Caribbean - Central America Weather

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cycloneye
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Re: Caribbean - Central America Weather

#18441 Postby cycloneye » Sat Oct 29, 2016 5:13 am

Area Forecast Discussion
National Weather Service San Juan PR
442 AM AST Sat Oct 29 2016

.SYNOPSIS...Upper level ridge will persist across the region
through the weekend. Ridge is to then erode by Tuesday with the
approach of a polar trough which will become amplified and sink
southward across the region into the central and eastern Caribbean
by Wednesday. The low level pattern is also expected to persist
through the weekend with high pressure ridge north and east of the
region and broad troughiness extending northwards across the area
from the central and eastern Caribbean basin. With this pattern
the easterly trade winds will gradually become more southeasterly
during the rest of the weekend and into early next week. By Tuesday
winds are to become more southerly,as a surface trough is forecast
to develop with a low forming just north of the region by Wednesday.

&&

.DISCUSSION...Sufficient trade wind moisture transport across the
region during the rest of the weekend to support early morning shower
development across the coastal waters. Some showers will continue
to reach portions of the north and east coastal sections of the islands
from time to time but no significant rainfall accumulations is anticipated.

During the afternoons local and diurnally induced afternoon convection
can be expected and the focus of the activity should be across part
of the north central and and northwest sections of Puerto Rico. Parts
of the San Juan metro area may also experience showers and possible
isolated afternoon thunderstorms, as the low level wind flow should
steer some streamer like activity over these areas. Urban and small
stream flooding will again be possible in some areas with the periods
of localized heavy rainfall.

As for the U.S Virgin Islands...mostly isolated passing showers
can be expected over the islands with a mixture of sunshine and
clouds during the day. No significant rainfall accumulations of
flooding situation is expected at this time except for some minor
ponding of water on roadways and poor drainage areas with the moderate
to locally heavy rainfall.

By Tuesday and Wednesday of next week...all model guidance continue
to suggest the deepening of the aformentioned polar trough which
is expected to set up across the region by Wednesday. This trough
is forecast to interact with a developing low and surface trough
which is to extend across the region by mid week. If this pattern
unfolds it should be a very moist and unstable environment and therefore
increased potential for enhanced convection across the region. However,
will continue to monitor and see how things unfold over the next few
days. Regardless of how this expected weather pattern, soil remain fairly
saturated across much of central and northern sections of Puerto Rico
and any locally heavy rainfall may lead to minor urban and small stream
flooding as well mudslides in area of steep terrain.

&&

.AVIATION...Mostly VFR conds expected through 29/16Z across the
local terminals. However,VCSH expected for TJSJ, TJPS, TISX, TIST
and TNCM, TKPK this morning. Winds are expected to increase after
29/13Z from the E-ESE to around 10KT with sea breeze variations.
Afternoon convection across PR could cause at least VCTS for TJSJ,
TJMZ, and TJBQ after 29/16Z with possible TEMPO MVFR conds at those
terminals.

&&

.MARINE...The light to gentle east to southeast trade winds will
become more southerly on Sunday and continue through Monday and Tuesday.
Slowly Fading north swell will continue to affect the local atlantic
waters today based on latest info from the surrounding buoys over the
Atlantic waters. Small craft should therefore exercise caution across
the offshore and nearshore Atlantic waters of northern Puerto Rico.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 78 90 78 / 20 40 40 30
STT 88 79 87 77 / 50 40 40 30
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Re: Caribbean - Central America Weather

#18442 Postby cycloneye » Sat Oct 29, 2016 1:52 pm

Area Forecast Discussion
National Weather Service San Juan PR
225 PM AST Sat Oct 29 2016

.SYNOPSIS...
A mid-upper level high pressure will persist over the region
through at least Monday. The ridge will erode over the area
through the upcoming work week, when a mid-upper level trough
amplified over the region. The mid-upper level trough is expected
to linger through the work week. At low levels...a south easterly
wind flow is expected to prevailed until Sunday, when winds are
expected shift more from the south. A surface low pressure is
expected to linger across the area between Tuesday and Thursday.
This surface low along with the trofiness aloft will produce
enough instability to enhance in the development of showers and
thunderstorms each day.

&&

.DISCUSSION...
A broad mid to upper level high continues to influence the local
weather conditions. However, plenty of moisture combined with
local effects and diurnal heating is resulting in showers and
thunderstorms. This activity should be focused across the
interior, west and north sections of Puerto Rico. Urban and small
stream flooding are likely due to the already saturated soils and
slow moving showers and thunderstorms. In addition, pedestrians
and motorist should remain alert to rapid rising of water levels
and ponding of water on roadways and heed to any road closures.

The San Juan Metro area can expect showers and maybe locally
induced isolated thunderstorms. Although, the U.S. Virgin Islands
should continue to see a mixture of Sunshine and clouds during
the rest of the day, showers can be expected downwind from the
islands.

Ridge aloft will erode next workweek as a broad upper level
trough develops across the tropical Atlantic and into the
Caribbean basin. In addition, a surface low pressure is expected
to linger across the islands between Tuesday and Thursday. This
will result in deep tropical moisture pooling across the forecast
area Tuesday-Thursday with a rainy weather pattern possible.

&&

.AVIATION...
MVFR conds will remain possible at PR and USVI TAF sites till
29/22z as locally induced SHRA/ isolated TSRA prevails across the
area. Elsewhere, VFR conds expected. ESE winds around 10 knots
with sea breeze variations till 29/22z becoming light and variable
overnight.

&&

.MARINE...There is a moderate to high risk of rip currents along
the north coastline of Puerto Rico and the Northern U.S. Virgin
Islands. Small boat operators should exercise caution across the
Atlantic waters due to seas up to 6 feet. Elsewhere, seas up to 5
feet and seas below 18 knots.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 90 77 88 / 20 30 20 40
STT 77 87 77 87 / 30 30 20 30

&&
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Re: Caribbean - Central America Weather

#18443 Postby cycloneye » Sun Oct 30, 2016 5:28 am

Area Forecast Discussion
National Weather Service San Juan PR
454 AM AST Sun Oct 30 2016

.SYNOPSIS...Mid to upper level high pressure ridge will persist
over the region today but will begin to erode on monday and during
the rest of the week as an upper trough becomes amplified over the
region. The broad mid to upper level trough is to then linger
across the region through the end of the work week. In the low
levels...a fairly light southeast to south wind flow will prevail
today through at least the early part of next week, in response to
a surface trough and associated area of low pressure expected to
develop and gradually lift northwards across the region.


&&

.DISCUSSION...Isolated to scattered showers and a few thunderstorms
lingered across the regional waters during the overnight and early
morning hours. Some light to moderate showers briefly affected
Vieques,Culebra and parts of Saint Croix and Saint Thomas. However
little or no rainfall was observed or detected in Puerto Rico. Rivers
and streams across the west and northern half of Puerto Rico remained
at high levels due the previous days rainfall. Excessive runoff from
these rains maintained Rio Culebrinas, Rio Guanajibo and Rio Grande
de Manati above flood stage during the overnight hours. For this
reason River flood warnings will remain in effect at least until
later this morning.

