Tuesday, November13, 2018 L-36.com


Marine Weather and Tides
National Harbor, 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 4:57PM Tuesday November 13, 2018 9:17 PM EST (02:17 UTC) Moonrise 11:58AMMoonset 10:01PM Illumination 35% Phase: Waxing Crescent; Moon at 6 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- 637 Pm Est Tue Nov 13 2018
.small craft advisory in effect until 6 am est Wednesday...
Tonight..NW winds 10 kt with gusts to 20 kt. Waves 1 ft.
Wed..N winds 5 to 10 kt. Waves 1 ft.
Wed night..NE winds 5 kt. Waves less than 1 ft.
Thu..NE winds 5 to 10 kt. Waves 1 ft. Rain with a chance of sleet.
Thu night..N winds 5 to 10 kt. Waves 1 ft. Rain.
Fri..NW winds 5 to 10 kt with gusts to 20 kt. Waves 1 ft. A chance of rain.
Fri night..W winds around 5 kt. Waves 1 ft.
Sat..NW winds around 5 kt. Waves 1 ft.
Sun..W winds around 5 kt. Waves 1 ft.
ANZ500 637 Pm Est Tue Nov 13 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build into the region through Wednesday, then retreat to the north as low pressure developing over the tennessee valley Thursday and moves up the east coast. Small craft advisories may be needed late Wednesday night through Friday. Gale warnings may be needed Friday for portions of the waters.


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 132045
afdlwx
area forecast discussion
national weather service baltimore md washington dc
345 pm est Tue nov 13 2018

Synopsis
A cold front will push east of the area tonight. High pressure
will follow for Wednesday before retreating into new england
Thursday. An area of low pressure will develop over the
tennessee valley Thursday, with a second area of low pressure
moving up the east coast Thursday night. High pressure will
return Friday into the weekend.

Near term through Wednesday
Low pressure is near CAPE cod this afternoon and is pulling away to
the northeast. A lingering low-level frontal zone coupled with an
approaching mid upper trough axis aloft and right-entrance upper jet
dynamics is keeping clouds and scattered light showers around. As
the forcing shifts southeast by this evening, this precipitation
will come to an end. Some upslope snow showers may linger into the
evening along the allegheny front but little accumulation is
expected.

Even though precipitation will end, high clouds will stick around
much of the night with the upper jet in place. Temperatures should
drop below freezing everywhere except the immediate downtown
dc baltimore areas and right along the bay shore tonight.

High pressure will pass by to the north on Wednesday. The weather
will be dry but cirrus will likely be prevalent due to the upper jet
nearby. Seasonably cold air will move into the area, with highs only
in the upper 30s to mid 40s.

Short term Wednesday night through Thursday night
High pressure will move off to new england Thursday night and wedge
down the appalachians, funneling cold and dry air into our area.

While there is some question on lows depending on how dense the
cirrus is, dew points will be well into the 20s, so if anything
these clouds would just keep temperatures closer to freezing versus
falling further. That will set the stage for a wintry mix ahead of
an upper level low in the mississippi valley, one surface low
lifting through the tn valley, with another developing along the
carolina coast on Thursday. Deep moisture and ascent will bring
widespread precipitation to the area, with storm total liquid
amounts of at least an inch expected. Synoptically, the set-up
is favorable for a winter storm. However, since it's so earlier
in the season, the quality of the cold air is in question, and
ground temperatures aren't especially cold yet. Further, there
are still a range of model solutions regarding the strength of
the warm nose aloft. Precipitation is expected to move northward
late Wednesday night and encompass the entire area by Thursday
morning. Am offering a mixed bag of precipitation, with snow
most likely during the early stages of the event, and it's
possible several inches of accumulation occur, particularly
northwestern parts of the cwa. Subfreezing temperatures are most
likely west of i-95, so this area will be the focus of
accumulations. Areas near and west of the blue ridge catoctins
will likely remained entrenched in the cold air for much of the
day as cold, dry air continues to feed into the precipitation.

The question is how much falls as sleet versus freezing rain.

Have kept accumulations conservative for now, but there is
concern for significant wintry accumulations over parts of the
mountainous areas given the synoptic setup and quantity of qpf
(though of course if rates are too high it is detrimental to ice
accretion). Will therefore be hoisting a winter storm watch,
with the option to resolve it to an advisory if it become
apparent neither snow nor ice will meet warning criteria.

Additional advisories will be possible once the areas of
freezing rain potential become apparent. Other than the wintry
aspect, the moderate to locally heavy rainfall could lead to an
isolated flooding issue.

The surface low will deepen and move up the coast Thursday
night, but the upper level low will be approaching, which will
likely lead to additional precipitation. By that time, more
areas (especially east of the blue ridge) will be favored to see
rain, but a changeover to snow is expected in the western
mountains, and it's not impossible some wet flakes make it to
the metros before the precipitation ends.

Long term Friday through Tuesday
The coastal low that will bring the region active weather on
Thursday will be located off the south jersey shoreline early Friday
morning. Some early morning rain showers will be possible,
especially over northeastern md. Any residual showers should move
out of the area by afternoon as the coastal low tracks off to the
northeast. Breezy northwesterly winds are expected in the wake of
the coastal low, with high temperatures reaching into the upper 40s
to near 50.

Following this system, an extended period of dry weather is forecast
for the weekend. Mostly sunny skies are expected Saturday as a weak
area of high pressure crests overhead. There may be a few more
clouds around on Sunday, but dry conditions are expected once again.

By Monday a deep trough will slide down in northwesterly flow and
move over the great lakes. This system will drive a potent cold
front through the area somewhere in the Monday through Monday night
timeframe, bringing well below normal temperatures into the area.

