Marine Weather and Tides
3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
|Sunrise 5:46AM||Sunset 8:18PM||Sunday May 20, 2018 10:09 AM EDT (14:09 UTC)||Moonrise 10:00AM||Moonset 12:00AM||Illumination 31%|
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|ANZ538 Patapsco River Including Baltimore Harbor- 731 Am Edt Sun May 20 2018 |
.small craft advisory in effect until 6 pm edt this evening...
Today..W winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. Isolated showers with patchy drizzle this morning, then scattered showers and tstms this afternoon.
Tonight..N winds 5 to 10 kt. Waves 1 ft or less.
Mon..E winds 5 kt. Waves less than 1 ft.
Mon night..SE winds around 5 kt. Waves flat. Showers likely.
Tue..SE winds around 5 kt. Waves flat. Showers likely with a chance of tstms.
Tue night..SW winds around 5 kt. Waves flat. A chance of showers.
Wed..N winds around 5 kt. Waves 1 ft or less. A chance of tstms. A chance of showers.
Thu..SW winds around 5 kt. Waves 1 ft. A chance of showers in the morning. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 731 Am Edt Sun May 20 2018 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front approaching from the ohio valley will approach the waters today before passing through tonight. The boundary will stall to the south Monday before returning north as a warm front Monday night and Tuesday. Another cold front will pass through the waters later Wednesday and Wednesday night before high pressure possibly returns late in the week.
7 Day Forecast for Marine Location Near Riviera Beach, MDHourly EDIT Help
Area Discussion for - Baltimore, MD/Washington  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 klwx 200740|
area forecast discussion
national weather service baltimore md washington dc
340 am edt Sun may 20 2018
A warm front will lift to our north this morning and a cold
front over the ohio valley will drop southeast into our area
tonight. The boundary will stall out overhead for Monday before
another cold front passes through on Wednesday. Weak high
pressure may build overhead for late in the week.
Near term through tonight
A warm front is hung up over the eastern panhandle of west
virginia and western maryland early this morning. To the south
of the boundary, a southerly flow has allowed for warm and humid
conditions to return, but to the north of the boundary it is a
bit cooler along with patchy dense fog. A weak upper-level
disturbance is passing through the area early this morning as
well. This may bring a couple showers, but coverage should
remain isolated to widely scattered since the system is weak and
it is an unfavorable time in regards to instability.
The upper-level disturbance will pass by to our east this
morning and the warm front will lift off to our north as well.
There will be some sunshine and it will turn out noticeably
warmer compared to recent days with MAX temps well into the 80s
for most areas. A weak pressure trough will develop overhead
today due to differential heating between the appalachian
mountains and the valleys to the east. This boundary will
propoagate eastward throughout the day as mixing increases. A
few showers and thunderstorms may develop along and ahead of
this boundary, but coverage should be isolated to widely
scattered since there will be plenty of westerly flow at the
low-levels and even down to the surface behind the surface
trough. Some thunderstorms may contain locally heavy rain and
this will have to be monitored closely since we had so much rain
over the last several days, but again any issues should be
A weak cold front will drop south into the area tonight. A few
showers and thunderstorms are possible ahead of the boundary,
especially across central virginia into southern maryland.
Again, coverage should be isolated to widely scattered.
Short term Monday through Tuesday night
The cold front will stall out over central virginia by midday Monday
and high pressure will build over the atlantic during this time.
This will cause the boundary to slowly return north and east as
a warm front, and moisture will increase once again due to a
southwest flow through all levels of the atmosphere. Therefore,
popup showers and thunderstorms are more likely along and behind
the boundary where instability will be highest. Latest guidance
shows the highest likelihood for convection to be across the
potomac highlands into central virginia Monday afternoon.
Convection may spread farther north and east toward the
washington and baltimore metropolitan areas Monday night as the
boundary slowly retreats as a warm front. Thunderstorms Monday
afternoon into Monday night may contain locally heavy rain and
this could cause issues with flooding since the ground is
The boundary will remain nearby Tuesday and with plenty of
moisture in place, popup showers and thunderstorms are likely.
