temperatures ranged
from the low to mid 70s in the mountains to the upper 70s to low
80s elsewhere.

Under weakening mid level ridge, moderate to locally fresh
easterly winds and near to below normal precipitable water, a
mainly fair weather pattern will prevail through Monday morning
with locally induced afternoon showers and thunderstorms across
west Puerto Rico today. The local weather regime is expected to
change Monday as a tropical wave continues to move across the
eastern Caribbean.

Based on the latest NHC Tropical Weather Outlook at 2 am AST, the
wave was located about 250 miles east of the Lesser Antilles with
environmental conditions expected to become less conducive for
any significant development. The formation chance through the next
48 hours is low, 20 percent.

Guidance continued to suggest low level moisture increasing across
the forecast area Monday afternoon through Tuesday with the bulk
of moisture remaining over the Caribbean waters and south of PR
and the USVI. Winds are also expected to increase across the
forecast area as the local pressure gradient tightens and the
tropical moves across the area. This will result in periods of
squally weather Monday afternoon and into Tuesday, but still
focused across the east and south sections of the forecast area.

As the tropical wave moves away late Tuesday, a seasonable weather
pattern will prevail across the forecast area Wed thru Friday with
a few passing showers affecting USVI and E PR in the morning,
followed by locally induced showers and thunderstorms across W PR.

&&

.AVIATION...Mainly VFR conditions expected across most of the
terminals through the next 24 hours. Saharan dust is present which
will cause hazy skies but visibilities expected to be P6SM.
SHRA/TSRA associated to a tropical wave is expected to increase
across the general vicinity after 04/16Z but staying mainly over the
waters except some activity across SW-PR. Low level winds will
continue ENE at 10-15KT until 04/12Z...increasing to 15-20KT and
gusty thereafter with sea breeze variations.

&&

.MARINE...Marine conditions will deteriorate later today and Monday
as winds and seas increase due to a tropical wave passage. Although
the shower activity associated with the wave will remain mostly
over the Caribbean Waters, seas will build to around 5-7 feet
across most of the waters. Therefore... Small Craft Advisories
will be in effect shortly.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 80 89 78 / 10 30 40 30
STT 91 80 88 79 / 10 30 30 40

[cycloneye]

8 AM TWO:

A tropical wave located just east of the Lesser Antilles is
producing a large area of cloudiness and showers and winds to near
tropical storm force. Upper-level winds are not expected to be
conducive for significant development of this disturbance while it
moves westward at 15 to 20 mph through the Caribbean Sea this week.
Regardless of whether or not development occurs, this wave will
produce locally heavy rainfall and gusty winds over portions of the
Lesser Antilles through early Monday.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...low...30 percent

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
204 PM AST SUN SEP 4 2016

.SYNOPSIS...Saharan dust continues to limit visibilities to 10
miles or less across the area. Dry air ahead of a tropical wave
has limited convection. The tropical wave will pass mainly south
but will enhance shower activity Monday and Tuesday. Relatively
dry conditions with scattered showers and thunderstorms will
prevail the rest of the week.

At upper levels..Southerly flow accompanies the approach of a high
pressure that will pass north of the area Tuesday. Northeast flow
will continue until the next trough crosses on Friday night.

At mid levels...High pressure to the north will intensify further
northeast early in the week and then continue over the west
central Atlantic through the rest of the week drifting somewhat
west southwest. An approaching tropical wave will pull a trough
across the area Monday night with good moisture beginning 05/18z.
Much drier air with bubbles of moisture will move across until
the next wave passage around Saturday.

At lower levels...High pressure will build into the north Central
Atlantic while low pressure continues in the southern Caribbean.
Flow becomes more southeasterly late in the 10-day period. An
approaching tropical wave has brought showers and thunderstorms
with wind gusts up to at least 36 knots to the Leeward Islands.
This wave will continue to track just slightly north of west with
the bulk of it passing to the south of the area. Showers and
thunderstorms are expected to increase across the area Monday and
continue intermittently through Tuesday. Then, a weak wave will
pass through late Wednesday with a second wave on Friday each
accompanied by a burst of better moisture but surrounded by
relatively drier air. Models show a weak low with a tropical wave
early next week...passing well south of the area but spreading
some moisture over Puerto Rico and the U.S. Virgin Islands. For
now, only traces of the ubiquitous Saharan dust should be left by
Wednesday.

&&

.DISCUSSION...Showers and thunderstorms were seen moving slightly
north of west toward the area. As of 04/1750Z the closest showers
were 150 miles southeast of Humacao, Puerto Rico. Winds in the
Leeward Islands are generally running 10 to 15 knots with higher
gusts in thunderstorms. This area is not expected to make it to
land areas in the forecast area until after 05/12z, but showers
and thunderstorms could certainly move through the southern
Caribbean portion of our waters by early evening. At this time
showers, under a 4 degree celsius cap, have not formed, but some
convection is expected over isolated areas of southwest Puerto
Rico.

