Friday, March24, 2017 L-36.com


Marine Weather and Tides
National Harbor, 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 7:02AMSunset 7:26PM Friday March 24, 2017 10:05 AM EDT (14:05 UTC) Moonrise 4:02AMMoonset 2:50PM Illumination 10% Phase: Waning Crescent; Moon at 27 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- 957 Am Edt Fri Mar 24 2017
.small craft advisory in effect through this evening...
Rest of today..S winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. A chance of rain late this morning...then a slight chance of rain this afternoon.
Tonight..SW winds 5 to 10 kt. Gusts up to 20 kt early in the evening. Waves 1 ft.
Sat..SW winds 5 kt. Waves less than 1 ft.
Sat night..S winds around 5 kt. Waves 1 ft.
Sun..SE winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Sun night..S winds 5 to 10 kt. Waves 1 ft. Showers likely.
Mon..S winds around 5 kt. Waves 1 ft. Showers likely in the morning...then a chance of showers through the night.
Tue..NW winds around 5 kt. Waves 1 ft. Showers likely .
ANZ500 957 Am Edt Fri Mar 24 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will drift east to bermuda through this evening. Two low pressure systems will enter and weaken over the midwest Saturday and Monday night. Small craft advisories may be needed for portions of the waters Sunday and Sunday night.

7 Day Forecast for Marine Location Near National Harbor, MD
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location: 38.8, -77.03     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 240934
afdlwx
area forecast discussion
national weather service baltimore md/washington dc
534 am edt Fri mar 24 2017

Synopsis
A warm front will cross the region today. A low pressure system
will then approach the region on Sunday, and cross the area
Sunday night into Monday. Another system will cross the region
Tuesday.

Near term /until 6 pm this evening/
Latest surface analysis shows high pressure sliding east off the
atlantic coast and a warm front approaching from the west.

Aloft, a vort lobe is rotating eastward ahead of the warm front,
which when combined with warm advection, is supporting a band of
light rain which is moving into the region. The forecast for the
region remains tricky as temperatures in many spots are either
side of freezing. Southeast winds have helped some areas stay
above, while other spots which have gone calm have dropped
below. With rain now almost on our doorstep and temperatures
still below freezing in some areas, have issued freezing rain
advisory for northwestern parts of the CWA (w md, E wv, N va)
through 9 am. May have to extend or expand based radar and temp
trends. Will continue to follow closely.

Otherwise, the band of rain should fall apart as it approaches
the i-95 corridor this morning, and afterwards, southerly winds
should start flooding the region with much milder air. While
clouds should remain common today, the gusty south wind should
elevate most places into the 50s, with most of virginia and west
virginia likely to hit 60. Some warm interior valleys of
eastern west virginia may crack 70.

Short term /6 pm this evening through Sunday night/
Southerly winds and milder air flooding the area will be the
main theme tonight through Saturday evening. While a ridge will
be in place aloft and high pressure will not be far off the east
coast at the surface, it will be rather dirty, with plenty of
high and mid clouds. However, with very warm air surging north
and some breaks of Sun expected, we still expect Saturday to be
the first day with widespread 70+ temps since march 9th. Iad's
record is only 76, but dca and bwi, who's records include the
old downtown offices, have records into the mid 80s.

Saturday night into Sunday morning we will continue to watch
the potential for a back door cold front to slip back south
across the region, particularly maryland. Uncertainty remains,
as guidance has continued to flip back and forth on this
somewhat, but right now it looks like most of our forecast
region will stay in the warm sector. However, with the next
system moving in later Sunday and Sunday night, clouds and
showers will keep temperatures down on Sunday. So, Saturday is
definitely the better day this weekend. With limited if any
instability, we don't expect much if any thunder through
Sunday night, so have kept it out of the forecast for now.

Long term /Monday through Thursday/
Low pressure currently over co/nm will continue to drift east
to the midwest through Saturday night before dissipating near
the great lakes under a northern stream ridge Sunday. A second
low currently off california will trail the first low, reaching
the midwest Monday night before reaching the eastern great lakes
Tuesday (and also dissipating) per 00z ecmwf/gfs. Continued
moist southwesterly flow warrants high chance pops for the lwx
cwa Monday through Tuesday. Possibly a break in action, so
Monday night was kept low at this time and Tuesday was raised to
likely pops across the cwa.

Instability possible Tuesday ahead of the cold front, so slight
chance thunderstorms were maintained. Continued swly flow
brings MAX temps well into the 70s Monday/Tuesday assuming no
widespread rain.

High pressure to the south starting Wednesday maintains above
normal temperatures through the rest of the work week.

Aviation /10z Friday through Tuesday/
GenerallyVFR through the TAF period and beyond into Saturday
night. Main concern is whether temperatures will be low enough
to cause freezing rain as a band of precipitation associated
with the passing warm front moves through this morning. Most
terminals should warm enough to keep it plain rain, but there
remains the chance of some freezing rain at mrb where temps may
not have time to warm. Further southeast, rain may dissipate
before even reaching bwi/iad/dca, but if it does reach there,
temps should be warm enough for plain rain. Otherwise, gusty
southwest wind develops today with the warm front passing. This
evening, as low levels decouple, there could be some low level
wind shear as the wind a few thousand feet up will remain quite
strong even as surface winds become much lighter. Winds may be a
bit lighter on Saturday than today. Sub-vfr CIGS and vis become
a concern Sunday and especially Sunday night as a low pressure
system moves in with some showers. Winds will be uncertain as a
back door front tries to drop south into the area, with the
greatest uncertainty around mtn/bwi.

