Tuesday, November21, 2017 L-36.com


Marine Weather and Tides
Kemps Mill, 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 7:01AMSunset 4:52PM Tuesday November 21, 2017 4:26 PM EST (21:26 UTC) Moonrise 9:34AMMoonset 7:32PM Illumination 10% Phase: Waxing Crescent; Moon at 3 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- 332 Pm Est Tue Nov 21 2017
.small craft advisory in effect until 6 pm est this evening...
.small craft advisory in effect from Wednesday morning through Wednesday afternoon...
Rest of this afternoon..SW winds 10 kt with gusts to 20 kt. Waves 1 ft.
Tonight..SW winds 5 to 10 kt. Waves 1 ft. A chance of rain.
Wed..NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft.
Wed night..NW winds 5 to 10 kt. Waves 1 ft.
Thu..SW winds around 5 kt. Waves 1 ft.
Thu night..W winds around 5 kt. Waves 1 ft.
Fri..S winds around 5 kt. Waves 1 ft or less.
Sat..W winds 5 kt. Waves less than 1 ft.
ANZ500 332 Pm Est Tue Nov 21 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move offshore through this afternoon. A cold front will pass through late tonight into early Wednesday morning. High pressure will return later Wednesday through early Friday, then another cold front will approach late Friday into Saturday. A small craft advisory will likely be needed for portions of the waters Wednesday night, and again Friday night through Saturday.

7 Day Forecast for Marine Location Near Kemps Mill, MD
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location: 39.63, -77.79     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 212000
afdlwx
area forecast discussion
national weather service baltimore md washington dc
300 pm est Tue nov 21 2017

Synopsis
High pressure will move offshore today. A cold front will pass
through tonight into early Wednesday, while weak low pressure
moves up the coast. High pressure will build back overhead
later Wednesday through thanksgiving day. High pressure will be
overhead Friday. A front approaches from the west on Saturday,
high pressure builds later on Sunday and will remain in control
through Tuesday.

Near term through tonight
High pressure ebbs away tonight as we get caught in between a
cold front moving in from the west, and weak low pressure moving
up the coast. While the front is not expected to bring much if
any precip to our forecast area, the coastal low will bring rain
up the coast and into lower southern md and the southern md ches
bay. Precip pops fall back to chance levels over the major metro
areas, and then to slight chance and less for the shenandoah
valley. Looking at the latest convective allowing meso models
and lamp, the timing looks to be a few hours slower... Keeping
most of the precip in our CWA after midnight and possibly
lingering into Wed morning closer to the bay. Amounts for those
who get rain are expected to be a quarter inch or less.

A period of upslope snow showers are expected late tonight into
wed morning behind the cold front for locations along west of
the allegheny highlands. Accumulations should be an inch or
less since moisture will be limited... But this may cause
slippery conditions by the early morning hours Wednesday.

Short term Wednesday through Thursday night
The cold front will move off to the south and east early
Wednesday morning. Canadian high pressure will approach from the
north and west and a northwest flow ahead of the high will usher
in drier and chillier conditions. MAX temps will hold in the 40s
for most locations north and west of interstate 95 and in the
lower to middle 50s farther south and east.

High pressure will build overhead Wednesday night... Bringing dry
and cold conditions. Min temps will drop into the 20s for most
areas, except lower 30s downtown dc balt. High pressure will
remain overhead thanksgiving day through thanksgiving
night... Bringing more dry and chilly conditions.

Long term Friday through Tuesday
High pressure will be overhead Friday, keeping dry conditions
over our region, before it moves offshore late on Friday. A
front approaches from the west on Saturday, as upper trough
deepens over the eastern conus. Pops increases with this
boundary on Saturday, but deterministic guidance and GEFS are
not too aggressive with precipitation over our cwa. At the same
time a low pressure system will develop off of the southeast
atlantic coast but it is expected to stay offshore with little
to no impacts to our area.

