Thursday, August17, 2017 L-36.com


Marine Weather and Tides
Indian Head, MD

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 6:24AMSunset 8:01PM Thursday August 17, 2017 11:21 AM EDT (15:21 UTC) Moonrise 12:57AMMoonset 3:39PM Illumination 22% Phase: Waning Crescent; Moon at 25 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- 1103 Am Edt Thu Aug 17 2017
Rest of today..S winds 5 kt. Waves less than 1 ft. A slight chance of showers late this morning, then a chance of showers and tstms this afternoon.
Tonight..S winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Fri..S winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely.
Fri night..W winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Sat..NW winds 5 kt. Waves less than 1 ft.
Sat night..W winds around 5 kt. Waves 1 ft.
Sun..SE winds around 5 kt. Waves 1 ft.
Mon..S winds around 5 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1103 Am Edt Thu Aug 17 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A warm front will pass through the area today before a cold front approaches Friday. The cold front will then pass through Friday night into early Saturday. High pressure will build to the north and west of the waters while a pressure trough will remain nearby for later Saturday and Sunday. The high pressure will shift offshore early next week.

7 Day Forecast for Marine Location Near Indian Head, MD
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location: 38.62, -77.2     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 170749
afdlwx
area forecast discussion
national weather service baltimore md washington dc
349 am edt Thu aug 17 2017

Synopsis
A warm front will pass through the area today and a cold front
will approach from the west Friday before passing through Friday
night. Weak high pressure will build into the area for the
weekend before moving offshore early next week. A stronger cold
front will pass through the area during the middle portion of
next week.

Near term until 6 pm this evening
Partly to mostly clear skies and light winds combined with abundant
low level moisture has led to areas of fog again early this morning.

Due to the presence of some cloud cover and being one day removed
from widespread rainfall, density is significantly less than
yesterday, however there will still likely be localized areas where
dense fog does develop.

Warm frontal boundary is also positioned near the region early this
morning, and this is continuing to help sustain a few rain showers
in central va and possibly into southern maryland. There could be
additional showers that develop along or south of the boundary
into the morning hours.

During the day today, warm frontal boundary will gradually lift
northward, providing for a warm and humid day. Once any fog lifts,
partly sunny skies are expected, but will likely give way to more
clouds than Sun through the day. Highs today should reach the upper
80s to around 90f. This combined with surface dew points in the low
70s will allow for the development of 1000-1500 j kg of mlcape,
especially west of i-95 where warm front will clear first. While
cape profiles are not that conducive for widespread strong to severe
convection with tall skinny CAPE depicted, 0-6km shear of near 30
knots and the presence of a warm frontal boundary and its
directional shear along it, may be enough for a few isolated strong
to locally severe thunderstorms. Convection-allowing models differ
on evolution and coverage, but highest threat area appears to be
west of the metros. In addition, precipitable water values
increase markedly as warm front lifts northward, with values
near or exceeding 2" by late in the day. This combined with
11-12k foot warm cloud depths, wet antecedent conditions, and
the potential for slow movement repeated convection sets up the
possibility for an isolated flood risk as well.

Short term 6 pm this evening through Saturday night
For tonight, warm and muggy conditions will persist. Convection
from this afternoon may continue to propagate eastward, with
additional scattered development also possible as low level jet
moves towards the region overnight. Potential for heavy rain
will exist with any showers storms overnight as well. Lows
tonight low to mid 70s.

Area of low pressure will push into southern canada on Friday,
with its trailing cold front entering the mid-atlantic states
during the day. This will serve as another focus for scattered
showers thunderstorms during the day Friday. A severe threat
will exist again on Friday, with potentially greater
coverage more intense storms than today. Temperatures and low
level moisture will surge out ahead of the front, leading to the
development of 1500- 3000 j kg of mlcape, with 30-35 knots of
shear moving overhead. In addition to the severe threat, flash
flooding is also a concern as precipitable water values surge
over 2", possibly exceeding 2.25", and potential for training
convection exists. Highs reach the upper 80s to around 90f.