Moisture peaks at over 2 inches on Monday night and tapers off
until around Friday thereafter. Nevertheless conditions will
remain favorable for some scattered showers and thunderstorms
through the week over much of the forecast area although upper
level conditions are mostly neutral. Moisture again rises to over
2 inches of precipitable water by next weekend with another
tropical wave.

At this time neither system appears to be strong enough to create
anything more than very isolated urban and small stream flooding.

&&

.AVIATION...Mainly VFR conditions expected across most of the
terminals through the next 24 hours. However, SHRA/TSRA associated
with a tropical wave entering the eastern Caribbean is expected
to increase across the Leeward terminals into the Caribbean
waters south of the USVI terminals thru the evening hours into
early Monday. HZ due to Saharan dust still expected through late
Monday. Low level winds will continue ENE at 15-25 kts.


&&

.MARINE...Borderline small craft advisory conditions are expected
to begin before the beginning of the next period in at least some
portions of our outer waters. Nevertheless winds and seas will
remain subject to rather local effects rather than widespread
strong winds whipping up seas. Conditions above small craft
advisory levels are not expected after Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 82 89 78 87 / 30 40 30 30
STT 82 88 79 88 / 30 30 40 40

[cycloneye]

8 PM TWO:

A broad area of low pressure associated with a tropical wave is
moving across the Lesser Antilles and continues to produce a large
area of disorganized showers and thunderstorms. Significant
development of this system appears unlikely while it moves westward
at 15 to 20 mph across the Caribbean Sea during the next several
days. This disturbance will continue to produce locally heavy
rainfall and gusty winds over portions of the Lesser Antilles
through Monday morning, and should spread over Puerto Rico and
Hispaniola during the next couple of days.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...low...30 percent

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
Issued by National Weather Service Miami FL
444 AM AST MON SEP 5 2016

...Heavy rain and strong wind gusts possible today...
...Small Craft Advisory for most of the waters today...

.DISCUSSION...
A vigorous tropical wave is pushing across the Lesser Antilles this
morning. Infrared satellite imagery shows a healthy area of
convection stretching from Guadeloupe across Dominica towards
Martinique. MeteoFrance radars on Guadeloupe and Martinique show
some higher returns over Dominica and Martinique that align very
well with the satellite representations. Observations in the
vicinity of the waves have pushed above 30 knots.

Current guidance keeps the wave south of Puerto Rico and the
United States Virgin Islands as it moves west today. The forecast
area will be in a location relative to the wave to see heavy
rainfall today. 00z San Juan sounding has a precipitable water
(PWat) value of 1.60 inches. The nearest 00z soundings to the
wave, Barbados and Trinidad & Tobago, both show PWat values above
2 inches and it is expected that PR and USVI will both see
additional moisture push across the area in conjunction with this
tropical wave. The moist environment combined with the presence of
the wave will create the potential for heavy rain and related
impacts include a non-zero chance for flash flooding.

As the wave passes the forecast area later today into tonight, a
weakening trend is expected. Both the 00z GFS and 00z ECMWF show a
less impressive system heading towards Hispanola. As the wave
exits, the wind should begin to diminish and rain chances will
fall a bit. Plenty of moisture will remain over the region behind
the wave, so it is possible that Tuesday could bring another
chance for heavy rain over the islands.

Slightly drier air enters the region on Wednesday, leading to
lower rain chances on Wednesday afternoon compared to earlier in
the week. This drier trend continues on Thursday before some more
moisture moves into the region from the east late Thursday into
Friday. Confidence in the latter parts of the forecast period
begins to wane as guidance begins to differ in the intensity and
character of the potential wave around the region heading into
the weekend. Other than Wednesday and portions of Thursday,
conditions still appear to be on the wet side for Puerto Rico and
the US Virgin Islands.

&&

.AVIATION...
Shower and storm chances will increase starting with the eastern
terminals and spreading west to all the terminals today. Gusty
winds and heavy rains with the passage of the tropical wave today
could impact operations, with brief bouts of IFR/LIFR possible
with a direct impact from heavy tropical rain. Otherwise, VFR is
generally expected.

&&

.MARINE...
Wind forecast continues on an uptrend this morning as a tropical
wave will pass south of the islands today and tonight. The Small
Craft Advisory has been expanded and the potential for gusts to
gale force exist south of Puerto Rico today. Mariners should
continue to monitor conditions and the forecast evolution as a
short fused Gale Warning might become necessary is the wave
produces stronger winds than expected as it transits south of the
islands today.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 85 81 85 80 / 60 70 60 30
STT 83 82 83 82 / 60 50 30 40

[Gustywind]

92 L discussion ...

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
632 AM EDT MON SEP 5 2016

A tropical wave is entering the Caribbean Sea. The wave extends
from 10N to 19N with axis near 61W, moving W at 15 kt within the
last 24 hours. A 1009 mb center of low pressure is associated
with the wave, which is located near 15N61W and is expected to
move NW to near 16N66W in less than 24 hours. Abundant moisture
in the vicinity of the wave along with a diffluent environment
aloft support heavy showers and isolated tstms from 14N to 18N
between 60W and 63W. A gale warning is in effect for the Leeward
Islands and adjacent waters through later this morning.

