Sunday, September24, 2017 L-36.com


Marine Weather and Tides
Williamsport, 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 7:00AMSunset 7:04PM Sunday September 24, 2017 2:49 AM EDT (06:49 UTC) Moonrise 10:13AMMoonset 8:55PM Illumination 13% Phase: Waxing Crescent; Moon at 4 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
    EDIT      (on/off)   Help
ANZ535 Tidal Potomac From Key Bridge To Indian Head- 131 Am Edt Sun Sep 24 2017
Overnight..NW winds 5 kt. Waves less than 1 ft.
Sun..NE winds around 5 kt. Waves 1 ft.
Sun night..N winds around 5 kt. Waves 1 ft or less.
Mon..NE winds around 5 kt. Waves 1 ft. Patchy fog.
Mon night..NE winds around 5 kt. Waves 1 ft.
Tue..NE winds 5 kt. Waves less than 1 ft.
Tue night..NE winds 5 kt. Waves less than 1 ft.
Wed..N winds 5 kt. Waves less than 1 ft. A chance of showers.
Thu..N winds 5 to 10 kt. Waves 1 ft.
ANZ500 131 Am Edt Sun Sep 24 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A ridge of high pressure will remain over the eastern united states through the first part of the week. Small craft advisories may be needed Tuesday and Wednesday as hurricane maria approaches north carolina. Refer to the latest statements from the national hurricane center for up-to-date information on hurricane maria.

7 Day Forecast for Marine Location Near Williamsport, MD
   Hourly   EDIT   Help
location: 39.58, -77.81     debug


Area Discussion for - Baltimore, MD/Washington
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 klwx 240041
afdlwx
area forecast discussion
national weather service baltimore md washington dc
841 pm edt Sat sep 23 2017

Synopsis
High pressure will remain in place through the weekend and the
first part of the week. This will slowly weaken its grip over
the area by the midweek as hurricane maria moves northward
through the western atlantic.

Near term tonight
High pressure in control of the synoptic pattern both at the
surface and aloft. Anticipate that tonight's weather will be
comparable to last night. Guidance backing off slightly on fog
coverage, which is slightly curious. Would think that virginia
would be preferred due to light onshore flow. Am carrying patchy
coverage, favoring the valleys of the piedmont and foothills.

Lows in the mid 50s-lower 60s, except 65-70 in the urban
centers.

Short term Sunday night through Monday night
The synoptic pattern will change little Sunday and Monday. If
anything, ridging aloft will only grow stronger until a weakness
emerges as a result of maria. A slight warming surface through
925 mb suggests that upper 80s near 90 will be within reach
Sunday afternoon. Highs may retreat a degree or so by Monday.

Latest guidance does suggest that maria will be approaching the
nc coast Tuesday. It is unclear how close or what the full
impacts will be, although they likely will be minimal through
Monday night. Have increased cloud cover and pops Monday
night... But only enough for partly cloudy skies and a slight
chance of precip over the tip of southern maryland. Consult the
latest bulletins from NHC on the latest thinking on the progress
of maria.

Long term Tuesday through Saturday
High pressure on the surface an aloft will allow for dry
conditions over the region part of Tuesday. At the same time
hurricane maria will be moving north-northwest Tuesday.

Guidance suggests that maria will get close to the nc outer
banks and it will stall there Tuesday night into maybe Thursday
when an upper trough cold front pushes it out to sea. Most
guidance does not show significant impact to our region. Please
visit the national hurricane center's website hurricanes.Gov
for more information.

The cold front that is expected to move through our CWA Thursday
will increasing the chance of showers over our area. Dry
conditions return behind it later Thursday and Friday. Another
front approaches Saturday.

Aviation 01z Sunday through Thursday
Vfr flight conditions will prevail for the valid TAF period,
aside from early morning fog concerns. Cho mrb terminals will be
the most impacted. Am forecasting MVFR at this point. Ifr
possible, but its likely to be brief and would be tough to
pinpoint.

The pattern will be similar through Monday. There may be an
increase in cloud cover on Monday night in advance of maria; its
extent unclear at this point.

MainlyVFR conditions expected Tuesday into Thursday but some
sub-vfr conditions possible later with maybe some showers
around. A further deviation northwest in the track of maria
could bring worse conditions.

Marine
Light north flow (10 kt or less) will prevail thorugh Monday
night. Wind gusts increase Tuesday into Thursday with hurricane
maria over the west atlantic ocean. Small craft advisory
anticipated. If the storm's track deviates further northwest,
more significant impacts are possible (though not likely). Refer
to latest NHC statements for up- to-date information on maria.

