Monday, June18, 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 5:42AMSunset 8:37PM Monday June 18, 2018 12:04 AM EDT (04:04 UTC) Moonrise 10:08AMMoonset 11:48PM Illumination 22% Phase: Waxing Crescent; Moon at 5 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- 1049 Pm Edt Sun Jun 17 2018
Rest of tonight..S winds 5 kt. Waves less than 1 ft.
Mon..SW winds around 5 kt. Waves 1 ft.
Mon night..W winds 5 kt. Waves less than 1 ft.
Tue..NW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Tue night..NE winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Wed..W winds around 5 kt. Waves 1 ft. Scattered showers and tstms.
Wed night..N winds around 5 kt. Waves 1 ft. Showers likely.
Thu..NE winds around 5 kt. Waves 1 ft. Showers likely in the morning. A chance of showers.
Fri..SE winds 5 kt. Waves less than 1 ft. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1049 Pm Edt Sun Jun 17 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will remain in the western atlantic through Monday. A cold front will approach from pennsylvania Tuesday, then stall over the waters during the middle and latter portion of the week.

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 180109
afdlwx
area forecast discussion
national weather service baltimore md washington dc
909 pm edt Sun jun 17 2018

Synopsis
High pressure will remain off of the mid-atlantic coast through
Monday. A cold front will approach the area from the north on
Tuesday and stall across the area during the middle of the
week.

Near term until 6 am Monday morning
High level clouds and a fairly impressive inversion near the
freezing level (per 00z lwx raob) pretty much kept convection in
check today. With sunset upon us, chances for additional
thunderstorms are nil at best.

The additional atmospheric moisture relative to the past few
days suggest that there will be a greater chance at overnight fog
development... Contingent upon cloud cover. Going forecast has
favored the valleys low spots, which would be where potential
would be the greatest.

Since dewpoints in the upper 60s around 70, lows shouldn't be
far from that... As already advertised.

Short term 6 am Monday morning through Tuesday
Ridge builds in with higher temperatures Monday. Went with our
ensemble guidance that has been performing the best recently.

That gives highs 90-95, and heat index values around 100 with
dewpoints in the low 70s. Think any showers and tstms will be
isolated Mon afternoon.

Tue continues with the heat, but a cold front approaching the
area will increase our odds of thunderstorms, as well as bring a
bigger gradient of temps Tue pm in our forecast area. Heat index
values are currently expected to get into the lower 100s on our
southern tier, but only low 90s on our northern tier... High
temps in the upper 80s, and low to mid 90s respectively.

Westerly winds, weak lapse rates, and weak shear will likely
limit thunderstorm organization, but plenty of moisture and
instability will be pooled ahead of the front. With steering
flow parallel to the boundary, some training is possible for a
locally heavy rain threat. Frontal progression starting to trend
a pinch quicker. The boundary will begin to stall out Tuesday
night, though most models have winds turning northerly over at
least parts of the area. While some showers could persist
through the night, coverage should decrease with loss of
instability.

Long term Tuesday night through Sunday
Model guidance is in good agreement that a frontal boundary will
stall out over, or just south of our area on Wednesday. Low-level
convergence in the vicinity of this frontal boundary will facilitate
the development of showers and thunderstorms across the area.

The main feature of interest locally for the remainder of the week
will be the positioning of the aforementioned frontal boundary. The
eventual location of this boundary will likely be modulated by the
positioning of a longwave trough tracking across eastern canada and
new england. The 12z GFS is more progressive and amplified with this
trough compared to the 00z euro. The GFS solution allows high
pressure to build in the wake of the trough across the great lakes
on Thursday, which acts to push the frontal boundary further south.

The euro keeps high pressure centered over ontario, which enables
the frontal boundary to remain stalled out just to our south.

Ensemble guidance shows a variety of solutions, but in general the
gefs are more progressive with the boundary, while the eps favors a
more stalled out boundary. If the boundary remains stalled out over
our area, chances for showers and storms will persist through
Friday. On the other hand, if the boundary is pushed further off to
our south, Thursday and Friday will be mostly dry.

By next weekend an upper-level low is progged to track from the
central us to the great lakes. Some showers and storms may be
possible as this system passes to our north.

Aviation 01z Monday through Friday
Vfr flight conditions will prevail through the evening with
light winds. Fog may develop overnight, but thats still
contingent on cloud cover. With that uncertainty still in play,
made no forecast adjustments... Still a period of MVFR possible
predawn at cho and especially mrb. Greater fog risk resides in
the valleys away from TAF sites.

Vfr conditions are expected Monday. A cold front will drop
southward on Tuesday, increasing chances of showers and
thunderstorms with local ifr conditions during the afternoon
and evening.

A frontal boundary is expected to stall over our area on
Wednesday, bringing chances for showers and thunderstorms. This
could make sub-vfr conditions possible at times. The position of
this boundary is less certain Thursday and Friday, but if it
were to remain overhead showers and storms would be possible.

Marine
Winds will generally be 10 kt or less today. Monday, possible
channeling flow up the bay will increase speeds from today, but
still expected to remain below small craft advisory at this
time. Tue is more uncertain and will depend on the timing of the
cold front. But winds may approach small craft level Tue pm, also
with an increasing chance of thunderstorms.

