Sunday, August20, 2017 L-36.com


Marine Weather and Tides
Broadlands, VA

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 6:27AMSunset 7:58PM Sunday August 20, 2017 8:59 PM EDT (00:59 UTC) Moonrise 4:04AMMoonset 6:21PM Illumination 2% Phase: Waning Crescent; Moon at 28 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- 732 Pm Edt Sun Aug 20 2017
Tonight..SE winds 5 kt. Waves less than 1 ft. A slight chance of showers and tstms after midnight.
Mon..S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Mon night..S winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Tue..SW winds 5 to 10 kt. Waves 1 ft.
Tue night..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Wed..NW winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Wed night..N winds 5 kt. Waves less than 1 ft.
Thu..N winds 5 kt. Waves less than 1 ft.
Fri..N winds 5 kt. Waves less than 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 732 Pm Edt Sun Aug 20 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move offshore through tonight. A cold front will cross the waters late Tuesday night into early Wednesday. High pressure will return for the second half of the week. Small craft advisories will likely be needed Monday night through Wednesday night.

7 Day Forecast for Marine Location Near Broadlands, VA
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location: 39.02, -77.52     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 201812
afdlwx
area forecast discussion
national weather service baltimore md washington dc
212 pm edt Sun aug 20 2017

Synopsis
High pressure over the area will move offshore tonight through
Monday. A cold front will approach the area Tuesday before
passing through Wednesday. High pressure will build in behind
the boundary for Thursday through Saturday.

Near term through Monday
High pressure is overhead this afternoon. A CU field is developing
along the ridge lines out west. High pressure will slowly move
eastward today and a light southerly flow will begin mainly across
the va highlands, central shenandoah valley and central foothills.

This will increase dewpoints some and iso showers and
thunderstorms are possible in this area this afternoon evening.

High pressure will continue to move eastward and off the coast
tonight, and southerly flow will increase moisture into the
region overnight. Although any shower thunderstorm activity will
likely be diurnally driven, waning early this evening, some
activity may continue to move eastward possibly reaching i-95 by
early Monday morning. Many ncar ensemble members show this.

Moisture advection will continue Monday and low stratus will likely
be across much of the region Monday morning. Daytime mixing will
help break up low status by late morning and breaks of sunshine are
expected early Monday afternoon. We are concerned with the activity
across ia mo this afternoon as it will track eastward in the
westerly flow aloft and be near our outlook area Monday afternoon.

Increased instability and shear will lead to an environment
conducive for showers and thunderstorms to form across the region.

There should be a lee trough in place and coupled with a crossing
disturbance some storms may become strong to severe.

Short term Monday night through Tuesday night
Convection will likely be ongoing Monday night mainly near i-95
and east. Little change to the environment overnight into
Tuesday so leftover boundaries may cause a pop-up shower and
thunderstorm into Tuesday morning.

Warm and humid conditions will continue Tuesday as a cold front
crosses the ohio valley. Showers and thunderstorms are
possible... Especially late Tuesday into Tuesday night across
northern and central portions of the CWA closer to the cold front.

Some storms may be strong to severe given the instability and
strengthening shear profiles.

Long term Wednesday through Saturday
Most of the guidance is in decent agreement that the cold front
won't clear southern parts of the CWA (cho to southern md) by
Wednesday afternoon, which means another round of scattered showers
and thunderstorms will be possible for these areas. With the upper
trough diving down 0-6 km shear still modestly high (especially for
august), can't rule out a few strong to isolated severe storms for
this corridor Wednesday afternoon and early evening, as well.

A rather strong area of high pressure for this time of year (~1025
mb) will drop across the great lakes Wednesday night into Thursday
which should push the front well south. The high pressure center
will gradually weaken as it drifts just north of the area Friday
into the weekend, which should result in below average temperatures
and humidity with mainly clear and dry weather conditions.

Aviation 18z Sunday through Friday
Light flow AOB 10 kts today gradually veers from W to SE by
evening. Lamp met guidance wants to bring in widespread ifr
vsbys but given climo synoptic setup believe this is over done.