Tides coastal flooding
Water levels remain between a foot and a foot and a half above
astronomical normals. There has been a slight weakening in this
influx though, something that guidance suggests will continue.

While the pattern will support minor inundation for several
days, confidence in any inundation is highest for the upcoming
tide cycle. Ensemble guidance supports this approach.

Advisory in effect for the overnight cycle for dc alexandria
and annapolis, and through Sunday morning for st marys and
calvert.

Beyond that, will need to monitor trends and latest guidance.

Anticipate the threat of minor inundation at sensitive
locations will be an issue for several days at least.

Lwx watches warnings advisories
Dc... Coastal flood advisory until 2 am edt Sunday for dcz001.

Md... Coastal flood advisory until 8 am edt Sunday for mdz017-018.

Coastal flood advisory until 1 am edt Sunday for mdz014.

Va... Coastal flood advisory until 2 am edt Sunday for vaz054.

Wv... None.

Marine... None.

Update... Woody!
previous... Hts imr


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 64 mi50 min NW 1.9 G 2.9 71°F 76°F1018 hPa (-0.6)
BLTM2 - 8574680 - Baltimore, MD 69 mi50 min N 2.9 G 6 74°F 78°F1017.2 hPa (-0.5)
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 72 mi50 min W 5.1 G 6 73°F 1017.4 hPa (-0.6)

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
Last
24hr
NW2
--
--
--
N1
W1
W2
NW3
G6
NW3
G6
E3
NE1
G4
N5
G10
NE4
G10
NW6
G11
E2
G9
N5
N2
N2
G5
NW1
S1
--
--
--
W2
1 day
ago
NW3
NW3
NW2
NW3
W1
NW2
NW3
W1
NW4
NW4
NW2
W5
NW6
G9
N7
G10
N8
NW7
G10
NW6
G9
NW1
S1
--
NW2
W1
NW2
NW2
2 days
ago
W2
NW3
NW1
NW1
W2
W3
SW4
SW2
NW9
N3
G8
N3
G6
NE2
G6
NW5
G8
NW4
N6
G9
N3
NW2
--
NW1
NW1
NW3

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD10 mi57 minN 010.00 miFair67°F57°F71%1019.7 hPa
Eastern WV Regional Airport/Shepherd Field, WV15 mi57 minN 010.00 miFair58°F55°F90%1018.6 hPa

Wind History from HGR (wind in knots)
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
Last 24hrNE3N8N6NW4CalmCalmCalmCalmCalmW54NW6NE8N4NE5NE5NE5NE4E4CalmW3CalmCalmCalm
1 day agoW5CalmCalmCalmCalmCalmCalmCalm34N7NE7N5N6NW8N9N4N3CalmCalmCalmNW4NW5N7
2 days agoNW5CalmCalmE3CalmCalmCalmCalmCalmCalm3N665NW6N4N4N4E3CalmCalmCalmCalmNW3

Tide / Current Tables for Chain Bridge, Washington, D.C.
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Chain Bridge
Click for Map
Sun -- 06:44 AM EDT     0.35 feet Low Tide
Sun -- 06:58 AM EDT     Sunrise
Sun -- 11:09 AM EDT     Moonrise
Sun -- 12:16 PM EDT     3.12 feet High Tide
Sun -- 06:37 PM EDT     0.35 feet Low Tide
Sun -- 07:01 PM EDT     Sunset
Sun -- 09:53 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
3.43.12.51.81.20.80.50.40.71.52.32.83.132.51.81.20.70.40.40.71.52.43

Tide / Current Tables for Chain Bridge, D.C.
   EDIT      (on/off)   Help   One Week of Data
Chain Bridge
Click for Map
Sun -- 06:46 AM EDT     0.34 feet Low Tide
Sun -- 06:58 AM EDT     Sunrise
Sun -- 11:09 AM EDT     Moonrise
Sun -- 12:19 PM EDT     3.14 feet High Tide
Sun -- 06:41 PM EDT     0.34 feet Low Tide
Sun -- 07:01 PM EDT     Sunset
Sun -- 09:53 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
3.53.22.61.91.30.80.50.40.71.52.32.83.132.51.91.20.70.40.40.71.42.33

Weather Map and Satellite Images
       (on/off)   Help
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 (2,6,7,8)
      (on/off)   Help

Ground Weather Radar Station Sterling, VA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.