Monday, December18, 2017 L-36.com


Marine Weather and Tides
Dahlgren, VA

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 7:20AMSunset 4:51PM Monday December 18, 2017 4:00 AM EST (09:00 UTC) Moonrise 7:23AMMoonset 5:29PM Illumination 0% Phase: New Moon; Moon at 0 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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ANZ536 Tidal Potomac From Indian Head To Cobb Island- 331 Am Est Mon Dec 18 2017
Rest of the overnight..SW winds 5 kt. Waves less than 1 ft.
Today..SW winds around 5 kt. Waves 1 ft.
Tonight..SW winds around 5 kt. Waves 1 ft.
Tue..SW winds 5 to 10 kt. Waves 1 ft.
Tue night..W winds 5 to 10 kt. Waves 1 ft.
Wed..NW winds 5 kt. Waves less than 1 ft.
Wed night..N winds 5 kt. Waves less than 1 ft.
Thu..SE winds around 5 kt. Waves 1 ft.
Fri..S winds 5 to 10 kt. Waves 1 ft. A chance of rain through the night.
ANZ500 331 Am Est Mon Dec 18 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will control the weather pattern through Tuesday before a cold front crosses the area Tuesday night. High pressure will build to the north Wednesday into Thursday as a front stalls to the south. A small craft advisory may be needed Tuesday night into Wednesday for portions of the waters.

7 Day Forecast for Marine Location Near Dahlgren CDP, VA
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location: 38.31, -77.06     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 180130
afdlwx
area forecast discussion
national weather service baltimore md washington dc
830 pm est Sun dec 17 2017

Synopsis
A weak boundary overhead will lift to the north as a warm front
tonight into Monday. An upper level disturbance will approach
the area from the west Monday afternoon and evening. This
disturbance could bring some light precipitation to the
appalachian front later Monday. High pressure will build in
briefly before the next storm system scoots by to our south
during the middle of the week.

Near term through Monday
A warm front was stationed just north of the potomac river as
of 8 pm. Removed mention of sleet along the mason-dixon line as
dew points have risen to 30+ degrees and air temperatures are
in the lower 40s. Wet bulb 0 c heights are, at best, 2500 feet.

Otherwise, forecast on track with sprinkles or spotty light
rain ending this evening as the warm front lifts north. Skies
are expected to remain mostly cloudy overnight. Low temperatures
will bottom out near or slightly above freezing outside of the
major cities, upper 30s in the downtown areas.

As for the upslope areas west of the allegheny front,
moisture lift appear too shallow weak for appreciable snowfall
accumulation. Some light rain and drizzle mixed with pellets or
snow grains seems most likely, with perhaps a light coating at
the highest elevations between midnight and daybreak before
temperatures warm.

Short term Monday night through Tuesday night
As a warm front pushes to the north Monday, so do the milder
temperatures will highs about 5 degrees warmer than Sunday. A
light persistent southwest wind will aid in this milder trend.

By Monday afternoon into Monday evening, clouds and precipitation
will return with the bulk of any precipitation remaining light
and mainly confined to the appalachian front in the form of
light rain or drizzle. A leeside trough of low pressure should
set up just to the east of the appalachian spine, thus, allowing
for this precipitation to occur with the help from a weak mid-
level disturbance.

Tuesday should be even milder yet with highs ranging from the
middle 50s to the middle 60s widespread across the region. A
persistent southwest wind and a little added sunshine during the
day should aid in this. Tuesday night will be about the same as
Monday night with low temperatures dropping into the middle to
upper 30s for the most part.

Long term Wednesday through Sunday
Southern stream shortwave energy will be approaching the mid-atlantic
region on Wednesday into Wednesday night. Guidance suggests that the
forcing will stay south of us, but showers associated to this system
could reach the southern counties of our cwa. Still to be determined
in more detail is timing and p-types.

A ridge of high pressure builds over the region on Thursday and into
Thursday night bringing a period of dry weather. Sometime on Friday
a warm front will push through, followed by a cold front on Saturday.

Models suggest that Friday will remain on the drier side while Friday
night we might see showers ahead of the front, but it all depends
on the timing of it. Saturday's pops are higher with the front moving
through the region from the west. Uncertainty exists on Sunday's
weather depending on how close to the area the front stalls.

Aviation 00z Monday through Friday
Winds generally southwest less than 5 knots through Monday.VFR
conditions expected tonight through Tuesday night. Hrrr hinting
at some MVFR visibility 9-12z INVOF iad bwi mtn tonight. Can't
rule out brief patchy fog in these areas if breaks in clouds
develop given high rh values calm winds.

