Thursday, June21, 2018 L-36.com


Marine Weather and Tides
Broadlands, VA

Version 3.4
What's New / NOTES
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.

Sunrise 5:43AMSunset 8:40PM Thursday June 21, 2018 4:07 AM EDT (08:07 UTC) Moonrise 1:27PMMoonset 12:56AM Illumination 54% Phase: First Quarter Moon; Moon at 8 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- 131 Am Edt Thu Jun 21 2018
Overnight..W winds 5 kt. Waves less than 1 ft. A chance of showers.
Thu..N winds 5 kt. Waves less than 1 ft.
Thu night..E winds around 5 kt. Waves 1 ft. A chance of showers.
Fri..E winds 5 to 10 kt. Waves 1 ft. Showers likely.
Fri night..E winds 5 to 10 kt. Waves 1 ft. Showers likely.
Sat..S winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely.
Sat night..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Sun..W winds 5 kt. Waves less than 1 ft. A chance of tstms. A chance of showers.
Mon..N winds 5 to 10 kt. Waves 1 ft. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 131 Am Edt Thu Jun 21 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will track from west virginia east over the waters along a stalled front overnight. The front will then drop farther south Thursday as high pressure briefly builds from the ohio valley to new england. The front will then return north as a warm front Friday night into Saturday as the high moves offshore and low pressure moves from the midwest to the great lakes. A small craft advisory may be needed for a portion of the waters Friday into Saturday.

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 210122
afdlwx
area forecast discussion
national weather service baltimore md washington dc
922 pm edt Wed jun 20 2018

Synopsis
Low pressure over southwest pennsylvania will move along a
stalled front overnight. This stalled front across central
virginia Thursday and Friday will return north as a warm front
Saturday. A stronger cold front will approach Sunday before
passing through Sunday night into Monday. High pressure will
return by the middle portion of next week.

Near term through Thursday
A surface low currently over southwest pennsylvania will move
along a front in a southeastward direction. It is expected to
bring additional showers and a few thunderstorms to the region
overnight. This activity is currently noted from near pittsburgh,
pennsylvania south into central west virginia. Stronger
thunderstorms are noted in a separate cluster extending from
baltimore, maryland to near charlottesville, virginia. Winds to
the south, along, and to the north of the stalled front are
erratic. With the strongest thunderstorms, winds become a quick
northwest punch with speeds of nearly 40 mph.

Showers and thunderstorms are expected to diminish in coverage
and intensity behind the departing low pressure system and its
associated upper level energy. A few showers may linger later
overnight, despite this diminishing trend. Patchy low clouds
and fog are possible toward morning with low- level moisture
possibly being trapped underneath the nocturnal inversion.

A stalled front across our region Thursday will spawn additional
heavy showers and strong thunderstorms. This time... It appears
that the areas with the greatest threat of encountering this
activity will be along and south of i-66 and south of u.S. 50 in
eastern west virginia. The timing on this activity still appears
to be during the afternoon into the early evening hours. We
can't out a heavy shower or thunderstorm north of these zones
toward the mason-dixon region or during the mid to late morning
hours. Showers and thunderstorms, primarily in the virginia
piedmont and central shenandoah valley, could produce very heavy
rain that could lead to localized flooding or flash flooding
during the afternoon. Temperatures on Thursday could be a few
degrees cooler than Wednesday, but this factor should not
downplay our threat for heavy rain activity as dewpoint
temperatures will still be in the 60s to near 70 in most places.

Short term Thursday night through Friday night
Heavy showers and thunderstorms near the metro areas would be
toward Thursday evening and overnight hours.

With a stalled front across our region Thursday night through
Friday night, the threat or chance for heavy showers and gusty
thunderstorms still exist each period.

There should be more stability over the metro areas overnight
Thursday into Friday that could limit shower and thunderstorm
activity over the northeastern quarter of our cwa.

A closed off low at the surface and aloft that is expected to
move across the ohio valley toward our CWA will bring an
increased chance for showers and heavy thunderstorms to our cwa
Friday into Friday night.

High pwats and frontogenetical forcing is expected to increase
near a developing warm front Friday; thus, increasing coverage
of showers and gusty thunderstorms in our region.

Long term Saturday through Wednesday
By Saturday morning a surface warm front will be working it's way
through the region. As the warm front progresses through, some
showers will be possible during the morning hours. This warm
front is expected to make it just north of our area by afternoon.

At mid to upper levels, a low will track over the great lakes as it
starts to shear out into more of an open wave. Model guidance
suggests around 1000-2000 j kg of MLCAPE over much of our area
Saturday afternoon, with about 35-40 kts of 0-6 km shear. Given that
environment, organized thunderstorms will be possible Saturday
afternoon, some of which may be strong.

Conditions should dry out Saturday night, but showers and
thunderstorms will be possible again Sunday afternoon and evening as
a shortwave approaches from the ohio valley. A more potent trough
will slide across the northeast Sunday night. The surface cold front
associated with that trough will move through our area late Sunday
night or Monday morning. Some showers or thunderstorms along the
front can't be ruled on Monday, especially if the front slows up a
bit and some daytime heating occurs ahead of it. Once the front
passes however, a northerly wind will advect a drier cooler airmass
into the area. High pressure is expected to build from the great
lakes to the mid-atlantic Monday night through Tuesday, bringing dry
conditions and slightly below normal temperatures.

