Tuesday, March28, 2017 L-36.com


Marine Weather and Tides
St. James, MD

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:58AMSunset 7:33PM Tuesday March 28, 2017 5:36 PM EDT (21:36 UTC) Moonrise 6:33AMMoonset 7:21PM 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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ANZ535 Tidal Potomac From Key Bridge To Indian Head- 432 Pm Edt Tue Mar 28 2017
.small craft advisory in effect from Wednesday morning through Wednesday afternoon...
Rest of this afternoon..SW winds 5 kt. Waves less than 1 ft. Showers likely with a chance of tstms.
Tonight..N winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Wed..N winds 5 to 10 kt with gusts to 20 kt. Waves 1 ft.
Wed night..N winds 5 to 10 kt. Waves 1 ft.
Thu..SE winds around 5 kt. Waves 1 ft.
Thu night..SE winds 5 kt. Waves less than 1 ft. A chance of rain.
Fri..W winds around 5 kt. Waves 1 ft. Rain...then showers likely after midnight.
Sat..N winds 5 to 10 kt. Waves 1 ft. Showers likely in the morning. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 432 Pm Edt Tue Mar 28 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front is expected to cross the chesapeake bay this evening. High pressure will build into the waters for midweek, followed by a low pressure system moving towards the region on Friday. This system will exit the region Saturday. Small craft advisories are possible Thursday night through Saturday.

7 Day Forecast for Marine Location Near St. James, MD
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location: 39.59, -77.77     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 281858
afdlwx
area forecast discussion
national weather service baltimore md/washington dc
258 pm edt Tue mar 28 2017

Synopsis
A cold front will cross the area tonight. High pressure builds
over the region Wednesday into Thursday. Another disturbance
will approach the area late Thursday into early Saturday.

Near term /through tonight/
Latest surface analysis depicts a stationary front draped near
the mason-dixon line on east, with low pressure over central
maryland. West of the low, the front continues west into the
upper ohio valley, then turns southwest down the valley towards
missouri. Aloft, a sharp trough is located over the region, with
ridges aloft to the immediate east and west.

Through this evening, both the surface low and upper level
trough will push eastward into the atlantic. Dry air will slowly
move into the region aloft, so despite relatively moist and warm
low levels, the drying aloft will start to gradually limit storm
development as CAPE dwindles. Shear is pretty low so think there
should be very limited severe threat, but a few strong gusts are
not impossible. With cold temps aloft, small hail will also be a
concern.

The surface front will then start dropping south across the
region later this evening and overnight. Low levels will start
to cool and dry out and the showers should completely end after
midnight. Some patchy fog may try to develop in spots where the
wind doesn't pick up fast enough, but overall, think it should
be minor since clouds will likely linger for a while. Lows will
remain on the mild side, with 40s and 50s common.

Short term /Wednesday through Friday/
High pressure builds in from the north on Wednesday with a
breezy north wind. Temperatures will not be as warm and the
humidity will be noticeably lower, but still on the nice side
for late march with 60s common. Winds will relax Wednesday night
as the pressure ridge pushes directly overhead, and with dry air
in place, we may radiate down towards freezing or even a bit
below in the colder spots.

By Thursday, clouds will start to increase as warm advection
begins ahead of the next approaching low pressure. The clouds
should limit the insolation and temps will get stuck in the
50s. Some rain may move into western areas late in the day, but
think for most areas, it will wait until after dark Thursday
night. Low pressure will slide east toward us through the day
Friday, with periods of rain looking likely. There is a good
southerly fetch with this system overruning the cool wedge at
the surface, so potential for some decent rain. Right now, it
appears the wedge will mostly hold with this system, so highs
Friday look to remain in the 50s.

Long term /Friday night through Tuesday/
The chance for rain showers linger Saturday before drier and
cooler air can filter into the region Saturday night when high
pressure works its way into the mid-atlantic.

High pressure will settle into the region Sunday through early
Monday. Dry and seasonable temperatures expected throughout the
period.

The next storm system will move into the region midday Monday
through Tuesday, bringing the chance for rain showers to the
region once again.

