Tuesday, May22, 2018 L-36.com


Marine Weather and Tides
Potomac Heights, MD

Version 3.4
What's New / NOTES
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.

Sunrise 5:48AMSunset 8:21PM Tuesday May 22, 2018 3:29 PM EDT (19:29 UTC) Moonrise 12:19PMMoonset 1:10AM Illumination 55% Phase: First Quarter Moon; 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- 133 Pm Edt Tue May 22 2018
This afternoon..S winds 5 kt. Waves less than 1 ft. Showers and tstms.
Tonight..SW winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Wed..NW winds 5 to 10 kt. Waves 1 ft.
Wed night..NW winds 5 to 10 kt. Waves 1 ft.
Thu..N winds 5 kt. Waves less than 1 ft.
Thu night..S winds around 5 kt. Waves 1 ft.
Fri..SW winds 5 kt. Waves less than 1 ft.
Sat..SW winds 5 kt. Waves less than 1 ft. A chance of tstms. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 133 Pm Edt Tue May 22 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A warm front will pass through the waters today and a cold front will approach from the northwest tonight before passing through Wednesday. High pressure will build overhead Thursday through Friday before moving offshore during the weekend. Small craft advisory conditions are possible Wednesday.

7 Day Forecast for Marine Location Near Potomac Heights, MD
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location: 38.62, -77.13     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 221422
afdlwx
area forecast discussion
national weather service baltimore md washington dc
1022 am edt Tue may 22 2018

Synopsis
A warm front will lift northward through the area today and a
cold front will approach from the northwest tonight before
passing through on Wednesday. Weak high pressure will then build
over the area for the second half of the week.

Near term through tonight
This morning's RAOB at iad sampled a very moist atmosphere with
a precipitable water value of 1.60 inches, tying the daily 12z
record for this date. Showers are ongoing this morning as a warm
front lifts through our cwa, with some embedded areas of
moderate to heavy rainfall. Good news is this activity is moving
right along at around 25 mph to the east, helping keep any
potential flooding threat at a minimum. Rainfall amounts this
morning have generally a quarter of an inch or less.

The warm front will lift to our north this afternoon, moving
much of the area in to the warm sector. Latest satellite imagery
indicate clouds starting to break up a bit across west virginia
and western virginia, and this trend will likely continue
eastward this morning. This will help destabilize the atmosphere
this afternoon, with MLCAPE reaching the 1000-1500 j kg range,
steepening low level lapse rates, and dewpoints well in to the
60s. Modest shear on the order of 25-30 knots along with the
aforementioned variables will support a potential for strong to
severe storms.

As a result, the storm prediction center has placed a portion
of our area in a slight risk for severe thunderstorms today,
with damaging winds being the primary threat. This area
encompasses the district on the northern tier, extending south
and eastward into southern maryland, portions of northern
virginia and the northern piedmont. Hi-res guidance favoring a
linear storm mode over this area this afternoon and early
evening, with again damaging winds being the primary threat.

Expect temperatures to top out today in the lower to middle 70s
across northeastern maryland to the lower 80s across central
virginia. Convection will wane this evening and a cold front
will approach from the northwest tonight and cross the area
towards morning. This could trigger some additional showers or
perhaps a thunderstorm, but expect coverage will be mostly
isolated in nature due to the nocturnal passage and meager
support aloft. Lows will hold in the lower to middle 60s for
all.

Short term Wednesday through Thursday night
A weak cold front will pass through the area Wednesday. A north
to northwest flow behind the boundary will usher in drier
conditions. A couple showers and thunderstorms cannot be ruled
out depending on the exact timing of the frontal passage. As of
now, the best chance for a shower thunderstorm will be across
central virginia into southern maryland, but even across these
areas much of the time should turn out dry and any coverage will
be isolated to widely scattered.

High pressure will build overhead for Wednesday night through
Thursday night, bringing dry conditions along with low humidity.

Long term Friday through Monday
High pressure will remain in control of the weather pattern for
Friday before building offshore Friday night through the
weekend. A southwest flow will usher in a return of hotter and
more humid conditions. The increased humidity may lead to popup
showers and thunderstorms, especially during the afternoon and
evening hours each day. As of now, it appears that convection
coverage will be scattered, but still watching the potential for
tropical moisture to get drawn into the area. As of now, it
appears more likely that it would remain to our south and west
during this time.

For memorial day, tropical moisture may make a push northward
toward our area. This may enhance the chances for showers and
thunderstorms but confidence remains low this far out.

Aviation 14z Tuesday through Saturday
A warm front is lifting through the terminals this morning,
bringing periods of MVFR ifr vis and CIGS with passing showers.

This will continue for the remainder of the morning while winds
trend light and southerly.

Popup showers and thunderstorms will develop behind the warm
front this afternoon, but CIGS should lift a bit as well. Some
thunderstorms will be capable of producing gusty winds, hail and
heavy rains that can reduce vsbys below 2 miles briefly. A cold
front will approach the terminals tonight before passing through
Wednesday. A light gradient ahead of the front will allow for
patchy fog to develop overnight. Any fog should lift by mid-
morning Wednesday.VFR conditions are expected most of the
time Wednesday afternoon through Friday. A few popup showers
and thunderstorms are possible Saturday afternoon and evening.

Marine
A warm front will pass through the waters through midday,
residing to our north this afternoon. Showers this morning will
transition to a thunderstorm threat this afternoon and early
evening. These storms will be capable of producing gusty winds,
and heavy rain that briefly reduces visibility below 2 miles.

