Wednesday, September20, 2017 L-36.com


Marine Weather and Tides
Arlington, VA

Version 3.4
What's New / NOTES
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.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 6:53AMSunset 7:08PM Wednesday September 20, 2017 9:02 AM EDT (13:02 UTC) Moonrise 6:09AMMoonset 6:41PM Illumination 0% Phase: New Moon; Moon at 29 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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ANZ535 Tidal Potomac From Key Bridge To Indian Head- 855 Am Edt Wed Sep 20 2017
Today..NW winds 5 to 10 kt. Waves 1 ft.
Tonight..N winds around 5 kt. Waves 1 ft.
Thu..N winds 5 kt. Waves less than 1 ft.
Thu night..N winds around 5 kt. Waves 1 ft or less.
Fri..N winds around 5 kt. Waves 1 ft.
Fri night..N winds around 5 kt. Waves 1 ft or less.
Sat..NW winds around 5 kt. Waves 1 ft or less.
Sun..N winds around 5 kt. Waves 1 ft.
ANZ500 855 Am Edt Wed Sep 20 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A ridge of high pressure will remain over the eastern united states through early next week. Hurricane maria may approach the coast of the carolinas by the middle of next week. Consult products from the national hurricane center for the latest information on maria.

7 Day Forecast for Marine Location Near Arlington, VA
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location: 38.87, -77.06     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 200758
afdlwx
area forecast discussion
national weather service baltimore md washington dc
358 am edt Wed sep 20 2017

Synopsis A ridge of high pressure will remain over the eastern united
states through early next week. Hurricane maria may approach the
coast of the carolinas by the middle of next week.

Near term through tonight
Showers have mostly dissipated across the region as a lingering
outer band of jose pushes westward. Could still be a sprinkle out
there, but nothing more than that expected early this morning.

Otherwise, high pressure continues to dominate across the
appalachians, while tropical storm jose is still located off the
delmarva and continues heading northeast away from us. Though high
pressure is present aloft, there is a weak upper level low aloft
over ohio. Thanks to light winds and clearing skies plus moist low
levels, patchy fog has developed. This fog may become locally dense,
but at this point do not expect a need for a dense fog advisory.

Through the day, any fog should dissipate mid morning, and it should
turn out partly to mostly sunny. However, while subsidence around
jose should prevent showers near the metro, the upper low over ohio
is expected to dive southeast into the appalachians and weaken. This
may allow enough instability for a shower or thunderstorm across our
southwestern zones in eastern WV and western va. Otherwise, the
increased sunshine and subsidence plus warmer air aloft should
result in above normal temps, with highs in the mid-upper 80s.

Tonight, surface high pressure remains, so it should turn out mostly
clear after any cumulus (or CB in SW zones) dissipates. Patchy fog
will again be a concern. Lows will be mainly in the 60s.

Short term Thursday through Friday night
Northeast flow aloft will dominate Thursday through Friday night as
ridge builds to our west and jose stalls to the east. Jose should
have little to no effect on our weather during this time, so it will
be unseasonably warm and humid, but dry, with the ridging preventing
any convection. Highs will be in the mid to upper 80s, with lows in
the 60s. Patchy late night and early morning fog will be the main
forecast concern, mainly in the more rural, inland locations.

Long term Saturday through Tuesday
Ridge of high pressure will gradually strengthen through early
next week. Latest euro is much stronger than gfs GEFS with the
h5 ridge showing a 591 decameter ridge. No wx is expected as a
result. The first half of next week, flow will turn more onshore
north of hurricane maria. Latest euro has trended westward and
slower with the track of maria bringing it closer to the nc
outerbanks, but so far models have been inconsistent on track
longitude thus far, limiting confidence. Please refer to NHC for
the latest on maria.

Aviation 08z Wednesday through Sunday
Patchy fog is developing in parts of the area and mrb has already
gone ifr as of this writing. Cho is possibly next, and a chance
(albeit much smaller) exists for iad and bwi. Dca has little chance
of ifr or even MVFR this morning. For locations where the fog does
develop, it should dissipate mid morning withVFR presiding rest of
the day.

Patchy fog will be a concern again over the next several late night
and early morning periods thanks to persistent high pressure and
light winds. Best odds same as early this morning as described
above. Other than that, should beVFR thru Friday night.

Vfr conditions through Sun with no sig wx.

Marine
Winds gradually declining as jose slowly moves northeast away from
the area. SCA ends on much of the waters around 6am and remaining
waters near noon. Might need to add extend SCA for some waters this
afternoon with mixing resulting in a little higher gusts despite
jose's movement away, but uncertainty is high so have not done so
yet.

From tonight through Friday night, high pressure and light winds
will dominate, with no SCA concerns at present.

Light winds through the weekend. Winds will start strengthening
during the first half of next week as pressure gradient tightens
in response to approaching hurricane maria.

Tides coastal flooding Minor coastal flooding appears will
continue for the foreesable future from annapolis south to
straits point.

