Marine Weather and Tides
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 6:49AM||Sunset 4:49PM||Saturday November 18, 2017 3:15 AM EST (08:15 UTC)||Moonrise 6:43AM||Moonset 5:22PM||Illumination 0%|
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|ANZ540 Eastern Bay- 1232 Am Est Sat Nov 18 2017 |
.small craft advisory in effect from 6 am est this morning through late tonight...
Overnight..S winds 5 to 10 kt. Waves 1 ft.
Sat..S winds 15 to 20 kt. Gusts up to 30 kt. Waves 2 to 3 ft.
Sat night..SW winds 20 to 25 kt with gusts to 30 kt. Waves 3 ft. Showers.
Sun..W winds 20 to 25 kt with gusts to 35 kt. Waves 4 ft.
Sun night..NW winds 20 kt with gusts to 30 kt. Waves 3 ft.
Mon..W winds 15 to 20 kt with gusts to 25 kt. Waves 2 to 3 ft.
Mon night..SW winds 5 to 10 kt. Waves 1 ft.
Tue..SW winds 5 to 10 kt. Waves 1 to 2 ft. A chance of showers through the night.
Wed..NW winds 5 to 10 kt. Waves 1 ft. A chance of showers through the day.
|ANZ500 1232 Am Est Sat Nov 18 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move offshore tonight through Saturday. A strong cold front will move across the waters late Saturday night and high pressure will build to the south for Sunday through Monday. The high will move offshore Tuesday and a cold front will pass through late Tuesday night into Wednesday. Gale force winds are possible over the waters this weekend.
7 Day Forecast for Marine Location Near St. Michaels, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 180225|
area forecast discussion
national weather service mount holly nj
925 pm est Fri nov 17 2017
High pressure will weaken and move to our south tonight. An
area of low pressure will move into the eastern great lakes
later Saturday, then into new england Saturday night into
Sunday. A warm front will lift across the area later Saturday,
followed by a strong cold front overnight Saturday into early
Sunday morning. High pressure will build to our south Monday
into Tuesday, before a cold front moves across the area Tuesday
night. High pressure then builds toward he area later Wednesday
into Thursday, before weakening and shifting southward Friday.
Near term until 6 am Saturday morning
High pressure west of the appalachians will build to the south
and east tonight and move off the mid-atlantic coast by daybreak
Temperatures have dropped off quickly this evening, so adjusted
hourly temperatures to match. Lows will generally be in the 20s
across much of the region, and 30s for the urban corridor and
With temperatures dropping off so quickly, and already small dew
point depressions, there is a small chance for fog or freezing
fog to develop across the areas that normally have efficient
radiational cooling. There is low confidence on this occuring,
but have added mention of patchy for the three hours around
sunrise in the morning.
Short term 6 am Saturday morning through 6 pm Saturday
High pressure off the mid-atlantic coast continues to move
offshore on Saturday. Ahead of low pressure moving through the
great lakes and into the ohio valley on Saturday, a warm front
will lift north through the region during the late morning
hours. Southerly flow develops in the afternoon, and with strong
low level jet passing through the region, expecting 25-30 mph
wind gusts across much of the DELMARVA and southern nj, while
winds will gust to 20 mph across northern nj and southeast pa.
Showers associated with this system will move into the lehigh
valley and northern nj by late morning, but the bulk of the
activity should hold off until the afternoon. Best chances will
be north and west of the i-95 corridor.
Long term Saturday night through Friday
Gusty and rainy conditions start the long term period, then
drier weather returns to the forecast.
As we move into Saturday night, a strong cold front is expected
to move across the area. Ahead of this front, gusty southwest
winds will continue through the night with gusts of 25-35 mph
possible. It will likely not be gusty everywhere overnight as
mixing will not be very deep everywhere during the night time
period. However, as any showers move through, and as the cold
front approaches, gusts have a better chance of mixing down. As
the front moves through during the overnight, shower chances
will be increasing across the area, and move from west to east
fairly quickly. There is not much instability forecast, so we do
not have thunder in the forecast at this time. Although it
would not be surprising for an isolated lightning strike or
rumble of thunder with the strength of the short wave. However,
pw values continue to be forecast to reach 1.00-1.25 inches, so
there could be some moderate, to occasionally heavy rainfall at
The cold front is forecast to have moved through the area, and
either be offshore, or just along the coastal areas of new
jersey and delaware by around daybreak Sunday. Showers will come
to an end behind the cold front, with the exception of possible
continued showers in the poconos as some lake effect streamers
may develop. As the strong cold front moves across the area,
winds will continue to be gusty, but become west to northwest as
it shifts eastward. Wind gusts could reach 35-45 mph at times
as the front crosses the area early Sunday, before slowly
diminishing during the day. It is possible that a wind advisory
may be needed in the future as winds increase abruptly early
As we go into Sunday night, winds could remain gusty around
25-30 mph and precipitation is expected to have ceased. The only
exception is the possibility for some flurries in the poconos
Sunday evening if any lake effect streamers remain.
High pressure builds to our south Monday into Tuesday. Dry
weather is expected Monday through Tuesday, but winds will
likely remain gusty around 20-25 mph.
A cold front is forecast to move across the area Tuesday night
into early Wednesday. The GFS remains dry, but the ECMWF has the
front ingesting some moisture associated with an area of low
pressure located to our south offshore of the east coast. With
the uncertainty, we introduced a slight chance of showers.
Dry weather is expected to continue through the end of the week
as high pressure is forecast to build to our west then south
with our area on the eastern and northern side.
