Tuesday, June19, 2018 L-36.com


Marine Weather and Tides
Frederick, MD

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 5:41AMSunset 8:41PM Tuesday June 19, 2018 11:34 PM EDT (03:34 UTC) Moonrise 11:17AMMoonset 12:00AM Illumination 42% Phase: Waxing Crescent; Moon at 7 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- 1031 Pm Edt Tue Jun 19 2018
Rest of tonight..NE winds 5 kt. Waves less than 1 ft.
Wed..SE winds 5 kt. Waves flat.
Wed night..W winds 5 kt. Waves less than 1 ft. Showers likely with a chance of tstms.
Thu..N winds 5 to 10 kt. Waves 1 ft.
Thu night..NE winds around 5 kt. Waves flat.
Fri..E winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Fri night..E winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely.
Sat..SW winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely .
Sun..NW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1031 Pm Edt Tue Jun 19 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front approaching from the north will stall near the waters through Wednesday. Low pressure will track along the boundary and pass near the waters Wednesday. The front will then drop farther south Thursday. High pressure will briefly build toward the waters from the ohio valley Friday before moving into the western atlantic over the weekend.

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 200128 aaa
afdlwx
area forecast discussion... Updated
national weather service baltimore md washington dc
928 pm edt Tue jun 19 2018

Synopsis
A cold front dropping south out of pennsylvania will stall over
the mid-atlantic during the middle part of the week. A wave of
low pressure will move along this front Wednesday into
Wednesday night. The front will sag southward toward the north
carolina border Friday as high pressure briefly builds in from
the ohio valley, then the front will return northward over the
weekend.

Near term through Wednesday
Still a low chance for showers overnight mainly west of the blue
ridge as activity west of the appalachians spills over the mtns
in wnw flow. Otherwise, dry with low clouds developing toward
morning. Most reliable guidance suggest stratus development
toward dawn rather than fog.

The boundary will stall out over the potomac highlands into
central virginia overnight. A few showers are possible along the
boundary, but much of the time may end up dry due to the loss of
daytime heating. Patchy fog is expected along and ahead of the
boundary as well.

Short term Wednesday night through Thursday night
Low pressure will track along the boundary, passing through our
area later Wednesday into Wednesday night. Widespread showers
and thunderstorms are likely, especially later Wednesday
afternoon into Wednesday evening. There is an isolated severe
threat for locally damaging wind gusts and large hail. Also,
moisture convergence from the low and the instability will cause
thunderstorms to produce heavy rain. Localized flash flooding is
possible as well. More details are in the hydro section below.

The boundary will drop to the south overnight Wednesday through
Thursday night. A few showers are possible near the potomac
highlands into the central shenandoah valley, but most other
locations should be dry as cooler and more stable air moves in.

Long term Friday through Tuesday
On Friday attention will turn to an upper-level low located over the
central mississippi valley. At the surface, an area of low pressure
will develop ahead of the upper-level low and move into the lower
ohio river valley. Meanwhile, high pressure will depart off the new
england coast. We'll be located in stable air to the north of a
frontal boundary, but rain chances can't be ruled out by late
afternoon as warm advection commences aloft. Chances for rain will
increase Friday night as deeper warm air advection and
associated overrunning precipitation overspreads the area.

By Saturday morning, the upper-level low will shear out into more of
an open wave as it tracks toward the lower great lakes. The surface
low is also forecast to track toward the lower great lakes. As
this low moves off to the northeast, it will move a surface warm
front northward through the area Saturday morning. As a result,
Saturday will be noticeably warmer and more humid than previous
days. Model guidance suggests that areas to the south of the
warm front will destabilize by Saturday afternoon, with mlcape
values reaching around or slightly above 1000 j kg. This
instability coupled with seasonably strong flow aloft (0-6 km
shear values around 40 kt), could lead to some stronger storms
Saturday afternoon.

The area of low pressure will continue to track off to the northeast
toward the canadian maritimes on Sunday. The cold front
associated with this system will progress through the region
sometime during the Sunday afternoon through Monday time period,
but differences between individual models and their respective
ensembles are substantial. Rain chances can't be ruled out on
Sunday or Monday, but the general trend with time will be for
rain chances to lessen and drier, cooler air to work into the
region in the wake of the cold front.

Aviation 02z Wednesday through Sunday
Stratus development possible toward dawn but most guidance keep
cigs abv 3 kft.