For the rest of the day...the relatively moist environment and
light southerly winds along with local and diurnal effects will
support another round of significant showers and thunderstorm
activity during the afternoon and possibly into the early evening.
The activity should be focused particularly across the northern
half and east interior sections of Puerto Rico as the light steering
winds become more southerly. Parts of the U.S Virgin Islands as well
as Vieques and Culebra my also experience brief periods of moderate
to locally heavy rainfall during the afternoon. However the potential
for urban and small stream flooding as well as mudslides, will remain
high across Puerto Rico where the soil remains saturated and therefore
it would not take much for rivers and stream to quickly react.

For the rest of the week. Recent model guidance and the overall synoptic
pattern both suggest a moist and very unstable airmass across the region,
with the best upper level instability and worst weather conditions expected
Tuesday through Wednesday, when the upper trough and supported surface
low just to our interact and lift east and north across the region.

&&

.AVIATION...Mostly VFR conds expected through 30/16Z across the
local terminals. However,VCSH expected for TISX, TIST, TNCM, AND
TKPK till 30/14z and psbl at TJPS. Winds will be less than 10 kt and
generally variable with sea breeze variation begg at 30/14z.
Afternoon convection across PR likely to cause at least VCTS for
TJSJ, TJMZ, and TJBQ after 30/16Z with possible TEMPO MVFR conds at
those terminals.

&&

.MARINE...Local offshore buoys indicate seas now near 5 feet and
the near shore suggests 4 feet or less. Expect these conditions to
continue during the rest of the day under a light to gentle southerly
wind flow. There is a moderate risk of rip currents across the Atlantic
shorelines of the local islands.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 90 78 87 77 / 60 10 40 10
STT 87 78 86 77 / 40 30 30 20
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Re: Caribbean - Central America Weather

#18444 Postby cycloneye » Sun Oct 30, 2016 1:55 pm

Area Forecast Discussion
National Weather Service San Juan PR
156 PM AST Sun Oct 30 2016

.SYNOPSIS...A ridge aloft will continue to erode as a broad
trough amplifies across the tropical Atlantic and into the
eastern Caribbean. A developing surface low north of the
local islands will continue to promote light to gentle
southerly winds through Wednesday. Showers and thunderstorms
will continue to prevail across the forecast area each day
with the wettest/unstable period expected Tuesday and Wednesday.
In a nutshell, flooding potential will continue to increase
across the forecast area through at least midweek.

&&

.DISCUSSION...As the upper level ridge erodes and a board
trough amplifies across the tropical Atlantic and into the
eastern Caribbean, atmospheric conditions will become more
conductive for widespread convection across the forecast area
early next workweek. This evolving pattern combined with
plenty of moisture and a developing surface low north of the
area which is promoting light winds will result in showers and
thunderstorms across the local islands with an increasing
potential in flooding as well as mudslides in ares of steep
terrain. At this time, the wettest/unstable period is between
Tuesday and Wednesday with widespread activity across land areas
as well as waters. Although trough will weaken Thursday and into
Friday, locally induced showers and thunderstorms are expected.

Meanwhile, during the evening hours, shower and thunderstorm
activity over land areas should decrease with shower activity
remaining over waters overnight. Another round of showers and
thunderstorms will prevail tomorrow afternoon over and north
of the Cordillera Central, including the San Juan Metro Area,
under light to gentle southerly winds.

&&

.AVIATION...MVFR conds will remain possible at PR and USVI TAF
sites till 30/22z as locally induced SHRA/TSRA are expected along
and to the West/North of the Cordillera Central. This activity is
expected to affect TJSJ/TJBQ/TJMZ and the Vicinity of TJPS from
times. Elsewhere, VFR conds expected. S winds at less than 10
knots with sea breeze variations till 30/22z becoming light and
variable overnight.

&&

.MARINE...The developing surface low north of the local islands
will continue to promote a light to gentle southerly wind flow
through at least midweek. shower and thunder activity will
increase across the local waters Tuesday and Wednesday as the
surface low combines with favorable upper level dynamics. Seas and
winds will remain below SCA criteria.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 87 77 87 / 40 60 10 60
STT 78 86 77 87 / 40 50 20 60
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Re: Caribbean - Central America Weather

#18445 Postby cycloneye » Mon Oct 31, 2016 4:51 am

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
524 AM AST Mon Oct 31 2016

.SYNOPSIS...A ridge aloft will erode rapidly today as a broad
trough amplifies across the western Atlantic and into the central
Caribbean. A developing surface low north of the local islands
will continue to promote light to gentle low levels southerly
winds through late Tuesday night. Showers and thunderstorms will
continue to prevail across the forecast area each day with the
wettest/unstable period expected Tuesday and Wednesday. Due to
saturated soils, flooding potential will continue to increase
across the forecast area through at least midweek.

&&

.DISCUSSION...Numerous showers and isolated to scattered
thunderstorms affected many sectors of Puerto Rico Sunday
afternoon and evening. This activity caused many areas to
observe urban and small stream flooding, especially across
eastern interior through western sections of PR. Several flood
advisories were issued. The combination of the already saturated
soils and the excessive rainfall also caused several major rivers
to go above their respective flood stages, some of which are
expected to remain under a flood warning until early Monday
morning.

The upper level ridge across the region is expected to erode
rapidly today as a broad trough amplifies across the western
Atlantic and into the central Caribbean. Atmospheric conditions
across the region will become even more conductive for widespread
convection across the forecast area today and through at least
Wednesday. This evolving weather pattern combined with plenty of
moisture and a developing surface low north just north of the area
which is promoting light low level winds across the region will
result in numerous showers and isolated to scattered thunderstorms
across the local islands. Due to saturated soils across most of
the region, a high potential of flooding as well as mudslides in
areas of steep terrain are expected to continue until at least
midweek. At this time, the wettest/unstable period is between
Tuesday and Wednesday with widespread activity across land areas.

Shower and Thunderstorm activity is expected to decrease late in
the evenings, overnights and early in the mornings, but the runoff
from the afternoons rainfall will maintain some of the local
rivers at high levels all the period.

&&

.AVIATION...Flow has become southwesterly below FL330. VFR conds
will prevail at all TAF sites thru 31/16z with VCSH, very brief
MVFR CIGS may occur at TNCM and TKPK. Aft 31/15Z, +TSRA will
develop over interior PR and spread towards the coasts with brief
MVFR psbl at TJPS, TJBQ, TJMZ. Mtn obscurations aft 31/16z. Winds
10 kt or less below FL160 with little change through 01/00z.
Southerly wind across the leewards and brief MVFR will continue to
be psbl through 01/02z in SHRA due to CIGS.

