Saturday, October21, 2017 L-36.com


Marine Weather and Tides
Halfway, 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 7:27AMSunset 6:23PM Saturday October 21, 2017 11:42 AM EDT (15:42 UTC) Moonrise 8:02AMMoonset 6:52PM Illumination 2% Phase: Waxing Crescent; Moon at 1 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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ANZ538 Patapsco River Including Baltimore Harbor- 1031 Am Edt Sat Oct 21 2017
Rest of today..E winds 5 kt. Waves flat.
Tonight..SE winds around 5 kt. Waves flat.
Sun..SE winds around 5 kt. Waves flat.
Sun night..SE winds 5 kt. Waves less than 1 ft.
Mon..S winds 5 to 10 kt. Waves 1 ft or less.
Mon night..S winds 10 to 15 kt. Gusts up to 20 kt after midnight. Waves 1 ft. Showers likely.
Tue..S winds 15 to 20 kt...becoming W 5 to 10 kt. Waves 1 to 2 ft. Showers.
Wed..NW winds 5 kt. Waves less than 1 ft. A chance of showers in the morning.
ANZ500 1031 Am Edt Sat Oct 21 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move east of the waters through Monday. A low pressure system will affect the region Tuesday. A small craft advisory is likely for portions of the waters Monday through Tuesday. Gales are also possible for portions of the waters on Tuesday.

7 Day Forecast for Marine Location Near Halfway, MD
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location: 39.62, -77.79     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 211421 aaa
afdlwx
area forecast discussion... Updated
national weather service baltimore md washington dc
1021 am edt Sat oct 21 2017

Synopsis
High pressure will move east into the western atlantic through
Monday. Low pressure and its attendant cold front will sweep
through the area Tuesday. Troughing will remain overhead for
much of the second half of the week.

Near term through tonight
High pressure will remain in control through the weekend. Highs
in the mid 70s with increasing high clouds in the afternoon.

Short term Sunday through Monday night
Ridging shifts eastward into the north atlantic during the
second half of the weekend. Meanwhile, an amplifying ridge over
western noam will result in lowering heights over the eastern
half of the CONUS by late Monday. Southern stream shortwave
moving northeastward out of the lower mississippi river valley
will interact phase with digging northern stream wave crossing
the great lakes resulting in the development of a surface low
which will bring widespread (much needed) rain to the area
starting late Monday night. Until then, only a modest and
gradual increase in clouds with above normal temperatures will
continue.

Long term Tuesday through Friday
The big story in the long term will happen right off the bat as
a cold front crosses the region. Have upped the pops to 90%. The
question at the moment is one of timing - models actually appear
to favor the first part of the day for precip while the
numerical guidance is more in the afternoon. For now will keep
pops at 90 for the entire period. Fine tuning will come later.

If this does come through earlier this will limit thunderstorm
chances.

Highs Tuesday should reach the lower 70s. Afterwards mid
atlantic will be on the backside of upper level cyclonic flow.

This will bring temperatures back down to more normal later
october values: highs in the 60s, low in the 40s.

Aviation 14z Saturday through Wednesday
Lower ceilings possible by late Monday night as low pressure
approaches and atmosphere moistens. Showers develop west to east
late Monday night. Low-level wind shear is possible as well by
Tuesday morning as a southerly low-level jet (~40 knots at 2kft)
develops. Latest model guidance remains consistent and in
reasonably good agreement at this time range.

Tuesday will be an interesting day as a cold front brings
showers and isolated thuderstorms to all TAF sites. Periods of
sub-vfr ceilings will be likely, as well as the potential for
low level speed shear as well as a wind shift.

Conditions should improve Tuesday night and Wednesday.

Marine
Light winds are expected as high pressure remains in control
of the weather over the waters through the weekend. Small craft
advisories may be needed as early as Monday afternoon due to
tightening pressure gradient increasing southerly winds ahead of
developing low pressure.

Tuesday winds will definitely reach SCA levels with the
potential for gales, especially on the wider part of the md
ches bay. SCA will continue to be possible Tuesday night and
Wednesday.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Update... Lfr
products... Dfh woody!


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 66 mi42 min SW 1.9 G 2.9 68°F 67°F1028.3 hPa (+1.2)
BLTM2 - 8574680 - Baltimore, MD 69 mi42 min S 1 G 4.1 66°F 70°F1028 hPa (+1.4)
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 72 mi42 min SSE 1.9 G 1.9 64°F 1028.4 hPa (+1.4)

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD7 mi55 minWNW 310.00 miClear61°F48°F63%0 hPa
Eastern WV Regional Airport/Shepherd Field, WV18 mi49 minN 010.00 miFair59°F46°F62%1028.3 hPa

Wind History from HGR (wind in knots)
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Last 24hrNW13NW8W4NW8N6NW3NE3E3E4E3CalmCalmE7CalmE3CalmS4Calm--------W3--
1 day ago5SW7SW5SW5S9S5S5S4S6W11SW5W5SW3SW3SW5SW5W5W7W4S3CalmW4NW9NW6
2 days agoSW6SW4S5S7S9S7S4SE5E5SE6SE3S5S4S4CalmS4S3CalmCalmCalmS5S5S3SW4

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Sat -- 04:55 AM EDT     0.07 feet Low Tide
Sat -- 07:24 AM EDT     Sunrise
Sat -- 08:58 AM EDT     Moonrise
Sat -- 10:28 AM EDT     3.13 feet High Tide
Sat -- 04:56 PM EDT     0.14 feet Low Tide
Sat -- 06:21 PM EDT     Sunset
Sat -- 07:50 PM EDT     Moonset
Sat -- 10:41 PM EDT     3.40 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.61.91.30.80.30.10.41.222.73.13.12.61.91.20.70.30.10.41.22.12.93.33.4

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Sat -- 04:53 AM EDT     0.04 feet Low Tide
Sat -- 07:24 AM EDT     Sunrise
Sat -- 08:58 AM EDT     Moonrise
Sat -- 10:25 AM EDT     3.15 feet High Tide
Sat -- 04:53 PM EDT     0.12 feet Low Tide
Sat -- 06:21 PM EDT     Sunset
Sat -- 07:50 PM EDT     Moonset
Sat -- 10:39 PM EDT     3.41 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.61.91.20.70.200.41.22.12.73.13.12.61.91.20.60.30.10.41.22.12.93.33.4

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.