Friday, January19, 2018 L-36.com


Marine Weather and Tides
Frederick, MD

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 7:24AMSunset 5:17PM Friday January 19, 2018 12:18 PM EST (17:18 UTC) Moonrise 8:58AMMoonset 7:50PM Illumination 9% Phase: Waxing Crescent; Moon at 3 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- 930 Am Est Fri Jan 19 2018
Rest of today..SW winds 10 kt. Waves 1 ft.
Tonight..SW winds 5 kt. Waves flat.
Sat..SW winds 5 kt. Waves less than 1 ft.
Sat night..W winds 5 kt. Waves flat.
Sun..SW winds around 5 kt. Waves flat.
Sun night..S winds around 5 kt. Waves flat.
Mon..S winds 5 to 10 kt. Waves 1 ft or less. Showers through the night.
Tue..W winds 5 to 10 kt. Waves 1 ft. Showers likely through the day.
ANZ500 930 Am Est Fri Jan 19 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build from the gulf coast to the eastern seaboard through this weekend. The next cold front will approach the area Monday and cross the area early Tuesday. Small craft advisories may be necessary Tuesday.

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 191443
afdlwx
area forecast discussion
national weather service baltimore md washington dc
943 am est Fri jan 19 2018

Synopsis
High pressure to the south will dominate the weather through
the weekend. A storm system and cold front will cross the region
late Monday and early Tuesday. High pressure will return by the
middle of next week.

Near term through tonight
Surface high pressure is located across the southeastern conus
this morning. The only weather impact comes from a band of
cirrus, which is greatly filtering the sunshine west of i-95.

Have added this into the database, although expect improvement
through the afternoon. It could impede the temperature rise, but
based on yesterday that could balance the forecast out. No other
changes at this time.

For tonight, the high will remain along the gulf coast. A few
cirrus may cross the area while winds become light. Have lows
ranging from the mid 20s to lower 30s. It could be colder in
spots if prolonged decoupling occurs, as dew points will still
be in the teens lower 20s.

Short term Saturday through Sunday night
High pressure will continue eastward off the southeast coast
into the atlantic over the weekend, resulting in continued
west southwest flow and mild weather. Saturday will be
(aesthetically) the better day of the weekend with plentiful
sunshine and temperatures into the 50s across much of the area
(maybe even 60 for charlottesville- fredericksburg). Low level
moisture return around the high will begin to encroach on the
appalachians by Saturday night. Given the shallow nature, any
precipitation likely remains west of the divide and would likely
be very light rain. There's still a chance temperatures could
be just below freezing, supported by forecast soundings but less
so in GEFS sref wpc fzra probabilities. However, continued warm
advection will end any limited ice threat by daybreak Sunday
(if not much sooner).

Any light rain will likely remain west of the allegheny front
Sunday. However, lower clouds may spread east of the mountains
as well, particularly northern parts of the area. Combined with
surface flow that may become more southeast than southwest,
temperatures will likely be a little cooler than Saturday. The
question is just by how much, and where the dividing line
between 45-50 and 55-60 degree temperatures will be. A backdoor
cold front may drop into northeastern parts of the area by
Sunday night, which could lead to some light rain or drizzle.

Low temperatures will be in the upper 30s.

Long term Monday through Thursday
At the start of the long term, a warm front will be lifting
north across the region as low pressure strengthens to our west
across the corn belt. Southerly flow will be enhanced south of
the front, and temperatures stand a shot at reaching the 60s
across a decent portion of the area on Monday. A little rain is
possible as the front lifts north, most likely near the pa
border and most likely earlier in the day.

Ec and to a lesser extent the GFS is now hinting that a triple
point low may try to develop along the approaching cold front as
it crosses our region later Monday night. This would enhance
the rainfall and increase the risk of potential convection. Will
need to monitor this in case it looks like a low-end squall
line with heavy rain and gusty winds could develop as the system
passes. Monday night will remain mild, at least through the
time of cold frontal passage, with temps staying in the 50s,
perhaps even low 60s, much of the night.

