Saturday, February23, 2019 L-36.com


Marine Weather and Tides
Accokeek, MD

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 6:47AMSunset 5:55PM Saturday February 23, 2019 4:35 PM EST (21:35 UTC) Moonrise 10:48PMMoonset 9:30AM Illumination 80% Phase: Waning Gibbous; Moon at 19 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- 339 Pm Est Sat Feb 23 2019
.small craft advisory in effect Sunday afternoon...
.gale warning in effect from Sunday afternoon through Sunday evening...
Rest of this afternoon..E winds 5 kt. Waves less than 1 ft. Rain.
Tonight..S winds around 5 kt. Waves 1 ft. Rain. Vsby 1 to 3 nm.
Sun..W winds 15 to 20 kt with gusts to 30 kt. Waves 1 to 2 ft. Showers likely.
Sun night..W winds 15 to 20 kt with gusts to 40 kt. Waves 2 ft.
Mon..NW winds 10 to 15 kt with gusts to 40 kt. Waves 2 ft.
Mon night..NW winds 5 to 10 kt. Gusts up to 20 kt in the evening. Waves 1 ft.
Tue..N winds 5 kt. Waves less than 1 ft.
Wed..W winds around 5 kt. Waves 1 ft.
ANZ500 339 Pm Est Sat Feb 23 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will approach the middle mississippi river valley tonight, strengthening as it moves northeastward across the great lakes into canada through Sunday. High pressure will build from the northern great plains toward the great lakes and eventually into the northeast through the first half of next week. Gale conditions are likely overnight Sunday and Monday.


7 Day Forecast for Marine Location Near Accokeek, MD
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location: 38.68, -77     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 231958
afdlwx
area forecast discussion
national weather service baltimore md washington dc
258 pm est Sat feb 23 2019

Synopsis
Strong low pressure will move northeastward across
the western great lakes this weekend, bringing a warm front
northward into the area by early Sunday. A cold front
approaching from the ohio valley will quickly follow Sunday
afternoon. High pressure will then build from the great lakes
into new england through much of next week. Meanwhile, an area
of low pressure may approach from the ohio valley during the
middle of the week, and again by the end of the week.

Near term through tonight
Low pressure is will move from the central CONUS into the great
lakes tonight. A stationary boundary to its east will be lifted
north as a warm front through tonight, but with surface high
pressure over new england and the parent surface low passing so
far west, our area will remain on the cool side of the boundary.

An upper-level disturbance will pass through late this afternoon
and another upper-level disturbance will move into the area
overnight.

Overrunning warm moist advection has allowed for light rain
across most areas. Steadier rain has occurred over central
virginia where the overrunning is deeper, and also closer to the
upper-level disturbance that is passing through. The heavier
rain may taper off for a bit this evening behind the
disturbance, but areas of light rain and drizzle remain likely
as warm and moist air from the gulf of mexico overruns the
surface colder air in place. Temperatures are expected to hold
near or below freezing for elevations between 1500 and 4000
feet or so with cold air draining in from high pressure to the
north. A glaze of ice freezing rain expected through this
afternoon. A winter weather advisory remains in effect until 6
pm, but that advisory may need to be expanded into tonight,
especially across the ridges of western maryland.

The next disturbance is expected to pass through overnight. A
steadier rain will develop after midnight, and with copious
amounts of moisture in place locally heavy rain is possible. In
fact, a rumble of thunder cannot be ruled out due to elevated
instability. In general around an inch of rain is expected in
the washington and baltimore metropolitan areas with slightly
higher amounts possible in southern maryland and the virginia
piedmont. A little less rain (three quarters of an inch) is
expected over eastern west virginia and western maryland.

Confidence is not quite high enough for a watch at this time,
given the breaks in steadier periods of rainfall along with
little or no snow pack. However, localized flooding is possible
because soils are already saturated due to the recent snow melt.

Further south across west- central virginia, amounts of up to
an inch and a half are possible. A little higher confidence in
flooding threat here (where there is a flood watch through
tonight).

Short term Sunday through Monday night
Low pressure will move into southern canada and the warm front
will gradually lift through our area during the morning. Rain
and drizzle to start will taper off from west to east during the
morning hours. A strong cold front associated with the low will
pass through the area Sunday afternoon into Sunday evening from
west to east.

Strong winds are expected behind the cold front for much of the
area. A strong pressure gradient combined with a deep mixing
layer and winds around 50-55 knots at the top of the mixing
layer suggests that winds can be quite strong. A high wind
warning is in effect for the blue ridge and catoctin mountains
as well as the allegheny and potomac highlands. Wind gusts
around 60 mph are expected across these areas. Do think that not
quite all of the wind at the top of the mixing layer will make
it into the valleys, since peak heating will be ending around
the time of the maximum pressure gradient. However, it will
still turn out windy with gusts around 45-55 mph across most of
maryland, northern virginia, portions of central virginia and
the valleys in eastern west virginia. Wind advisories are in
effect for these areas.

