Sunday, August19, 2018 L-36.com


Marine Weather and Tides
Frederick, MD

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Sunrise 6:25AMSunset 8:00PM Sunday August 19, 2018 10:06 AM EDT (14:06 UTC) Moonrise 2:12PMMoonset 12:00AM Illumination 56% 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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ANZ538 Patapsco River Including Baltimore Harbor- 734 Am Edt Sun Aug 19 2018
Today..N winds 10 kt. Waves 1 ft. Isolated showers this morning, then scattered showers this afternoon.
Tonight..NE winds 5 to 10 kt. Waves 1 ft.
Mon..NE winds 5 to 10 kt. Waves 1 ft.
Mon night..E winds 5 to 10 kt. Waves 1 ft.
Tue..SE winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Tue night..S winds 5 to 10 kt. Waves 1 ft. Showers likely with a chance of tstms.
Wed..NW winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Thu..N winds around 5 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 734 Am Edt Sun Aug 19 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front will push south of the area today. High pressure will build to the north tonight and Monday before a warm front lifts northward through the waters on Tuesday. A cold front will sweep to the east on Wednesday followed by modified canadian high pressure taking hold through week's end. A small craft advisory may be needed Tuesday into Wednesday.


7 Day Forecast for Marine Location Near Frederick, MD
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location: 39.43, -77.41     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 190802
afdlwx
area forecast discussion
national weather service baltimore md washington dc
402 am edt Sun aug 19 2018

Synopsis
A cold front will push south of the area today but stall nearby.

High pressure will build to the northeast Monday before low
pressure passes northwest of the area Tuesday. A cold front will
sweep eastward by early Wednesday, with high pressure building
from the west for the end of the week.

Near term through tonight
A cold front currently stretches across the area. Lower dew
points are only slowly advecting in though, so some locally
dense fog is occurring in the central shenandoah valley. Some
lower clouds are also sliding down from the northeast. These
clouds could persist across the baltimore metro for a good part
of the day, with the dc area possibly being on the southwestern
fringe.

Even though the cold front is expected to push south of the area
today, the theta-e gradient aloft will remain across southern
portions of the cwa, resulting in some instability. Low level
flow will take an easterly upslope component. Most models
suggest convection forms across our southwestern zones this
afternoon and evening... With potentially some showers persisting
through the night as shortwave energy approaches. With
precipitable water values around 1.5 inches, the potential
repetitive nature of this activity could lead to some isolated
high rain totals. The limiting factor is that individual cells
should have sufficient motion. While a few showers are possible
across the remainder of the CWA as a shortwave crosses this
afternoon, they should be lighter and more widely scattered to
isolated.

Clouds and cold advection behind the front will result in high
temperatures in the upper 70s to mid 80s today. Clouds should
thicken and lower tonight, with some potential for fog and
drizzle, especially across the mountains. Lows will be in the
60s to around 70.

Short term Monday through Tuesday night
High pressure will be positioned over new england Monday.

Onshore flow will dominate with plenty of cloud cover. A few
light showers or drizzle could occur at time, aided by a slowly
departing shortwave and the upslope component to the wind.

However, instability will be shunted to the south, so
precipitation should be light in nature. High temperatures will
be in the upper 70s and lower 80s. Low pressure will be tracking
from the mid mississippi valley to the great lakes Monday night.

The front will begin to return north, though the surface portion
of the front will likely struggle to lift north east of the
mountains with the high pressure wedge. With warm, moist air
overrunning this boundary, shower chances will increase,
particularly in the mountains.

Showers and perhaps some embedded thunderstorms will continue
into Tuesday morning as the warm front continues to lift north.

This activity and abundant cloud cover put the amount of
destabilization through the day in question. However, seasonally
strong winds aloft will overspread the area ahead of an
approaching upper level trough, so deep layer shear will be
plentiful. While convective details are uncertain at this
juncture, there will be some attendant severe weather threat
with this weather system. Locally heavy rain could also occur as
precipitable water jumps back near 2 inches. A cold front
trailing the low will sweep across the area sometime after dark
Tuesday, eventually ending the thunderstorm threat.

Long term Wednesday through Saturday
The surface cold front associated with the aforementioned primary
surface low will have progressed through the area by Wednesday
morning. However, model guidance suggests that a secondary shortwave
and an associated reinforcing surface cold front will work through
during the day on Wednesday. With less moisture to work with in the
wake of the first front, any afternoon showers and thunderstorms
should be much more limited in scope compared to Tuesday.

The secondary front will clear the area by Thursday morning,
ushering a much cooler and less humid airmass into the area. High
pressure will gradually work in from the ohio valley late Thursday
through Friday, leading to sunny skies and no precipitation. High
temperatures Thursday and Friday should be in the upper 70s to
low 80s, with dewpoints in the 50s. High pressure will slide
off the coast on Saturday as another system will be moving in
from the west. At this time, expecting things to stay dry
through Saturday as well, with temperatures being slightly
warmer than on Friday. However, more humid air will return to
the region as we return to a southerly flow, allowing dew points
to return to the mid 60s. So it will probably feel noticeably
warmer than Friday.

