Wednesday, September19, 2018 L-36.com


Marine Weather and Tides
North Chevy Chase, MD

Version 3.4
What's New / NOTES
9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.

Sunrise 6:52AMSunset 7:10PM Wednesday September 19, 2018 5:23 PM EDT (21:23 UTC) Moonrise 3:24PMMoonset 12:34AM Illumination 74% Phase: Waxing Gibbous; Moon at 10 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- 435 Pm Edt Wed Sep 19 2018
Rest of this afternoon..N winds 10 kt. Waves 1 ft.
Tonight..N winds 5 kt. Waves less than 1 ft.
Thu..SE winds around 5 kt. Waves 1 ft.
Thu night..SE winds 5 kt. Waves less than 1 ft.
Fri..S winds 5 to 10 kt. Waves 1 ft.
Fri night..SW winds 5 to 10 kt. Waves 1 ft.
Sat..N winds 5 kt. Waves less than 1 ft. A chance of showers through the night.
Sun..NE winds 5 kt. Waves less than 1 ft. A chance of showers.
ANZ500 435 Pm Edt Wed Sep 19 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build over the waters through Thursday before moving offshore Friday. A cold front will approach from the northwest this weekend, then stall near or just south of the waters.


7 Day Forecast for Marine Location Near North Chevy Chase, MD
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location: 39, -77.09     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 191904
afdlwx
area forecast discussion
national weather service baltimore md washington dc
304 pm edt Wed sep 19 2018

Synopsis
High pressure will build over the region through Thursday
before migrating over the western atlantic on Friday. A cold
front will approach from the northwest toward the end of the
week before stalling near or over the region through the
weekend.

Near term through tonight
High pressure over the tennessee river valley this afternoon
with a frontal boundary nearing the allegheny highlands and the
mason dixon line to the northwest. This front will dissipate
the remainder of the day, with isolated shower activity
possible across the central foothills and the shenandoah valley
as a weak upper level disturbance traverses overhead.

Counteracting this activity is increasing heights aloft and an
unfavorable right exit region of the jet, so not expecting
widespread shower coverage for the remainder of the afternoon.

Will maintain isolated showers and perhaps a rumble of thunder
with any stronger cells. Locations east of the blue ridge should
be spared of any shower activity, with plentiful sunshine
winning out. Temperatures this afternoon are ranging in the
middle 80s for most, with some upper 80s readings across central
va.

High pressure will continue to nudge its way into the region
tonight, promoting clear skies and light winds. This will allow
for patchy fog development in the favored valley locations, but
widespread fog is not expected. Lows tonight will be in the 60s
area wide as dewpoints continue to fall further in to the upper
50s to middle 60s.

Short term Thursday through Friday night
With high pressure expected to dominate at the surface and aloft
through Thursday night, dry weather and near normal temperatures
are expected. Light northerly winds tonight will turn out of the
east southeast on Thursday, before favoring a more southerly
trajectory come Friday morning as the high shifts over the
western atlantic. Patchy fog potential once again Thursday night
with mostly clear skies and light winds expected, however
coverage should be less than previous nights given lower
dewpoints and less moisture to work with at the surface.

Low pressure will pass north of the great lakes on Friday,
continuing its path northeastward to close out the work week.

The associated frontal boundary will approach our region from
the northwest late Friday and into Friday night. Current
progression of the front by model guidance keeps precipitation
mostly northwest of the CWA through the day on Friday, with
coverage increasing Friday night. As such, have pushed back the
timing and have low end chance pops Friday afternoon for only
our far northwestern zones. Rain chances increase further east
Friday night, primarily west of the blue ridge, but will stick
with chance pops for now given the nocturnal arrival and timing
uncertainty. Temperatures Thursday through Friday will run in
the low to mid 80s for highs and lows generally in the 60s,
with near 70 degree readings Friday night ahead of the front.

Long term Saturday through Wednesday
A cold front will be moving southward across the area on
Saturday. Showers and perhaps a few thunderstorms will be
possible near the boundary. It does appear the surface boundary
will move south of the area before stalling during the latter
part of the weekend, which will put the forecast area on the
stable side of the boundary. However, the frontal zone aloft
will likely remain near or perhaps even north of the area. At
the same time, surface high pressure will be building over new
england, resulting in a cold air damming pattern. Assuming the
frontal zone aloft remains nearby, moist ascent over the surface
wedge will result in plentiful clouds and the potential for
light to moderate rain at times. Temperatures (especially highs)
will likely fall below normal... And there's potential highs
don't get out of the 60s for some areas by Sunday and Monday. It
is worth noting that there is some potential the frontal zone
gets far enough south at some point to preclude appreciable rain
chances, but if the pattern over the past several months
indicates anything, that won't be the case.

The frontal zone will be lifting north early next week as low
pressure moves through the upper great lakes. If when we break out
of the surface wedge, it will result in a slight warming trend.