The system will be rather moisture starved, so little precipitation
is expected outside of some upslope snow in western portions of the
forecast area.

Aviation 21z Tuesday through Sunday
Ceilings have lifted toVFR and are expected to remain that way
through Wednesday. Some light showers are lingering ahead of an
upper level trough but are not expected to cause any vsby reductions
and will exit by this evening. NW winds 10-15 kts with gusts 20-25
kts will remain possible through this evening, with lighter winds
from late tonight through Wednesday.

Low pressure approaches from the tennessee valley by Thursday
morning, with a wintry mix and sub-vfr likely west of i-95, and
mainly rain (but still sub-vfr) east of i-95. Generally NE flow
around 10 kts, with llws possible at times. Will have more details
on these threats in the coming forecasts, although mrb will likely
experience wintry precip the longest.

Gusty northwesterly winds will be possible on Friday in the wake of
a departing coastal low. Otherwise,VFR conditions are expected
through the weekend.

Marine
Nw winds are increasing as a surface cold front pushes east, with
gusts of 20-25 kts likely through much of tonight. High pressure
will build in from the west late tonight, with winds diminishing
first on the upper potomac. Winds will continue to diminish through
Wednesday as the high moves overhead, then retreats to the north.

Northeast flow will increase between the departing high and low
pressure approaching from the tennessee valley late Wednesday night
into Thursday with SCA likely again. Will hold off on additional
scas at the moment since there is some uncertainty near the end of
the third period. Near-gales are possible in the wake of the coastal
low by late Thursday night.

High end small craft, if not gale conditions will be possible on
Friday in the wake of a departing coastal low. Will await for
additional guidance before advertising gales on the synopsis and
hazardous weather outlook. Winds should drop below SCA levels by
Saturday morning and remain low through the weekend as high pressure
moves overhead.

Lwx watches warnings advisories
Dc... None.

Md... Winter storm watch from late Wednesday night through late
Thursday night for mdz501-502.

Va... Winter storm watch from late Wednesday night through late
Thursday night for vaz025-503-504-508.

Winter storm watch from late Wednesday night through late
Thursday night for vaz026>030-507.

Wv... Winter storm watch from late Wednesday night through late
Thursday night for wvz050-051-055-501>506.

Marine... Small craft advisory until noon est Wednesday for anz530>532-
538>540.

Small craft advisory until 6 pm est Wednesday for anz533-534-
537-541>543.

Small craft advisory until 6 am est Wednesday for anz535-536.

Synopsis... Ads
near term... Ads
short term... Ads
long term... Kjp
aviation... Ads kjp
marine... Ads kjp


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 5 mi30 min NW 5.1 G 7 46°F 51°F1023.4 hPa
BSLM2 - Chesapeake Bay, MD 17 mi108 min NNW 4.1 46°F 1021 hPa35°F
TPLM2 - Thomas Point, MD 32 mi18 min WNW 8 G 9.9 46°F 52°F1023.6 hPa (+2.9)36°F
APAM2 - 8575512 - Annapolis, MD 32 mi30 min 46°F 1022.3 hPa
44063 - Annapolis 33 mi24 min NW 9.7 G 12 46°F 52°F1023.1 hPa
NCDV2 33 mi36 min NNW 6 G 8 46°F 52°F1022.4 hPa
CPVM2 37 mi30 min 46°F 35°F
44062 - Gooses Reef, MD 37 mi28 min 48°F 1023.1 hPa
FSNM2 39 mi30 min W 9.9 G 13 46°F 1021.9 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 39 mi30 min W 9.9 G 12 46°F 1022.2 hPa
BLTM2 - 8574680 - Baltimore, MD 40 mi36 min NW 1.9 G 5.1 46°F 55°F1021.9 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 44 mi30 min NNW 14 G 17 47°F 1023.2 hPa
SLIM2 - 8577330 - Solomons Island, MD 45 mi30 min NNW 9.9 G 15 47°F 55°F1022.4 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 mi26 minWNW 610.00 miOvercast47°F34°F61%1023.4 hPa
Camp Springs / Andrews Air Force Base, MD9 mi82 minWNW 710.00 miA Few Clouds45°F32°F63%1022.2 hPa
Fort Belvoir, VA9 mi82 minNW 610.00 miFair46°F36°F71%1022.7 hPa
College Park Airport, MD14 mi36 minWNW 410.00 miMostly Cloudy44°F32°F65%1022.7 hPa
Fort Meade / Tipton, MD24 mi36 minW 310.00 miFair43°F35°F76%1023.4 hPa

Wind History from DCA (wind in knots)
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Last 24hrNE4NE5NE7NE9N8N9N8NW10NW12NW12N12NW12NW11NW13NW11NW8NW14
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1 day agoCalmSW4SW3SW4CalmCalmCalmCalmCalmCalmS4S5CalmS3S5S6SE5S4SW4CalmE5E6E3E4
2 days ago4W5SW3N8W4N8NW6N6N6N63NW5N34E3SE3S4S6S7SW6S6SW5S3SW3

Tide / Current Tables for Alexandria, Virginia
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Alexandria
Click for Map
Tue -- 06:25 AM EST     0.27 feet Low Tide
Tue -- 06:48 AM EST     Sunrise
Tue -- 11:57 AM EST     Moonrise
Tue -- 12:10 PM EST     2.56 feet High Tide
Tue -- 04:56 PM EST     Sunset
Tue -- 06:11 PM EST     0.30 feet Low Tide
Tue -- 10:01 PM EST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.92.521.40.90.50.30.30.71.422.42.62.421.40.80.50.30.40.81.42.22.6

Tide / Current Tables for Riverview, Potomac River, Maryland
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Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Weather Map and Satellite Images
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GOES Local Image of Mid-Atlantic    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 (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.