A strong gradient and cold advection means that Sunday night and
Monday will turn out blustery and cold. Winds may a little for
most areas Sunday night due to the loss of daytime heating.

Therefore, allowed the wind advisories to expire. However, the
high wind warnings continue for the ridges. Another pressure
surge is expected early Monday morning through midday, and more
gusts around advisory criteria (50 mph) are possible across much
of the area. A wind advisory may be needed.

High pressure will build overhead Monday night, causing winds to
diminish but it will remain seasonably cold.

Long term Tuesday through Saturday
Canadian high pressure over the upper midwest on Tuesday will
continue tracking eastward toward our region through midweek, and
with zonal flow aloft, dry weather and below normal temperatures
are forecast. A weak area of low pressure and a subtle
shortwave will track to our north Wednesday night into Thursday,
promoting the potential for upslope rain snow showers. High
pressure is then expected to build to our north through weeks
end. The GFS indicates a potential quick moving shortwave
crossing the area Friday morning delivering a period of
rain snow, however the ECMWF depicts a much stronger high over
the mid atlantic, suppressing any precipitation well to our
south. Will carry low end chance pops for now given the model
discrepancy at day 6 7.

Aviation 20z Saturday through Thursday
Conditions will continue deteriorate this afternoon to MVFR
levels (ifr at kcho). Ifr levels are expected to develop
everywhere this evening and subifr conditions are possible
overnight. Low clouds and fog rain drizzle will be around to
start Sunday, but CIGS vsbys and drier air will gradually return
later Sunday morning into Sunday afternoon.

Strong winds are expected behind a cold front Sunday afternoon
for kcho and kmrb, and late Sunday afternoon or early evening
for the rest of the terminals. Gusts around 40 to 45 knots are
possible. Isolated gusts around 50 knots cannot be completely
ruled out. Winds will diminish some later Sunday night for most
of the terminals, but another uptick in wind gusts around 40-45
knots are possible Monday morning. Winds will gradually diminish
later Monday afternoon into Monday night as high pressure builds
closer.

PredominateVFR conditions expected Tuesday through Wednesday as
canadian high pressure builds toward the region. Dry conditions
and light winds will prevail as a result.

Marine
Winds should remain below SCA criteria tonight. A warm front
will gradually pass through the waters Sunday morning through
midday. A stronger gradient and increasing mixing layer will
cause winds to increase during this time. A small craft advisory
is in effect for the waters. A cold front will pass through late
Sunday afternoon, and stronger winds are expected. Gusts around
40 to 45 knots are likely, and a gale warning is in effect for
the waters late Sunday afternoon through Sunday evening. The
gale warning may need to be extended for overnight Sunday and
Monday as another pressure surge passes through the waters.

Confidence was too low at this time to do so, thinking there may
be a break in the stronger winds for a period late Sunday night.

Winds will gradually diminish late Monday and Monday night as
high pressure builds overhead.

Mainly sub SCA conditions are expected Tuesday through Wednesday as
canadian high pressure builds toward the region, delivering gentle
to moderate northerly breezes.

Hydrology
Highest confidence in higher rainfall totals over an inch and
subsequently the threat for areal flooding is over west-central
virginia tonight, which is where the current flood watch lies.

Further north, rainfall amounts may come in a little shy of an inch,
but saturated ground and or snowmelt lends to a non-zero flood
threat just about everywhere. East of the blue ridge to the i-95
corridor should average near an inch, with slightly higher amounts
possible over southern maryland. Outside of the areal flood watch,
mainstem river flooding may be the biggest threat given these
waterways will be catching all the excess runoff.

Lwx watches warnings advisories
Dc... Wind advisory from 3 pm to 10 pm est Sunday for dcz001.

Md... High wind warning from 10 am Sunday to 10 am est Monday for
mdz501.

Winter weather advisory until 6 pm est this evening for mdz501.

High wind warning from 1 pm Sunday to 10 am est Monday for
mdz003-004-502.

Wind advisory from 3 pm to 10 pm est Sunday for mdz005-006-011-
013-014-016>018-503>508.

Va... High wind warning from 10 am Sunday to 10 am est Monday for
vaz503-504-507-508.

Flood watch through late tonight for vaz025-036-037-503-504-
508.

Winter weather advisory until 6 pm est this evening for vaz503-
504-507-508.

Wind advisory from 1 pm to 10 pm est Sunday for vaz025>031-
036>040-501-505.

Wind advisory from 3 pm to 10 pm est Sunday for vaz052>054-506.

