Tuesday, January16, 2018 L-36.com


Marine Weather and Tides
National Harbor, MD

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 7:22AMSunset 5:13PM Tuesday January 16, 2018 4:33 AM EST (09:33 UTC) Moonrise 6:57AMMoonset 5:02PM 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- 331 Am Est Tue Jan 16 2018
Rest of the overnight..SE winds 5 kt. Waves flat.
Today..E winds around 5 kt. Waves 1 ft.
Tonight..N winds 5 to 10 kt. Waves 1 ft. Snow. Vsby 1 to 3 nm.
Wed..NW winds 10 kt. Waves 1 ft. A chance of snow.
Wed night..NW winds 5 to 10 kt. Waves 1 ft.
Thu..W winds 5 to 10 kt. Waves 1 ft.
Thu night..W winds around 5 kt. Waves 1 ft.
Fri..SW winds around 5 kt. Waves 1 ft.
Sat..SW winds around 5 kt. Waves 1 ft.
ANZ500 331 Am Est Tue Jan 16 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front will approach from the west today and cross the waters tonight. Low pressure will develop offshore Wednesday. High pressure will return for late in the week. A small craft advisory may be needed for the waters late Tuesday night through Thursday.

7 Day Forecast for Marine Location Near National Harbor, MD
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location: 38.8, -77.03     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 160904
afdlwx
area forecast discussion
national weather service baltimore md washington dc
404 am est Tue jan 16 2018

Synopsis A cold front will approach the area today before
passing through tonight into Wednesday. Low pressure will
develop along this boundary offshore later Wednesday before high
pressure settles to our south Thursday. High pressure will
remain to our south through the weekend.

Near term through Wednesday Cdfnt will cross the
appalachians later today and slowly progress ewd reaching the
i-81 corridor by 00z wed. Snow today will fall mainly over the
upslope areas of the appalachians behind the front wind shift.

Some snow could also affect NRN md counties along the mason-
dixon line but this is not a done deal as some models and
ensemble keep this area dry through much of the day.

Tonight and the first half of Wed is when the majority of
precip will fall as heights fall in response to approaching
upper level trof and forcing for upward vertical motion
increases. Deterministic models and their respective ensembles
depict precip breaking up as it crosses the mtns with a
secondary area of snow over the va piedmont late tonight into
wed. Ensemble QPF is generally 0.1 to 0.2 inches along and south
of the i-64 and west of the i-81 corridors. A big minima or hole
in the precip is shown over NRN va and central md. Even with
these small amounts of qpf, the very cold temperatures will
result in slrs in the order of 15 to 1 and even a little bit of snow
potentially causing moderate impacts given sfc temps expected in
the mid 20s. It is possible that additional advisories may be
needed for the charlottesville and fredericksburg areas, but
since precip is not expected to begin until late second period
or perhaps closer to 12z Wed decided to hold off on any
advisories. Also, our snow probs indicate only a 50% prob of
snow exceeding 2 inches and 80% confidence is needed. For the
metro areas, the prob of exceeding one inch is about 50-60%
which would require an advzy given snow is expected to impact
the Wed morning commute, but this is again late second or even
third period event.

Short term Wednesday night through Thursday night
Snow will begin to taper off quickly in the afternoon Wed with
snow ending by 7 pm Wed if not sooner. Clearing and turning
blustery Wed night and thu. Wind and wind chill advisories may
be needed for the mtns.

Long term Friday through Monday
Surface high pressure will build over the southeastern states on
Friday while a shortwave trough swings eastward. Very little
moisture will be associated with this trough, and thus only some
increase in mid-level clouds can be expected. Temperatures will
begin to increase above climatology due to warm air advection.

The surface high will move off the southeast coast and broader
ridging aloft will develop over the southeastern CONUS through the
weekend. Meanwhile, low pressure will be developing in the lee of
the rockies and lifting toward the great lakes. A second low will be
crossing well to the north in canada. Overall, temperatures should
continue their above normal trend. It's worth noting that the 00z
ecmwf sends a backdoor cold front southward from the northern low
and thus prevents the really warm air from working into the area on
Sunday. For example, there is a 10 degree spread in the forecast
high temperature at baltimore between the ECMWF and GFS mos. It
looks like the weekend will be dry in most places, though a few
showers extending along the warm front could clip northwestern parts
of the cwa.

As the low lifts north of the great lakes Monday, the trailing cold
front will approach the area. There's fairly good model agreement
with the front crossing Monday afternoon and evening, though of
course timing could change some at this range. Showers will become
likely ahead of the front. Rain will be exiting with the front
anyway, but even so, flow will be zonal behind the front and cold
air limited. Only the upslope areas of the allegheny front may see a
changeover to snow showers briefly before ending.

Aviation 09z Tuesday through Saturday
Ifr CIGS across eastern terminals this morning lifting toVFR
this afternoon. Light snow developing tonight first at kmrb then
spreading slowly eastward overnight with MVFR ifr conditions
expected at all terminals. Snow begins to taper off by midday
wed with conditions improving rapidly and winds picking up from
the nw. Blustery Wed night and Thu with wind gusts well over 20
kts.