Aviation /19z Tuesday through Sunday/
Scattered to numerous showers and isolated to scattered
thunderstorms are expected through the rest of the day into this
evening. Brief reductions in cig and vis, small hail and gusty
winds to 35 knots are possible. Outside of storms, conditions
should be mostlyVFR, though some MVFR CIGS and vis remain in
spots. Overnight, some lower clouds look to linger until the
cold front moves through, with CIGS possibly dropping to ifr
levels for a time. Early Wednesday, the front should sweep away
the low clouds and it should turnVFR until Thursday night, when
the next system will bring more rain and potential for ifr cigs
and vis.

MVFR conditions Saturday. Winds northwest 10 knots Saturday.

Vfr conditions evolving Saturday night. Winds northwest 5 knots
Saturday night.

Marine
Isolated thunderstorms possible into this evening. Winds in any
storm could gust to 35 knots, though odds are low.

An SCA has been issued for tonight and Wednesday behind a cold
front. Northerly winds are expected to gust to 20 kt. Winds
should diminish Wednesday night and remain sub SCA during the
day Thursday with high pressure passing the area.

Potential for small craft advisory conditions increases Thursday
night and Friday with increasing southeasterly winds ahead of an
approaching system. Winds will then turn north/northwesterly on
Saturday behind the system, with continued potential for sca
conditions.

Lwx watches/warnings/advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory from midnight tonight to 6 pm edt
Wednesday for anz531>534-537-539>541-543.

Small craft advisory from 6 am to 6 pm edt Wednesday for
anz530-535-536-538-542.

Synopsis... Rcm
near term... Rcm
short term... Rcm
long term... Klw
aviation... Rcm/klw
marine... Rcm/klw


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 63 mi49 min WNW 6 G 8.9 70°F 51°F1009.3 hPa
BLTM2 - 8574680 - Baltimore, MD 67 mi49 min N 6 G 8.9 68°F 47°F1009.2 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 71 mi49 min NW 5.1 G 5.1 66°F 1009.6 hPa

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD9 mi44 minNNE 410.00 miLight Rain65°F57°F78%1011.3 hPa
Eastern WV Regional Airport/Shepherd Field, WV17 mi44 minNNW 410.00 miOvercast68°F54°F61%1009.9 hPa
Frederick Municipal Airport, MD24 mi50 minNNE 510.00 miOvercast70°F60°F73%1014.2 hPa

Wind History from HGR (wind in knots)
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Last 24hrS6S10S4SE4N4N5CalmNW6N5N7NW8E6NE8N3N5NE7N5E3CalmW5SW4CalmNW4NE4
1 day agoE7E7E5SE5E3E3CalmCalmE3E4NW6S6CalmW3N3CalmN3CalmW3W4CalmSE4SW6S5
2 days agoS3S3S4E4N11N9N6NE13E12NE9E12E9E9E6E7E7E7E7E6E8E8E9E7E8

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
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Tue -- 03:57 AM EDT     0.07 feet Low Tide
Tue -- 06:58 AM EDT     Sunrise
Tue -- 07:30 AM EDT     Moonrise
Tue -- 09:29 AM EDT     3.41 feet High Tide
Tue -- 04:31 PM EDT     -0.03 feet Low Tide
Tue -- 07:28 PM EDT     Sunset
Tue -- 08:17 PM EDT     Moonset
Tue -- 09:58 PM EDT     3.23 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.81.20.60.20.10.31.12.133.43.32.92.21.50.90.4000.51.52.533.23

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Tue -- 03:54 AM EDT     0.05 feet Low Tide
Tue -- 06:58 AM EDT     Sunrise
Tue -- 07:30 AM EDT     Moonrise
Tue -- 09:27 AM EDT     3.46 feet High Tide
Tue -- 04:28 PM EDT     -0.04 feet Low Tide
Tue -- 07:28 PM EDT     Sunset
Tue -- 08:17 PM EDT     Moonset
Tue -- 09:56 PM EDT     3.28 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.81.20.60.20.10.31.12.233.43.42.92.21.50.80.3000.61.52.53.13.33

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 (17,4,5,8)
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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.