Convection will push eastward and gradually wane Friday night.

Model guidance has come into better agreement regarding
progression of the front for Saturday. It now appears more
likely that the front will clear most of the region before
stalling out along the atlantic coastline and into southeastern
virginia. This will provide for a drier day Saturday, although a
few isolated- scattered showers storms are still possible,
mainly near the front, as well as in the higher terrain as an
upper trough moves across later in the day. Highs will still be
in the upper 80s, although dew points will drop back into the
60s behind the front.

Long term Sunday through Wednesday
High pressure will remain overhead Sunday... Bringing dry
conditions for most areas along with warm conditions. A
downsloping low-level flow along with some sunshine will cause
max temps to range from the mid to upper 80s in northern
maryland to the lower 90s in central virginia.

High pressure will slowly move offshore Sunday night through
Monday. A return flow will develop and this will allow for
humidity to increase along with very warm conditions. The
increased humidity may trigger some showers and
thunderstorms. Coverage should be isolated to scattered since
there will not be a strong lifting mechanism. A southerly flow
will continue Tuesday with more warm and humid condtions along
with isolated to scattered showers thunderstorms.

A cold front will approach the area from the north Wednesday
before passing through Wednesday night. Showers and
thunderstorms are possible ahead of the boundary... Especially
during the afternoon and evening hours. More warm and humid
conditions will persist ahead of the boundary... But noticeably
cooler and less humid conditions are expected behind the
boundary.

Aviation 07z Thursday through Monday
Reductions possible again this morning in areas of fog, with
greatest risk for ifr at mrb bwi. Dca has lowest probabilities
of seeing fog br. Once any fog lifts, scattered to broken
clouds expected, although mainlyVFR. Isolated to scattered
showers thunderstorms then develop this afternoon, possibly
lingering into tonight, and some may bring heavy rain gusty
winds. Some patchy fog and low clouds are possible again
tonight.

Additional showers thunderstorms are then likely Friday
afternoon evening with potential additional reductions and gusty
winds. Conditions improve for Saturday.

High pressure will remain over the terminals Sunday.VFR
conditions are likely. The high will move offshore Sunday night
into Monday. Warm advection may bring an MVFR deck of lower
clouds later Sunday night into Monday. A few showers and
thunderstorms are possible... But coverage should remain isolated
to scattered.

Marine
Sub-sca conditions exist on the waters this morning, but south
winds will be on the increase later today, tonight, and
through Friday ahead of a frontal system. A small craft advisory
is in effect for portions of the central chesapeake and lower
tidal potomac from late this afternoon and through Friday.

Additionally, isolated to scattered showers and thunderstorms
are possible both today and Friday, mainly in the
afternoon evening, and special marine warnings may be necessary.

High pressure will remain just to the north and west Sunday
while a weak surface trough remains over the waters. Light winds
are expected. The high will move offshore Sunday night into
Monday and a return southerly flow will develop. The southerly
flow will continue through Tuesday. Increased moisture from the
southerly flow may trigger a few showers and thunderstorms... But
coverage should remain isolated to scattered.

Tides coastal flooding
Elevated water levels continue early this morning. However... The
next high tide will be the lower of the two so no minor flooding
is expected today.

The high tide cycle tonight into early Friday will be the higher
of the two. Also... Southerly winds may increase a bit ahead of a
cold front over the ohio valley. This may cause minor flooding
for sensitive areas such as annapolis... Straits point and
possibly washington dc. Coastal flood advisories may be needed.

The southerly flow will continue through Friday evening before
turning offshore behind the boundary. More minor flooding is
possible with the high tide cycle Friday night into early
Saturday for sensitive areas. Anomalies should decrease later
Saturday due to the offshore flow.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory from 4 pm this afternoon to 6 am edt
Friday for anz533-534-537-541-543.

