Tuesday, November21, 2017 L-36.com


Marine Weather and Tides
North Chevy Chase, 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 6:57AMSunset 4:51PM Tuesday November 21, 2017 12:42 PM EST (17:42 UTC) Moonrise 9:29AMMoonset 7:31PM Illumination 9% Phase: Waxing Crescent; Moon at 3 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- 1231 Pm Est Tue Nov 21 2017
.small craft advisory in effect until 6 pm est this evening...
.small craft advisory in effect from Wednesday morning through Wednesday afternoon...
This afternoon..SW winds 10 kt with gusts to 20 kt. Waves 1 ft.
Tonight..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Wed..NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft.
Wed night..NW winds 5 to 10 kt. Waves 1 ft.
Thu..SW winds around 5 kt. Waves 1 ft.
Thu night..W winds around 5 kt. Waves 1 ft.
Fri..S winds around 5 kt. Waves 1 ft or less.
Sat..W winds 5 kt. Waves less than 1 ft.
ANZ500 1231 Pm Est Tue Nov 21 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move offshore through this afternoon. A cold front will pass through late tonight into early Wednesday morning. High pressure will return later Wednesday through early Friday, then another cold front will approach late Friday into Saturday. A small craft advisory will likely be needed for portions of the waters Wednesday night, and again Friday night through Saturday.

7 Day Forecast for Marine Location Near North Chevy Chase, MD
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location: 39, -77.09     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 211529
afdlwx
area forecast discussion
national weather service baltimore md washington dc
1029 am est Tue nov 21 2017

Synopsis
High pressure will move offshore today and a cold front will
pass through tonight into early Wednesday. High pressure will
build back overhead later Wednesday through thanksgiving day.

The high will build to our south for Friday and Saturday before
a cold front moves through Saturday night. Canadian high
pressure will build overhead early next week.

Near term through tonight
A southwest flow around high pressure will usher in milder
conditions after a chilly start early this morning. MAX temps
will range from the upper 40s and lower 50s in the mountains to
the upper 50s and lower 60s across most other locations. There
will be a thin deck of high clouds due to a southwest flow
aloft... But the cloud deck should be thin enough for a partly to
mostly sunny sky.

A cold front over the ohio valley this evening will move into
the area late tonight. A southerly flow ahead of the boundary
will cause clouds to increase early this evening and a few
showers are possible with the frontal passage later this evening
into the overnight hours. Moisture will be limited and forcing
will be weak with most of the dynamics off to the north. Most
meso camodels keep rain with the fronts west of the ridge and
north of the mason dixon line. The best chance for showers will
be across eastern areas where moisture will have a little more
time to advect in from the south before the frontal passage.

Most morning meso models agree with this. MAX extent over the se
part of the forecast area should be around 9z. Min temps will
range from the upper 20s to around 30 in the allegheny highlands
to the mid and upper 40s in downtown washington and baltimore
into southern maryland.

A period of upslope snow showers are expected late tonight
behind the cold front for locations along west of the allegheny
highlands. Accumulations should be around one inch or less since
moisture will be limited... But this may cause slippery
conditions by the early morning hours Wednesday.

Short term Wednesday through Thursday night
The cold front will move off to the south and east early
Wednesday morning. Canadian high pressure will approach from the
north and west and a northwest flow ahead of the high will usher
in drier and chillier conditions. MAX temps will hold in the 40s
for most locations north and west of interstate 95 and in the
lower to middle 50s farther south and east.

High pressure will build overhead Wednesday night... Bringing dry
and cold conditions. Min temps will drop into the 20s for most
areas. High pressure will remain overhead thanksgiving day
through thanksgiving night... Bringing more dry and chilly
conditions.

Long term Friday through Monday
High pressure will be in control of the region's weather on
Friday leading to fair skies and dry weather.

By Friday night, a potent northern stream system and its
associated cold fronts will move into the upper midwest,
before barreling towards the mid-atlantic states Saturday and
Saturday night. The series of cold fronts will cross the region
during this time period with chances of some showers. Southern
stream energy will be present as well near the southeastern
states but at this time, the fast flow aloft and orientation of
the upper level trough suggests that any surface low that can
develop will favor a track well offshore with little to no
impact to the region.

On Sunday, behind the fronts and with the upper trough moving
overhead, blustery and colder conditions are likely, along with
the potential for snow showers over the higher terrain. As the
upper trough does move overhead, some scattered flurries snow
showers are even possible in lower terrain.

High pressure will build back overhead by Monday with
fair skies and diminishing winds.

Temperatures will start out near normal or even a bit above for
Friday and Saturday (50s), before falling back below for Sunday
and Monday (40s).

Aviation 16z Tuesday through Saturday
Southwest winds will gust around 20 knots today. A cold front
will pass through the terminals tonight. A few showers cannot be
ruled out... But any precipitation amounts will be light. Brief
MVFR conditions are possible in any showers that do occur... But
vfr conditions are most likely for most of the time. Northwest
winds will develop behind the cold front early Wednesday morning
and gusts around 20 to 25 knots are expected for most of
Wednesday behind the cold front.