Aviation 08z Sunday through Thursday
Cold front is currently progressing south across the area. Some
lower (mainly MVFR) clouds are advecting from the northeast
behind the front. These are most likely to affect the baltimore
area, but some patches are also affecting the dc area. CIGS may
be slow to lift today in baltimore, but am hopeful for
improvement by afternoon. A stray shower can't be ruled out
through the day as a disturbance crosses. Thunderstorms could
occur at cho where instability will linger.

As high pressure builds to the northeast tonight through Monday,
an onshore component to the wind will develop. MVFR CIGS are
likely tonight, potentially reaching ifr. CIGS may eventually
lift toVFR Monday afternoon, only to return down Monday night
and Tuesday morning. A stray shower or drizzle is possible
during this time, but impacts should be minimal. A strong low
pressure system will pass to the northwest, bringing potential
for strong thunderstorms Tuesday afternoon or evening.

Aside from a passing shower or thunderstorm on Wednesday afternoon,
which could lead to temporary sub-vfr conditions, expecting to
remainVFR through Thursday.

Marine
Cold front sinking south through the waters early this morning
is bringing northerly winds to 15 knots. Expect this to continue
today, with flow becoming onshore tonight into Monday. Winds
during this period may approach SCA criteria, but it's looking
unlikely at this time. A stray thunderstorm is also possible
today, with the highest chance across southern maryland.

A warm front will lift northward Tuesday, and marginal sca
conditions may develop in its wake. Thunderstorms, potentially
strong, will be possible later Tuesday as a cold front
approaches.

Some gusty winds are possible on Wednesday morning ahead of a cold
front, but not sure these will necessarily reach SCA criteria.

However, a chance for showers and storms does exist Wednesday
afternoon, which could bring temporary gusty winds with them.

Sub- SCA winds are expected on Thursday, as high pressure builds
into the region.

Tides coastal flooding
Onshore flow will develop Monday through early Tuesday. The
favored (higher astronomical) tides Monday night and Tuesday
night could approach minor flood stage as anomalies increase.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Ads
near term... Ads
short term... Ads
long term... Cjl
aviation... Ads cjl
marine... Ads cjl
tides coastal flooding... Ads


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 44 mi36 min N 1.9 G 2.9 79°F 81°F1013.9 hPa
BLTM2 - 8574680 - Baltimore, MD 45 mi36 min NNE 8 G 11 73°F 84°F1013.2 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 49 mi36 min N 6 G 8 73°F 1013.4 hPa
FSNM2 49 mi60 min N 8.9 G 9.9 72°F 1013 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Frederick Municipal Airport, MD2 mi79 minN 07.00 miMostly Cloudy73°F71°F94%1015.2 hPa
Gaithersburg - Montgomery County Airport, MD22 mi70 minVar 310.00 miOvercast69°F66°F90%1016.8 hPa

Wind History from FDK (wind in knots)
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Last 24hrSW5SW8SW3SW9SW12SW10SW10CalmCalmCalmS4CalmSW5CalmN6N4N6NE6NE3CalmN3CalmCalmNE8
1 day agoCalmW3S4SW4SW7SW6W6SW14SW7SW4CalmCalmCalmCalmSE4CalmSW3S3CalmCalmS3SW4SW3SW3
2 days agoS3--SW4SW6SW6CalmCalmS4CalmCalmCalmCalmCalmCalmCalmSE3CalmCalmCalmCalmSE4CalmSW3SW4

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Sun -- 12:41 AM EDT     Moonset
Sun -- 03:40 AM EDT     3.32 feet High Tide
Sun -- 06:25 AM EDT     Sunrise
Sun -- 10:37 AM EDT     0.45 feet Low Tide
Sun -- 03:09 PM EDT     Moonrise
Sun -- 04:15 PM EDT     2.89 feet High Tide
Sun -- 07:57 PM EDT     Sunset
Sun -- 10:31 PM EDT     0.45 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.52.32.93.23.332.51.91.40.90.50.50.91.62.22.62.92.82.31.71.10.70.50.5

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Sun -- 12:41 AM EDT     Moonset
Sun -- 03:44 AM EDT     3.28 feet High Tide
Sun -- 06:25 AM EDT     Sunrise
Sun -- 10:40 AM EDT     0.45 feet Low Tide
Sun -- 03:09 PM EDT     Moonrise
Sun -- 04:18 PM EDT     2.85 feet High Tide
Sun -- 07:57 PM EDT     Sunset
Sun -- 10:35 PM EDT     0.44 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.52.32.83.23.332.51.91.40.90.60.50.91.52.12.62.82.82.31.71.20.80.50.5

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.
target = "new">Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Baltimore, MD/Washington (10,2,3,4)
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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.