&&

.MARINE...Local buoys are reporting seas mainly in the 2-4 ft
range in the northern waters and around 1-2 ft across the
nearshore southern waters. Seas are expected to be up to 5 feet
tonight. There is a moderate risk of rip currents across the
Atlantic facing coasts of the local islands.

&&

.HYDROLOGY...Moisture transport and instability across the
region will continue to increase today and at least through
Wednesday due to the combination of an upper trough and an elongated
surface trough. Additionally, an area of low pressure is forecast
to develop north of the region. Models have been consistent in
maintaining high moisture content across the region with the best
chance for increased showers and thunderstorm activity expected
Tuesday through Wednesday. There is a high probability that areas
in the west and along the northern half of Puerto Rico will
continue to receive excessive rainfall which will lead to flooding
of local rivers...streams...urban and low-lying areas. In addition
mud slides are also expected in areas of steep terrain.

Residents in the flood prone areas are urged to take precautionary
measures which would include preparing plans to move or protect
pets...livestock...equipment and personal belongings. These plans
should be put in place if the National Weather Service issues a
Flash Flood Watch or Flash Flood Warnings.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 76 86 76 / 80 30 60 60
STT 86 77 86 76 / 40 30 60 60
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Re: Caribbean - Central America Weather

#18446 Postby cycloneye » Mon Oct 31, 2016 9:55 am

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Re: Caribbean - Central America Weather

#18447 Postby cycloneye » Mon Oct 31, 2016 1:23 pm

Area Forecast Discussion
National Weather Service San Juan PR
200 PM AST Mon Oct 31 2016

.SYNOPSIS...Surface low pressure north of the local area will
continue to promote a light wind flow with a westerly and south
components over the local area until Wednesday. Upper level trough
is expected to develop and dig over the local islands on Tuesday
and Wednesday, increasing the local instability. Available
moisture will remain above normal through Wednesday. Showers and
thunderstorms are expected every afternoon through Wednesday.
Drier air moving in late on Wednesday. There is now a Flash Flood
Watch for the local islands which will be in effect from Tuesday
morning to Wednesday afternoon.

&&

.DISCUSSION...Once again the abundant moisture today combined with
the local effects and diurnal heating to cause the development of
showers and thunderstorms across many sectors of Puerto Rico, with
the most significant showers across the south and eastern interior
sections of Puerto Rico while the USVI as well as Vieques and
Culebra remained with mainly fair weather with brief isolated to
scattered showers. The showers across the eastern interior of PR
caused some flooding on urban and poor drainage areas.

Overnight and early in the morning we can expect scattered showersacross
the local waters, some of the showers will affect the islands
briefly. But then on Tuesday there is an upper trough that is
expected to develop and slowly dig down over the local area. This
upper trough will cause more instability over the area which will
combine with the available moisture and weak steering winds to
develop persistent showers and thunderstorms on Tuesday afternoon,
particularly across the interior sections of PR, which will only
exacerbate the situation in those sectors. Wednesday also looks
like there is a good chance of showers and thunderstorms but
slightly drier is expected to start to filter in for Wednesday
afternoon. However, there will still be enough moisture to combine
with the favorable upper level dynamics on Wednesday as well.

Drier air and significantly less shower and thunderstorm activity
is expected for Thursday with north northeasterly winds starting
late Wednesday and prevailing through Thursday.

&&

.AVIATION...Westerly winds will keep SHRA/TSRA across S/SE PR.
Impacting mainly TJPS thru 23z with MVFR to brief IFR conds. Sfc
low pressure north of the region will continue to slowly move to
the south and open into a trough overnight into early Tuesday.
Resulting in SHRA/TSRA over the waters and across PR and the
USVI/Leeward terminals. Tempo MVFR to IFR possible between 01/12z-
20z across the eastern/southern terminals of PR and the USVI
terminals. Winds continue light from the W-SW at 10 kt or less.

&&

.MARINE...Seas will be up to 4 feet today and gradually increasing
up to 6 feet on Wednesday and Thursday. Winds will be generally
light through Wednesday but gusty near the showers and
thunderstorms. There is a moderate risk of rip currents today
across the north facing coasts of Puerto Rico.

&&

.HYDROLOGY...Moisture transport and instability across the
region will continue through Wednesday due to the combination of
the upper trough and an elongated surface trough. Additionally,
an area of low pressure is forecast to develop northeast of the
region. Models have been consistent in maintaining high moisture
content across the region with the best chance for increased
showers and thunderstorm activity expected Tuesday through
Wednesday. There is a high probability that areas in the interior
to eastern PR and along the northern half of Puerto Rico will
continue to receive excessive rainfall which will lead to flooding
of local rivers...streams...urban and low lying areas. In
addition mud slides are also expected in areas of steep terrain.

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 86 76 86 / 30 60 60 60
STT 77 86 76 86 / 30 60 60 60
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Re: Caribbean - Central America Weather

#18448 Postby cycloneye » Tue Nov 01, 2016 5:21 am

Area Forecast Discussion
National Weather Service San Juan PR
406 AM AST Tue Nov 1 2016

.SYNOPSIS...Surface low pressure just over Puerto Rico this
morning is forecast to remain very close to the local islands,
promoting a light low level wind flow across the area until
Wednesday. An upper level trough across the Western Atlantic is
expected to amplify across the local islands, maintaining a very
unstable weather pattern over the region today and Wednesday.
Scattered to numerous showers and isolated to scattered thunderstorms
are expected this afternoon and tomorrow afternoon. A Flash Flood
Watch for the local islands is in effect from this morning to
Wednesday afternoon.

&&

.DISCUSSION...Doppler radar detected numerous showers and
isolated thunderstorms across the surrounding waters and western
sections of Puerto Rico overnight and early this morning. This
activity was associated with a surface low just over the region
this morning. This surface low is expected to remain very close
to the area until at least Wednesday, maintaining a wet and
unstable weather pattern across the region until at least late
Wednesday. An upper level trough across the western Atlantic will
amplify across the northeast Caribbean today and Wednesday. These
features in combination with the abundant moisture over the region
and very weak low level winds will enhance ever more the showers
and thunderstorms across interior sections of Puerto Rico.
However, due to the light steering flow this activity is expected
to propagate across any part of the islands this afternoon and
Wednesday afternoon.

The combination of the already saturated soils and the excessive
rainfall also caused several major rivers to go above their
respective flood stages for the past few days. The threat of
widespread urban and small stream flooding is expected to continue
this afternoon and Wednesday. For those reasons a Flash Flood
Watch will be in effect for all of Puerto Rico and the U.S. Virgin
Islands beginning at 8 AM AST this morning.

A relatively drier air and significantly less shower and
thunderstorm activity is expected for Thursday. A north
northeasterly low level wind flow is expected across the region
late Wednesday through Thursday. This northerly wind flow is
expected to maintain pleasant temperatures across the region.