However, moist southwest flow ahead of a broad trough moving into
the plains will continue to result in clouds and chances for showers
and some thunderstorms. The next cold front remains well to our
northwest through Wednesday, with its passage occurring after the
end of the forecast period. Given the multiple days of rain and
precipitable water rebounding to 1.5-2.0 inches by Tuesday and
Wednesday, some hydro concerns are not out of the question.

Aviation 18z Wednesday through Monday
Vfr conditions expected at all terminals through Thursday night
as high pressure moves overhead. Isolated showers may traverse
cho later this afternoon but timing and impact remains in
question. Patchy fog will be possible at mrb cho both tonight
and again Thursday night, with ifr MVFR vis the most likely
restriction. A cold front will approach the terminals late
Friday and Friday night, increasing rain chances. At this time,
mrb would serve to see the highest chance of restrictions with
the remaining terminals likely holding off until Saturday
morning. Northerly breezes today will subside tonight, veering
southeasterly on Thursday at less than 10 knots, then turning
southerly and increasing on Friday ahead of the front.

There will be a chance of showers and perhaps a thunderstorm as a
cold front drops into the area. The frontal zone will remain nearby,
and showers may reduce visibility at times through the period.

Ceilings may eventually drop belowVFR levels as well.

Marine
Northerly breezes are bringing SCA conditions to the maryland
portion of the lower chesapeake bay this afternoon. Winds
expected to abate by this evening as high pressure builds
overhead, with sub SCA conditions prevailing through Thursday
night. SCA conditions may return on Friday as southerly flow
increases ahead of an approaching cold front to the northwest.

A cold front will drop across the waters on Saturday,
then stall nearby through early next week. This front will bring
a wind shift to the north, then eventually easterly. Winds may
be the strongest Monday as high pressure builds into new
england. Showers will be possible through the period, with the
highest chance of thunderstorms (though still low) on Saturday.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory until 6 pm edt this evening for anz534-
537-543.

Synopsis... Bkf
near term... Bkf
short term... Bkf
long term... Ads
aviation... Ads bkf
marine... Ads bkf


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 10 mi42 min NNE 5.1 G 6 87°F 72°F1013.3 hPa
BSLM2 - Chesapeake Bay, MD 25 mi114 min N 1.9 83°F 1013 hPa64°F
APAM2 - 8575512 - Annapolis, MD 32 mi36 min 81°F 1013 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 33 mi36 min N 5.1 G 8 82°F 1013.2 hPa
BLTM2 - 8574680 - Baltimore, MD 33 mi42 min N 7 G 9.9 83°F 78°F1012.9 hPa
FSNM2 34 mi36 min NNE 7 G 9.9 82°F 1013.4 hPa
44063 - Annapolis 34 mi34 min E 5.8 G 7.8 79°F 1014 hPa
TPLM2 - Thomas Point, MD 35 mi24 min ENE 7 G 8 78°F 76°F1014.3 hPa (+0.0)68°F
CPVM2 37 mi36 min 79°F 66°F
44062 - Gooses Reef, MD 47 mi34 min NNE 12 G 14 80°F 1014.1 hPa
NCDV2 47 mi36 min N 6 G 8.9 85°F 77°F1012.7 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 47 mi36 min N 1.9 G 4.1 79°F 75°F1013.6 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
College Park Airport, MD9 mi36 minN 510.00 miFair83°F62°F49%1013.5 hPa
Washington/Reagan National Airport, DC, VA10 mi32 minNE 510.00 miPartly Cloudy87°F66°F50%1013.4 hPa
Gaithersburg - Montgomery County Airport, MD12 mi28 minN 010.00 miFair83°F68°F61%1016.6 hPa
Camp Springs / Andrews Air Force Base, MD17 mi88 minN 1110.00 miFair84°F60°F46%1014 hPa
Fort Meade / Tipton, MD18 mi36 minN 310.00 miFair81°F64°F58%1014.2 hPa
Washington/Dulles International Airport, DC, VA19 mi32 minNNW 910.00 miA Few Clouds86°F66°F53%1013.4 hPa
Fort Belvoir, VA19 mi28 minN 410.00 miFair87°F73°F65%1013.4 hPa

Wind History from CGS (wind in knots)
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Last 24hrCalmCalmCalmCalmCalmNW3CalmCalmCalmCalmCalmCalmCalmCalmNW5N5N6N7N10N7N7N8N5N4
1 day agoSE9SE3SE4CalmCalmCalmS4SW3CalmCalmCalmCalmCalmCalmS3CalmCalmCalmCalmNW3NW5N9N7NW5
2 days agoNE5CalmCalmCalmCalmCalmCalmCalmCalmCalmNE3NE3CalmCalmCalmE7SE4E6SE7SE5SE4SE8SE5SE4

Tide / Current Tables for Chain Bridge, D.C.
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Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Tide / Current Tables for Chain Bridge, one mile below, Washington, D.C.
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Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Weather Map and Satellite Images
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wmap_A
GOES Local Image of    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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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Baltimore, MD/Washington (17,4,5,8)
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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.