Thursday, August24, 2017 L-36.com


Marine Weather and Tides
Mount Vernon, 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 6:30AMSunset 7:51PM Thursday August 24, 2017 6:31 AM EDT (10:31 UTC) Moonrise 8:26AMMoonset 8:44PM Illumination 5% Phase: Waxing Crescent; Moon at 2 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- 551 Am Edt Thu Aug 24 2017
Today..N winds 5 kt. Waves less than 1 ft.
Tonight..N winds around 5 kt. Waves 1 ft.
Fri..N winds 5 kt. Waves less than 1 ft.
Fri night..N winds around 5 kt. Waves 1 ft.
Sat..NE winds 5 kt. Waves less than 1 ft.
Sat night..NE winds around 5 kt. Waves 1 ft.
Sun..E winds around 5 kt. Waves 1 ft.
Mon..E winds 5 to 10 kt. Waves 1 ft.
ANZ500 551 Am Edt Thu Aug 24 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will drift from the great lakes today to the northeastern united states this weekend.

7 Day Forecast for Marine Location Near Mount Vernon, VA
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location: 38.68, -77.1     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 240719
afdlwx
area forecast discussion
national weather service baltimore md washington dc
319 am edt Thu aug 24 2017

Synopsis
High pressure will drift from the great lakes today to the
northeastern united states this weekend. Meanwhile, an upper
level trough will sweep southeastward across the area this
afternoon and evening. High pressure will remain in control into
early next week.

Near term through tonight
Although the cold front has passed east of the area, dewpoints
in the 60s still hanging on from dc southeast. The threat for
showers has ended, but there is still a decent amount of cloud
cover, mainly across virginia. Anticipate this may increase a
little through dawn due to nocturnal cooling. Am leaning a bit
more toward clouds vs fog, which should be held in check not
just by clouds but also due to dry advection and light gradient
flow.

During the daylight hours, a vorticity MAX will pivot across the
area... Especially late in the day. As was my concern at the
beginning of the week, guidance now picking up on the PVA and
steep lapse rates. Broken clouds and scattered showers will
result, especially in the appalachians and along i-81. The loss
of daytime heating will allow these showers to fall apart as the
vort continues east this evening, but will still hold onto a
small chance for north central maryland and dc suburbs.

Since high pressure will be building into the area at the
surface, winds should be light north. And with a canadian air
mass comes canadian temperatures-- high will be in the 70s west
of the blue ridge and across northern maryland. It will be
equally crisp tonight... In the 50s to lower 60s dc-baltimore
metro.

Short term Friday through Saturday night
High pressure will be passing north of the area Friday and
Saturday. There will be no significant weather features through
this time, just lower heights northeast as the trough axis
slowly lifts. Expect Friday to be dry, but not completely sunny
as flow will be off the water and there will be a window for
diurnal clouds.

By Saturday, the overunning lift will manifest in a developing
inverted trough over the appalachians. Anticipate a fairly thick
cumulus field, with sufficient moisture and lift for scattered
showers. While the precip should dissipate soon after sunset,
the clouds may leak east Saturday night.

High temperatures shouldn't get much higher than the source
region of the airmass... Which is in the 70s. Low temps should
stay fairly consistent too.

Long term Sunday through Wednesday
Surface high pressure lingers over new england Sunday and at least
into Tuesday. This will produce an onshore flow for the central mid-
atlantic and maintain below normal temperatures.

00z operational gfs ECMWF consensus is for low pressure to develop
off the southeast CONUS coast early in the week and drift northeast
with the gulf stream off CAPE hatteras into the midweek. At a
minimum this would enhance the onshore flow over the central mid-
atlantic and allow stratiform rain or drizzle to develop.

This is a complex scenario in the midweek as there will be remnants
of harvey to contend with. Global models suggest we are over a week
away from any impacts in the mid-atlantic.

Aviation 07z Thursday through Monday
While there is a fairly thick cloud field early this morning,
especially across virginia,VFR conditions remain as these
clouds have bases 050-070. That should remain the case through the
day and into the evening as a shortwave crosses the area. There
may be a few showers too late day (mrb) or early evening (rest
of terminals). However, the risk of restrictions low... And if
they did occur it would be brief.

Vfr will primarily continue Friday-Saturday as well. Patchy
early morning fog possible Friday morning, but coverage should
be limited to valleys. If a terminal impacted, best bet would be
cho. A couple of mtn showers possible on Saturday. Again, these
should mainly avoid the airfields.

High pressure persists over new england Sunday and Monday with
onshore flow andVFR conditions. Rain may move into the area
Tuesday Wednesday.

