Sunday, August19, 2018 L-36.com


Marine Weather and Tides
National Harbor, MD

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Sunrise 6:25AMSunset 7:58PM Sunday August 19, 2018 9:22 PM EDT (01:22 UTC) Moonrise 2:09PMMoonset 12:00AM Illumination 61% Phase: Waxing Gibbous; Moon at 8 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- 735 Pm Edt Sun Aug 19 2018
Tonight..NE winds 10 kt. Waves 1 ft. Isolated showers this evening.
Mon..E winds 5 to 10 kt. Waves 1 ft.
Mon night..E winds 5 to 10 kt. Waves 1 ft.
Tue..SE winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely.
Tue night..SW winds 10 kt. Waves 1 ft. Showers and tstms likely.
Wed..W winds 5 to 10 kt. Waves 1 ft.
Wed night..NW winds 5 to 10 kt. Waves 1 ft.
Thu..N winds around 5 kt. Waves 1 ft.
Fri..SE winds around 5 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 735 Pm Edt Sun Aug 19 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build to the north tonight and Monday before a warm front lifts northward through the waters on Tuesday. A cold front will sweep to the east on Wednesday followed by modified canadian high pressure taking hold through week's end. A small craft advisory may be needed Tuesday into Wednesday.


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 191909
afdlwx
area forecast discussion
national weather service baltimore md washington dc
309 pm edt Sun aug 19 2018

Synopsis
High pressure will build to the northeast tonight through Monday
before low pressure passes northwest of the area Tuesday. A cold
front will sweep eastward by early Wednesday, with high
pressure building from the west for the end of the week.

Near term through Monday
Latest surface analysis depicts a stalled cold front draped
across southern virginia, with one weak low pressure off the
jersey shore and another much further west in kansas. High
pressure is centered near the mouth of the st. Lawrence river.

Aloft, a shortwave is situated over new jersey heading east away
from us, while another is diving southeast across michigan,
heading towards us. A ridge of high pressure remains centered
off the east coast of florida.

Tonight through Monday, the main issue will involve the
northeast flow as the high tries to build into the region. A
cooler but still relatively moist flow will help keep clouds
around most of the time, though some breaks will allow the sun
to shine through. Closer to the front in central and western
virginia and eastern west virginia, instability and upslope flow
will aid in the develop of some showers and perhaps some drizzle
as well. A little thunder can't be ruled out, though storms
probably be too weak to produce excessive rain and definitely
too weak to produce severe weather. That said, these showers and
storms could be further enhanced on Monday as the shortwave
diving southeast over michigan crosses virginia. None of this
will likely affect the metro area itself, however, which will
probably stay dry, aside from perhaps a little patchy drizzle,
through Monday. Lows tonight will drop into the 60s, with highs
in the 70s to lower 80s on Monday.

Short term Monday night through Tuesday night
Next system, an unseasonbly strong low pulling northeast from
the southern plains towards the great lakes, will push the
stalled front back north as a warm front Monday night into
Tuesday. Showers will increase in coverage once again, with
perhaps some isolated thunder. However, main story is with the
cold front on Tuesday night. With 30-40 knots of shear and 2000+
j kg of CAPE expected late Tuesday, severe weather is looking
increasingly probable, while pw's above 2 inches also make
flooding a significant possibility as well. Bottom line is that
Tuesday afternoon and evening is looking like a very active
period, and this has already been highlighted in the hwo. Lows
Monday night will be in the 60s to near 70, highs Tuesday will
reach the 80s again, with lows back down in the 60s to near 70
Tuesday night.

Long term Wednesday through Sunday
On Wednesday, a cold front will move through the region early
in the day. Winds will be west to northwesterly leading to some
upslope flow on the west side of the blue ridge. Precipitation
on Wednesday will be limited to western parts of the blue ridge
mountains and few isolated showers early on Wednesday in the
rest of the cwa. Skies look to remain mostly clear throughout
the region as high pressure settles over region behind the
frontal passage. Daytime temperatures look to remain mild in the
mid to upper 70s to low 80s which will be below average for
this time of the year.

Thursday into Friday, high pressure will settle over the region
from the west. Winds will remain light out of the northwest to
northerly with mostly clear skies throughout our region. Daytime
high temperatures will remain mild in the 70s and lower 80s.

On Saturday, a weak shortwave trough will approach and move to
our north. A cold front associated with this system will try to
move through our region. Both the 00z euro and 12z GFS show the
front being fairly weak. GFS has most of the region seeing
little to no precipitation while the euro tries to bring in rain
Sunday but is very scattered. With high pressure sitting over
our region for a extended period, it looks like it may be too
dry for the frontal boundary to really bring much precipitation
to the region. Afternoon temperatures look to remain in the 70s
and lower 80s. Winds are very light out of the south which
suggest not much moisture transport into the region.

Aviation 19z Sunday through Friday
Other than a stray shower around cho, the rest of this afternoon
looks dry at the terminals. MVFR CIGS linger at mtn, but
generallyVFR elsewhere, except occasional MVFR at cho with the
showers.

Tonight, northeast flow looks likely to bring a widespread MVFR
stratus deck to the terminals. Ifr is possible but hesitated
given the season and limited rainfall leading into the event,
which would tend to keep the low levels a little drier than
models suggest. That having been said, some patchy drizzle or
mist with reduced visibilities is also possible later tonight
into Monday morning.

Cigs probably lift some as we head through Monday, but will
probably lower again Monday night as the next system approaches.

Reduced CIGS and vis with gusty showers and t-storms are
possible Tuesday into Tuesday night as a strong cold front
crosses the region.