&&

.AVIATION...SHRA/TSRA will continue over the waters and across PR
and the USVI/Leeward terminals. VCSH expected across most TAF
sites through 01/12Z. Showers will increase after 01/14Z with
Tempo MVFR to IFR possible until 01/22Z across the
eastern/southern terminals of PR and the USVI terminals. Low level
winds will continue from the W at 10 kt or less.

&&

.MARINE...Increasing winds over the northwestern portion of the
outer Atlantic waters from a developing low moving into the waters
from the north are expected to generate 7 foot seas by Tuesday
night over the northwest section. Seas are expected to diminish
Wednesday night.

&&

.HYDROLOGY...Moisture transport and instability across the
region will continue through Wednesday due to the combination of
an upper trough with an area of low pressure just over the region.
Models have been consistent in maintaining high moisture content
across the region with the best chance for increased showers and
thunderstorm activity expected Today through Wednesday. Due to the
light steering winds showers and thunderstorms can develop over
any sections of Puerto and the U.S. Virgin Islands. These showers
and thunderstorms are expected to produce excessive rainfall
which will lead to flooding of local rivers, streams, urban and
low lying areas. In addition mud slides are also expected in areas
of steep terrain. A Flash Flood Watch is in effect for all of
Puerto Rico and the U.S. Virgin Islands from 8 am this morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 85 77 / 90 60 60 30
STT 86 76 86 77 / 70 60 60 30
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Re: Caribbean - Central America Weather

#18449 Postby cycloneye » Tue Nov 01, 2016 2:12 pm

Area Forecast Discussion
National Weather Service San Juan PR
238 PM AST Tue Nov 1 2016

.SYNOPSIS...Upper level trough will continue to amplify over the
Western Atlantic as it approaches from the west. Surface low
pressure associated with an old frontal boundary located over the
region today will move northeast over the Central Atlantic during
the next few days. Unstable weather will likely prevail across the
area over the next 24 hours. Conditions will gradually improve
on Thursday after the upper level trough crosses the forecast
area...inducing a drier and subsidence air aloft.

&&

.DISCUSSION...Very moist and unstable conditions will continue
across the forecast area under the influence of the upper level
trough and the surface low. This pattern will support organized
convection across Puerto Rico and the U.S. Virgin Islands. The
risk of flooding remains high over the next 24 hours...mainly
because the soils are saturated across most of Puerto Rico and
northern USVI. Therefore...a Flash Flood Watch continues in effect
for Puerto Rico and the U.S. Virgin Islands until Wednesday
afternoon.

Operational models suggest that the overall moisture will gradually
diminish across the local region on Thursday. The remnants of the
old frontal boundary will move over the Caribbean Waters south of
Puerto Rico. Somewhat drier air mass is forecast across the region
between Thursday and Friday. Then...surface high pressure will
develop northeast of the region inducing a moist south-southeasterly
flow across the local region. At this time...looks like a wet pattern
will establish once again during the weekend.

&&

.AVIATION...Moist and unstable conditions continues across
the local flying area. Therefore, the risk for SHRA/TSRA continues
over the local flying area. Most of the TSRA are over the
surrounding waters of PR and the USVI and en route from the Leeward
islands. As a result, -SHRA will continue from time to time across
the TAF sites. MVFR or IFR possible btwn 01/18z-20z at TIST/TISX.
Low level winds will continue variable below 10 kt becoming NE
and increasing at 10 to 15 knots after 02/12z.

&&

.MARINE...Seas will continue to build across the local Atlantic
Waters during the next 24 hours. Buoy 41043 north of Puerto Rico
showed sustained winds above 20 kts and seas of 7 feet. This wave
enery will reach the local Atlantic Waters tonight into Wednesday.
A short-period swell of 5-7 feet and winds of 15-20 kts across
the waters north of PR and USVI.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 85 77 86 / 60 60 30 40
STT 76 86 77 87 / 60 60 30 30
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Re: Caribbean - Central America Weather

#18450 Postby cycloneye » Wed Nov 02, 2016 5:12 am

Area Forecast Discussion
National Weather Service San Juan PR
540 AM AST Wed Nov 2 2016

.SYNOPSIS...A moist pattern will continue through at least mid-
week next week. Rain will diminish somewhat Thursday and Friday.

At upper levels...A long wave trough will move through the
Atlantic waters north of the area but will regenerate just west of
Puerto Rico and the U.S. Virgin Islands until the end of the week.
Another trough will approach the area early next week.

At mid levels...Many short waves will keep a strong trough near or
over the local area through Friday. Another even stronger trough
in the western Atlantic will dig into the central Caribbean next
week and that will maintain moist southwesterly flow through mid-
week. High pressure from the tropical Atlantic will ridge east
over the area later next week.

At lower levels...A trough extends from low pressure northeast of
the Leeward Islands to another low pressure now southwest of
Ponce. This trough will shift back over Puerto Rico late this
week and return again next week as it connects with a strong low
in the Atlantic.

&&

.DISCUSSION...Winds shifted to the northeast across the local
Atlantic waters and brought quick passing showers to much of the
north half of Puerto Rico overnight. Accumulations, however were
generally minor. Northeast winds will continue to bring moisture
onshore over the local area with heavier amounts during the
afternoon areas and generally north of the Cordillera Central.
Have favored the precip distribution shown by the HIRESarw model
which did particularly well yesterday.

With troughiness at all levels persisting in the area, cloudy and
showery conditions will persist through the week. Although amounts
to be received are diminishing from the previous high amounts,
soils are saturated and rivers are continuing to run higher than
normal, making flash flooding easier to occur with any persistent
thunderstorms. Steep terrain is also at considerable risk for
mudslides.

Moisture is tapering off today as the back edge of deep moisture
approaches the area. Precipitable water will reach a minimum on
Thursday, but will return to previous high levels by early next
week since drier air never really makes it this far south.
Thunderstorms are likely for the next several days, but will be
mainly over land during the day time periods due to decreasing
mid-level moisture. Nearby troughs at upper levels will keep
conditions favorable for convective activity for at least another
7 days.


&&

.AVIATION...Moist and unstable conditions continue across the
local flying area. Therefore, the risk for SHRA/TSRA continues
over the local flying area. Most of the TSRA will continue over
the surrounding waters of PR and the USVI and en route from the
Leeward islands this morning. As a result, -SHRA will continue
from time to time across most of the TAF sites and mtns will be
obscured. MVFR or even IFR possible btwn 02/18Z-20Z across most
of the local taf sites. Low level NE winds will increase at 10 to
15 knots with higher gust after 02/12z.


&&

.MARINE...Seas will increase--mainly in the Atlantic waters--as
winds between the low in the Caribbean and the high pressure in
the Atlantic generate hazardous seas. Winds and seas will begin to
diminish on Thursday. Small craft advisories are not expected
after Thursday through mid-week next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 87 77 / 80 60 60 40
STT 87 76 88 77 / 80 80 80 70

&&
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Re: Caribbean - Central America Weather

#18451 Postby cycloneye » Wed Nov 02, 2016 2:20 pm

Area Forecast Discussion
National Weather Service San Juan PR
237 PM AST Wed Nov 2 2016

.SYNOPSIS...Upper level trough over the Anegada Passage is producing
a drier and subsidence air mass over the forecast area. This fair
weather pattern will dominate across the local region through the
end of the work week. Wetter pattern will probably establish over
the area during the weekend and early next week.