Aviation 01z Thursday through Monday
Gusty thunderstorms will frequent lightning and very heavy
downpours have exited to the south of the cho terminal. The mrb
terminal will have window of an hour or two of sprinkles or a
shower in the vicinity before additional showers approach from
southwest pennsylvania. Heavy rainfall will become light over
the next hour or two at iad, dca, bwi and mtn.

Any heavy showers or thunderstorms overnight would be mainly
near cho, mrb or iad and could reduce conditions briefly to MVFR
with wind gusts briefly over 30 knots. Otherwise, MVFR toVFR
conditions anticipated overnight. Patchy low clouds and fog are
possible overnight, as well, into Thursday morning due to low-
level moisture being trapped underneath the subsidence
inversion.

MainlyVFR conditions are expected later Thursday through
Thursday evening. There will be a few showers and thunderstorms
possible, especially near kcho. More widespread showers and
possible thunderstorms are expected overnight Thursday through
Friday night. An onshore flow will also lead to low clouds as
well.

Low ceilings and visiblities may be possible Saturday morning
until a warm front lifts north of our area. Showers and
thunderstorms will be possible both Saturday and Sunday
afternoon.

Marine
An area of low pressure will pass through the waters overnight
with a front sagging southward then stalling Thursday. Winds
may briefly approach SCA criteria for a few hours Thursday due
to the pressure surge with the sagging front, but confidence is
too low for a headline at this time. The boundary will remain
stalled to the south and west through Friday night. The gradient
may strengthen a bit Friday Friday night and an SCA may be
needed for portions of the waters.

Small craft advisory level winds may be possible in
southeasterly flow to the north of a warm front Saturday
morning, and then in southerly flow later on Saturday once we
break out into the warm sector. Thunderstorms will also be
possible both Saturday and Sunday afternoon.

Hydrology
A front associated with a departing low pressure system will
slide south Thursday before stalling out over central virginia
into the potomac highlands for Friday and Friday night. This
sagging front will be fueled by rich moisture and dewpoint
temperatures in the middle 60s to near 70 to spawn showers and
heavy thunderstorms Thursday afternoon into Thursday night.

These showers and thunderstorms will be capable of heavy
rainfall that could result in isolated instances of flooding
Thursday night. A modest low- level jet of 25-30 kts in the
900-800 mb layer is progged by the majority of the guidance
Friday into Friday night which will advect in more moisture
(pwats likely exceed 2 inches by Friday evening). Numerous
showers and possible thunderstorms are likely, and with the high
moisture returning rainfall may be locally heavy. The best
chance for heavy rain will be be across central virginia into
the potomac highlands where forcing will be stronger near the
stalled boundary.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Klw
near term... Klw
short term... Bjl
long term... Jmg
aviation... Klw jmg
marine... Klw jmg
hydrology... Klw


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 28 mi49 min S 1.9 G 2.9 73°F 78°F1007 hPa
BSLM2 - Chesapeake Bay, MD 46 mi157 min S 1 65°F 1008 hPa65°F
BLTM2 - 8574680 - Baltimore, MD 53 mi55 min NW 1.9 G 2.9 73°F 78°F1006.4 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
Leesburg / Godfrey, VA5 mi72 minN 010.00 miLight Rain66°F66°F100%1008.1 hPa
Washington/Dulles International Airport, DC, VA6 mi75 minN 010.00 miLight Rain70°F70°F100%1007.3 hPa
Gaithersburg - Montgomery County Airport, MD21 mi71 minWNW 410.00 miLight Rain69°F69°F100%1010.1 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA21 mi71 minN 010.00 miFair70°F69°F97%1008.3 hPa

Wind History from JYO (wind in knots)
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Last 24hrCalmNE4NE4NE3CalmNE3CalmCalmW3CalmS4SE4S3S3CalmW5
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1 day agoW6NW9W3NW9NW8NW10W12
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2 days agoCalmCalmCalmCalmCalmSW3CalmW4W3SW5CalmW6W4SW3SW6SW6CalmCalmSW5SW4W3SW3W5W6

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Thu -- 01:54 AM EDT     Moonset
Thu -- 03:49 AM EDT     3.30 feet High Tide
Thu -- 05:43 AM EDT     Sunrise
Thu -- 10:34 AM EDT     0.26 feet Low Tide
Thu -- 02:24 PM EDT     Moonrise
Thu -- 04:13 PM EDT     3.08 feet High Tide
Thu -- 08:37 PM EDT     Sunset
Thu -- 10:51 PM EDT     0.13 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.122.73.23.332.51.91.30.70.30.30.81.62.32.83.132.51.91.30.70.30.1

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Thu -- 01:54 AM EDT     Moonset
Thu -- 03:46 AM EDT     3.30 feet High Tide
Thu -- 05:43 AM EDT     Sunrise
Thu -- 10:31 AM EDT     0.30 feet Low Tide
Thu -- 02:24 PM EDT     Moonrise
Thu -- 04:10 PM EDT     3.08 feet High Tide
Thu -- 08:37 PM EDT     Sunset
Thu -- 10:49 PM EDT     0.18 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.22.12.83.23.332.41.81.20.70.40.40.81.62.42.93.12.92.51.81.20.70.30.2

Weather Map and Satellite Images
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wmap_A
GOES Local Image of Mid-Atlantic    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Wind Forecast for Baltimore, MD/Washington (4,6,7,8)
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Ground Weather Radar Station Sterling, VA
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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.