Friday, December15, 2017 L-36.com


Marine Weather and Tides
Mason Neck, 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 7:18AMSunset 4:49PM Friday December 15, 2017 9:06 AM EST (14:06 UTC) Moonrise 4:41AMMoonset 3:27PM Illumination 8% Phase: Waning Crescent; Moon at 27 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- 632 Am Est Fri Dec 15 2017
Today..S winds 5 kt. Waves less than 1 ft. A chance of snow this morning, then snow likely this afternoon. Vsby 1 to 3 nm.
Tonight..W winds 5 to 10 kt. Waves 1 ft.
Sat..W winds 5 to 10 kt. Waves 1 ft.
Sat night..SW winds 5 to 10 kt. Waves 1 ft.
Sun..SE winds 5 kt. Waves less than 1 ft.
Sun night..SW winds around 5 kt. Waves 1 ft.
Mon..SW winds around 5 kt. Waves 1 ft.
Tue..W winds 5 to 10 kt. Waves 1 ft.
ANZ500 632 Am Est Fri Dec 15 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A low pressure system will develop as it moves up the coast today into tonight. High pressure will return on Saturday before weak low pressure possibly impacts the waters early next week.

7 Day Forecast for Marine Location Near Mason Neck, VA
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location: 38.65, -77.13     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 150853
afdlwx
area forecast discussion
national weather service baltimore md washington dc
353 am est Fri dec 15 2017

Synopsis
Low pressure will develop along the north carolina coast this
morning, moving northeastward and out to sea tonight. High
pressure will return for Saturday before weak low pressure
impacts the area early next week.

Near term through tonight
An area of low pressure off the carolina coast will move
northeastward today, bringing light snow to the metro areas by
this afternoon. As a result, a winter weather advisory is in
effect from 1pm this afternoon through 7pm this evening for
metro baltimore and the district of columbia, including the
northern and eastern suburbs. Snowfall totals will be on the
order of one to perhaps two inches across the advisory area,
with the higher amounts expected to reside near the baltimore
area, and extending to the northeast.

A sharp gradient will exists to the west of the metro areas,
and exactly where this gradient falls will determine where the
accumulating snow will cease. Temperatures throughout the day
will hold at or slightly above the freezing mark, and with
favorable atmospheric profiles, any precipitation that falls
will be in the form of snow. Couple this with road temperatures
expected to remain at or below freezing during the event,
conditions could turn icy on untreated road surfaces. The snow
will exit the area to the northeast by early Friday evening.

Upslope snow showers are expected across the allegheny front
Friday evening as northwest flow takes hold. Accumulations up to
one inch will be possible in those favored locations.

Temperatures overnight will drop down in to the middle to upper
20s as skies start to clear.

Short term Saturday through Sunday night
High pressure builds in across the area on Saturday and Saturday
night with dry conditions expected. Temperatures will top out
during the day on Saturday in the upper 30s to middle 40s, with
overnight lows in the 20s to near freezing in the metro area.

High pressure will reside to our south on Sunday, resulting in
southerly flow across the region. This will generate moderating
temperatures in the mid to upper 40s. Conditions will remain dry
during the day with high clouds beginning to stream overhead
ahead of an approaching shortwave trough that will cross the
region Sunday night and early Monday morning. There is a slight
increase in precipitation as a result, but moisture looks
limited and with marginal temperatures, most favored
precipitation will be light rain showers across our northern
zones. Lows overnight Sunday will bottom out in the mid to upper
30s.

Long term Monday through Thursday
East coast 500 mb ridging will be the dominant feature for the
extended forecast. Consequently, as shortwave energy traverses the
conus Tuesday, the primary precip type will be rain. And, since the
northern and southern streams will remain unphased, it's looking
like a lighter QPF amount for the dc baltimore metro. Will be
carrying slight chance pops for most, chance for the mountains.

High pressure and mild conditions will prevail for the balance of
the week.

Aviation 08z Friday through Tuesday
PredominateVFR conditions are expected through Sunday. A period
of light snow is expected across our eastern terminals this
afternoon and early Friday evening, which could result in
periods of reductions to dca bwi mtn. High pressure builds in
to the area Saturday and Sunday with light to moderate westerly
winds of 10 knots or less.

Vfr will likely prevail mon-tue. There will be an impulse moving
through, so precip and flight restrictions will be possible, but
confidence low.

Marine
Low pressure passing to our east today and a cold front crossing
the region will bring gusty winds Friday night into Saturday. As
a result, SCA will go in to effect Friday night and will likely
be extended into Saturday. Winds expected to remain below
advisory criteria on Sunday.