Lwx watches warnings advisories
Dc... None.

Md... Coastal flood advisory until 6 pm edt this evening for mdz018.

Coastal flood advisory until 10 pm edt this evening for mdz014.

Coastal flood advisory until 7 pm edt this evening for mdz017.

Va... None.

Wv... None.

Marine... Small craft advisory until 6 am edt early this morning for
anz532-540.

Small craft advisory until noon edt today for anz533-534-537-
541-543.

Synopsis... Lfr
near term... Rcm
short term... Rcm
long term... Lfr
aviation... Rcm lfr
marine... Rcm lfr
tides coastal flooding... Lfr


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 2 mi45 min NW 6 G 7 71°F 74°F
APAM2 - 8575512 - Annapolis, MD 32 mi45 min 74°F 1013 hPa
TPLM2 - Thomas Point, MD 33 mi63 min NW 8.9 G 9.9 72°F 75°F
44063 - Annapolis 33 mi33 min N 9.7 G 12 73°F 1013.4 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 37 mi45 min NNW 12 G 15 74°F 1013.4 hPa
CPVM2 37 mi45 min 74°F 68°F
BLTM2 - 8574680 - Baltimore, MD 37 mi45 min N 6 G 8.9 74°F 78°F1013.2 hPa
NCDV2 38 mi45 min NW 4.1 G 6 69°F 76°F1013.6 hPa
44062 - Gooses Reef, MD 40 mi33 min NW 12 G 14 74°F 1014.6 hPa
44043 - Patapsco, MD 40 mi33 min NNW 12 G 16 74°F 1013.8 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 48 mi45 min NNW 15 G 18 74°F 1014.2 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 49 mi45 min N 14 G 15 73°F 75°F1013.7 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA2 mi71 minNW 810.00 miMostly Cloudy71°F64°F79%1014.4 hPa
Camp Springs / Andrews Air Force Base, MD10 mi65 minWNW 810.00 miA Few Clouds71°F62°F75%1014.3 hPa
College Park Airport, MD11 mi78 minN 010.00 miOvercast68°F63°F86%1013.9 hPa
Fort Belvoir, VA12 mi65 minWNW 610.00 miA Few Clouds69°F62°F79%1014.8 hPa
Gaithersburg - Montgomery County Airport, MD21 mi67 minN 010.00 miA Few Clouds66°F62°F87%1017.8 hPa
Washington/Dulles International Airport, DC, VA22 mi71 minNW 310.00 miPartly Cloudy65°F63°F93%1014.8 hPa
Fort Meade / Tipton, MD22 mi78 minWNW 410.00 miMostly Cloudy68°F62°F83%1014.6 hPa

Wind History from DCA (wind in knots)
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Last 24hrN10N11NW11NW12NW11N14N14NW14N13N14N9NW9N8N10N5N7N6NW8N9NW9NW10NW10NW8NW7
1 day agoNE9NE12NE9NE8NE10E8NE10N9N9NE10NE9N7N9NE7NE7N9N8N9NE7N9N11N12N9N10
2 days agoN3N5N6N6N5E3NE5SE9E7SE4CalmNE3E5CalmNE3NE4E4NE5NE4N3N4NE7N7NE8

Tide / Current Tables for Washington, Potomac River, D.C.
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Washington
Click for Map
Wed -- 01:30 AM EDT     New Moon
Wed -- 03:24 AM EDT     0.02 feet Low Tide
Wed -- 06:54 AM EDT     Sunrise
Wed -- 07:09 AM EDT     Moonrise
Wed -- 08:42 AM EDT     3.44 feet High Tide
Wed -- 03:48 PM EDT     -0.01 feet Low Tide
Wed -- 07:07 PM EDT     Sunset
Wed -- 07:41 PM EDT     Moonset
Wed -- 09:06 PM EDT     3.44 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.50.90.40.10.10.81.92.83.33.43.12.41.81.20.60.200.51.42.43.13.43.32.7

Tide / Current Tables for Bladensburg, Anacostia River, Maryland
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Bladensburg
Click for Map
Wed -- 01:30 AM EDT     New Moon
Wed -- 03:49 AM EDT     0.02 feet Low Tide
Wed -- 06:53 AM EDT     Sunrise
Wed -- 07:08 AM EDT     Moonrise
Wed -- 09:13 AM EDT     3.65 feet High Tide
Wed -- 04:13 PM EDT     -0.01 feet Low Tide
Wed -- 07:07 PM EDT     Sunset
Wed -- 07:41 PM EDT     Moonset
Wed -- 09:37 PM EDT     3.65 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.91.30.70.200.51.52.53.33.63.52.92.21.50.90.400.212.133.53.63.2

Weather Map and Satellite Images
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Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Mid-Atlantic    EDIT
Geos

Wind Forecast for Baltimore, MD/Washington (9,2,3,4)
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Ground Weather Radar Station Sterling, VA
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weather_mapweather_map weather_map

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Disclaimer:
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.