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 7:20AM||Sunset 5:12PM||Thursday January 18, 2018 12:31 AM EST (05:31 UTC)||Moonrise 8:17AM||Moonset 6:48PM||Illumination 2%|
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|ANZ531 Chesapeake Bay From Pooles Island To Sandy Point- 931 Pm Est Wed Jan 17 2018 |
.small craft advisory in effect until midnight est tonight...
.small craft advisory in effect from 8 am est Thursday through Thursday afternoon...
Rest of tonight..NW winds 15 kt with gusts to 20 kt. Waves 2 ft.
Thu..W winds 10 kt with gusts to 20 kt. Waves 2 ft.
Thu night..W winds 5 to 10 kt. Waves 1 ft or less.
Fri..W winds 5 kt. Waves less than 1 ft.
Fri night..SW winds 5 kt. Waves less than 1 ft.
Sat..SW winds 5 kt. Waves less than 1 ft.
Sat night..W winds 5 kt. Waves less than 1 ft.
Sun..S winds 5 kt. Waves less than 1 ft.
Mon..S winds 5 to 10 kt. Waves 1 ft. Showers likely through the night.
|ANZ500 931 Pm Est Wed Jan 17 2018 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will develop and move off the north carolina coast and move out to sea tonight. High pressure will then build south of the area Thursday through Sunday.
7 Day Forecast for Marine Location Near Tolchester, 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 Wed jan 17 2018
Low pressure with its attendant frontal system will move off
the east coast tonight. High pressure will build across the gulf
coast through the end of the week, then offshore over the
weekend, bringing fair weather to the mid- atlantic region. Low
pressure is forecast to develop over the central u.S. On Monday.
This low will move northeast through the great lakes Monday
night into Tuesday, pulling a cold front across the mid-
atlantic area on Tuesday.
Near term until 6 am Thursday morning
930 pm estf: very little change except to adjust some of the e
630 pm estf:
lowered min temps tonight NW nj and parts of E pa for some
expected radiational cooling where lows may dip to 5 above over
the typically cold sheltered areas when radiational cooling
develops later tonight over a nice new fresh snowpack.
Will post an updated snowfall pns later tonight and expect
another tomorrow. The snow analysis posted this afternoon on our
social media sites will have to suffice.
Remainder little change. From the 4 pm fcst discussion below.
Expecting a return to tranquil weather overnight. The mid and
upper level low progressing east should move off the carolinas
coast late tonight. The track of this low should be far enough
south that we won't see any additional precipitation, except for
some very light snow through early evening across southern
Otherwise, expect clearing skies. With the light northwesterly flow,
should see temperatures continue to fall, with lows in the single
digits and teens across the area. The strongest winds and lowest
temperatures should not be coincident with each other which will
limit the low wind chill threat. Still, wind chill values below zero
are possible across the southern poconos (cold, but still above
advisory level, and a far cry better than a few weeks ago).
Short term 6 am Thursday morning through 6 pm Thursday
On the heels of the low, a mid level short wave ridge is
expected to propagate over the region through the day tomorrow
resulting in mostly sunny conditions. At the surface, the
pressure gradient is expected to increase for a period tomorrow
as the surface high builds in. As a result, could see some gusty
conditions, but on land, not expecting gusts above 25 mph.
Temperature wise, we will still have cold air advection with the
northwesterly flow. As a result, expect highs to be from the mid 20s
to near 40 across the region, or about 5 degrees below normal.
Long term Thursday night through Wednesday
The extended forecast will feature somewhat above normal
temperatures (for a change) and generally fair weather at least
through this weekend. A fairly strong frontal passage with
associated low pressure and precipitation is expected sometime
on Tuesday of next week.
