Wednesday, June20, 2018 L-36.com


Marine Weather and Tides
Woodbridge, VA

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 8:38PM Wednesday June 20, 2018 8:54 PM EDT (00:54 UTC) Moonrise 12:22PMMoonset 12:23AM Illumination 51% 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- 732 Pm Edt Wed Jun 20 2018
Tonight..SW winds 5 kt. Waves less than 1 ft. Showers likely with a chance of tstms this evening, then a chance of showers after midnight.
Thu..N winds 5 kt. Waves less than 1 ft.
Thu night..E winds around 5 kt. Waves 1 ft. A chance of showers.
Fri..E winds 5 to 10 kt. Waves 1 ft. Showers likely.
Fri night..E winds 5 to 10 kt. Waves 1 ft. Showers likely.
Sat..S winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely.
Sat night..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Sun..W winds 5 kt. Waves less than 1 ft. A chance of tstms. A chance of showers.
Mon..N winds 5 to 10 kt. Waves 1 ft. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 732 Pm Edt Wed Jun 20 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will track from west virginia east over the waters along a stalled front through tonight. The front will then drop farther south Thursday as high pressure briefly builds from the ohio valley to new england. The front will then return north as a warm front Friday night into Saturday as the high moves offshore and low pressure moves from the midwest to the great lakes. A small craft advisory may be needed for a portion of the waters Friday into Saturday.

7 Day Forecast for Marine Location Near Woodbridge, VA
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location: 38.65, -77.22     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 201826
afdlwx
area forecast discussion
national weather service baltimore md washington dc
226 pm edt Wed jun 20 2018

Synopsis
Low pressure will track along a boundary, passing through our
area tonight. The boundary will stall out over central virginia
Thursday and Friday before returning north as a warm front
Saturday. A stronger cold front will approach Sunday before
passing through Sunday night into Monday. High pressure will
return by the middle portion of next week.

Near term through tonight
Latest analysis shows a nearly stationary boundary that extends
from the eastern west virginia panhandle southeast into central
virginia, then eastward toward extreme southern maryland. The
boundary separates warm and very humid air to the south and west
from relatively drier air to the north and east. Dewpoints are
in the 60s north and east of the boundary, and lower to middle
70s south and west of the boundary.

A shortwave in the nearly zonal flow aloft can be seen on water
vapor image this afternoon moving into west virginia. This
system will approach the area late this afternoon, before
passing through tonight. As this system approaches through late
this afternoon, surface low will develop and that will cause
the boundary over our area to continue retreating north and
east as a warm front. In fact... Dewpoints are already on the
rise across the washington and baltimore metro areas (locations
that were on the cool side of the boundary).

Shower and thunderstorm coverage has begun to increase,
with the heaviest activity near and to the south west of the
weak boundary where the air is most unstable. Scattered showers
are also occurring north and east of the boundary as well due to
limited instability.

More widespread showers and thunderstorms are expected late this
afternoon and evening across the entire area as the surface low
and shortwave move through. Any thunderstorms will be capable
of heavy rain, which may result in isolated instances of flash
flooding across the entire area. A flash flood watch remains in
effect for eastern west virginia northern virginia and western
maryland. Across these locations there is a better chance for
multiple rounds of showers and thunderstorms through this
evening, where convergence is a bit stronger along the boundary.

Although shear is marginal, ample low-level moisture along and south
of the boundary (mainly near and SW of the potomac river again)
will result in CAPE sufficient for strong convection capable of
locally damaging wind gusts... Especially late this afternoon and
evening. A few linear segments may develop due to the
unidirectional flow aloft.

Convection should dissipate behind the departing low and upper-
level disturbance overnight, but a few showers are still
possible. Patchy low clouds and fog are possible toward morning
with low-level moisture possibly being trapped underneath the
nocturnal inversion.

Short term Thursday through Friday night
A weak cold front associated with the departing low will drop
south through our area Thursday morning midday and it will stall
out over central virginia toward the potomac highlands late
Thursday through Friday night.

For Thursday, a few showers and thunderstorms are possible near
and to the south west of the boundary. Therefore, the best
chance for showers and thunderstorms will be over central
virginia into the potomac highlands Thursday afternoon evening.

However, an isolated shower t-storm cannot be ruled out farther
north Thursday morning midday as the boundary is sliding
through.