&&

.DISCUSSION...Water Vapor satellite imagery indicated that the
upper level trough crossed Puerto Rico this morning. In the
backside of the upper level trough...a dry and subsidence air
prevails. This stable air mass at mid to upper levels have limited
the vertical development of showers so far this afternoon. At low
levels...brisk northeast winds will continue to push passing
showers across portions Puerto Rico, Culebra, Vieques and the
U.S. Virgin Islands. Still expecting some isolated convection
across portions of Puerto Rico later this afternoon.

Operational models suggest that the overall moisture will continue
to diminish across the local region through Thursday. The fair
weather conditions will likely prevail across the islands through
Friday.

A wetter and unstable pattern is forecast for the weekend and
early next week. Southerly low level flow will establish during
the weekend favoring the moisture transport across the local
area. Some guidance suggest that the deep moisture and instability
will prevail through Tuesday. In addition...steering winds will
subside to around 5 knots allowing showers and thunderstorms to
linger over the islands. We will continue to monitor the model
solutions to provide you further details about this unsettled
pattern.

&&

.AVIATION...SHRA/TSRA in the VCTY of TNCM/TKPK/TIST/TISX are
expected to continue during the morning. Some of this showers will
move across the terminals, but mainly -RA. TJSJ will also be
affected by this -RA from time to time during the day. SHRA/TSRA are
expected to continue across the interior/south coastal areas of PR.
MVFR or even IFR possible til 02/22Z expected at TJPS. NE winds will
increase at 10 to 20 knots with higher gust, followed by calm and
light/VRB after 02/23z.

&&

.MARINE...Winds have increased to around 20 knots across the Atlantic
waters...resulting seas of 6-8 feet in the coastal waters north of
Puerto Rico and the U.S. Virgin Islands. Therefore...Small Craft
Advisories continue across the local Atlantic Waters and Mona Passage
through tonight. Marine conditions will gradually improve on Thursday
as local winds and seas are forecast will subside to 15-20 knots
and 4-6 feet respectively.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 87 77 88 / 60 60 40 40
STT 76 88 77 86 / 80 80 70 50
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Re: Caribbean - Central America Weather

#18452 Postby cycloneye » Thu Nov 03, 2016 5:11 am

Area Forecast Discussion
National Weather Service San Juan PR
546 AM AST Thu Nov 3 2016

.SYNOPSIS...Moist flow will continue to bring showers over the
local area from the northeast today. Winds will shift direction
and become more southerly beginning Friday. Showers will increase
over the weekend and into early next week. Southerly flow is
expected to hold showers mostly over the north half of the island.

At upper levels...Short wave ripples will keep troughiness over
the local area through Saturday. Southwesterly flow will begin as
another long wave digs weakly into the Caribbean on Sunday. This
long wave will lift to the northeast by mid week next week, but
weak cyclonicity will remain over the area afterward.

At mid levels...Troughing will continue over the area until a
second long wave trough drops into the western Caribbean to bring
more southwesterly flow loaded with moisture. The moisture will
abate after the trough moves east of the area on Wednesday.

At lower levels...A trough associated with low pressure well
northeast of the Leeward Islands will drift back north west and
over the local area on Friday bringing more moisture to the area.
It will return from the west under the influence of a mid-latitude
low moving out into the Atlantic for a third pass. For most of
next week a boundary just northwest of the area will keep clouds
and scattered showers in the forecast driven by high pressure over
the Western Atlantic.

&&

.DISCUSSION...Showers in the northeast flow passed over the U.S.
Virgin Islands and most of the northeastern two thirds of Puerto
Rico. Amounts ranged from a few hundredths to half an inch where
rain fell. The proximity of the trough and another weak pulse of
moisture will keep much of the northeastern two thirds of Puerto
Rico wet through this afternoon. Dynamics are weak and moisture is
still not very deep (the transition from wet to dry goes from
10-15 kft) so only expect a few isolated thunderstorms over Puerto
Rico and only a meager chance anywhere else. The trough at low
levels will drift back over the area on Friday bringing an
increase in moisture. This trend will continue through Monday when
the trough returns after toughing Hispaniola. Flow is expected to
turn southerly by Friday and with an increase in warmth and
instability. This will cause more showers during the afternoon on
the north side of the Cordillera Central through Tuesday.
Northeast low level flow returns late next week. Although the
chances of rain will remain higher than normal, rain amounts are
not expected to be extreme.


&&

.AVIATION...Sct to Numerous SHRA expected across the local area on a
NE wind flow...at about 10KT...will affect TJBQ/TJSJ and the
USVI/Leeward terminals through 03/16Z. After 03/16Z, SHRA through
the local area with possible TSRA will affect the vicinity of the
local terminals. However, there should be enough SHRA/TSRA activity
to cause brief MVFR conditions at TJSJ, TIST, TIST, TNCM, and TKPK
terminals and mtn obscurations.

&&

.MARINE...Since the original low pressure that moved south from
north of Puerto Rico into the Caribbean has become more of an open
trough, winds have weakened and marine conditions will slowly
improve. High moisture content will mean showers and thunderstorms
will continue for much of the next 7 day over the local waters,
but seas will likely remain below small craft advisory conditions
during that time. Later strong lows forming in the Atlantic will
be able to send swell toward the area that may bring seas back to
7 feet. Winds will shift to a more southerly direction Friday and
into the weekend. High Rip current risk on the north coast will
remain today, be spotty tonight and should be gone by Friday
afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 87 77 / 80 40 40 60
STT 88 77 86 79 / 70 70 50 60
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Re: Caribbean - Central America Weather

#18453 Postby cycloneye » Thu Nov 03, 2016 1:40 pm

Area Forecast Discussion
National Weather Service San Juan PR
207 PM AST Thu Nov 3 2016

.SYNOPSIS...A trough pattern aloft will dominate the weather
conditions across the region the rest of the week. This feature is
expected to flatten by Saturday, then another Polar trough is
forecast to move across the Western Atlantic and into the northern
Caribbean isles. At the surface, plenty of tropical moisture will
continue over the region. Also, a migratory surface high pressure
will promote northeast winds today, becoming east southeast
tomorrow. Rainy conditions with pleasant temperatures are
expected the rest of the work week.