On Wednesday, a frontal boundary will exit the region early to
the west. Precipitation will be focused on the western side of
the mountains. Winds should be out of the west to northwest. May
be some concern for fog behind the front as temperatures likely
drop to dewpoint and winds are light. Skies should clear during
the day. Some subVFR conditions will be possible early
Wednesday.

On Thursday, high pressure settles over region with light winds
out of the west to northwest. Skies should remain mostly clear.

Vfr conditions are expected.

Marine
High building south will continue bringing winds of 10-15 knots
tonight, and it could reach marginal SCA levels, but confidence
remains low so have capped gusts just below threshold. Winds
should diminish Monday night as they shift easterly and then
southeast ahead of the next system. Then, winds will increase
Tuesday into Tuesday night ahead of the next cold front, with
sca looking likely. Convective-wise, no thunderstorms are
expected through Monday night, but the risk increases
significantly Tuesday into Tuesday night with the next front,
and gusty winds are a concern, with special marine warnings
possible.

Showers will exit the region early on Wednesday. Winds will be
out of the west to northwest. Winds strength should be limited
over the bay.

On Thursday, high pressure settles over the region. Skies
should be mostly clear with light westerly winds.

Tides coastal flooding
Onshore flow will develop Monday through early Tuesday. The
favored (higher astronomical) tides Monday night and Tuesday
night could approach minor flood stage as anomalies increase.

Best odds appear to be Tuesday night.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Rcm
near term... Rcm
short term... Rcm
long term... Jmg
aviation... Rcm jmg
marine... Rcm jmg
tides coastal flooding... Rcm


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 5 mi35 min ENE 5.1 G 12 76°F 81°F1015.9 hPa
BSLM2 - Chesapeake Bay, MD 17 mi113 min NE 1.9 73°F 1015 hPa68°F
TPLM2 - Thomas Point, MD 32 mi23 min ENE 13 G 15 74°F 82°F1017.1 hPa (+1.5)71°F
APAM2 - 8575512 - Annapolis, MD 32 mi35 min 74°F 1015.8 hPa
44063 - Annapolis 33 mi33 min E 12 G 16 75°F 1016.2 hPa
NCDV2 33 mi35 min ENE 1 G 6 77°F 84°F1014.8 hPa
CPVM2 37 mi35 min 75°F 71°F
44062 - Gooses Reef, MD 37 mi33 min E 12 G 16 78°F 1015.8 hPa
FSNM2 39 mi83 min NE 9.9 G 14 72°F 1015.9 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 39 mi35 min NE 11 G 13 73°F 1016.1 hPa
BLTM2 - 8574680 - Baltimore, MD 40 mi35 min E 8.9 G 14 72°F 84°F1016.1 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 44 mi35 min E 13 G 15 77°F 1016.2 hPa
SLIM2 - 8577330 - Solomons Island, MD 45 mi41 min N 5.1 G 7 78°F 83°F1015.3 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA4 mi31 minENE 1510.00 miOvercast77°F68°F74%1015.8 hPa
Camp Springs / Andrews Air Force Base, MD9 mi87 minNE 810.00 miFair74°F67°F82%1015.7 hPa
Fort Belvoir, VA9 mi87 minN 010.00 miMostly Cloudy78°F69°F74%1015.5 hPa
College Park Airport, MD14 mi49 minENE 410.00 miPartly Cloudy73°F67°F85%1016.3 hPa
Fort Meade / Tipton, MD24 mi50 minENE 410.00 miFair70°F68°F94%1017.3 hPa

Wind History from DCA (wind in knots)
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Last 24hrW8W5W5NW5NW7N6NW7NW9N9N7NW9N7N8N6N7NW7N8N6N8NE7NE7NE8NE9NE15
1 day agoSW3SW3W6SW4SW3NW7
G21
CalmSW4SW4W3SW4S3S5SW8SW8W9W9W10W11W10W8SW8W7NW4
2 days agoS7S6S6S5S6S5S6S4S5S4S6S7S7S7S9S10S12S12S12S10
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Tide / Current Tables for Alexandria, Virginia
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Alexandria
Click for Map
Sun -- 12:41 AM EDT     Moonset
Sun -- 03:14 AM EDT     3.22 feet High Tide
Sun -- 06:25 AM EDT     Sunrise
Sun -- 10:04 AM EDT     0.45 feet Low Tide
Sun -- 03:08 PM EDT     Moonrise
Sun -- 03:48 PM EDT     2.80 feet High Tide
Sun -- 07:57 PM EDT     Sunset
Sun -- 09:58 PM EDT     0.45 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.92.533.23.12.72.11.61.10.70.50.61.21.82.42.72.82.521.40.90.60.40.6

Tide / Current Tables for Riverview, Potomac River, Maryland
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Riverview
Click for Map
Sun -- 12:41 AM EDT     Moonset
Sun -- 03:02 AM EDT     2.93 feet High Tide
Sun -- 06:25 AM EDT     Sunrise
Sun -- 09:52 AM EDT     0.40 feet Low Tide
Sun -- 03:08 PM EDT     Moonrise
Sun -- 03:36 PM EDT     2.55 feet High Tide
Sun -- 07:57 PM EDT     Sunset
Sun -- 09:47 PM EDT     0.39 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.82.42.82.92.82.31.81.30.90.60.40.71.21.82.22.52.52.21.71.20.70.50.40.6

Weather Map and Satellite Images
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wmap_A
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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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Baltimore, MD/Washington (21,6,7,8)
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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.