High pressure will settle overhead for Thursday through Thursday
night withVFR conditions likely.

Vfr and light winds expected Friday with surface high pressure.

Chances for some showers exist on Saturday with a frontal
system, but widespread restrictions are not currently expected.

Marine
With the southwest flow ahead of a cold front today, a small
craft advisory is in effect for the waters. The SCA continues
through this evening for most of the bay and lower tidal
potomac. Winds should decrease overnight as the gradient
relaxes. A cold front will pass through early Wednesday morning
and northwest winds will increase behind the boundary with gusts
20 to 30 knots most likely. An SCA is in effect for the waters.

High pressure will build over the waters for Wednesday night
through Thursday night. An SCA may be needed for portions of the
waters Wednesday night.

Sub-sca conditions expected Friday with surface high pressure. Sca
possible Friday night and Saturday ahead of next frontal system.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory until midnight est tonight for anz530>534-
537-539>543.

Small craft advisory from 6 am to 6 pm est Wednesday for
anz530>543.

Small craft advisory until 6 pm est this evening for anz535-
536-538.

Strong fling lasorsa muccilli


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 10 mi42 min S 12 G 17 56°F 48°F1018.8 hPa (-2.4)
BSLM2 - Chesapeake Bay, MD 25 mi72 min S 9.9 58°F 1020 hPa31°F
APAM2 - 8575512 - Annapolis, MD 32 mi42 min 58°F 1018.2 hPa (-2.2)
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 33 mi42 min S 12 G 18 56°F 1018.4 hPa (-1.6)
BLTM2 - 8574680 - Baltimore, MD 33 mi42 min W 6 G 11 55°F 54°F1018 hPa (-2.1)
44063 - Annapolis 34 mi32 min S 16 G 19 55°F 1 ft1018 hPa
TPLM2 - Thomas Point, MD 35 mi42 min S 21 G 24 55°F 52°F
CPVM2 37 mi42 min 55°F 39°F
44043 - Patapsco, MD 39 mi32 min S 9.7 G 12 53°F 1 ft1019.7 hPa
44062 - Gooses Reef, MD 47 mi32 min S 14 G 18 55°F 2 ft1028.9 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 47 mi42 min S 8 G 12 55°F 49°F1019.1 hPa (-2.0)
NCDV2 47 mi42 min SSW 6 G 11 57°F 50°F1019.1 hPa (-1.6)

Wind History for Washington, DC
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1 day
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W12
G25
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G27
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G25
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G21
NW14
G28
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G26
NW16
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G27

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
College Park Airport, MD9 mi56 minSSW 610.00 miFair55°F29°F39%1019 hPa
Washington/Reagan National Airport, DC, VA10 mi50 minS 15 G 2010.00 miOvercast59°F32°F36%1019.1 hPa
Gaithersburg - Montgomery County Airport, MD12 mi46 minSSW 710.00 miFair55°F30°F38%1021.9 hPa
Camp Springs / Andrews Air Force Base, MD17 mi46 minSSW 18 G 2610.00 miFair and Breezy59°F32°F36%1019.4 hPa
Fort Meade / Tipton, MD18 mi57 minSW 710.00 miFair55°F30°F38%1019.6 hPa
Washington/Dulles International Airport, DC, VA19 mi50 minSW 1410.00 miMostly Cloudy54°F30°F42%1018.7 hPa
Fort Belvoir, VA19 mi1.8 hrsSSW 810.00 miFair54°F30°F40%1020.3 hPa

Wind History from CGS (wind in knots)
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Last 24hrW5SW9
G14
SW7SW5SW4CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmS4SW6SW5S6
G14
1 day agoW14
G18
NW10
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W7W10
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W5W4CalmW4W5NW8W6
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CalmW5W7W4W4W3W4W8W7W9W8
2 days agoS7
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S3S3S5S5S3S7S8
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G17
--------NW14
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NW11
G26

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Tue -- 04:53 AM EST     0.10 feet Low Tide
Tue -- 06:58 AM EST     Sunrise
Tue -- 09:28 AM EST     Moonrise
Tue -- 10:24 AM EST     2.66 feet High Tide
Tue -- 04:35 PM EST     0.14 feet Low Tide
Tue -- 04:50 PM EST     Sunset
Tue -- 07:31 PM EST     Moonset
Tue -- 10:25 PM EST     2.97 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.21.610.60.20.10.41.11.82.42.62.62.21.50.90.40.20.20.51.222.72.92.9

Tide / Current Tables for Chain Bridge, one mile below, Washington, D.C.
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Chain Bridge
Click for Map
Tue -- 04:45 AM EST     0.06 feet Low Tide
Tue -- 06:57 AM EST     Sunrise
Tue -- 09:28 AM EST     Moonrise
Tue -- 10:17 AM EST     2.69 feet High Tide
Tue -- 04:26 PM EST     0.10 feet Low Tide
Tue -- 04:50 PM EST     Sunset
Tue -- 07:31 PM EST     Moonset
Tue -- 10:18 PM EST     3.00 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.21.50.90.50.20.10.41.11.92.42.72.62.11.40.80.40.10.10.51.32.12.732.9

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 (12,3,4,5)
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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.