Some guidance (namely the met) is hinting at fog development
near the bay Monday night which makes sense given light winds
and environmental dew points higher than water temperatures.

MainlyVFR conditions expected the second half of the week.

Marine
No marine hazards through Monday night. Winds become light and
variable tonight, then southwest 5-10 kts Monday into Tuesday.

Fog is possible over the waters Monday night which makes sense
given light winds and environmental dew points (mid to upper
40s) higher than water temperatures (around 40).

Winds should increase late Tuesday into Wednesday near and behind
a cold front. Small craft advisories may be needed for portions
of the waters during this time. Near shore waters likely see
gusts first since open waters will be much cooler than
environmental airmass. Mixing would presumably be more
difficult over open waters until a cooler airmass arrives later
Tuesday night into Wednesday.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Klw
near term... Klw dhof
short term... Klw
long term... Imr
aviation... Imr klw dhof
marine... Imr klw dhof


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
NCDV2 1 mi43 min Calm G 0 41°F 41°F1019 hPa
PPTM2 - 8578240 - Piney Point, MD 30 mi43 min SSW 1.9 G 2.9
SLIM2 - 8577330 - Solomons Island, MD 32 mi43 min S 1.9 G 2.9 42°F 44°F1019.6 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 36 mi43 min SSW 5.1 G 6 43°F 1020.6 hPa
LWTV2 - 8635750 - Lewisetta, VA 38 mi43 min WSW 6 G 7 44°F 41°F1020 hPa
44062 - Gooses Reef, MD 38 mi31 min SSW 1.9 G 3.9 44°F 1020.4 hPa
BSLM2 - Chesapeake Bay, MD 38 mi151 min Calm 36°F 1020 hPa35°F
WASD2 - 8594900 - Washington, DC 39 mi49 min Calm G 1.9 41°F 40°F1020.1 hPa
44042 - Potomac, MD 43 mi31 min WSW 3.9 G 3.9 44°F 1019.5 hPa

Wind History for Piney Point, MD
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Quantico Marine Corps Airfield - Turner Field, VA19 mi65 minWNW 310.00 miOvercast40°F36°F86%1020.6 hPa
Fredericksburg, Shannon Airport, VA21 mi66 minN 010.00 miPartly Cloudy39°F36°F91%1019.6 hPa
Stafford, Stafford Regional Airport, VA22 mi66 minN 010.00 miMostly Cloudy38°F37°F100%1021.3 hPa

Wind History from NYG (wind in knots)
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Last 24hrNW6NW6NW5NW5NW4NW3Calm--CalmCalmS3CalmCalmCalmCalmCalmCalmSW3CalmS4CalmCalmCalmW3
1 day agoNW6NW6NW6SW3W10W8W8W13
G18
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SW8SW6SW6SW7SW8W4CalmNW3NW4NW5NW5NW6
2 days agoE7E9E9E7NE5E5E3E3N5N4N7N5CalmN3W3CalmCalmCalmCalmW43W3NW6W5

Tide / Current Tables for Dahlgren, Upper Machodoc Creek, Virginia
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Dahlgren
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Mon -- 01:31 AM EST     New Moon
Mon -- 02:46 AM EST     1.31 feet High Tide
Mon -- 07:19 AM EST     Sunrise
Mon -- 07:22 AM EST     Moonrise
Mon -- 09:00 AM EST     -0.26 feet Low Tide
Mon -- 03:11 PM EST     1.59 feet High Tide
Mon -- 04:49 PM EST     Sunset
Mon -- 05:28 PM EST     Moonset
Mon -- 09:38 PM EST     -0.19 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.611.21.31.20.90.50.1-0.2-0.3-0.20.20.61.11.41.61.51.30.90.50.1-0.1-0.20

Tide / Current Tables for Upper Cedar Point Light, Potomac River, Maryland
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Upper Cedar Point Light
Click for Map
Mon -- 01:31 AM EST     New Moon
Mon -- 03:58 AM EST     1.06 feet High Tide
Mon -- 07:20 AM EST     Sunrise
Mon -- 07:23 AM EST     Moonrise
Mon -- 09:56 AM EST     -0.06 feet Low Tide
Mon -- 04:07 PM EST     1.20 feet High Tide
Mon -- 04:49 PM EST     Sunset
Mon -- 05:28 PM EST     Moonset
Mon -- 10:43 PM EST     -0.07 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.30.60.811.10.90.70.40.20-0.100.30.60.91.11.21.10.90.60.40.2-0-0.1

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 (4,6,7,8)
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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.