Thursday, October19, 2017 L-36.com


Marine Weather and Tides
Alexandria, 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 7:21AMSunset 6:24PM Thursday October 19, 2017 5:18 AM EDT (09:18 UTC) Moonrise 6:00AMMoonset 5:44PM Illumination 1% Phase: Waning Crescent; 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- 431 Am Edt Thu Oct 19 2017
Rest of the overnight..SW winds 5 kt. Waves less than 1 ft.
Today..SW winds 5 kt. Waves less than 1 ft.
Tonight..W winds 5 to 10 kt. Waves 1 ft.
Fri..NW winds 5 to 10 kt. Waves 1 ft.
Fri night..N winds around 5 kt. Waves 1 ft or less.
Sat..SE winds around 5 kt. Waves 1 ft or less.
Sat night..S winds around 5 kt. Waves 1 ft.
Sun..S winds around 5 kt. Waves 1 ft or less.
Mon..S winds 5 kt. Waves less than 1 ft. A chance of showers through the night.
ANZ500 431 Am Edt Thu Oct 19 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will remain near the region for the rest of the week and into the weekend. A weak front will pass by to the north tonight before a stronger front approaches early next week. A small craft advisory may be needed for portions of the waters Monday.

7 Day Forecast for Marine Location Near Alexandria, VA
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location: 38.83, -77.04     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 190737
afdlwx
area forecast discussion
national weather service baltimore md washington dc
337 am edt Thu oct 19 2017

Synopsis
High pressure will remain across the mid atlantic through this
weekend. A low pressure system will affect the region early
next week.

Near term through tonight
Its chilly again this morning, but with higher dew points, its
not quite as cold or frosty as the last couple mornings. The
higher dew points have led to a little patchy fog, but not much
as of this writing. High pressure is centered over the southern
appalachians at present, and will generally remain in control
of the weather through the day. We'll have a few high clouds
around, but nothing to prevent temps from rising rapidly after
sunrise. With relatively dry air in place and plenty of Sun (if
filtered a little), we should manage the low 70s in most spots.

A very weak cold front will cross the region this evening. This
will result in a bit more wind overnight, but little more than
that. Because of the wind keeping it stirred up, temps should be
a bit higher than the last few nights. In areas where the wind
diminishes late, patchy fog could redevelop.

Short term Friday through Saturday night
High pressure will remain over the region through the short
term. It will be centered just to our southwest Friday, then
slowly migrate northeastward to a position off CAPE cod by
Saturday night. Winds may be a little breezy Friday in the wake
of the previous night's cold frontal passage, but should be very
light Saturday as the high drifts on by. Temps will remain warm
during the day thanks to minimal air mass change, with 70s
common both Friday and Saturday, with lows falling back into the
40s each night thanks to good radiational cooling under the
high and limited if any cloud cover. Patchy fog will be possible
late each night.

Long term Sunday through Wednesday
A significant change to the synoptic height pattern is forecast
to take place across the northern hemisphere this period. A
large deep upper-level low will retrograde out of northern
canada into the bering strait western alaska over the weekend.

This will force a building ridge over western north america, and
lowering heights across the eastern conus. With a blocking
ridge downstream over the north atlantic, interaction between
the northern and southern streams seems likely early next week.

The exact evolution is, of course, uncertain at this time range.

But the pattern should transition from warm dry to cool stormy
over the mid-atlantic early next week. Latest 00z deterministic
runs and their respective ensembles continue to show this
overall evolution, with spread in finer scale details which will
be ironed out in the coming days.

Aviation 08z Thursday through Monday
Patchy fog possible at mrb cho iad over the next few mornings,
but odds are low and if it does happen, it should generally be
MVFR at worst. Otherwise,VFR through Saturday night all
terminals with light winds under high pressure.

Some low CIGS vsbys may develop early Monday morning as
moisture returns aroud departing high pressure. Otherwise
guidance in agreement with pattern which would favorVFR Sunday
into Monday.

Marine
High pressure will generally keep winds below SCA criteria
through Saturday night. The exception will be tonight into
Friday morning, when a weak passing cold front will stir the
winds up. Soundings show some sustained winds of 20-30 knots
just above the surface, and while upstream, near shore areas
will probably have a surface inversion, just off shore,
especially as one heads further downstream, that inversion
should be weaker if present at all given the warm water temps,
so expect some of that wind to start mixing down later tonight
into Friday morning. As temps warm and the winds just above the
surface diminish during the day Friday, gusts should drop below
sca criteria.