No aviation impacts are expected Friday and Saturday as high
pressure builds south of the area.

Marine Light and variable winds through this evening, then
winds strengthening late tonight into Wed with SCA conditions
expected Wed into thu. Risk of gales appears low at this time
for late Wed night and thu.

A weak disturbance will be passing Friday, which could kick up
westerly winds a little, but it's uncertain at this time if they
will reach SCA levels. High pressure will slide south of the area
Friday night into Saturday with a light southwest flow developing.

Lwx watches warnings advisories
Dc... None.

Md... Winter weather advisory from 7 am this morning to 10 pm est
this evening for mdz501.

Winter weather advisory from 10 am this morning to 10 pm est
this evening for mdz003-502.

Winter weather advisory from 4 pm this afternoon to 7 am est
Wednesday for mdz004>006-507.

Va... Winter weather advisory from 7 am this morning to 10 pm est
this evening for vaz503.

Wv... Winter weather advisory from 7 am this morning to 10 pm est
this evening for wvz501-503-505.

Winter weather advisory from 10 am this morning to 10 pm est
this evening for wvz050>053-055-502-504.

Marine... None.

Synopsis... Lfr
near term... Lfr
short term... Lfr
long term...

aviation... Ads lfr
marine... Ads lfr


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 5 mi45 min SSE 1.9 G 2.9 30°F 33°F1031.7 hPa
BSLM2 - Chesapeake Bay, MD 17 mi123 min Calm 27°F 1032 hPa24°F
APAM2 - 8575512 - Annapolis, MD 32 mi45 min 29°F 1031.1 hPa
TPLM2 - Thomas Point, MD 32 mi33 min N 2.9 G 4.1 29°F 32°F
NCDV2 33 mi45 min SSE 1.9 G 2.9 30°F 32°F1030.7 hPa
CPVM2 37 mi45 min 29°F 26°F
44062 - Gooses Reef, MD 37 mi33 min N 3.9 G 5.8 29°F 33°F1031.9 hPa (+0.0)
FSNM2 39 mi45 min E 1 G 1 28°F 1030.8 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 39 mi45 min E 1.9 G 1.9 28°F 1031.8 hPa
BLTM2 - 8574680 - Baltimore, MD 40 mi45 min SE 1 G 1.9 29°F 32°F1031.2 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 44 mi45 min N 6 G 8 28°F 1032 hPa
SLIM2 - 8577330 - Solomons Island, MD 45 mi51 min N 2.9 G 5.1 29°F 34°F1031.2 hPa

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
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NW8
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NW11
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA4 mi41 minSE 410.00 miOvercast31°F28°F89%1031.5 hPa
Camp Springs / Andrews Air Force Base, MD9 mi37 minESE 34.00 miFog/Mist28°F26°F95%1031.9 hPa
Fort Belvoir, VA9 mi37 minN 010.00 miOvercast30°F27°F90%1031.9 hPa
College Park Airport, MD14 mi56 minN 05.00 miOvercast29°F26°F90%1031.5 hPa
Fort Meade / Tipton, MD24 mi57 minN 07.00 miOvercast28°F26°F93%1032.2 hPa

Wind History from DCA (wind in knots)
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Last 24hrN7N8N9N8N7NE6NE4NE4N6NE4E5NE4E6SE6E7SE5SE5SE5S5SW3CalmSE4S4SE4
1 day agoNW15N14N13NW12NW12
G19
N14N16N8N11
G17
N6N9N10N11N7N9N9N10NE8NE10N7NE7N8NE7N8
2 days agoNW15
G26
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NW13

Tide / Current Tables for Alexandria, Virginia
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Alexandria
Click for Map
Tue -- 02:05 AM EST     -0.11 feet Low Tide
Tue -- 06:56 AM EST     Moonrise
Tue -- 07:24 AM EST     Sunrise
Tue -- 07:47 AM EST     2.34 feet High Tide
Tue -- 01:58 PM EST     -0.10 feet Low Tide
Tue -- 05:02 PM EST     Moonset
Tue -- 05:11 PM EST     Sunset
Tue -- 07:57 PM EST     2.62 feet High Tide
Tue -- 09:18 PM EST     New Moon
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.50.1-0.10.10.61.31.92.22.321.50.90.40-0.10.10.71.52.12.52.62.41.91.3

Tide / Current Tables for Riverview, Potomac River, Maryland
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Riverview
Click for Map
Tue -- 01:51 AM EST     -0.14 feet Low Tide
Tue -- 06:56 AM EST     Moonrise
Tue -- 07:24 AM EST     Sunrise
Tue -- 07:34 AM EST     2.18 feet High Tide
Tue -- 01:45 PM EST     -0.13 feet Low Tide
Tue -- 05:02 PM EST     Moonset
Tue -- 05:11 PM EST     Sunset
Tue -- 07:45 PM EST     2.43 feet High Tide
Tue -- 09:18 PM EST     New Moon
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.40-0.10.10.71.31.82.12.11.81.20.70.2-0-0.10.10.81.522.32.42.11.71.1

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 (4,6,7,8)
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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.