Marine Weather and Tides
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.
|Sunrise 5:16AM||Sunset 5:58PM||Tuesday May 21, 2019 8:35 PM CST (02:35 UTC)||Moonrise 8:25PM||Moonset 10:14AM||Illumination 90%|
7 Day Forecast for Marine Location Near Arroyo, PRHourly EDIT Help
Area Discussion for - San Juan, PR  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxca62 tjsj 220120|
area forecast discussion
national weather service san juan pr
920 pm ast Tue may 21 2019
Showers and isolated thunderstorms dissipated across the
northwestern areas of puerto rico before sunset today. Tonight
partly cloudy skies are expected for most of the area with east to
southeast winds of 5 to 10 kts. Tonight partly cloudy skies with
east to southeast winds of 5 to 10 mph are expected over the area.
Overnight low temperatures are forecast to be near the lower to
middle 70s near coastal locations, and middle to upper 60s in
Tomorrow scattered showers and thunderstorms are forecast to
develop across the northwest and interior areas of the island
during the afternoon. These showers and thunderstorms will produce
locally heavy to moderate rainfall which could lead to urban and
small stream flooding. Also, showers are forecast to develop
across the interior and northeastern areas of the island during
the early morning, and afternoon. Showers and thunderstorms will
be induce by mid to upper-level instability, diurnal heating, and
Vrf conds will continue across all terminal sites until 22 18z.
Then shra vcts are forecast to develop across tjbq and tjmz which
could cause mvrf conds until 23 01z. The other terminal sites
shra vcsh could develop until 23 01z. Sfc winds out of the east to
south at 5 to 10 kts tonight, then winds will increase to 10 to
15 with higher gusts by 22 12z.
Across the regional waters and local passages, seas are expected
to remain at 5 feet or below. East to southeast winds will
continue between 10 to 15 knots. There is a moderate risk of rip
currents for the north facing beaches of puerto rico.
Prev discussion issued 440 pm ast Tue may 21 2019
synopsis... The chance for shower and thunderstorm activity will
continue to increase as a mid to upper level trough moves closer
to the forecast area. Although this feature is expected to weaken
by the end of the week, trofiness and plenty of moisture will
persist much of the upcoming week.
Short term... .Tonight thru thu...
heights will continue to fall as a mid to upper level trough
-now located in the vicinity of the bahamas- shifts southeast;
reaching the northeast caribbean by Thursday. This feature will
also induce a surface trough enhancing moisture advection across
the local islands with precipitable water near 2 inches by
Under plenty of moisture and favorable upper level conditions,
the chance for showers and thunderstorms will continue to increase
through the forecast period. Expect shower and thunderstorm
development across central and western puerto rico Wednesday
afternoon. The intensity and areal coverage of showers and
thunderstorms will increase on Thursday as the aformentioned|
trough moves closer to the forecast area. The best chance for
shower and thunderstorm development across the usvi is on
Thursday, as well. As a result, there is an increasing potential
for urban and small streams flooding, particularly Thursday.
Meanwhile, shower activity over western areas of puerto rico will
diminish late this afternoon, leaving partly cloudy skies.
Passing showers will remain possible across the eastern third of
puerto rico and the outlying islands overnight.
Long term... Fri thru Tue issued 504 am ast Tue may 21 2019
a trof pattern will maintain unstable weather conditions across
the area throughout the week. Model guidance continues to suggest
precipitable water values ranging between 1.7 and 2.20 inches
through the long term period. Therefore, the combination of
abundant tropical moisture with good instability will result in
periods of enhanced shower and thunderstorm activity, especially
across along and north of the cordillera central of puerto rico
each afternoon. Showers and isolated thunderstorms should not be
ruled out across portions of eastern pr and the usvi, especially
during the overnight hours.
Global models continues to suggest an amplifying trough
interacting with deep tropical moisture early next week, between
Sunday or Monday. If these solutions are correct, unsettle weather
conditions could be expected the first part of the upcoming week.
In addition, a tropical wave will reach the local islands around
Wednesday of the upcoming week. At this time, confidence is low to
moderate because this solutions are to far in time. However,
please continue to monitor the latest forecast updates during the
next several days as the picture becomes clearer.
Aviation... Shra tsra across nw-pr to continue through 20 22z,
possibly causing tempo MVFR conds at tjbq tjmz. -shra at tjsj
through 21 18z. The rest of the local terminals will observeVFR
conds. After 21 23z, all of the local terminals are expected to
observeVFR conds, with only brief vcsh possible at tist and tisx
during the overnight hours. Local winds from the ese at 10-15kt
expected through 21 23z with sea breeze variations and occasional
gusts, gradually decreasing thereafter through the night.
Marine... Seas below 5 feet and winds 15 to 20 knots to continue
during the forecast period. Along the coastal areas, a low to
moderate risk of rip currents is expected to continue through
much of the week. Criteria for scas are not expected to be
Preliminary point temps pops
Sju 79 90 76 87 20 40 40 70
stt 78 86 76 86 30 50 50 40
Sju watches warnings advisories
Short term... Tw
long term... .Tw
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