MVFR vsbys CIGS psbl cho mrb included in taf, maybe iad bwi mtn
by daybreak but not confident enough to put in TAF at these
sites. May be vcsh near cho this aftn 20-23z but again
confidence too low coverage too sparse for taf.

Brief break in clouds (from bkn to sct) between 14-18z tue, then
back to bkn E of blue ridge (all terminals except mrb) W pop up
shower or TSTM seeming plausible 18-00z timeframe. Too sparse this
far out for mention in TAF just yet. Brief vsby restrictions psbl.

Tstm psbl Wed pm near cho, should stay S of dca iad unless
front slows its southward progress. Otherwise mainlyVFR. Generally
nw flow AOB 10 kts.

Marine
High pressure will build over the waters today before shifting
toward the mid-atlantic coast tonight. The high will move offshore
Monday through Monday night and a cold front will approach the
waters Tuesday through Tuesday night. The boundary will pass through
Wednesday and high pressure will build over the waters for late next
week. A small craft advisory may be needed for portions of the
waters Monday night through Wednesday night.

Isolated thunderstorms are possible over the waters late tonight
through Monday morning. Scattered thunderstorms are possible Monday
afternoon and evening. Some storms may produce gusty
winds... Especially later Monday into Monday evening. A few showers
and thunderstorms are possible later Tuesday into Wednesday ahead of
a cold front as well... And some of these storms have the potential
to be strong to locally severe.

Northerly pressure surge channeling behind cold frontal
passage Wednesday into Wednesday night will likely require the
issuance of small craft advisories.

Tides coastal flooding
Minor coastal flooding is possible at annapolis Tuesday and
Wednesday morning.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Products... Hsk dfh woody!


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 28 mi41 min E 1.9 G 7 83°F 82°F1019.6 hPa
BSLM2 - Chesapeake Bay, MD 46 mi149 min E 2.9 85°F 1019 hPa69°F
BLTM2 - 8574680 - Baltimore, MD 53 mi41 min SSW 4.1 G 7 80°F 82°F1019.8 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Leesburg / Godfrey, VA5 mi64 minN 010.00 miFair81°F66°F62%1020.7 hPa
Washington/Dulles International Airport, DC, VA6 mi67 minE 410.00 miA Few Clouds78°F66°F67%1019.8 hPa
Gaithersburg - Montgomery County Airport, MD21 mi63 minN 010.00 miFair74°F63°F69%1023.2 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA21 mi63 minN 010.00 miFair77°F72°F85%1021 hPa

Wind History from JYO (wind in knots)
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Last 24hrN12
G22
CalmCalmCalmCalmN5N4N3N5N3CalmN4N5N5N3CalmNE3CalmCalmN5CalmNE3CalmSE4
1 day agoCalmSW4CalmCalmSW3W4NW5NW5NW4CalmCalmNW4NW4NW9
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W8NW5W6S4SW5SW4SW5SW3SW3
2 days agoS8S7S3S5S3S3S4S4SW4S4S3S3S3S3S6S6SW6S8SW3N6NW3S3CalmW3

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Sun -- 02:06 AM EDT     0.15 feet Low Tide
Sun -- 05:02 AM EDT     Moonrise
Sun -- 06:26 AM EDT     Sunrise
Sun -- 07:49 AM EDT     3.64 feet High Tide
Sun -- 02:54 PM EDT     0.01 feet Low Tide
Sun -- 07:19 PM EDT     Moonset
Sun -- 07:56 PM EDT     Sunset
Sun -- 08:23 PM EDT     3.31 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.80.40.20.41.12.133.53.63.32.721.40.80.200.41.22.22.93.33.22.72

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Sun -- 02:08 AM EDT     0.16 feet Low Tide
Sun -- 05:02 AM EDT     Moonrise
Sun -- 06:26 AM EDT     Sunrise
Sun -- 07:51 AM EDT     3.63 feet High Tide
Sun -- 02:56 PM EDT     0.01 feet Low Tide
Sun -- 07:19 PM EDT     Moonset
Sun -- 07:56 PM EDT     Sunset
Sun -- 08:26 PM EDT     3.31 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.80.40.20.41.12.12.93.53.63.32.721.40.80.300.41.22.12.93.33.22.72.1

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 (20,4,5,8)
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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.