No hazards anticipated Monday into Tuesday. Winds will increase
thereafter, but any flags may hold off til beyond current forecast
period.

Lwx watches warnings advisories
Dc... Winter weather advisory from 1 pm this afternoon to 7 pm est
this evening for dcz001.

Md... Winter weather advisory from 1 pm this afternoon to 7 pm est
this evening for mdz004>006-011-013-014-503>508.

Va... Winter weather advisory from 1 pm this afternoon to 7 pm est
this evening for vaz054.

Wv... None.

Marine... Small craft advisory from 9 pm this evening to 6 am est
Saturday for anz530>533-538>541.

Small craft advisory from 3 pm this afternoon to 6 am est
Saturday for anz534-537-543.

Synopsis... Bkf
near term... Bkf
short term... Bkf
long term... Hts
aviation... Bkf hts
marine... Bkf hts


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 16 mi55 min E 4.1 G 4.1 29°F 40°F1019.3 hPa
NCDV2 23 mi49 min ENE 2.9 G 7 31°F 39°F1017.9 hPa
BSLM2 - Chesapeake Bay, MD 24 mi157 min ENE 1.9 28°F 1020 hPa13°F
44062 - Gooses Reef, MD 38 mi37 min ESE 9.7 G 12 30°F 1019.4 hPa
TPLM2 - Thomas Point, MD 41 mi67 min ESE 8.9 G 9.9 29°F 44°F
APAM2 - 8575512 - Annapolis, MD 41 mi49 min 30°F 1018.7 hPa
SLIM2 - 8577330 - Solomons Island, MD 43 mi55 min ENE 8 G 12 31°F 45°F1018.4 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 43 mi49 min E 9.9 G 13 30°F 1019.1 hPa
CPVM2 46 mi49 min 29°F 11°F
PPTM2 - 8578240 - Piney Point, MD 48 mi49 min E 5.1 G 7

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
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Last
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SW2
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W12
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G7
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G28
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G24
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G24
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W13
G20

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA6 mi71 minE 410.00 miOvercast29°F12°F50%1019.3 hPa
Quantico Marine Corps Airfield - Turner Field, VA13 mi71 minENE 510.00 miOvercast31°F17°F56%1019.7 hPa
Washington/Reagan National Airport, DC, VA15 mi75 minE 610.00 miOvercast30°F12°F47%1019.4 hPa
Camp Springs / Andrews Air Force Base, MD19 mi71 minNE 510.00 miOvercast28°F11°F50%1018.6 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA21 mi71 minESE 510.00 miOvercast29°F15°F56%1020.1 hPa
Stafford, Stafford Regional Airport, VA24 mi72 minENE 410.00 miOvercast31°F17°F59%1020 hPa

Wind History from DAA (wind in knots)
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Last 24hrNW4NW17
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CalmNW7N3N8N3NW4CalmCalmCalmCalmCalmCalmCalmCalmE4
1 day agoW19
G26
W16
G22
NW12
G16
W10
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W10
G17
W9
G18
SW8W5S3S3SE4S5S6SE5S6S7S5S4S4S4SW4CalmNW3Calm
2 days agoNW5CalmW4CalmNW7NW9
G23
NW17
G25
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G25
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G31
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G28
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Tide / Current Tables for Gunston Cove, Virginia
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Gunston Cove
Click for Map
Fri -- 04:40 AM EST     Moonrise
Fri -- 05:22 AM EST     1.80 feet High Tide
Fri -- 07:19 AM EST     Sunrise
Fri -- 11:40 AM EST     -0.10 feet Low Tide
Fri -- 03:26 PM EST     Moonset
Fri -- 04:48 PM EST     Sunset
Fri -- 05:42 PM EST     2.03 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.10.20.71.21.61.81.71.410.50.2-0-0.10.20.71.21.7221.81.40.90.60.2

Tide / Current Tables for Riverview, Potomac River, Maryland
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Riverview
Click for Map
Fri -- 12:00 AM EST     -0.20 feet Low Tide
Fri -- 04:40 AM EST     Moonrise
Fri -- 05:45 AM EST     2.32 feet High Tide
Fri -- 07:19 AM EST     Sunrise
Fri -- 12:03 PM EST     -0.18 feet Low Tide
Fri -- 03:26 PM EST     Moonset
Fri -- 04:47 PM EST     Sunset
Fri -- 06:04 PM EST     2.61 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.200.61.31.82.22.321.50.90.40-0.200.61.322.42.62.421.40.90.4

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.