&&

.DISCUSSION...
Rainy conditions with pleasant temperatures prevailed across the
U.S. Virgin Islands, North and East Puerto Rico today. These
showers moved quickly and sometimes they have gusty winds. In
addition, showers were detected across the South and Southwest
sections of PR early in the afternoon. This pattern is expected to
continue the rest of this afternoon. Therefore, trade wind showers
will continue to affect North Central, Northeast and East Puerto
Rico, as well as the U.S. Virgin Islands, and locally induced
showers and thunderstorms may affect the Southwest quadrant of
Puerto Rico during the rest of the afternoon. Expect ponding of
water on roadways and in low lying areas, as well as moderate to
heavy rainfall and gusty winds with the strongest activity.

Satellite imagery and model guidance indicate plenty of tropical
moisture during the rest of the work week and into the weekend.
This air mass is expected to continue across the islands, as a
result rainy conditions and pleasant temperatures are forecast
once again.

Model guidances continues to indicate a moist and unstable
tropical air mass interacting with a polar trough. If this
pattern materializes, unsettled weather conditions can be expected
during the first part of the upcoming week.

&&

.AVIATION...
MVFR conds will remain possible at the USVI terminals
as well as JSJ as trade wind showers continue to move across the
area. Locally induced SHRA/TSRA possible later this afternoon
affecting JMZ and JPS. Elsewhere prevailing VFR conds. Easterly
winds at around 10 knots will continue this afternoon, becoming
light and variable overnight, and shifting from the east
southeast tomorrow.

&&

.MARINE...Marine conditions have been slowly improving during the
day. However, small craft operators should exercise caution across
the Mona Passage and Atlantic Waters due to seas up to 6 feet.
Elsewhere, seas at 5 feet or less. Showers are expected to
continue across the local waters. High Rip current risk on the
north coast will remain until 6 pm this evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 77 87 77 90 / 60 50 60 60
STT 77 86 79 87 / 60 50 60 60
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Re: Caribbean - Central America Weather

#18454 Postby cycloneye » Fri Nov 04, 2016 4:57 am

Area Forecast Discussion
National Weather Service San Juan PR
531 AM AST Fri Nov 4 2016

.SYNOPSIS...A weak trough will move northwest across the area
today causing winds to become more southerly and generating
showers and thunderstorms over the local area. Moisture levels
will remain high through about Wednesday.

At upper levels...General troughiness in the area will gradually
weaken through Sunday when a short wave trough passes north of
the area. A second trough around a deep low over the western
Atlantic will bring southwest flow Monday and Tuesday. High
pressure will build south of Cuba after mid week forcing flow over
the local area more northwest.

At mid levels...High pressure over the western tropical Atlantic
will continue into next week. Low pressure will move into the
western Atlantic well north of the area and southwest flow will
result beginning Sunday and continuing through Tuesday. High
pressure will build over the western Caribbean later next week.
Mid levels will be moist Saturday night through Tuesday night,
but much drier air will advance into the area from the north by
late next week.

At lower levels...a double-lobed trough over the Mona Channel and
the Leeward Islands will shift west to Hispaniola today, but
troughiness with very good moisture will remain in the vicinity
through at least Tuesday. High pressure filling in the western
Atlantic will force the trough east of the lesser Antilles later
next week.

&&

.DISCUSSION...Showers continued in a horse-shoe shape over the
local waters in generally easterly flow around the island.
Thunderstorms increased in frequency and number overnight with
tops exceeding 40 kft. As winds veer to the southeast during the
day activity will form over Puerto Rico and move toward the
northwest corner. Showers over the local waters will also affect
the northern U.S. Virgin Islands. Mid levels are moistening but
will see the best moisture Sunday through Tuesday. Good divergence
aloft during each afternoon today through Tuesday will cause
thunderstorms to fire up over Puerto Rico until the upper level
flow turns northwest on Wednesday. Some of this activity may spill
over into the U.S. Virgin Islands as flow above 850 mb acquires a
westerly component by 04/18z (today) that continues through
Tuesday.

Instability over the area will be considerable with afternoon
surface-based lifted indices ranging from minus 6 to minus 9
Friday through Tuesday, with minus 9 on Saturday. Hence expect
thunderstorms to increase into the weekend.

Urban and small stream flooding is likely many areas, but showers
will show some movement and are not as likely to cause major
flooding. Saturated soils, however, could easily give way in
steep terrain.

&&

.AVIATION...Mainly VFR conditions are expected to prevail across
most TAF sites through 04/13Z. However, SHRA and ISOLD TSRA are
expected across the local flying area, affecting the vicinity of
TIST, TISX, TKPK, TNCM, and TJSJ. Afternoon convection may cause
TSRA to affect TJMZ, TJBQ and TJSJ between 04/17Z and 04/23Z,
possibly causing MVFR conds. Low level winds will continue mainly
light and variable before 04/13Z, becoming SE at about 10KT
thereafter.

&&

.MARINE...Seas are diminishing today and will continue through
Monday in the Atlantic waters. Southerly winds will cause seas to
rise in the Caribbean through Saturday up to 5 feet. Small craft
advisories become possible again in the Atlantic after next
Wednesday as lows again develop north of the area.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 86 76 88 78 / 50 40 60 30
STT 86 78 87 79 / 50 60 40 30
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Re: Caribbean - Central America Weather

#18455 Postby cycloneye » Fri Nov 04, 2016 2:35 pm

Area Forecast Discussion
National Weather Service San Juan PR
202 PM AST Fri Nov 4 2016

.SYNOPSIS...Upper level long wave trough with axis extending south
across the local area in the northern Caribbean. A strong energy
impulse exiting the Atlantic seaboard moving eastward into the
north Atlantic. abundant deep layer moisture across the northeast
Caribbean.


&&

.DISCUSSION...The energy/short wave exiting the Atlantic seaboard
will result in the long wave trough...mentioned above...deepening
across the eastern Caribbean. This will in turn contribute to
further destabilize the local atmosphere through the weekend and
into the early part of next week. while the upper trough
will provide the lifting mechanism...abundant moisture will also
provide the fuel for a rather wet period through at least the
middle part of next week. Models continue to suggest a rather wet
Sunday through Tuesday period. Too early to tell precipitation
amounts for the early part of next week...but if current trend
persists...this bears watching...especially since grounds are
already saturated across Puerto Rico and the USVI.


&&

.AVIATION...MVFR conds will remain possible at JMZ/JBQ and JSJ
till around 04/22z as SHRA/TSRA continues to develop over and north
of the Cordillera Central and Sierra de Luquillo. VCTS likely ISX
and the Leeward terminals this afternoon. Aft 04/22z, mostly VFR
conds at all PR terminals with VCTS expected at USVI and Leeward
terminals. ESE winds around 10 knots becoming light and variable
overnight.


&&

.MARINE...surface winds should continue from southeast at 15 knots
or less through at least the early part of next week.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 88 78 88 / 30 60 30 60
STT 78 87 79 87 / 50 40 60 60
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Re: Caribbean - Central America Weather

#18456 Postby cycloneye » Sat Nov 05, 2016 5:10 am

Area Forecast Discussion
National Weather Service San Juan PR
501 AM AST Sat Nov 5 2016

.SYNOPSIS...Moist southeasterly flow on the east side of a surface
trough and upper level short waves in a weak trough over the area will
keep weather unstable and generally showery with isolated to
scattered thunderstorms through Tuesday. Shower activity will
decrease after mid-week.