Latest guidance has converged on a solution that has closed off
low pressure both at the surface and aloft developing over the
midwest. A southwest flow at the low and mid-levels will cause
warm and moist air to overrun the relatively cooler air in
place, bringing the likelihood for showers and possible
thunderstorms across the entire area. High pwats and
frontogenetical forcing increasing near the boundary suggests
that some of the rain may be locally heavy. The best chance for
heavy rain will be near the boundary across central virginia
into the potomac highlands.

Long term Saturday through Wednesday
By Saturday morning a surface warm front will be working it's way
through the region. As the warm front progresses through, some
showers will be possible during the morning hours. This warm
front is expected to make it just north of our area by afternoon.

At mid to upper levels, a low will track over the great lakes as it
starts to shear out into more of an open wave. Model guidance
suggests around 1000-2000 j kg of MLCAPE over much of our area
Saturday afternoon, with about 35-40 kts of 0-6 km shear. Given that
environment, organized thunderstorms will be possible Saturday
afternoon, some of which may be strong.

Conditions should dry out Saturday night, but showers and
thunderstorms will be possible again Sunday afternoon and evening as
a shortwave approaches from the ohio valley. A more potent trough
will slide across the northeast Sunday night. The surface cold front
associated with that trough will move through our area late Sunday
night or Monday morning. Some showers or thunderstorms along the
front can't be ruled on Monday, especially if the front slows up a
bit and some daytime heating occurs ahead of it. Once the front
passes however, a northerly wind will advect a drier cooler airmass
into the area. High pressure is expected to build from the great
lakes to the mid-atlantic Monday night through Tuesday, bringing dry
conditions and slightly below normal temperatures.

Aviation 18z Wednesday through Monday
Scattered to numerous showers and thunderstorms are expected
through this evening. Brief ifr subifr conditions are likely in
any heavier showers or thunderstorms. Thunderstorms will also be
capable of producing locally gusty winds as well. Patchy low
clouds and fog are possible overnight into Thursday morning due
to low-level moisture being trapped underneath the subsidence
inversion.

MainlyVFR conditions are expected later Thursday through
Thursday evening. There will be a few showers and thunderstorms
possible, especially near kcho. More widespread showers and
possible thunderstorms are expected overnight Thursday through
Friday night. An onshore flow will also lead to low clouds as
well.

Low ceilings and visiblities may be possible Saturday morning
until a warm front lifts north of our area. Showers and
thunderstorms will be possible both Saturday and Sunday
afternoon.

Marine
Low pressure will pass through the waters tonight and the cold
front associated with the low will drop to the south and west
for Thursday. Winds may briefly approach SCA criteria for a few
hours Thursday due to the pressure surge with the cold front,
but confidence is too low for a headline at this time. The
boundary will remain stalled to the south and west through
Friday night. The gradient may strengthen a bit Friday Friday
night and an SCA may be needed for portions of the waters.

Small craft advisory level winds may be possible in
southeasterly flow to the north of a warm front Saturday
morning, and then in southerly flow later on Saturday once we
break out into the warm sector. Thunderstorms will also be
possible both Saturday and Sunday afternoon.

Hydrology
Showers and thunderstorms will increase in coverage late this
afternoon into this evening as low pressure tracks through the
area. Pwats over 2 inches suggest that any thunderstorms that do
develop will contain torrential downpours, which means that
there is an isolated threat for flood flash flooding with
convection through this evening across the entire area. Will
continue with the flash flood watch for the northwestern portion
of the cwa. Across this area, convergence has been a bit
stronger along the boundary which has led to more development of
showers and thunderstorms. Most of the development has remained
over southwest pa through mid-afternoon, but more convection
should fill in across this area. Multiple rounds of showers and
thunderstorms may lead to a better chance for flash flooding,
which is why the watch is in effect for this area.

Will have to watch for another round of heavy rain late tonight.

Latest thinking is that there is a better chance for this to
develop to our north and east, closer to the departing low
pressure system.

A cold front associated with the departing low will slide south
Thursday before stalling out over central virginia into the
potomac highlands for Friday and Friday night. A modest low-
level jet of 25-30 kts in the 900-800 mb layer is progged by the
majority of the guidance Friday into Friday night which will
advect in more moisture (pwats likely exceed 2 inches by Friday
evening). Numerous showers and possible thunderstorms are
likely, and with the high moisture returning rainfall may be
locally heavy. The best chance for heavy rain will be be across
central virginia into the potomac highlands where forcing will
be stronger near the stalled boundary.