By Thursday night the low pressure aloft now over the southern
appalachians will be well offshore. A fast-moving shortwv trof
will swing across new england but should have little effect on
sensible weather over the mid-atlantic region. Thereafter
through the weekend zonal flow aloft will prevail across the
north-central and northeast us. Meanwhile a large area of high
pressure centered along the glfmex coast will gradually shift
east and off the southeast us coast by Sunday. Westerly flow
around the northern periphery of this high will help maintain
fair weather with a trend toward moderating temps, especially
A fairly deep trof aloft is forecast to move into the western us
over the weekend and into the central grtplns by Monday. In
response surface low pressure should develop over the plains and
move eastward into the grtlks by Tuesday. The associated cold
front should move through nj and vicinity roughly in the Tuesday
morning time frame, although the latest ECMWF looks a bit
slower. Increasing SW low-level flow ahead of the low front will|
result in increasing moisture starting Sunday night. At that
time the forecast includes slight chance pops well north of phl,
with the possibility of some freezing rain or drizzle,
depending on the degree of overnight surface cooling.
Forecast pops increase from chance on Monday to likely Monday
night with the approaching cold front. Depending on how quickly
cold air moves in, there could be some changeover to snow in the
poconos late Monday night. Due to timing uncertainty, the
forecast maintains some chance for precip through Tuesday,
mainly in the morning. Forecast MAX temps for Tue are still
above freezing (and above normal) but cold advection aloft could
produce snow showers well N W of phl.
The air mass behind the front is not terribly cold and forecast
max temps for Wednesday look to be still slightly above normal.
Aviation 03z Thursday through Monday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Overnight...VFR conditions are expected with CIGS abv 9000 ft
e of ilg phl ttn clearing east during the night. Northwesterly
winds near or below 12kt are expected to continue overnight with
isolated gusts 20 kt vcnty phl acy. High confidence.
Tomorrow...VFR conditions with few, if any clouds. Northwesterly
winds 10 to 15 kt with gusts up to 20 kt. High confidence.
Friday through Sunday...VFR conditions expected. West to
southwest winds, generally less than 10 kt. High confidence.
Monday... MainlyVFR conditions but occasional MVFR possible in
Expect the highest winds, and most widespread small craft advisory
conditions to occur late tonight through mid morning Thursday. Gusts
near or above 25 kt are likely to continue through the rest of
Thursday. Therefore, have continued the SCA as is for now.
Small chance we'll need a short fuse gale warning for the de
waters and lower de bay in the 08-14z 18 time frame. Sct gusts
Thursday night... Conditions expected to drop below advisory
Friday-Sunday... Conditions expected to remain below advisory levels,
but winds may periodically gust around 20 knots.
Monday... Increasing south winds with gusts possibly approaching
sca levels late in the day.
The NOAA all-hazards weather radio transmitter in sudlersville
has returned to service with the correction of earlier phone
line issues. Rdg temp has rts.
Phi watches warnings advisories
Marine... Small craft advisory until 6 pm est Thursday for anz450>455.
Small craft advisory until 10 am est Thursday for anz430-431.