At upper levels...Several short waves will pass through a long
wave trough pattern north of the area before the last trough
crosses through Wednesday. Then high pressure will dominate the
local area and the Caribbean Sea into mid-November.

At mid levels...Moisture in the mid levels will increase through
Monday, with only moderate moisture thereafter through 14 Nov. A
trough over the Bahama Islands today will pass north of the area
Sunday night when a strong low drops south into the western
Atlantic across from Delaware. Then high pressure will build from
the western tropical Atlantic over the Caribbean sea and persist
through at least the next 8 days.

At lower levels...An inverted trough will persist west of the area
until it crosses Puerto Rico and the U.S. Virgin Islands again on
Tuesday. A weak trough rebuilds late next week and good moisture
persists through the entire period, reaching a minimum on Thursday
morning.

&&

.DISCUSSION...Southeast flow brought showers and thunderstorms
over the U.S. Virgin Islands and the southeastern two thirds of
Puerto Rico overnight. Amounts of 1 to 3 inches fell over the area
causing several rivers, including the Guayanes, Cerrillos and the
Rio Grande de Arecibo to rise above flood stage. Showers
dissipated by 2 AM AST. More showers and thunderstorms are
expected to develop over the area, possibly as early as mid-
morning this morning and persist beyond sunset. These showers
could cause urban and small stream flooding again today,
especially if some of the thunderstorms reform persistently over
the same areas. Moisture will increase through Monday with much
the same pattern in southeasterly flow. Mid level moisture will
diminish after Tuesday and shower and thunderstorm activity will
diminish, but not disappear. Models also indicate that the best
moisture may form east of Puerto Rico over the U.S. Virgin Islands
today, but only have moderate confidence considering spatial
performance of the models last several days.

&&

.Hydrology...The level of water in Lago Dos Bocas has fallen 5
feet in about 6 hours. Most of this water should reach the ocean
through the down stream stretches during the next 10 to 15 hours.
A flood warning continues on the Rio Grande de Arecibo in
anticipation of rapidly rising waters later this morning.

&&

.AVIATION...Mainly VFR conditions will prevail across most TAF sites
through at least 05/15z. However, VCSH/VCTS can be expected across
TJSJ and TJBQ through 05/017z. Brief periods of MVFR conditions can
be expected across TNCM and TKPK through at least 05/16z. Low level
winds will continue mainly southeast at 10 to 15 kts with higher
gusts in SHRA/TSRA. Mountain obscurations are expected. Winds
aloft, will become more southwesterly during the day today up
through FL180 at 10 to 15 knots.

&&

.MARINE...Seas are expected to continue to diminish. Thunderstorms
that develop later today may cause seas to roughen in their
vicinity. Small craft advisories are not expected until Wednesday
night, when lows from several days before send swell into the
local area. Nevertheless showers and thunderstorms will be
scattered across the area with heavy visibility-limiting rains and
gusty winds through Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 89 76 89 76 / 30 30 80 60
STT 86 79 87 77 / 60 40 40 70
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Re: Caribbean - Central America Weather

#18457 Postby cycloneye » Sat Nov 05, 2016 1:24 pm

Area Forecast Discussion
National Weather Service San Juan PR
156 PM AST Sat Nov 5 2016

.Synopsis...Broad upper level trough continued across the region
with the base of the trough extending south across the local area.
A short wave trough crossing the southwest Atlantic will move
through the base of the trough Sunday through Monday to maintain
upper leve instability across the region through at least early
Tuesday. In the low levels...Surface high pressure across the
Central Atlantic and an elongated trough extending over Hispaniola
will maintain a moist southeasterly wind flow across the region
through the rest of the weekend and into early next week.


.DISCUSSION...The moist south to southeast low level wind flow
and unstable conditions aloft will continue to favor moisture
transport and pooling across the region during the rest of the
weekend and into next week. Local and diurnal effects along with
aforementioned ingredients will give way to late afternoon and
early evening convection across portions of the islands. At this
time...most of the showers and thunderstorm development was focused
over the coastal waters just south of the islands, and across portions
of the interior and northwest sections showers. Steering flow continued
from the south, so expect all convection to move towards the north
coastal areas of PR. Activity is expected to diminish over land areas
by late evening, but should redevelop over the coastal waters and move
inland across portions of the south and east sections of the islands
by early morning.

The moist and unstable weather pattern will continue through at least
Tuesday with the best potential for enhanced convection late Sunday
through Monday and possibly into early Tuesday. A gradual improvement
in the weather conditions is so far expected by mid week when the high
pressure ridge is to build north of the region and induce an east to
northeast wind flow.

&&

.AVIATION...VFR conds will continue across most of the TAF sites.
Periods of MVFR/IFR conds still possible with SHRA/TSRA at TNCM,
TKPK and TJBQ thru 22Z. SSE to SSW winds at 10-20 kts will prevail
below FL100.

&&

.MARINE... Seas are subsiding across the local waters. Main hazard
across the regional waters will continue to be the lightning activity
due to isolated to strong thunderstorms mainly across the Caribbean
Waters and Anegada Passage overnight and during the rest of the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 76 89 76 88 / 20 80 60 90
STT 79 87 77 85 / 40 40 70 100
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Re: Caribbean - Central America Weather

#18458 Postby cycloneye » Sun Nov 06, 2016 5:12 am

Area Forecast Discussion...UPDATED
National Weather Service San Juan PR
514 AM AST Sun Nov 6 2016

.UPDATE...Have done an early update to the zones to reflect the
growing showers extending southeast across the Mona channel. This
will increase the POPs slightly in the southwest portion of Puerto
Rico.

&&

.PREV DISCUSSION... /issued 435 AM AST Sun Nov 6 2016/

SYNOPSIS...Southeast flow will continue for the next several days
until long wave troughs become too far north to affect the local
area in a significant way. Showers and thunderstorms should
increase Sunday through Tuesday and then diminish through mid-
November.

At upper levels...Short waves around a long wave trough well north
of the local area will move through the local area until
Wednesday. After which high pressure will dominate the Caribbean
Sea through mid week next week.

At mid levels...Strong low pressure digging south into the western
Atlantic will keep a broad trough over the area until Wednesday.
Then high pressure will dominate the Caribbean and surrounding
islands through mid November. Mid layer moisture will return
Monday and Tuesday, but otherwise it will be mostly dry save for a
weak band passing through the area on Saturday.

At lower levels...Low pressure in the southwest Caribbean will
continue to extend a trough through Hispaniola today and then the
local area Monday and Tuesday. High pressure does not capture the
Atlantic north of the area until late this week. Troughiness will
return early next week. The troughiness will keep at least
scattered showers in the area with good chances for rain over
higher terrain during the afternoons.