Aviation 02z Saturday through Wednesday |
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Tonight...VFR conditions expected. Only some high cirrus clouds
around 15000 ft agl expected overnight. Winds will be light and
variable overnight. Model guidance depicts a low level jet
approaching SE pa after 09z. This could result in low level wind
shear at krdg and kabe generally between 09 and 15z. The low
level jet looks to stay far enough west not to affect the other
taf sites. Confidence on flight category is high. Confidence on
llws is moderate.
Saturday... Starting with mostlyVFR conditions. Ceilings will
lower through the day as rain moves in from the southwest. Do
not expect much visibility restriction through the day even with
precipitation. It is likely that MVFR ceilings will reach kabe
and krdg before the end of the day (currently forecasting around
21z). However, for the delaware valley (kphl, kpne, kttn, and
kilg) and coastal (kmiv and kacy) sites, expectVFR conditions
to continue through the day. South winds increase to around 10
kt in the late morning, and then to 10-15 kt with gusts up to 20
kt after 18z. Confidence on flight category is moderate.
Confidence on the timing of precipitation or lower flight
category is low.
Saturday night... Conditions lowering to MVFR and ifr overnight,
with periods of showers associated with a cold frontal passage.
Gusty southwest winds 25-30 knots possible. Moderate to high
Sunday... Improving to MVFR, thenVFR behind the cold frontal
passage. Gusty west-northwest winds 30-35 knots. Moderate to
Sunday night... GenerallyVFR. Gusty northwest winds 25-30
knots. Moderate to high confidence.
Monday... GenerallyVFR. Gusty west-northwest winds 20-25 knots.
Moderate to high confidence.
Monday night-Tuesday night...VFR. Winds may gust 15-20 knots
during the afternoon Tuesday. Moderate ti high confidence.
Wednesday... Slight chance of showers, though CIGS likely to
Tonight... Winds and seas should stay below small craft advisory
Saturday... SCA conditions develop in the late morning as
southerly flow increases ahead of low pressure moving through
the great lakes and ohio valley. Gales develop on the ocean
waters in the late afternoon. Will upgrade gale watch to gale
warning for the ocean. For de bay, looks as if gales will not
develop during the day, but wind gusts of 25-30 kt will develop
late Saturday morning. Will go ahead and hoist a SCA from late
morning through Saturday evening.
Saturday night-Sunday night... An extended period of gale force
wind gusts are expected starting Saturday afternoon, then
continuing Saturday night through early Sunday night. Conditions
likely to lower to small craft advisory levels overnight.
Monday-Tuesday night... Small craft advisory conditions expected
to continue into Monday and Tuesday. A brief lull may be
possible late Monday into Monday evening.
Wednesday... Conditions likely to fall below advisory levels.
Phi watches warnings advisories
Marine... Gale warning from 1 pm Saturday to 6 pm est Sunday for
Gale watch from Saturday evening through Sunday afternoon for
Small craft advisory from 9 am to 6 pm est Saturday for anz430-
near term... Johnson mps
short term... Mps
long term... Robertson
aviation... Johnson robertson mps
marine... Johnson robertson mps
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|TPLM2 - Thomas Point, MD||13 mi||76 min||SSW 9.9 G 12||46°F||53°F|
|BSLM2 - Chesapeake Bay, MD||26 mi||46 min||SE 2.9||33°F||1017 hPa||33°F|
|DRSD1 - Delaware Reserve, DE||45 mi||46 min||SE 1||31°F||1018 hPa||31°F|
Wind History for Cambridge, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Easton / Newman Field, MD||7 mi||20 min||N 0||10.00 mi||Fair||37°F||31°F||80%||1018.6 hPa|
|Bay Bridge Field, MD||13 mi||36 min||S 5||10.00 mi||Fair||43°F||35°F||76%||1017.3 hPa|
|Cambridge-Dorchester Airport, MD||21 mi||31 min||SE 4||3.00 mi||Fog/Mist||34°F||32°F||93%||1017.9 hPa|
Wind History from ESN (wind in knots)
|1 day ago||Calm||Calm||W||Calm||W||W||W||W||W||SW||W||W||NW||N|
|2 days ago||N||NE||NE||NE||NE||E||NE||NE||NE||E||E||E||E||Calm||E||SE||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|St. Michaels |
Click for Map
Sat -- 03:46 AM EST 1.14 feet High Tide
Sat -- 06:42 AM EST New Moon
Sat -- 06:43 AM EST Moonrise
Sat -- 06:50 AM EST Sunrise
Sat -- 10:11 AM EST -0.00 feet Low Tide
Sat -- 04:35 PM EST 1.69 feet High Tide
Sat -- 04:48 PM EST Sunset
Sat -- 05:21 PM EST Moonset
Sat -- 11:50 PM EST 0.32 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Baltimore Harbor Approach |
Click for Map
Sat -- 02:34 AM EST 0.00 knots Slack
Sat -- 05:05 AM EST 0.57 knots Max Flood
Sat -- 06:42 AM EST New Moon
Sat -- 06:44 AM EST Moonrise
Sat -- 06:52 AM EST Sunrise
Sat -- 07:45 AM EST -0.00 knots Slack
Sat -- 10:41 AM EST -0.67 knots Max Ebb
Sat -- 01:22 PM EST 0.00 knots Slack
Sat -- 04:49 PM EST Sunset
Sat -- 05:00 PM EST 1.14 knots Max Flood
Sat -- 05:22 PM EST Moonset
Sat -- 08:26 PM EST -0.00 knots Slack
Sat -- 11:43 PM EST -1.05 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  Help
|Weather Map ||IR Satellite Image from GEOS|
GOES Local Image of Mid-Atlantic EDIT
Wind Forecast for Philadelphia/Mount Holly, PA (3,6,7,8)(on/off)  Help
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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.