Saturday, January20, 2018 L-36.com


Marine Weather and Tides
Olney, 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 7:21AMSunset 5:17PM Saturday January 20, 2018 9:25 PM EST (02:25 UTC) Moonrise 9:29AMMoonset 8:47PM Illumination 19% Phase: Waxing Crescent; Moon at 4 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- 631 Pm Est Sat Jan 20 2018
Tonight..W winds around 5 kt. Waves 1 ft or less.
Sun..S winds around 5 kt. Waves 1 ft.
Sun night..S winds 5 kt. Waves less than 1 ft.
Mon..S winds 5 to 10 kt. Waves 1 ft.
Mon night..S winds 5 to 10 kt. Gusts up to 20 kt after midnight. Waves 1 ft. Rain.
Tue..SW winds 10 kt. Waves 1 ft. Showers.
Tue night..W winds 5 to 10 kt. Waves 1 ft.
Wed..NW winds 5 to 10 kt. Waves 1 ft.
Thu..NW winds 5 to 10 kt...becoming light. Waves 1 ft or less.
ANZ500 631 Pm Est Sat Jan 20 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build from the gulf coast to the eastern seaboard through this weekend. The next cold front will approach the area Monday and cross the area early Tuesday. This will be followed by another area of high pressure for the middle and end of next week. Small craft advisories may be necessary Monday through Wednesday.

7 Day Forecast for Marine Location Near Olney, MD
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location: 39.15, -77.07     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 210134
afdlwx
area forecast discussion
national weather service baltimore md washington dc
834 pm est Sat jan 20 2018

Synopsis
High pressure will remain near the southeastern us coastline
through the rest of the weekend. A cold front will approach the
region Monday before passing through Monday night into Tuesday.

High pressure will then return for Wednesday through Friday of
next week.

Near term until 6 am Sunday morning
High pressure will remain to our south tonight. A warm front,
and in reality more of a moisture boundary, will lift
northeastward and towards the region overnight. Other than some
thin high clouds, skies have started out mainly clear this
evening. However... Increased moisture around the periphery of
the high will move in from west to east... Starting late this
evening in the allegheny and potomac highlands and overnight
across locations farther east. Increasing clouds are expected
for most areas. However... An upslope flow to the low-level wind
will result in some light rain and drizzle for locations along
and west of the allgheny front. Other locations should remain
dry. Min temps will range from the upper 20s near 30 in colder
valleys and rural areas late this evening to the mid and upper
30s across most other locations. Temperatures may actually rise
toward morning as clouds increase.

Short term 6 am Sunday morning through Monday night
As noted by low level theta-e advection, moisture will continue
to increase across the region on Sunday. This is expected to
lead to a deck of strato-cumulus across the area during the day.

Some light upslope rain or drizzle remains possible along and
west of the allegheny front. Under the clouds, temperatures,
while still mild, will likely be 5 to as much as 10 degrees
cooler than today, with highs from 50-60 degrees, coolest across
northeast md and warmest in central va.

The warm front moisture boundary will pull further north Sunday
night, leading to continuing warming and moistening low levels.

Some patchy light rain, drizzle, or fog cannot be ruled out.

Lows should be within a few degrees of 40f.

By Monday, with increasing southerly flow and surging warmth in
the low and mid levels, the boundary should be well north of the
area, placing the region fully in the warm sector by Monday
afternoon. Thus, even with potential for morning low clouds and
increasing afternoon high clouds as a cold front begins to
approach the region, highs are likely to reach well into the 50s
and low 60s again.

The cold front will push towards the region Monday evening and
begin to cross the area Monday night. This will lead to
widespread rain, and with the potential for some marginal
instability, there is the possibility of a convective fine line
with some gusty winds. Rain totals will be generally from a half
inch to an inch.

Long term Tuesday through Saturday
Cold front will finish crossing the area Tue morning with a
weak triple point low riding near or over the region. The
details of how that low evolves will determine if enough
instability can be brought far enough north over us to bring
about gusty thunderstorms showers. Strong winds off the deck
will provide the winds if there is any convection robust enough
to tap it. At the moment, instability looks very weak. Upslope
snow showers will follow in the mountains.

A secondary cold front trails and passes through Wed morning,
ensuring temps don't get out of the 40s on wed... Seasonable, and
again with upslope mountain snow showers. After that, high pressure
gradually passes over and east of the region late week with warming
temps again for next weekend.