[msbee]

good morning Gusty
How are things down there? showery weather for us but nothing heavy

[Gustywind]

good morning Gusty
How are things down there? showery weather for us but nothing heavy

Hi Barbara i'm safe and dry. Looks like the same scenario is occuring in Guadeloupe with maybe moderate showers but honestly nothing bad here. IMO much of the convection has diminished significantly since this morning even if another rounds of big showers and tstorms could spread on us. If i've more infos i will keep you informed.
Gustywind.

[msbee]

good morning Gusty
How are things down there? showery weather for us but nothing heavy

Hi Barbara i'm safe and dry. Looks like the same scenario is occuring in Guadeloupe with maybe moderate showers but honestly nothing bad here. IMO much of the convection has diminished significantly since this morning even if another rounds of big showers and tstorms could spread on us. If i've more infos i will keep you informed.
Gustywind.

Ok, Gusty, stay dry

[Gustywind]

good morning Gusty
How are things down there? showery weather for us but nothing heavy

Hi Barbara i'm safe and dry. Looks like the same scenario is occuring in Guadeloupe with maybe moderate showers but honestly nothing bad here. IMO much of the convection has diminished significantly since this morning even if another rounds of big showers and tstorms could spread on us. If i've more infos i will keep you informed.
Gustywind.

Ok, Gusty, stay dry

Thanks Barbara i've my blanket in case of . Stay safe and dry as you're in yellow alert since this morning 6AM for a risk of strong showers and tstorms. We should continue to monitor 92 L.
http://www.meteofrance.gp/vigilance-antilles-guyane
http://www.meteofrance.gp/integration/s ... s_nord.pdf (FRENCH VERSION).

[msbee]

SPECIAL WEATHER BULLETIN ST MAARTEN

DATE ISSUED: Monday, September 05 2016
TIME: 08:00AM (12:00UTC)

The tropical wave passing through the local region has been producing showers last night into this morning. These conditions are expected to continue through the morning hours. Therefore, street-flooding is likely. Residents and motorists in areas prone to flooding and rock falls should be vigilant and use caution.
Seas also deteriorated near 9 feet. Thus, sea users and persons with interests along the coast should exercise caution.

FORECASTER: Connor/Isaac

[cycloneye]

Area Forecast Discussion
National Weather Service San Juan PR
519 AM AST TUE SEP 6 2016

.SYNOPSIS...The tropical wave is now at about 70W and continues to
move west. However, deep moisture is expected to remain over the
local area today which will help in the development of showers
over the local area. Surface high pressure will promote an East
to ESE wind flow over the local area for the next several days.
Upper level ridge will dominate the area for most of this week
with an upper low passing through the area from Thursday to
Saturday.

&&

.DISCUSSION...The tropical wave that passed through the local area
left minimal rain accumulations across the USVI and eastern and
southern Puerto Rico during the overnight hours with the exception
of some sectors across the eastern interior and northeastern
portions of Puerto Rico where isolated areas received a half to
one inch of rain. The tropical wave is now over 70W and continues
to move west. However, there is still deep moisture trailing the
tropical wave with precipitable water values expected to be over 2
inches through the day today. Even though there is a ridge in the
upper levels, the latest guidance and observations indicate that
some showers and thunderstorms are likely this afternoon,
especially across western PR, isolated to scattered showers
elsewhere. Drier air is expected to move in on Wednesday
continuing through the rest of the week with some patches of
moisture, which would indicate that mainly locally induced showers
and thunderstorms are to be expected this week. having said that,
late this week, an upper low is expected to move through the local
area, which will cause an increase in the local instability
particularly late on Saturday when the upper low appears to
induce a surface trough moving close to the local islands.

&&

.AVIATION...Although the tropical wave will continue to move away
from the local area today...brief MVFR conds still possible in and
around the USVI terminals and JSJ in SHRA this morning. Aft 06/16z..
SHRA/TSRA development expected across W PR...and this may cause MVFR
conds and mountain obscurations in and around JMZ/JBQ till 06/22z.
Sfc winds will continue mainly from the E at around 15 kt with
higher gusts in/near SHRA/TSRA.

&&

.MARINE...Local buoys indicate that the coastal winds and the
local seas are subsiding. Latest guidance indicates that the local
winds and seas are expected to be up to 20 knots and up to 6 feet
respectively. Small craft operators should exercise caution. There
is a moderate risk of rip currents across many of the local
beaches.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 89 78 / 20 20 10 30
STT 87 77 89 78 / 30 10 10 30