Again, some thunderstorms may contain gusty winds and locally
heavy rainfall. Convection should wane a bit with the loss of
daytime heating Tuesday night, but with an other cold front
approaching from the north... A few showers and thunderstorms
Long term Wednesday through Saturday
A front across the center portions of our CWA could spawn a
couple of showers and thunderstorms Wednesday into Wednesday
evening. High temperatures will be about 5 to 7 degrees above
By Wednesday overnight into Thursday, the front pushes farther
to from the north. High pressure will remain in control
Thursday night. High temperatures Thursday could be 2 to 5
degrees cooler than Wednesday, but might still be slightly above
normal for late may.
The high will move off of the coast Friday and Friday night. A
slight southerly return flow should develop and help to bring in
more humid air to our cwa. Conditions should remain dry Friday into
A pre-frontal trough of low pressure could develop on the
leeside of the potomac highlands and over the shenandoah
valley Saturday. Any threat for showers and thunderstorms could
start over the potomac highlands before making their way east
and over the pre-frontal trough. High temperatures could be a
few degrees above normal.|
Aviation 07z Sunday through Thursday
A warm front is hung up over eastern west virginia this morning,
but it will move off to our north by mid-morning. Low clouds and
dense fog are occurring at kmrb. Conditions are better to the
south and east, but ifr CIGS are possible through around 12z due
to moisture trapped underneath the nocturnal inversion. Will
continue to carry this in the forecast for now.
Conditions will improve by mid-morning behind the warm front. A
shower or thunderstorm cannot be ruled out today, but coverage
should be isolated to widely scattered. A weak cold front will
pass through the terminals tonight, some drier air will move in
but it will not be much. With light winds, patchy fog is
possible overnight into early Monday. The boundary will get hung
up over central virginia Monday and return north as a warm front
Monday night into Tuesday. Showers and thunderstorms are likely
near the boundary both Monday and Tuesday. For Monday, the best
chance will be near kcho, and for Monday night and Tuesday the
best chance will be across all of the terminals. Low clouds are
possible Monday night into Tuesday as well. Coverage of
convection may wane some for Tuesday night.
MainlyVFR conditions Wednesday through Thursday night. Showers
and any thunderstorms could briefly reduce conditions to MVFR
or ifr Wednesday and Wednesday evening. Winds northwest 5 to 10
knots Wednesday, becoming light and variable Wednesday night and
Thursday. Winds becoming southeast 5 to 10 knots Thursday
Will continue with an SCA for the waters through today as the
gradient strengthens just a bit ahead of a cold front. The sca
may need to be extended into this evening, but confidence is too
low at this time. A weak cold front will pass through the waters
tonight and it will stall to the south Monday before retreating
toward the waters Monday night and Tuesday as a warm front.
Showers and thunderstorms are likely ahead of the boundary,
No marine hazards expected Wednesday through Thursday night.
Winds northwest around 10 knots Wednesday becoming light and
variable Wednesday night and Thursday. Winds veering to the
southeast around 10 knots Thursday night.
Tides coastal flooding
A persistent onshore flow has led to elevated water levels. Will
continue with the coastal flood advisory for annapolis and
straits point through the high tide cycle this morning, but it
will be marginal since a westerly component to the surface wind
For washington dc and alexandria, elevated water levels will
continue through today due to freshwater coming down from the
potomac. A coastal flood warning remains in effect for
washington dc through this evening. The highest water levels
will be around high tide this afternoon and moderate flooding is
expected. Water levels should gradually fall later tonight
through Monday, but minor flooding is still likely. A coastal
flood advisory may be needed. A coastal flood advisory is in
effect for alexandria through this afternoon, and that may need
to be extended into tonight.
It has been an unusually wet pattern over the last week. For dca
(reagan national), there has been at least 1 4" of rain each of
the last 7 days. This is the longest streak on record. The previous
longest was 5 days in 2011, 2009, 1975, 1950, 1942, and 1937.
Precipitation records date back to 1871.
Lwx watches warnings advisories
Dc... Coastal flood warning until 10 pm edt this evening for dcz001.
Md... Coastal flood advisory until 3 pm edt this afternoon for
Coastal flood advisory until noon edt today for mdz017.