near term... Drag johnson 925
short term... Johnson
long term... Amc
aviation... Amc drag johnson 925
marine... Amc drag johnson 925
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|
|TCBM2 - 8573364 - Tolchester Beach, MD||0 mi||44 min||NNW 16 G 19||22°F||32°F||1025.4 hPa|
|FSNM2||15 mi||44 min||NW 14 G 19||20°F||1024.4 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||15 mi||44 min||NW 14 G 19||21°F||1025.3 hPa|
|CPVM2||17 mi||44 min||22°F||9°F|
|BLTM2 - 8574680 - Baltimore, MD||18 mi||44 min||N 6 G 12||20°F||33°F||1025.1 hPa|
|APAM2 - 8575512 - Annapolis, MD||20 mi||44 min||21°F||1024.6 hPa|
|TPLM2 - Thomas Point, MD||24 mi||32 min||NW 14 G 15||21°F||31°F|
|CHCM2 - 8573927 - Chesapeake City, MD||32 mi||50 min||NNW 7 G 8.9||20°F||32°F||1025 hPa|
|BSLM2 - Chesapeake Bay, MD||38 mi||122 min||NNW 8||21°F||1026 hPa||9°F|
|RDYD1 - 8551910 - Reedy Point, DE||43 mi||44 min||20°F||32°F||1024.1 hPa|
|DELD1 - 8551762 - Delaware City, DE||43 mi||44 min||NW 9.9 G 14||20°F||29°F||1024.4 hPa|
|DRSD1 - Delaware Reserve, DE||44 mi||122 min||WNW 6||22°F||1024 hPa||10°F|
|CA2 - 8571892 - Cambridge, MD||45 mi||44 min||23°F||32°F||1025.1 hPa|
|44062 - Gooses Reef, MD||46 mi||32 min||NNW 19 G 23||23°F||33°F||3 ft||1023.9 hPa (-1.3)|
|WASD2 - 8594900 - Washington, DC||47 mi||44 min||NW 8 G 13||20°F||33°F||1026.5 hPa|
|SJSN4 - 8537121 - Ship John Shoal, NJ||47 mi||44 min||NW 19 G 23||22°F||31°F||1023.3 hPa|
Wind History for Tolchester Beach, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Baltimore / Martin, MD||13 mi||50 min||W 10||10.00 mi||Fair||21°F||12°F||68%||1026.1 hPa|
|Bay Bridge Field, MD||17 mi||57 min||NNW 13 G 18||10.00 mi||Partly Cloudy||21°F||8°F||58%||1025.4 hPa|
|Phillips Army Air Field / Aberdeen, MD||18 mi||94 min||N 0||10.00 mi||Fair||0°F||0°F||%||1025.7 hPa|
|Annapolis, United States Naval Academy, MD||20 mi||38 min||NNW 13 G 19||10.00 mi||Fair||24°F||12°F||62%||1025.1 hPa|
|Baltimore, Inner Harbor, MD||20 mi||38 min||no data||mi||21°F||7°F||54%||1025.2 hPa|
|Baltimore, Baltimore-Washington International Airport, MD||22 mi||38 min||WNW 8||10.00 mi||Mostly Cloudy||18°F||7°F||62%||1025.2 hPa|
Wind History from MTN (wind in knots)
|1 day ago||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||W||Calm||Calm||Calm||Calm||Calm||Calm||Calm||W||W|
|2 days ago||Calm||Calm||Calm||Calm||Calm||Calm||Calm||N||N||NE||Calm||Calm||Calm||Calm||N||Calm||NW||Calm||Calm||Calm||Calm||Calm||Calm||NW |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Tolchester Beach |
Click for Map
Thu -- 02:25 AM EST -0.21 feet Low Tide
Thu -- 07:21 AM EST Sunrise
Thu -- 07:32 AM EST 0.54 feet High Tide
Thu -- 08:16 AM EST Moonrise
Thu -- 01:32 PM EST -0.42 feet Low Tide
Thu -- 05:09 PM EST Sunset
Thu -- 06:47 PM EST Moonset
Thu -- 08:18 PM EST 1.17 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Baltimore Harbor Approach |
Click for Map
Thu -- 12:17 AM EST -1.04 knots Max Ebb
Thu -- 03:59 AM EST 0.00 knots Slack
Thu -- 06:31 AM EST 0.54 knots Max Flood
Thu -- 07:21 AM EST Sunrise
Thu -- 08:16 AM EST Moonrise
Thu -- 09:17 AM EST -0.00 knots Slack
Thu -- 12:00 PM EST -0.53 knots Max Ebb
Thu -- 02:32 PM EST 0.00 knots Slack
Thu -- 05:10 PM EST Sunset
Thu -- 06:11 PM EST 1.00 knots Max Flood
Thu -- 06:48 PM EST Moonset
Thu -- 09:32 PM EST -0.00 knots Slack
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 (0,6,7,8)(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.