Synopsis... Bjl
near term... Mm
short term... Mm
long term... Bjl
aviation... Bjl mm
marine... Bjl mm
tides coastal flooding... Bjl


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 20 mi51 min SSW 4.1 G 6 81°F 79°F1016.3 hPa
NCDV2 22 mi51 min ESE 5.1 G 6 82°F 83°F1015.9 hPa
BSLM2 - Chesapeake Bay, MD 28 mi111 min SSE 4.1 67°F 1017 hPa63°F
44062 - Gooses Reef, MD 42 mi41 min S 5.8 G 7.8 79°F 1017.7 hPa
TPLM2 - Thomas Point, MD 45 mi81 min S 4.1 G 5.1 79°F 80°F
SLIM2 - 8577330 - Solomons Island, MD 45 mi51 min S 1 G 1.9 81°F 81°F
COVM2 - 8577018 - Cove Point LNG Pier, MD 46 mi51 min SSW 7 G 8.9 77°F 1017.8 hPa
44063 - Annapolis 46 mi41 min S 5.8 G 7.8 80°F 1016.7 hPa
APAM2 - 8575512 - Annapolis, MD 46 mi51 min 83°F 1016.5 hPa
PPTM2 - 8578240 - Piney Point, MD 49 mi51 min S 7 G 8

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA8 mi83 minSSE 510.00 miFair82°F73°F76%1016.8 hPa
Quantico Marine Corps Airfield - Turner Field, VA9 mi25 minS 89.00 miMostly Cloudy82°F77°F85%1016.8 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA18 mi25 minS 510.00 miFair83°F75°F77%1017.5 hPa
Washington/Reagan National Airport, DC, VA19 mi29 minS 710.00 miPartly Cloudy84°F75°F74%1016.7 hPa
Stafford, Stafford Regional Airport, VA20 mi26 minN 010.00 miPartly Cloudy83°F77°F83%1017.9 hPa
Camp Springs / Andrews Air Force Base, MD23 mi83 minSSE 610.00 miFair81°F71°F74%1017.3 hPa

Wind History from DAA (wind in knots)
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Last 24hrCalmNW5NW3CalmNW7W4CalmCalmCalmCalmCalmNW3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmSE5SE4
1 day agoCalmCalmCalmCalmNW4NW3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalm
2 days agoCalmS4SE3CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalm

Tide / Current Tables for High Point, Occoquan Bay, Virginia
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High Point
Click for Map
Thu -- 01:57 AM EDT     Moonrise
Thu -- 03:06 AM EDT     1.92 feet High Tide
Thu -- 06:24 AM EDT     Sunrise
Thu -- 10:22 AM EDT     0.23 feet Low Tide
Thu -- 03:53 PM EDT     1.63 feet High Tide
Thu -- 04:38 PM EDT     Moonset
Thu -- 08:00 PM EDT     Sunset
Thu -- 10:17 PM EDT     0.21 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
11.51.81.91.81.61.20.90.60.40.30.30.611.41.61.61.51.20.80.50.30.20.3

Tide / Current Tables for Marshall Hall, Potomac River, Maryland
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Marshall Hall
Click for Map
Thu -- 01:57 AM EDT     Moonrise
Thu -- 04:06 AM EDT     2.81 feet High Tide
Thu -- 06:24 AM EDT     Sunrise
Thu -- 10:58 AM EDT     0.29 feet Low Tide
Thu -- 04:38 PM EDT     Moonset
Thu -- 04:51 PM EDT     2.40 feet High Tide
Thu -- 07:59 PM EDT     Sunset
Thu -- 10:52 PM EDT     0.26 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.91.62.32.72.82.72.21.71.20.80.40.30.50.91.522.32.42.11.61.10.60.40.3

Weather Map and Satellite Images
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Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Mid-Atlantic    EDIT
Geos

Wind Forecast for Baltimore, MD/Washington (11,2,3,4)
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Ground Weather Radar Station Sterling, VA
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weather_mapweather_map weather_map

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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.