Aviation 02z Sunday through Thursday
Vfr conditions expected through this evening. A strato-cumulus
deck around 3kft is expected late tonight through Sunday. Winds
become light and locally variable tonight and south to southeast
around 5 knots Sunday.

Strato-cumulus deck likely to persist Sunday night into Monday
morning, along with the possibility for some patchy fog, so
potential for some flight restrictions exists. Southerly flow
will increase by Monday afternoon and Monday night as a cold
frontal system approaches, and gusty southerly winds and low
level wind shear become concerns. Sub-VFR conditions also
likely Monday night in increasing rain chances.

Gusty showers and lowered vsbys and CIGS may continue into tue
morning with the cold front. Llws also possible. After that,VFR
expected.

Marine
Sub-sca winds will continue tonight and Sunday. As low level
winds increase by Monday, SCA probability increases, especially
Monday night ahead of a cold frontal system.

Gusty showers are possible Tue morning with a cold front. Small
craft advisories are possible Tue and Wed as colder air moves back
over the waters.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Bjl mm
near term... Bjl mm
short term... Mm
long term... Cs
aviation... Bjl mm cs
marine... Bjl mm cs


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 19 mi37 min Calm G 1 41°F 34°F1018.5 hPa
BLTM2 - 8574680 - Baltimore, MD 27 mi37 min WSW 1.9 G 4.1 48°F 34°F1017.7 hPa
FSNM2 29 mi37 min W 11 G 12 58°F 1017.6 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 29 mi37 min W 1.9 G 1.9 48°F 1018.1 hPa
BSLM2 - Chesapeake Bay, MD 32 mi115 min Calm 37°F 1017 hPa33°F
APAM2 - 8575512 - Annapolis, MD 33 mi37 min 35°F 1017.7 hPa
TPLM2 - Thomas Point, MD 38 mi25 min SSW 5.1 G 5.1 39°F 33°F
CPVM2 38 mi37 min 38°F 31°F
TCBM2 - 8573364 - Tolchester Beach, MD 44 mi37 min Calm G 1.9 39°F 33°F1018.4 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Gaithersburg - Montgomery County Airport, MD5 mi29 minN 010.00 miFair39°F28°F67%1021.7 hPa
College Park Airport, MD14 mi48 minN 010.00 miFair35°F28°F77%1018.3 hPa
Fort Meade / Tipton, MD16 mi49 minN 010.00 miFair34°F30°F87%1019 hPa
Washington/Reagan National Airport, DC, VA20 mi33 minN 010.00 miFair41°F32°F70%1018.5 hPa
Baltimore, Baltimore-Washington International Airport, MD21 mi31 minW 510.00 miPartly Cloudy42°F30°F62%1018.2 hPa
Washington/Dulles International Airport, DC, VA24 mi33 minN 710.00 miA Few Clouds45°F32°F61%1018.6 hPa

Wind History from GAI (wind in knots)
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Last 24hrCalmCalmCalmCalmCalmCalmCalm--CalmCalmCalmCalm3W9W10W11
G19
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SW5W5CalmCalmCalmCalm
1 day agoCalmCalmCalmCalmCalmCalmCalmCalmCalmW4CalmCalmNW10W10W12SW11W4W8W5S3CalmCalmCalmCalm
2 days agoNW11
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Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Sat -- 05:06 AM EST     -0.10 feet Low Tide
Sat -- 07:23 AM EST     Sunrise
Sat -- 09:28 AM EST     Moonrise
Sat -- 10:35 AM EST     2.50 feet High Tide
Sat -- 05:08 PM EST     -0.06 feet Low Tide
Sat -- 05:16 PM EST     Sunset
Sat -- 08:48 PM EST     Moonset
Sat -- 10:46 PM EST     2.70 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.21.610.40.1-0.100.61.42.12.52.52.21.610.50.1-0.100.51.32.12.62.7

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Sat -- 05:06 AM EST     -0.16 feet Low Tide
Sat -- 07:23 AM EST     Sunrise
Sat -- 09:28 AM EST     Moonrise
Sat -- 10:37 AM EST     2.53 feet High Tide
Sat -- 05:08 PM EST     -0.12 feet Low Tide
Sat -- 05:16 PM EST     Sunset
Sat -- 08:48 PM EST     Moonset
Sat -- 10:48 PM EST     2.73 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.21.60.90.40-0.2-00.51.42.12.52.52.21.710.50.1-0.1-00.51.32.12.62.7

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 (21,6,7,8)
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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.