DISCUSSION...Models have been backing off on the strength of the
upper level trough to affect the area and the amount of moisture
pulled into the area today through Tuesday. The trough over
Hispaniola today has some of the characteristics of a pre-frontal
trough and drying ahead of it is evident. Showers were almost
completely absent earlier this morning and the showers that have
re-formed are in the Mona channel. At this time areas of frequent
lightning are a good proxy for the front edge of that trough which
extends to the northeast of Hispaniola at this time.

Models are not handling convection that well and we are leaning
toward a slightly drier solution for the day. South winds will
heat up the north coast and onshore flow will also create a
minimum of shower activity over the south coast. Divergence aloft
looks strong as it approaches Puerto Rico across the Mona channel
this morning, but when it would normally gather strength from
stronger afternoon convection, it weakens and reforms north of the
U.S. Virgin Islands. This is taken as a sign that the prefrontal
trough will continue to be focused north and northwest of the
forecast area until Monday and Tuesday. With the effects of the
long wave trough being forced north, the convection generated even
then is expected to be weaker.

Hence although some urban and small stream flooding is expected
through mid-week, we should begin to see a transition to the drier
weather, to take hold early next week, begin on Thursday.

AVIATION...Mostly VFR conditions will prevail during the
morning hours across the local flying area. Periods of MVFR
conditions are possible with SHRA/TSRA over TJBQ and TJSJ
during the afternoon hours. Winds will continue from the south to
south southwest at around 10 to 15 mph with higher gusts after
06/13Z. Mountain obscurations should be expected after 06/16Z.

MARINE...Seas will continue to subside until Monday, but a strong
low pressure forming in the western Atlantic will begin to send
swell into the area that will peak on Thursday, with small craft
advisories likely to be necessary beginning Wednesday night in the
Atlantic waters and Caribbean passages. Seas subside after
Thursday. Caribbean seas will remain generally tranquil except for
local winds waves but small craft advisories are not expected
there for the foreseeable future.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 91 78 88 78 / 30 40 70 50
STT 87 78 85 77 / 20 50 70 50
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Re: Caribbean - Central America Weather

#18459 Postby cycloneye » Sun Nov 06, 2016 1:53 pm

Area Forecast Discussion
National Weather Service San Juan PR
139 PM AST Sun Nov 6 2016

.SYNOPSIS...
Broad upper level trough continued across the Western Atlantic
with the base of the trough now just north of the region. A short
wave trough crossing the southwest Atlantic will move through the
base of this trough overnight through Monday to maintain upper
level instability across the region. Surface high pressure centered
over the central Atlantic and a trough extending across Hispaniola
and the Mona passage, will maintain a light to moderate but moist
southeast wind flow across the region. Winds are forecast to gradually
become more east to northeast Monday through Tuesday, as a high pressure
ridge will build across the southwestern Atlantic then north of the
forecast area during the latter part of the upcoming week.

&&

.DISCUSSION....A moist and unstable weather pattern continued
across the region today. Showers and isolated thunderstorms moved
over portions of the west,south and eastern PR earlier today but
so far rainfall accumulations have been minimal. However, showers
and strong thunderstorms with areas of locally heavy rainfall have
continued over the Mona Passage and across portions of the offshore
Atlantic Waters.

For the rest of the afternoon and early evening...model guidance
as well as satellite imagery continued to suggest the possibility
of additional convective development with areas of moderate to
heavy rainfall affecting portions of the northern half of PR as
well as portions of the adjacent islands. For now, will maintain
persistence due to the present unsettled weather pattern. The limiting
factor however may be the cloud cover which may limit or delay the
convective development. Isolated to scattered showers may also move
inland and develop across portions of the USVI during the rest of
the afternoon.

By Monday and Tuesday, unstable conditions are still forecast to
persist, as the mid to upper short wave trough is expected to move
just north of the region. This scenario along with good low level
moisture convergence and diurnally induced instability will allow
for locally enhanced convection over the islands, but especially
over the central interior and northern portions of PR. Therefore
the potential for minor urban and small stream flooding will
remain high at least until Tuesday. A gradual improvement is so
far expected for the latter part of the upcoming week as high
pressure ridge will build aloft and north of the region bringing a
return of the prevailing low level easterlies.

&&

.AVIATION...BKN cigs mostly between FL050-FL080. MVFR conds in
SHRA/TSRA possible at TJBQ and TJSJ thru 22Z. VCSH or -SHRA could
affect the rest of terminal at times but VFR conds are expected thru
the forecast period. Mountain obscurations likely along the
Cordillera Central. Mostly southerly winds of 10-15 kts below FL150.


&&

.MARINE...Local buoys indicated seas of 3-5 feet across the
coastal waters. No significant changes expected through Tuesday.
Long period North swell could reach the local Atlantic Waters by
midweek.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 78 87 78 87 / 40 70 50 50
STT 78 87 77 87 / 50 70 50 50

&&
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cycloneye
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Re: Caribbean - Central America Weather

#18460 Postby cycloneye » Mon Nov 07, 2016 5:16 am

Area Forecast Discussion
National Weather Service San Juan PR
600 AM AST Mon Nov 7 2016

.SYNOPSIS...Upper level trough continued across the Western
Atlantic with the base of the trough now just north of the region.
Surface high pressure centered over the central Atlantic and a
trough extending across Hispaniola and the Mona passage, will
maintain a light to moderate but moist southeast wind flow across
the region. Winds are forecast to gradually become more east to
northeast through Tuesday, as a high pressure ridge will build
across the southwestern Atlantic then north of the forecast area
during the latter part of the upcoming week.


&&

.DISCUSSION...Showers with thunderstorms were seen across the
local waters this overnight. Some of these showers affected the
south and southeast sections of Puerto Rico and Saint Croix in the
Virgin Islands. A moist and unstable air mass will continue to
prevail across the local islands under the influence of an upper
level trough and a very moist southeasterly wind flow.

For today and tomorrow, no changes in this weather pattern is
expected as the upper level trough continues over the local area
and maintains favorable conditions for shower and thunderstorm
development. It is not until Wednesday, a drier trend is expected
as an upper level ridge develops across the area.

&&

.AVIATION...Brief SHRA are possible across TIST/TISX/TNCM/TKPK
during the morning. SHRA/TSRA are expected during the afternoon
mainly over mainland PR. Some of this SHRA can produce brief MVFR or
even IFR conditions between 07/16-22z at TJSJ/TJMZ/TJPS/TJBQ. Across
the rest of the local flying area only VCSH are expected. Winds will
continue very light but mostly from the south, increasing at around
10 knots with higher gusts after 07/13Z.

&&

.MARINE...Seas up to 4 feet and winds up to 10 knots are expected.
Moderate risk of rip current along some north facing beaches of
Puerto Rico.


&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 87 77 86 77 / 40 40 40 20
STT 87 77 86 77 / 50 40 30 20
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