Upslope showers expected on Sunday with the northwest flow and upper
trough axis moving through our area. Surface high pressure builds
later on Sunday and will remain in control through Tuesday.

Aviation 20z Tuesday through Sunday
Southwest winds will gust around 20 knots this afternoon over
the metro airports. A cold front will cross late tonight. A few
showers cannot be ruled out (especially for dca bwi mtn)... But
any precipitation amounts will be light. MVFR conditions are
expected late tonight into early wed, most prolonged for
dca bwi mtn. Northwest winds will develop behind the cold front
early Wednesday morning and gusts around 20 to 25 knots are
expected for most of Wednesday behind the cold front.

Vfr conditions expected Wednesday into early Saturday.

Precipitation possible later on Saturday as a cold front moves
trough our area. DryVFR conditions return on Sunday.

Marine
With the southwest flow ahead of a cold front today, a small
craft advisory is in effect for the waters. The SCA continues
through this evening for most of the bay and lower tidal
potomac. Winds should decrease overnight as the gradient
relaxes. A cold front will pass through early Wednesday morning
and northwest winds will increase behind the boundary with gusts
20 to 25 knots most likely. An SCA is in effect for the waters.

High pressure will build over the waters for Wednesday night
through Thursday night. An SCA was extended through Wed night
for most of the bay and lower potomac.

Winds are expected to stay less than 20 kts Friday into
Saturday night. Winds will increase on Sunday as low pressure
moves NE offshore the DELMARVA peninsula, therefore, a small
craft advisory is anticipated on Sunday.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory until midnight est tonight for anz530>534-
537-539>543.

Small craft advisory from 6 am to 6 pm est Wednesday for
anz530>543.

Small craft advisory until 6 pm est this evening for anz535-
536-538.

Strong fling imr


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 66 mi39 min S 5.1 G 8 59°F 48°F1016.7 hPa
BLTM2 - 8574680 - Baltimore, MD 69 mi39 min WSW 5.1 G 8 60°F 54°F1016 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 73 mi39 min S 8.9 G 12 60°F 1016.4 hPa

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
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G26
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W12
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD6 mi34 minSSE 810.00 miFair56°F30°F39%1016 hPa
Eastern WV Regional Airport/Shepherd Field, WV18 mi34 minSSE 810.00 miFair58°F28°F32%1014.7 hPa

Wind History from HGR (wind in knots)
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Last 24hrS4S4S5S6S6S5S8S8S8S8S6S8S7S8S6S63S3SW6S7S11S9S10S8
1 day agoW12W15W17
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W14W12W13NW12NW11
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NW12W15W12W7W14
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W6W3W8W9W10SW9SW9W9W7W7
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2 days agoNW6NW6W6NW6W4CalmS4S12S17S18SW9W20
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Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Tue -- 04:53 AM EST     0.10 feet Low Tide
Tue -- 06:58 AM EST     Sunrise
Tue -- 09:28 AM EST     Moonrise
Tue -- 10:24 AM EST     2.66 feet High Tide
Tue -- 04:35 PM EST     0.14 feet Low Tide
Tue -- 04:50 PM EST     Sunset
Tue -- 07:31 PM EST     Moonset
Tue -- 10:25 PM EST     2.97 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.21.610.60.20.10.41.11.82.42.62.62.21.50.90.40.20.20.51.222.72.92.9

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Tue -- 04:50 AM EST     0.06 feet Low Tide
Tue -- 06:58 AM EST     Sunrise
Tue -- 09:28 AM EST     Moonrise
Tue -- 10:22 AM EST     2.69 feet High Tide
Tue -- 04:31 PM EST     0.10 feet Low Tide
Tue -- 04:50 PM EST     Sunset
Tue -- 07:31 PM EST     Moonset
Tue -- 10:23 PM EST     3.00 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.21.610.50.20.10.41.11.92.42.72.62.11.50.90.40.10.10.51.22.12.732.9

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 (16,3,4,5)
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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.