Va... Coastal flood advisory until 4 pm edt this afternoon for
Marine... Small craft advisory until 6 pm edt this evening for
near term... Bjl
short term... Bjl
long term... Klw
aviation... Bjl klw
marine... Bjl klw
tides coastal flooding... Bjl
climate... Dfh bjl
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|
|FSNM2||4 mi||51 min||WSW 9.9 G 16||74°F||1016.6 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||4 mi||51 min||SW 8.9 G 14||74°F||1016.6 hPa|
|BLTM2 - 8574680 - Baltimore, MD||8 mi||57 min||W 5.1 G 8||75°F||69°F||1016.3 hPa|
|APAM2 - 8575512 - Annapolis, MD||13 mi||51 min||78°F||1016.4 hPa|
|44063 - Annapolis||14 mi||39 min||WSW 7.8 G 9.7||73°F||1017.3 hPa|
|CPVM2||14 mi||51 min||68°F||68°F|
|TCBM2 - 8573364 - Tolchester Beach, MD||16 mi||51 min||SSW 8 G 12||73°F||65°F||1016.9 hPa|
|TPLM2 - Thomas Point, MD||19 mi||69 min||S 12 G 13||69°F||64°F||1017.7 hPa (+0.8)||67°F|
|BSLM2 - Chesapeake Bay, MD||28 mi||159 min||SSW 5.1||67°F||1017 hPa||64°F|
|WASD2 - 8594900 - Washington, DC||33 mi||51 min||SSW 2.9 G 6||73°F||67°F||1017.3 hPa|
|44062 - Gooses Reef, MD||42 mi||39 min||SW 12 G 16||72°F||1018.2 hPa|
|CHCM2 - 8573927 - Chesapeake City, MD||46 mi||51 min||SSW 7 G 8.9||73°F||65°F||1016.7 hPa|
|CA2 - 8571892 - Cambridge, MD||47 mi||51 min||76°F||69°F||1018.5 hPa|
Wind History for Francis Scott Key Bridge, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Baltimore, Baltimore-Washington International Airport, MD||8 mi||75 min||SW 8||10.00 mi||Mostly Cloudy||74°F||70°F||88%||1016.2 hPa|
|Baltimore, Inner Harbor, MD||9 mi||75 min||no data||mi||73°F||70°F||90%||1016.9 hPa|
|Annapolis, United States Naval Academy, MD||13 mi||75 min||SW 5||10.00 mi||Mostly Cloudy||77°F||70°F||79%||1016.8 hPa|
|Fort Meade / Tipton, MD||14 mi||72 min||SW 11 G 16||10.00 mi||Mostly Cloudy||73°F||68°F||83%||1017.9 hPa|
|Baltimore / Martin, MD||14 mi||84 min||SSW 5||10.00 mi||Mostly Cloudy||73°F||73°F||100%||1017.3 hPa|
|Bay Bridge Field, MD||17 mi||74 min||SSW 8||7.00 mi||Fair with Haze||75°F||69°F||83%||1016.9 hPa|
|College Park Airport, MD||24 mi||72 min||S 4||10.00 mi||Overcast||74°F||68°F||84%||1016.9 hPa|
Wind History from BWI (wind in knots)
|1 day ago||E||NE||E||NE|
|2 days ago||N||NE||NE||NE||NE||E||E||NE||NE||NE||E||E||NE||NE||E||E||NE||NE||NE||E||NE||NE||E||E |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Stony Creek |
Click for Map
Sun -- 12:41 AM EDT Moonset
Sun -- 04:52 AM EDT 0.33 feet Low Tide
Sun -- 05:48 AM EDT Sunrise
Sun -- 11:00 AM EDT Moonrise
Sun -- 11:27 AM EDT 1.78 feet High Tide
Sun -- 06:44 PM EDT 0.31 feet Low Tide
Sun -- 08:16 PM EDT Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Baltimore Harbor Approach |
Click for Map
Sun -- 12:38 AM EDT -0.00 knots Slack
Sun -- 12:39 AM EDT Moonset
Sun -- 03:25 AM EDT -0.56 knots Max Ebb
Sun -- 05:48 AM EDT Sunrise
Sun -- 06:01 AM EDT 0.00 knots Slack
Sun -- 09:41 AM EDT 1.02 knots Max Flood
Sun -- 11:00 AM EDT Moonrise
Sun -- 01:03 PM EDT -0.00 knots Slack
Sun -- 04:27 PM EDT -1.03 knots Max Ebb
Sun -- 08:06 PM EDT 0.00 knots Slack
Sun -- 08:16 PM EDT Sunset
Sun -- 10:49 PM EDT 0.62 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  HelpWeather Map
GOES Local Image of Mid-Atlantic 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.
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Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for Baltimore, MD/Washington (10,2,3,4)(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.