Southerly channeling to SCA levels possible by Monday as high
pressure moves offshore.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory from 9 pm this evening to noon edt Friday
for anz531>534-537-539>541-543.

Synopsis... Rcm
near term... Rcm
short term... Rcm
long term... Dfh
aviation... Rcm dfh
marine... Rcm dfh


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 3 mi48 min SW 1.9 G 4.1 54°F 68°F1025.2 hPa
BSLM2 - Chesapeake Bay, MD 18 mi108 min Calm 44°F 1025 hPa
APAM2 - 8575512 - Annapolis, MD 32 mi48 min 52°F 1024.7 hPa
TPLM2 - Thomas Point, MD 32 mi78 min SW 11 G 12 58°F 67°F
NCDV2 35 mi48 min WSW 6 G 8 53°F 64°F1024.5 hPa
CPVM2 36 mi48 min 59°F 50°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 38 mi48 min SW 4.1 G 6 52°F 1024.8 hPa
44062 - Gooses Reef, MD 38 mi178 min W 12 G 12 62°F 1026 hPa
BLTM2 - 8574680 - Baltimore, MD 39 mi48 min WSW 1.9 G 4.1 52°F 70°F1024.5 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 46 mi48 min SW 8 G 11 58°F 1026.1 hPa
SLIM2 - 8577330 - Solomons Island, MD 47 mi48 min SW 8 G 8.9 58°F 69°F1025.2 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 mi26 minSSW 310.00 miMostly Cloudy51°F46°F86%1025.3 hPa
Camp Springs / Andrews Air Force Base, MD9 mi20 minS 410.00 miFair44°F42°F93%1025.7 hPa
Fort Belvoir, VA10 mi22 minN 010.00 miFair41°F39°F96%1025.7 hPa
College Park Airport, MD12 mi33 minN 010.00 miFair42°F41°F97%1025.1 hPa
Fort Meade / Tipton, MD23 mi33 minN 010.00 miFair37°F37°F100%1025.7 hPa
Washington/Dulles International Airport, DC, VA24 mi26 minN 010.00 miPartly Cloudy40°F39°F100%1025 hPa
Gaithersburg - Montgomery County Airport, MD24 mi22 minN 010.00 miFair42°F41°F96%1028.2 hPa

Wind History from DCA (wind in knots)
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Last 24hrSW3SW3CalmSW4SE4SE4S6S7S7S8S6S7S9S7S6S5S6SW4SW4SW5SW4SW4SW4SW3
1 day agoN6N6N8NE8NE9NE126N8NE4CalmNE4CalmS3SW6S6SE6SE5SW4SW5SW5CalmCalmSW3SW3
2 days agoNW5NW10
G16
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NW11NW8N9NW12NW10NW12NW9NW6N8N8N11

Tide / Current Tables for Bellevue, Potomac River, Washington, D.C.
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Bellevue
Click for Map
Thu -- 03:01 AM EDT     -0.05 feet Low Tide
Thu -- 06:59 AM EDT     Moonrise
Thu -- 07:21 AM EDT     Sunrise
Thu -- 08:40 AM EDT     3.30 feet High Tide
Thu -- 03:12 PM EDT     New Moon
Thu -- 03:15 PM EDT     -0.02 feet Low Tide
Thu -- 06:23 PM EDT     Sunset
Thu -- 06:44 PM EDT     Moonset
Thu -- 08:59 PM EDT     3.47 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.40.80.2-0.10.211.92.73.23.32.82.21.50.90.3-00.10.81.82.73.33.53.22.6

Tide / Current Tables for Benning Bridge, D.C.
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Benning Bridge
Click for Map
Thu -- 03:17 AM EDT     -0.02 feet Low Tide
Thu -- 06:59 AM EDT     Moonrise
Thu -- 07:21 AM EDT     Sunrise
Thu -- 08:56 AM EDT     3.39 feet High Tide
Thu -- 03:12 PM EDT     New Moon
Thu -- 03:31 PM EDT     0.01 feet Low Tide
Thu -- 06:23 PM EDT     Sunset
Thu -- 06:43 PM EDT     Moonset
Thu -- 09:16 PM EDT     3.59 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.710.400.10.81.82.63.23.43.12.51.71.10.50.10.10.71.62.53.23.63.42.9

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 (5,6,7,8)
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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.