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 6:33AM||Sunset 5:51PM||Friday November 16, 2018 11:35 AM AST (15:35 UTC)||Moonrise 1:38PM||Moonset 12:39AM||Illumination 61%|
7 Day Forecast for Marine Location Near Santo Domingo, PRHourly EDIT Help
Area Discussion for - San Juan, PR  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxca62 tjsj 160932|
area forecast discussion
national weather service san juan pr
532 am ast Fri nov 16 2018
Synopsis Low level moisture will increase somewhat across the
local islands today and Saturday as a wind surge propagates
across the northeast caribbean region. This feature will likely
increase showers activity across the u.S. Virgin islands and
puerto rico from time to time. A drying trend is forecast next
week as a mid-upper level ridge will bring drier and more stable
Short term Today through Sunday...
high pressure weakens and settles into the central atlantic ocean
from out of maine yesterday. This will maintain easterly trade wind
flow that will be enhanced by a wind surge and pulse of moisture.
That moisture is visible as an arc of precipitable water of greater
than 2 inches that developed and moved into the leeward islands
overnight. The GFS is in agreement with model runs from yesterday--
at least qualitatively. It brings that higher moisture through
puerto rico today and tonight, with the best moisture over san juan
by 17 00z. The pulse of moisture and the low-level convergence the
wind surge will bring bodes well for showers to increase during the
day. Working against this, the GFS sounding does show a layer of
relatively dry air (less than 15 percent between 14-15 kft) at
16 18z with precipitable water still at a hefty 1.88 inches. This is
an increase from the 1.77 inches measured in the 16 00z sounding,
but the layer cuts the convective potential and limits instability
where the lapse rate becomes more stable, which will limit the
amounts of rain that fall when they fall. By 17 00z, however the
model is showing 1.97 inches of precipitable water and no less than
35 percent in the previously dry layer. Hence, most windward slopes
on the eastern part of puerto rico should get some rain before the
evening ends and nearly all of puerto rico is expected to get at
least a little rain before then. Western puerto rico will also see
very good chances of showers and isolated thunderstorms with the
heating allowed during the morning hours. Expect shower formation
there by 16 16z. Afternoon and evening rains across the u.S.
Virgin islands and puerto rico respectively, should end rather
abruptly as the model shows precipitable water dropping rapidly
overnight to only 1.2 inches.
Some showers are still possible over the eastern mountains of puerto
rico, but the rest of of the island should see a dry Saturday
morning. Then showers and a few thunderstorms become likely in west
northwest puerto rico with only isolated to scattered showers
elsewhere under a pulse of moisture more evident at 700 mb. The
drying trend continues into Sunday. Although some moisture is around
during the day, mid levels become quite dry. Most areas outside of
the general area just east of the rincon peninsula will see only
isolated showers Sunday afternoon. Then later in the afternoon the
gfs shows more moisture moving in from the southeast as fragmented
patches of low level moisture move through the area in rapid
succession. This will generate a few showers, but coverage should be
Upper level divergence aloft is very limited during the entire
period and most of the action that occurs will be dependent on
conditions in the lowest levels.
Long term Monday through Thursday...
mid to upper level ridge will hold most of the next week, under
generally fair weather conditions. The drier and more stable air
mass at mid-levels will reduce the coverage of the showers and
the probability of thunderstorms. However, weak easterly
perturbation embedded in the trade winds will briefly enhance the
diurnal shower activity Monday and Wednesday when these
pertubations are forecast to move across the eastern caribbean.
The rest of the week expect typical weather conditions with brief
passing showers over eastern puerto rico and the u.S. Virgin
islands during the morning hours, followed by some afternoon
showers over western puerto rico. Winds will gradually diminish as
the week progresses due a weakening of the surface high pressure
over the north central atlantic. All in all, a drying trend and a
decrease in shower activity is forecast next week under the
influence of a mid-upper level ridge.
Aviation In the leeward islands a band of moisture is moving through
bringing brief MVFR CIGS and light showers.VFR is expected there
aft arnd 16 18z till 17 06z. A band of moisture is moving into
the usvi, but MVFR conds are expected to be brief--if any-- with
sct shra till arnd 16 18z. Shra tsra will dvlp WRN and interior pr
aft arnd 16 16z with mtn obscurations and areas of MVFR ifr til
arnd 16 22z. Periods of shra are expected in most areas of pr till
arnd 17 00z. Sfc winds e- ese 10-18 knots with gusts to 26 kt
psbl. MAX winds blo fl540 will be 20-26 kt blo fl120 as a low
level wind surge pushes through the area.
Marine Choppy seas will continue through the end of the week
as breezy conditions will likely prevail across the regional
waters. As a result, small craft advisories are in effect for most
of the local waters through Saturday, except for offshore
atlantic water where choppy conditions will prevail through
Sunday. Mariners can expected seas of 6-8 feet with occasional up
to 10 feet across the offshore waters and between 3-6 feet
elsewhere. Also, a high risk of rip currents continue for the
north facing beaches of puerto rico as well as the north and east
coast of st. Croix.
Preliminary point temps pops
Sju 87 77 87 77 80 40 30 20
stt 85 78 86 78 70 30 30 30
Sju watches warnings advisories
Pr... High rip current risk through late tonight for northeast-
High rip current risk through late Saturday night for north
central-northwest-san juan and vicinity-western interior.
Vi... High rip current risk through late tonight for st croix.
Am... Small craft advisory until 8 pm ast Saturday for anegada passage
southward to 17n-caribbean waters of puerto rico from 10 nm
to 17n-coastal waters of northern puerto rico out 10 nm-
coastal waters of northern usvi and culebra out 10 nm-
coastal waters of southern usvi vieques and eastern puerto
rico out 10 nm-mona passage southward to 17n.
Small craft advisory until 8 pm ast Sunday for atlantic waters
of puerto rico and usvi from 10 nm to 19.5n.
Short term... Ws
long term... .Er
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|MGIP4 - 9759110 - Magueyes Islands, PR||18 mi||36 min||SSE 5.1 G 9.9||86°F||82°F||1015.7 hPa (+0.3)|
|42085 - Southeast of Ponce, PR||20 mi||96 min||ENE 14 G 19||85°F||83°F||1015.1 hPa (+1.1)|
|MGZP4 - 9759394 - Mayaguez, PR||23 mi||42 min||83°F||83°F||1015.4 hPa|
|AROP4 - 9757809 - Arecibo, PR||26 mi||36 min||ENE 8 G 13|
|JOXP4 - Jobos Bay Reserve, Puerto Rico||30 mi||51 min||E 4.1||1017 hPa|
|PTRP4||32 mi||21 min||ENE 5.1 G 8.9||87°F|
|41115 - Rincon, Puerto Rico (181)||34 mi||36 min||84°F||3 ft|
|SJNP4 - 9755371 - San Juan, PR||42 mi||42 min||E 8.9 G 16||82°F||82°F||1016 hPa|
|41053 - San Juan, PR||43 mi||36 min||E 14 G 18||82°F||83°F||5 ft||1015 hPa (+0.0)|
|YABP4 - 9754228 - Yabucoa Harbor, PR||49 mi||36 min||86°F||76°F|
Wind History for Penuelas (Punta Guayanilla), PR(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
Click EDIT to select an airport
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
EDIT (on/off)  Help One Week of Data
Weather Map and Satellite Images(on/off)  HelpWeather Map
GOES Local Image of Puerto Rico EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop
Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for (10,2,3,4)(on/off)  Help
Ad by Google
The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.