Lwx watches warnings advisories
Dc... None.

Md... Flash flood watch until 10 pm edt this evening for mdz003-501-
502.

Va... Flash flood watch until 10 pm edt this evening for vaz028-031.

Wv... Flash flood watch until 10 pm edt this evening for wvz050>053-
503-504.

Marine... None.

Synopsis... Bjl dhof
near term... Bjl
short term... Bjl
long term... Kjp
aviation... Bjl kjp
marine... Bjl kjp
hydrology... Bjl dhof


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 19 mi55 min W 7 G 13 80°F 78°F1009.5 hPa (+0.8)
NCDV2 25 mi55 min WSW 5.1 G 8 78°F 83°F1007.6 hPa (-0.3)
BSLM2 - Chesapeake Bay, MD 29 mi145 min Calm 74°F 1008 hPa72°F
44062 - Gooses Reef, MD 43 mi45 min WSW 9.7 G 12 80°F 1008.5 hPa
TPLM2 - Thomas Point, MD 45 mi55 min N 5.1 G 6 76°F 77°F1009.7 hPa (-0.0)68°F
APAM2 - 8575512 - Annapolis, MD 46 mi55 min 77°F 1008.2 hPa (-0.0)
COVM2 - 8577018 - Cove Point LNG Pier, MD 47 mi55 min SSW 8.9 G 12 78°F 1009 hPa (-0.3)
44063 - Annapolis 47 mi45 min NNW 1.9 G 3.9 77°F 1009 hPa
SLIM2 - 8577330 - Solomons Island, MD 47 mi55 min SSW 6 G 6 77°F 80°F1008.1 hPa (-0.4)

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA6 mi2 hrsN 010.00 miFair79°F73°F84%1008.4 hPa
Quantico Marine Corps Airfield - Turner Field, VA11 mi59 minN 010.00 miMostly Cloudy79°F75°F88%1009.8 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA17 mi59 minW 54.00 miThunderstorm in Vicinity Fog/Mist72°F70°F94%1011.7 hPa
Washington/Reagan National Airport, DC, VA18 mi63 minW 1010.00 miOvercast81°F70°F69%1009.6 hPa
Stafford, Stafford Regional Airport, VA21 mi60 minN 010.00 miThunderstorm in Vicinity77°F77°F100%1010.8 hPa
Camp Springs / Andrews Air Force Base, MD22 mi2 hrsENE 310.00 miMostly Cloudy78°F71°F81%1008.6 hPa

Wind History from DAA (wind in knots)
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Last 24hrCalmCalmW3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmS4CalmCalmCalmCalmNW12
1 day agoCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmNW6W7NW11
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N9W7N6CalmN3Calm
2 days agoSE4--------------------------------------S6S4S4S3

Tide / Current Tables for High Point, Occoquan Bay, Virginia
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High Point
Click for Map
Wed -- 01:08 AM EDT     1.81 feet High Tide
Wed -- 01:22 AM EDT     Moonset
Wed -- 05:44 AM EDT     Sunrise
Wed -- 06:52 AM EDT     First Quarter
Wed -- 07:46 AM EDT     0.17 feet Low Tide
Wed -- 01:21 PM EDT     Moonrise
Wed -- 01:29 PM EDT     1.77 feet High Tide
Wed -- 08:11 PM EDT     0.07 feet Low Tide
Wed -- 08:36 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.71.81.71.41.10.80.50.20.20.40.81.31.61.71.71.51.20.80.50.20.10.20.51

Tide / Current Tables for Deep Point, Mattawoman Creek, Potomac River, Maryland
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Deep Point
Click for Map
Wed -- 01:02 AM EDT     1.83 feet High Tide
Wed -- 01:22 AM EDT     Moonset
Wed -- 05:44 AM EDT     Sunrise
Wed -- 06:52 AM EDT     First Quarter
Wed -- 07:39 AM EDT     0.15 feet Low Tide
Wed -- 01:21 PM EDT     Moonrise
Wed -- 01:23 PM EDT     1.79 feet High Tide
Wed -- 08:04 PM EDT     0.05 feet Low Tide
Wed -- 08:36 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.71.81.71.41.10.70.40.20.20.40.91.31.61.81.71.51.20.80.50.20.10.20.61.1

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 (20,4,5,8)
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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.