The boundary will stall to the south of the terminals overnight
into Wednesday, before low pressure rides along the boundary
later Wednesday and Wednesday evening. Some storms may be strong
to locally severe and ifr subifr conditions are possible in
heavy rain. The boundary will stall to the south of the
terminals overnight Wednesday through Thursday night.

Showers and thunderstorms will be the main concern Friday into
Saturday as a warm front slowly lifts northward. Sub-vfr clouds
may also occur before the front lifts north, particularly Friday
night.

Marine
Winds should stay largely below SCA levels outside of any
convection through Thursday.

Another round of strong to locally severe storms are possible
later Wednesday afternoon and evening.

The main concern in the long term will be chances for
thunderstorms on Saturday. Otherwise, there may be a chance for low-
end SCA winds on Friday Friday night in easterly flow to the north
of a warm front.

Hydrology
A more widespread and possibly persistent round of showers and
a few heavy thunderstorms are likely Wednesday into Wednesday
night as low pressure developing over the ohio valley moves
eastward over the mid-atlantic along the stalled front. High
moisture content, wetter antecedent conditions and additional
training potential would result in a higher flood potential, and
may ultimately require a watch.

Climate
Above normal temperatures are forecast today. While record highs
are unlikely, record warm lows are still possible. Below is a
list of daily record warm temperatures.

Washington dc area (dca)
date record high record warm low
june 19 99 (1994) 75 (2011, 1994, 1981, 1978)
temperature records for the washington dc area have been kept
at ronald reagan washington national airport since 1945.

Additional temperature records observed downtown date back to
1872.

Baltimore md area (bwi)
date record high record warm low
june 19 99 (1994) 74 (1905)
temperature records for the baltimore md area have been kept at
baltimore-washington international thurgood marshall airport
since 1950. Additional temperature records observed downtown
date back to 1872.

Dulles va area (iad)
date record high record warm low
june 19 98 (1994) 71 (2014)
temperature records for the dulles va area have been kept at
washington dulles international airport since 1960.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Lfr
near term... Lfr
short term... Bjl
long term... Kjp
aviation... Lfr kjp
marine... Lfr kjp
hydrology... Bjl
climate... Bjl


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 44 mi46 min NW 2.9 G 4.1
BLTM2 - 8574680 - Baltimore, MD 45 mi52 min NNE 6 G 8 80°F 79°F1011 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 49 mi46 min N 7 G 8 80°F 1011.1 hPa
FSNM2 49 mi46 min N 8.9 G 9.9 80°F 1011.2 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Frederick Municipal Airport, MD2 mi49 minN 010.00 miPartly Cloudy72°F62°F73%1013.2 hPa
Gaithersburg - Montgomery County Airport, MD22 mi38 minN 010.00 miFair69°F64°F84%1014.6 hPa

Wind History from FDK (wind in knots)
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Last 24hrSW5SW3SW4S4CalmN3NE3CalmCalmNW8NW9
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1 day agoCalmCalmCalmCalmCalmCalmCalmCalmS4SW5SW6SW8SW7W8SW7W7S3S3W10S4--S3S5SW8
2 days agoCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmSW5S54S4CalmCalm--CalmCalmCalm

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Tue -- 12:48 AM EDT     Moonset
Tue -- 01:45 AM EDT     3.26 feet High Tide
Tue -- 05:42 AM EDT     Sunrise
Tue -- 08:29 AM EDT     0.25 feet Low Tide
Tue -- 12:15 PM EDT     Moonrise
Tue -- 02:02 PM EDT     3.33 feet High Tide
Tue -- 08:36 PM EDT     Sunset
Tue -- 09:02 PM EDT     0.07 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.73.23.22.92.41.71.10.60.30.30.81.82.63.13.33.12.621.30.80.30.10.31.1

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Tue -- 12:48 AM EDT     Moonset
Tue -- 01:48 AM EDT     3.23 feet High Tide
Tue -- 05:42 AM EDT     Sunrise
Tue -- 08:32 AM EDT     0.24 feet Low Tide
Tue -- 12:15 PM EDT     Moonrise
Tue -- 02:06 PM EDT     3.30 feet High Tide
Tue -- 08:36 PM EDT     Sunset
Tue -- 09:05 PM EDT     0.05 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.73.13.22.92.41.81.20.70.30.30.81.72.63.13.33.12.621.40.80.30.10.31

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 (23,6,7,8)
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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.