Marine Weather and Tides
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen
|Sunrise 6:19AM||Sunset 6:07PM||Monday October 14, 2019 6:17 AM AST (10:17 UTC)||Moonrise 6:55PM||Moonset 6:51AM||Illumination 100%|
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 140900|
area forecast discussion
national weather service san juan pr
500 am ast Mon oct 14 2019
Local effects and diurnal heating will bring showers and isolated
thunderstorms to the area, especially in western and interior
puerto rico this afternoon. A tropical wave will push into the
region late in the day today, and will likely enhance this shower
and convective activity. Though there will be somewhat less
moisture available tomorrow, similar conditions are likely.
Another tropical wave is forecast to make its way into the area on
Friday; higher moisture levels will last through the weekend.
Short term Today through Wednesday...
light easterly winds are expected today as moisture gradually
increases. There is an upper level low to the north of the leewards,
which will weaken, but an upper trough will remain north of the
leewards and NE of the local islands. However, the upper trough will
then re-strengthen late on Wednesday. This will keep the local area
with NW to N winds in the upper levels on today through Wednesday.
Forecast soundings indicate some instability with the chance of
thunderstorms. The available moisture will increase gradually
through the next few days, especially late tonight into Tuesday as a
tropical wave approaches the local area.
Given the current patterns, we expect mainly scattered showers
across the local waters this morning and then tonight, but
thunderstorms are expected across the interior and western sections
of pr this afternoon, with enough rainfall to cause urban and small
stream flooding. A similar pattern is expected on Tuesday but with
less coverage and intensity, because it is expected for the moisture
to be decreasing at that time and cloud cover may inhibit some
afternoon convection. Similarly for Wednesday, convection expected
across western pr but even less activity is expected as the moisture
decreases further, albeit slightly, and we are still in the
subsident side of the upper trough.
Long term Thursday through Monday...
on Friday, a tropical wave is expected push into the region,
bringing a marked increase in moisture levels over the local
islands. This is anticipated to bring an increase in shower and
thunderstorm activity caused by local effects and diurnal heating,
especially in western, northwestern, and interior portions of
puerto rico. The effects of this wave will be felt into the
weekend, with additional moisture making its way into the area on
On Thursday, an upper-level trough is forecast to be slowly
approaching the eastern portion of the region. There is increasing
agreement in long-range guidance with respect to the timing of
this system and the location at the start of the long-range
period, with the euro also placing this feature to the east as
well in the most recent run. Beyond Thursday, there is increasing
uncertainty in the exact direction that this feature aloft takes,
but it is likely that it will initially track to the southwest
slightly, potentially tracking it just over the local islands or
just to the south. The GFS then shows it turning to the northwest,
while the euro keeps it moving southwestward. With this lingering
uncertainty, there is also uncertainty in the degree to which
this low could enhance convection over the local islands. Should
the GFS solution verify, this upper-level low would be expected to
bring increased divergence aloft and upward motion to the islands
over the coming weekend, leading to an increase in shower and
Vcsh across the usvi terminals early in the morning. MainlyVFR
conds expected across the local terminals through 14 16z. Shra tsra
could affect tjbq and tjmz, between 14 17z and 14 23z. However, most
of the tsra activity is expected in the vicinity of tjmz and tjbq.
Elsewhere, vcsh is possible through the forecast period. Winds will
be light, favoring an easterly direction with sea breeze variations
after 14 13z.
There is a northwesterly swell persisting into the morning in
atlantic waters from tropical storm melissa, located, and to
remain, well north of the region. This swell will begin to
diminish today, and wave heights of around 3-5 feet are expected
for during the day today in atlantic waters, with calmer seas to
the south of the local islands. Isolated to scattered showers, and
isolated thunderstorms, will be a continuing concern as well.
Preliminary point temps pops
Sju 88 77 89 77 30 40 50 50
stt 88 79 88 77 40 50 50 50
Sju watches warnings advisories
Pr... High rip current risk through this afternoon for north central-
northeast-northwest-san juan and vicinity-southeast.
Short term... Ja
long term... .Crs
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||48 min||NNE 1 G 2.9||77°F||85°F||1014 hPa|
|42085 - Southeast of Ponce, PR||20 mi||78 min||N 7.8 G 7.8||82°F||86°F||2 ft||1012.2 hPa (-0.4)|
|MGZP4 - 9759394 - Mayaguez, PR||23 mi||48 min||87°F||1014.2 hPa|
|AROP4 - 9757809 - Arecibo, PR||26 mi||48 min||SSE 5.1 G 6|
|JOXP4 - Jobos Bay Reserve, Puerto Rico||30 mi||93 min||Calm||77°F||1014 hPa||73°F|
|PTRP4||32 mi||23 min||SE 4.1 G 4.1||78°F|
|41115 - Rincon, Puerto Rico (181)||34 mi||48 min||86°F||4 ft|
|SJNP4 - 9755371 - San Juan, PR||42 mi||48 min||SW 4.1 G 5.1||79°F||86°F||1013.7 hPa|
|41053 - San Juan, PR||43 mi||78 min||SSW 3.9 G 5.8||81°F||86°F||5 ft||1012.6 hPa (-0.4)|
|YABP4 - 9754228 - Yabucoa Harbor, PR||49 mi||48 min||76°F||73°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. Follow links for more data.
Click EDIT to select an airport
EDIT Weekend mode (on/off) (on/off)  Help One Week of Data
EDIT (on/off)  Help One Week of Data
Weather Map(on/off)  Help Weather Map
GEOS 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 (6,6,7,8)(on/off)  Help
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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.