While conditions are forecast to remain sub-sca, thunderstorm
activity this afternoon could result in the need for special
marine warnings, so remain ALERT if on the waters today.

A cold front will approach the waters tonight. A shower or
thunderstorm cannot be ruled out, but coverage should be limited
due unfavorable timing. This weak cold front will pass through
the waters Wednesday. A north to northwest flow will develop
behind the boundary. Winds may come close to SCA criteria, but
have gusts capped around 15 knots for now due to the relatively
cooler waters. High pressure will build over the waters
Wednesday night through Friday before moving offshore during the
weekend. A return southerly flow will develop during the
weekend and this may result in popup showers and thunderstorms,
especially during the afternoon and evening hours.

Tides coastal flooding
The latest water levels were below minor flooding thresholds for
washington dc. Freshwater continues to decrease upstream so that
is having less of an impact. However, the southerly flow will
continue today and the high tide this afternoon will be the
higher of the two. Therefore, the advisory has been extended in
time for the high tide cycle this afternoon. The best chance for
minor flooding will be at the washington channel with potomac
river at georgetown likely remaining below minor flooding
thresholds.

Lwx watches warnings advisories
Dc... Coastal flood advisory until 5 pm edt this afternoon for
dcz001.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Bjl bkf
near term... Bkf
short term... Bjl bkf
long term... Bjl imr
aviation... Bjl imr bkf
marine... Bjl imr bkf
tides coastal flooding... Bjl


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 18 mi42 min SSE 5.1 G 6 75°F 66°F1016.1 hPa
NCDV2 21 mi42 min SW 2.9 G 5.1 80°F 75°F1015.2 hPa
BSLM2 - Chesapeake Bay, MD 25 mi120 min SE 1.9 73°F 1018 hPa66°F
44062 - Gooses Reef, MD 38 mi30 min SSE 9.7 G 12 70°F 1 ft1017.6 hPa (-2.0)
SLIM2 - 8577330 - Solomons Island, MD 41 mi42 min SSW 8.9 G 11 76°F 70°F1016.2 hPa
TPLM2 - Thomas Point, MD 42 mi30 min S 6 G 6 69°F 68°F1017.3 hPa (-2.8)67°F
COVM2 - 8577018 - Cove Point LNG Pier, MD 42 mi42 min S 12 G 14 69°F 1017.3 hPa
APAM2 - 8575512 - Annapolis, MD 43 mi42 min 74°F 1016.3 hPa
44063 - Annapolis 44 mi40 min SSW 3.9 G 5.8 69°F 1017.3 hPa
PPTM2 - 8578240 - Piney Point, MD 46 mi42 min SW 6 G 6
CPVM2 47 mi42 min 71°F 68°F

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA8 mi94 minSSE 710.00 miMostly Cloudy77°F67°F74%1017.3 hPa
Quantico Marine Corps Airfield - Turner Field, VA12 mi34 minSSE 710.00 miMostly Cloudy79°F73°F82%1016.1 hPa
Washington/Reagan National Airport, DC, VA17 mi38 minSSE 710.00 miMostly Cloudy76°F66°F74%1016.1 hPa
Camp Springs / Andrews Air Force Base, MD20 mi94 minN 010.00 miOvercast74°F67°F79%1018.1 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA22 mi34 minS 410.00 miPartly Cloudy81°F70°F69%1016.5 hPa
Stafford, Stafford Regional Airport, VA23 mi35 minSW 310.00 miPartly Cloudy82°F70°F68%1017.3 hPa

Wind History from DAA (wind in knots)
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Last 24hrSE6SE5SE8SE6SE5CalmSE6Calm----------332CalmCalmS3SW4SE6S4SE7SE6
1 day agoW6NW7S3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmN4E5SE5CalmCalmS5SE7
2 days agoS3CalmCalmS3CalmSE5SE5S3S4S4CalmS3SE5S4S4S3S5SW5S4S5S4S6SW4W5

Tide / Current Tables for Glymont, Potomac River, Maryland
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Glymont
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Tue -- 01:46 AM EDT     2.01 feet High Tide
Tue -- 02:09 AM EDT     Moonset
Tue -- 05:51 AM EDT     Sunrise
Tue -- 08:20 AM EDT     0.23 feet Low Tide
Tue -- 01:19 PM EDT     Moonrise
Tue -- 02:04 PM EDT     2.05 feet High Tide
Tue -- 08:19 PM EDT     Sunset
Tue -- 08:56 PM EDT     0.12 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.7221.81.51.10.70.40.20.30.61.21.61.92.11.91.61.20.90.50.20.10.30.8

Tide / Current Tables for Mount Vernon, Virginia
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Mount Vernon
Click for Map
Tue -- 02:09 AM EDT     Moonset
Tue -- 02:13 AM EDT     2.44 feet High Tide
Tue -- 05:50 AM EDT     Sunrise
Tue -- 08:49 AM EDT     0.32 feet Low Tide
Tue -- 01:18 PM EDT     Moonrise
Tue -- 02:30 PM EDT     2.49 feet High Tide
Tue -- 08:19 PM EDT     Sunset
Tue -- 09:26 PM EDT     0.19 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.92.32.42.321.51.10.70.40.30.61.11.82.22.52.52.21.71.30.80.50.20.20.7

Weather Map and Satellite Images
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wmap_A
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 (15,3,4,5)
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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.