Winds are expected to remain below the SCA threshold throughout
the long term period. Showers and thunderstorms may be possible
each afternoon with a frontal boundary nearby.

Climate
Well above normal temperatures are forecast Monday through
Tuesday. Below is a list of daily record warm temperatures.

Washington dc area (dca)
date record high record warm low
june 17 97 (2014) 76 (1952, 1939)
june 18 97 (1944) 77 (2014, 1957)
june 19 99 (1994) 75 (2011, 1994, 1981, 1978)
temperature records for the washington dc area have been kept
at ronald reagan washington national airport since 1945.

Additional temperature records observed downtown date back to
1872.

Baltimore md area (bwi)
date record high record warm low
june 17 96 (1939) 76 (1913)
june 18 97 (1957, 1944) 75 (1957)
june 19 99 (1994) 74 (1905)
temperature records for the baltimore md area have been kept
at baltimore-washington international thurgood marshall
airport since 1950. Additional temperature records observed
downtown date back to 1872.

Dulles va area (iad)
date record high record warm low
june 17 92 (1994) 72 (1996)
june 18 94 (2007, 2006) 73 (2017)
june 19 98 (1994) 71 (2014)
temperature records for the dulles va area have been kept at
washington dulles international airport since 1960.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Cs
near term... Hts
short term... Cs hts
long term... Cs kjp
aviation... Cs hts kjp
marine... Cs kjp
climate... Dh


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 18 mi46 min SE 2.9 G 4.1 80°F 74°F1018.2 hPa
NCDV2 21 mi46 min SW 2.9 G 4.1 79°F 82°F1017.4 hPa
BSLM2 - Chesapeake Bay, MD 25 mi154 min Calm 75°F 1018 hPa71°F
44062 - Gooses Reef, MD 38 mi34 min SSW 9.7 G 14 78°F 1018.6 hPa
SLIM2 - 8577330 - Solomons Island, MD 41 mi46 min SE 6 G 8 77°F 79°F1018.2 hPa
TPLM2 - Thomas Point, MD 42 mi64 min S 11 G 11 78°F 76°F1019.3 hPa (+0.9)75°F
COVM2 - 8577018 - Cove Point LNG Pier, MD 42 mi46 min S 11 G 15 76°F 1018.9 hPa
APAM2 - 8575512 - Annapolis, MD 43 mi46 min 79°F 1017.7 hPa
44063 - Annapolis 44 mi34 min SSW 7.8 G 9.7 77°F 1018.3 hPa
PPTM2 - 8578240 - Piney Point, MD 46 mi52 min SE 9.9 G 11
CPVM2 47 mi46 min 77°F 73°F

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA8 mi3.1 hrsSE 410.00 miFair80°F70°F74%1018.2 hPa
Quantico Marine Corps Airfield - Turner Field, VA12 mi68 minSW 410.00 miA Few Clouds80°F70°F71%1018.7 hPa
Washington/Reagan National Airport, DC, VA17 mi72 minS 710.00 miPartly Cloudy80°F66°F62%1018.4 hPa
Camp Springs / Andrews Air Force Base, MD20 mi3.1 hrsSE 610.00 miA Few Clouds79°F66°F65%1018.4 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA22 mi68 minS 310.00 miOvercast77°F70°F79%1019.3 hPa
Stafford, Stafford Regional Airport, VA23 mi69 minSE 310.00 miPartly Cloudy74°F72°F93%1020 hPa

Wind History from DAA (wind in knots)
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Last 24hrCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmE4SW6SW5S3CalmS3CalmSE3SE4
1 day agoCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmS3S5S7S6CalmW4
G16
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2 days agoW5CalmCalmCalmCalmCalmN5NW4CalmCalmCalmNW4NW5NW8CalmW7NW8NW14
G21
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G18
NW8N6CalmE3

Tide / Current Tables for Glymont, Potomac River, Maryland
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Glymont
Click for Map
Mon -- 12:09 AM EDT     Moonset
Mon -- 05:43 AM EDT     Sunrise
Mon -- 06:03 AM EDT     0.14 feet Low Tide
Mon -- 11:08 AM EDT     Moonrise
Mon -- 11:41 AM EDT     2.17 feet High Tide
Mon -- 06:43 PM EDT     0.01 feet Low Tide
Mon -- 08:35 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
21.71.30.90.60.30.10.30.71.31.92.12.21.91.61.10.70.40.100.30.81.41.8

Tide / Current Tables for Mount Vernon, Virginia
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Mount Vernon
Click for Map
Mon -- 12:09 AM EDT     Moonset
Mon -- 05:43 AM EDT     Sunrise
Mon -- 06:31 AM EDT     0.18 feet Low Tide
Mon -- 11:07 AM EDT     Moonrise
Mon -- 12:08 PM EDT     2.67 feet High Tide
Mon -- 07:12 PM EDT     0.02 feet Low Tide
Mon -- 08:35 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.52.31.81.30.90.50.20.20.61.322.52.72.52.11.61.10.60.300.10.71.42

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 (0,6,7,8)
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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.