The front pushes east of the region as we head through Tuesday,
with steady or falling temps and rain ending. Some upslope
rain snow showers may linger along the alleghany front through
the whole day, however. Despite the falling temps, they should
stay fairly mild for late january, with readings unlikely to
drop severely.

This is due to the incoming high behind the system having more
of a pacific origin, versus the recent high pressures which have
dropped southeast from canada. Therefore, while Wednesday and
Thursday look to be dominated by this high, it should only be
close to normal for late january, versus the recent cold
outbreaks which dropped temps 10-20 degrees below normal each
time. With the high overhead, Wednesday and Thursday should turn
out dry with some Sun as well.

Aviation 15z Friday through Tuesday
No aviation concerns are expected through Saturday as high
pressure moves along the gulf coast. Winds will be between west
and south, and generally less than 10 kt.

Low level moisture return begins Saturday night and definitely
Sunday into Sunday night. Best case is scattered to broken low
vfr, although SREF indicates decent probabilities of MVFR by
Sunday, especially northern parts of the area (metros included),
and a greater chance of ifr by Sunday night with possible light
rain drizzle.

Cig and vis restrictions look likely by Monday night into
Tuesday as a cold front moves across the region, bringing
periods of rain.

Marine
Winds will remain between west and south through the weekend as
an area of high pressure moves from the gulf coast off the
southeast coast. Mixing (both due to warm air temperatures and a
subsidence inversion aloft) will likely keep winds less than 15
kt, although there could be some near-sca gusts near the shore
of the northern bay today and again Saturday.

Sca looking likely at some point Tuesday as a cold front
crosses the region.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Rcm
near term... Hts ads
short term... Ads
long term... Rcm
aviation... Ads rcm
marine... Ads rcm


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 44 mi49 min NW 5.1 G 8 47°F 33°F1020.1 hPa
BLTM2 - 8574680 - Baltimore, MD 45 mi49 min NW 5.1 G 11 45°F 33°F1019.3 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 49 mi49 min W 14 G 16 42°F 1019.6 hPa
FSNM2 49 mi55 min W 14 G 16 42°F 1019.1 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Frederick Municipal Airport, MD2 mi32 minSW 710.00 miClear43°F6°F22%1020 hPa
Gaithersburg - Montgomery County Airport, MD22 mi23 minWSW 1210.00 miFair46°F15°F29%1022.1 hPa

Wind History from FDK (wind in knots)
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Last 24hrW10W11
G17
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G23
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G18
W7W5CalmNW10NW6CalmCalmSE3SE5S4CalmCalmCalmCalmCalmW9
G15
W6W5W6SW7
1 day agoN8N8
G14
N8N9N7NW6NW7NW7NW8NW5W7W5W7W5W4NW5W7W6SW6W7W8
G19
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2 days agoW3NW3CalmNE3CalmCalmCalmCalmN5N5CalmCalmCalmNW6NW7NW7N4NW8NW11
G18
N7N9N12N9N8

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Fri -- 04:33 AM EST     -0.10 feet Low Tide
Fri -- 07:23 AM EST     Sunrise
Fri -- 08:55 AM EST     Moonrise
Fri -- 10:02 AM EST     2.46 feet High Tide
Fri -- 04:29 PM EST     -0.08 feet Low Tide
Fri -- 05:14 PM EST     Sunset
Fri -- 07:49 PM EST     Moonset
Fri -- 10:10 PM EST     2.70 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.81.20.70.2-0-0.10.31.11.92.32.52.31.81.20.60.2-0-00.31.11.92.52.72.6

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Fri -- 04:33 AM EST     -0.15 feet Low Tide
Fri -- 07:23 AM EST     Sunrise
Fri -- 08:55 AM EST     Moonrise
Fri -- 10:05 AM EST     2.48 feet High Tide
Fri -- 04:30 PM EST     -0.13 feet Low Tide
Fri -- 05:14 PM EST     Sunset
Fri -- 07:49 PM EST     Moonset
Fri -- 10:12 PM EST     2.73 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.81.20.60.2-0.1-0.10.31.11.82.32.52.31.91.20.60.2-0.1-0.10.311.92.52.72.6

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 (12,3,4,5)
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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.