Southwesterly flow from low pressure to the west/north Monday
and Tuesday brings rain showers to the dc metros Monday and
Tuesday with a low thunder threat Tuesday.

Marine
Sca over the bay this morning will spread to all waters this
afternoon as warm front crosses the waters. Winds will gradually
diminish tonight. With very warm air over the cool waters on
Saturday, right now it looks like winds will stay below sca, but
will need to be watched. SCA again possible Sunday with more
southerly channelling as a storm system approaches from the
west.

Generally sub-sca swly flow prevails Monday and Tuesday with
thunder chances Tuesday.

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

Md... Freezing rain advisory until 9 am edt this morning for mdz003-
501-502.

Va... Freezing rain advisory until 9 am edt this morning for vaz028.

Wv... Freezing rain advisory until 9 am edt this morning for
wvz050>052-503-504.

Marine... Small craft advisory until midnight edt tonight for anz531>533-
539>541.

Small craft advisory from noon today to midnight edt tonight
for anz535>537-542.

Small craft advisory until 6 am edt Saturday for anz534-543.

Small craft advisory from noon today to 6 pm edt this evening
for anz538.

Small craft advisory until midnight edt tonight for anz530.

Small craft advisory until 6 am edt early this morning for
anz536-537.

Synopsis... Rcm
near term... Rcm
short term... Rcm
long term... Baj
aviation... Baj/rcm
marine... Baj/rcm


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 5 mi47 min SSW 8.9 G 13 40°F 46°F1031.8 hPa
APAM2 - 8575512 - Annapolis, MD 32 mi47 min 42°F 1031.7 hPa
TPLM2 - Thomas Point, MD 32 mi65 min SSW 18 G 21 40°F 43°F23°F
NCDV2 33 mi53 min SSW 5.1 G 7 38°F 46°F1032.7 hPa
44062 - Gooses Reef, MD 37 mi35 min SSW 12 G 14 40°F 1033.3 hPa
CPVM2 37 mi47 min 41°F 28°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 39 mi47 min S 8 G 9.9 38°F 1031.8 hPa
FSNM2 39 mi47 min SSW 6 G 11 38°F 1031.1 hPa
BLTM2 - 8574680 - Baltimore, MD 40 mi47 min WSW 4.1 G 8 39°F 44°F1031.4 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 44 mi47 min SSW 13 G 16 40°F 1033.2 hPa
SLIM2 - 8577330 - Solomons Island, MD 45 mi47 min SW 11 G 12 41°F 44°F

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA4 mi13 minS 1210.00 miMostly Cloudy41°F28°F62%1031.5 hPa
Camp Springs / Andrews Air Force Base, MD9 mi7 minSSW 1610.00 miPartly Cloudy41°F25°F53%1031.7 hPa
Fort Belvoir, VA9 mi67 minSSE 810.00 miMostly Cloudy38°F26°F63%1032.5 hPa
College Park Airport, MD14 mi24 minS 510.00 miMostly Cloudy39°F28°F65%1031.5 hPa
Fort Meade / Tipton, MD24 mi26 minSSW 8 G 1510.00 miPartly Cloudy39°F26°F61%1031.8 hPa

Wind History from DCA (wind in knots)
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Last 24hrCalm33SE5S7S11E5S7S7S6SE6S8S11S11S8S13S8S11S11S12S16S10S12S12
1 day agoN21
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N14N12N10N11N8N12NE9NE9NE7NE5E6NE6E6NE7NE5
2 days agoCalmNW6N6N75NW10NW10N9NW8N7NW8W5SW5SW6W4W5NW10NW7NW15NW13
G27
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Tide / Current Tables for Alexandria, Virginia
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Alexandria
Click for Map
Fri -- 12:08 AM EDT     0.39 feet Low Tide
Fri -- 05:01 AM EDT     Moonrise
Fri -- 06:04 AM EDT     2.78 feet High Tide
Fri -- 07:04 AM EDT     Sunrise
Fri -- 12:19 PM EDT     0.35 feet Low Tide
Fri -- 03:50 PM EDT     Moonset
Fri -- 06:18 PM EDT     2.90 feet High Tide
Fri -- 07:24 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.40.511.72.32.62.82.62.11.510.60.40.40.81.52.22.72.92.82.41.81.30.8

Tide / Current Tables for Riverview, Potomac River, Maryland
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Riverview
Click for Map
Fri -- 05:01 AM EDT     Moonrise
Fri -- 05:49 AM EDT     2.51 feet High Tide
Fri -- 07:04 AM EDT     Sunrise
Fri -- 12:05 PM EDT     0.33 feet Low Tide
Fri -- 03:50 PM EDT     Moonset
Fri -- 06:03 PM EDT     2.61 feet High Tide
Fri -- 07:24 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.40.51.11.72.22.42.52.31.81.30.80.50.30.40.91.52.12.52.62.52.11.510.6

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 (10,2,3,4)
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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.