Wv... High wind warning from 10 am Sunday to 10 am est Monday for
wvz501>503-505-506.

Winter weather advisory until 6 pm est this evening for wvz501-
503-505-506.

High wind warning from 1 pm Sunday to 10 am est Monday for
wvz050>052-055-504.

Wind advisory from 1 pm to 10 pm est Sunday for wvz053.

Marine... Small craft advisory from 9 am to 3 pm est Sunday for
anz532>534-537-540>543.

Gale warning from 3 pm Sunday to midnight est Sunday night for
anz530>543.

Small craft advisory from noon to 3 pm est Sunday for anz530-
531-535-536-538-539.

Synopsis... Bjl
near term... Bjl
short term... Bjl
long term... Bkf
aviation... Bjl bkf
marine... Bjl bkf
hydrology... Dhof bjl


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 13 mi42 min ENE 1 G 1 38°F 41°F1026 hPa
BSLM2 - Chesapeake Bay, MD 17 mi126 min NE 2.9 38°F 1027 hPa35°F
NCDV2 25 mi42 min ENE 1.9 G 5.1 40°F 42°F1024.8 hPa
TPLM2 - Thomas Point, MD 34 mi36 min N 11 G 12 37°F 38°F1026.6 hPa (-3.0)37°F
APAM2 - 8575512 - Annapolis, MD 35 mi42 min 38°F 1025.7 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 38 mi42 min NE 8.9 G 11 39°F 1026.2 hPa
SLIM2 - 8577330 - Solomons Island, MD 38 mi42 min NNE 6 G 8.9 40°F 40°F1025.3 hPa
CPVM2 39 mi42 min 38°F 38°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 45 mi42 min ESE 6 G 6 38°F 1026.2 hPa
FSNM2 45 mi42 min ENE 8 G 8.9 38°F 1025.5 hPa
PPTM2 - 8578240 - Piney Point, MD 45 mi42 min E 6 G 7
BLTM2 - 8574680 - Baltimore, MD 46 mi42 min ESE 6 G 8.9 39°F 39°F1025.8 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA10 mi1.7 hrsN 05.00 miLight Rain Fog/Mist39°F36°F89%1027.1 hPa
Camp Springs / Andrews Air Force Base, MD12 mi1.7 hrsNE 55.00 miRain Fog/Mist37°F34°F92%1027 hPa
Washington/Reagan National Airport, DC, VA13 mi44 minENE 85.00 miLight Rain Fog/Mist39°F35°F86%1025.8 hPa
Quantico Marine Corps Airfield - Turner Field, VA20 mi40 minENE 94.00 miLight Rain Fog/Mist40°F37°F93%1025.6 hPa
College Park Airport, MD21 mi53 minN 05.00 miOvercast36°F33°F91%1026.4 hPa

Wind History from DAA (wind in knots)
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Last 24hrNW5NW4N3NW3NW5CalmN4NW4NW5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmE4Calm
1 day agoCalmCalmCalmCalmNE4CalmNW6NW5CalmCalmCalmCalmCalmSE3CalmCalmNW8CalmCalmCalmCalmNW4CalmCalm
2 days agoE4CalmSE3--CalmSE3CalmNW4E4CalmCalmCalmNW3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalm

Tide / Current Tables for Riverview, Maryland
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Riverview
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Sat -- 05:01 AM EST     -0.35 feet Low Tide
Sat -- 06:49 AM EST     Sunrise
Sat -- 09:29 AM EST     Moonset
Sat -- 10:45 AM EST     2.93 feet High Tide
Sat -- 05:34 PM EST     -0.33 feet Low Tide
Sat -- 05:54 PM EST     Sunset
Sat -- 10:47 PM EST     Moonrise
Sat -- 11:16 PM EST     2.73 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.31.60.90.3-0.1-0.4-0.10.61.62.42.82.92.621.30.70.1-0.2-0.30.211.92.42.7

Tide / Current Tables for Gunston Cove, Virginia
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Gunston Cove
Click for Map
Sat -- 04:38 AM EST     -0.28 feet Low Tide
Sat -- 06:49 AM EST     Sunrise
Sat -- 09:30 AM EST     Moonset
Sat -- 10:24 AM EST     2.29 feet High Tide
Sat -- 05:12 PM EST     -0.27 feet Low Tide
Sat -- 05:54 PM EST     Sunset
Sat -- 10:48 PM EST     Moonrise
Sat -- 10:55 PM EST     2.14 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.61.10.60.1-0.2-0.30.10.71.522.32.21.91.40.80.4-0-0.3-0.20.311.622.1

Weather Map and Satellite Images
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GOES Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Wind Forecast for Baltimore, MD/Washington (16,3,4,5)
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Ground Weather Radar Station Sterling, VA
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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.