Marine
Have a small craft advisory in effect until noon for most of the
waters due to mixing associated with the change of air mass. It
has not materialized yet. Will give it until sunrise; will
consider a cancellation at that time if it does not manifest by
then. After that, high pressure will build to the north of the
waters. Winds should generally be 10 kt or less this afternoon
into Saturday morning. East flow may pick up to 10-15 kt on
Saturday.

High pressure persists over new england Sunday and Monday with
onshore flow through this time. SCA level onshore flow looks to
begin by Monday. This onshore flow may be further enhanced by low
pressure developing over the gulf stream off the carolinas in the
middle of next week.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory until noon edt today for anz531>534-536-
537-539>541-543.

Synopsis... Hts
near term... Hts
short term... Hts
long term... Baj
aviation... Hts baj
marine... Hts baj


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 14 mi43 min WNW 5.1 G 6 72°F 83°F1013.2 hPa
BSLM2 - Chesapeake Bay, MD 22 mi121 min Calm 59°F 1013 hPa
NCDV2 25 mi43 min N 2.9 G 6 71°F 81°F1012.5 hPa
44062 - Gooses Reef, MD 37 mi31 min ENE 9.7 G 12 77°F 80°F1 ft1013.9 hPa (+1.1)
TPLM2 - Thomas Point, MD 38 mi31 min N 12 G 14 73°F 80°F
APAM2 - 8575512 - Annapolis, MD 39 mi43 min 72°F 1013.1 hPa
44063 - Annapolis 40 mi31 min SE 7.8 G 9.7 80°F
SLIM2 - 8577330 - Solomons Island, MD 42 mi43 min NW 4.1 G 6 73°F 81°F
COVM2 - 8577018 - Cove Point LNG Pier, MD 42 mi43 min NE 9.9 G 13 76°F 1013.8 hPa
PPTM2 - 8578240 - Piney Point, MD 48 mi43 min NNE 7 G 8
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 48 mi43 min N 11 G 14 72°F 1013.4 hPa
BLTM2 - 8574680 - Baltimore, MD 49 mi43 min N 9.9 G 13 71°F 83°F1013.1 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA5 mi93 minNW 410.00 miOvercast70°F59°F69%1013.5 hPa
Washington/Reagan National Airport, DC, VA13 mi39 minNW 710.00 miOvercast73°F57°F59%1013.9 hPa
Quantico Marine Corps Airfield - Turner Field, VA16 mi95 minNNW 310.00 miOvercast71°F60°F68%1013.8 hPa
Camp Springs / Andrews Air Force Base, MD16 mi93 minNNW 510.00 miOvercast67°F59°F75%1013.7 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA22 mi95 minN 010.00 miOvercast68°F59°F73%1014.6 hPa
College Park Airport, MD23 mi63 minN 010.00 miOvercast67°F60°F80%1013.5 hPa

Wind History from DAA (wind in knots)
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Last 24hrCalmNW3N4N6NW8NW7N7NW5NE3CalmCalmN3CalmCalmCalmCalmNW3CalmCalmCalmCalmCalmNW4NW4
1 day agoCalmS3S5S6S4S6S8S10S10S8
G16
S8S7S6SE5S5S4S6S4NW4CalmCalmCalmCalmNW5
2 days agoCalmCalmS4S6S3SE7S7S6CalmSW5S5S3S6CalmCalmCalmSE3SE3CalmCalmCalmCalmCalmCalm

Tide / Current Tables for Marshall Hall, Potomac River, Maryland
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Marshall Hall
Click for Map
Thu -- 04:31 AM EDT     0.08 feet Low Tide
Thu -- 06:30 AM EDT     Sunrise
Thu -- 09:25 AM EDT     Moonrise
Thu -- 10:34 AM EDT     2.81 feet High Tide
Thu -- 04:52 PM EDT     0.04 feet Low Tide
Thu -- 07:49 PM EDT     Sunset
Thu -- 09:44 PM EDT     Moonset
Thu -- 10:59 PM EDT     2.79 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.11.510.50.10.10.51.21.92.52.82.82.41.71.10.60.200.30.91.62.32.72.8

Tide / Current Tables for High Point, Occoquan Bay, Virginia
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High Point
Click for Map
Thu -- 03:54 AM EDT     0.05 feet Low Tide
Thu -- 06:31 AM EDT     Sunrise
Thu -- 09:26 AM EDT     Moonrise
Thu -- 09:36 AM EDT     1.95 feet High Tide
Thu -- 04:16 PM EDT     0.01 feet Low Tide
Thu -- 07:50 PM EDT     Sunset
Thu -- 09:44 PM EDT     Moonset
Thu -- 10:02 PM EDT     1.93 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.20.80.40.200.20.71.21.71.91.91.71.30.90.50.200.10.511.51.81.91.8

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 (6,6,7,8)
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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.