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 6:55AM||Sunset 6:58PM||Monday September 25, 2017 8:21 PM EDT (00:21 UTC)||Moonrise 11:03AM||Moonset 9:27PM||Illumination 28%|
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|ANZ531 Chesapeake Bay From Pooles Island To Sandy Point- 732 Pm Edt Mon Sep 25 2017 |
Tonight..NE winds 5 to 10 kt. Waves 1 ft.
Tue..NE winds 5 to 10 kt. Waves 1 ft.
Tue night..NE winds 5 to 10 kt. Waves 1 ft.
Wed..NE winds 5 to 10 kt. Waves 1 ft.
Wed night..N winds 5 to 10 kt. Waves 1 ft.
Thu..N winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft.
Thu night..N winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft.
Fri..NW winds 5 to 10 kt. Waves 1 ft.
Sat..N winds 5 to 10 kt. Waves 1 to 2 ft.
|ANZ500 732 Pm Edt Mon Sep 25 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A ridge of high pressure will remain over the waters through tonight, then it will weaken overhead Tuesday through Wednesday as hurricane maria drifts north to northeast off the north carolina coast. A cold front will pass through the area Thursday and a reinforcing cold front will pass through late Friday into Friday night. High pressure will likely return for the weekend. Small craft advisories may be needed Tuesday night through Wednesday night and gale force winds are possible Thursday. Refer to the national hurricane center for up-to-date information on hurricane maria.
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 251955|
area forecast discussion
national weather service mount holly nj
355 pm edt Mon sep 25 2017
High pressure across our region will gradually lift northeast as it
weakens through midweek. Hurricane maria will remain offshore the
outer banks of north carolina through Wednesday, then finally move
out to sea, in advance of a cold front moving through our area on
Thursday. Another fast moving cold front treks through our region on
Friday, followed by a large dome of high pressure settling over our
area early next week.
Near term until 6 am Tuesday morning
Another sunny day across the region with high pressure continuing to
influence the weather. High temperature are near daily records with
readings presently in the upper 80s inland and low 70s to low 80s
along the shore. There might be just enough of an onshore flow to
keep the records from being reached however.
An area of low clouds and light fog has been moving wward offshore
the cntrl an SRN nj and de shore areas so far this afternoon. The
clouds are 'melting' as they arrive over the well heated lands
areas. These clouds should resume the W motion as we approach dusk.
Winds will remain light from the E se.
Short term 6 am Tuesday morning through 6 pm Tuesday
There will be more clouds and patchy fog across the area Tuesday
morning. The greater concentration will be S E if i-95 corridor, but
areas N W of that will still have some fog and low clouds. Guidance
is showing a rather stubborn area of low level moisture remaining
across most areas thru the day. It is therefore difficult to get too
optimistic with regards to how much Sun will be over the area tue.
Mostly cloudy skies S E and partly sunny N W will probably describe
the situation best. High temperatures will be only in the low 80s
s E and mid 80s N w. Winds will continue to be rather gentle from
the SE or e.
Long term Tuesday night through Monday
The main forecast challenges will be midweek temperatures, pops
Wednesday into Thursday, a clipper-type system over the
weekend, and some uncertainty with the larger scale features by
early next week.
Direct impacts from hurricane maria are expected to remain
offshore. Indirect impacts will continue through at least
Thursday, including a high risk for the formation of dangerous
rip currents, high surf, and beach erosion.
We have increased temperatures a couple of degrees on Wednesday,
especially given the low bias exhibited by guidance recently.
This is with the expectation that low clouds will burn off early
in the day. These temperatures may still be a bit conservative,
especially given the low-level temperature profile per model
We have trended a bit drier with the forecast Tuesday night and
focused pops Wednesday into Wednesday night, which is in better
agreement with the ensembles, confining chance pops to the
coastal plain in the latter time frame.
A drying trend is expected to take hold Thursday and continue
into Friday, with a popless forecast at this time. The only
exception may be down the shore on Thursday with the potential
for some lingering showers.
Temperatures slightly above average (~5 degrees) on Thursday are
forecast to trend average to slightly below average into early
There is some uncertainty with a clipper-type system over the
weekend. Forecast reflects slight chance pops across the entire
area on Saturday, when ensembles indicate the greatest chance of
precip, then trending downward by Sunday, with pops confined to
the coastal plain.
There is quite a bit of uncertainty early next week with regard
to the large scale features, with a lack of model run to run
consistency. For now, we have not strayed far from the previous
forecast, bringing pops in again for Tuesday. But low
confidence at best.
Aviation 19z Monday through Saturday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Vfr conditions will continue at the terminals for the afternoon as
high pressure remain across the area. Low level onshore flow will
continue and this will result in the arrival of low clouds later
tonight and Tuesday. You can see the low clouds fog just offshore of
acy-wwd on the most recent satellite pics. This moisture is having a
difficult time moving inland with the sunshine today, but when it
approaches dusk, the clouds should resume a NW motion. We have tried
to time the arrival of the ifr conditions according to guidance and
climatological trends. There may be some fog developing before the|
low clouds arrive. The arrival times will be earlier and departure
times later into Tue morning for the S E sites. The timing for
improvement Tuesday for all sites is rather low confid attm. Winds
thru the period will be light E or se.
tue night and wed... Low clouds Tue night into Wed morning will
likely result in ifr conditions from the i-95 terminals (ttn-
pne-phl-ilg) and points southeast, with greatest confidence in
ifr at acy and miv. Cannot rule out some fog as well, but it
looks predominantly like a low cloud issue. Expect improving
conditions toVFR at all terminals Wednesday. Northeast winds
may gust up to 25 knots at times along the coast.
Wednesday night through Friday... PredominantlyVFR conditions
expected. Winds shifting to the northwest Wed night and cannot
rule out MVFR in a passing shower into Thursday. Some patchy
fog is possible at the normally more prone locations by
Saturday and Sunday... PredominantlyVFR conditions expected at
Seas across the NRN nj waters are closer to 5 ft than further to the
south. Nonetheless, we expect the the seas will rise overnight and
the SCA for haz seas will continue. Patchy ares of low clouds and
fog are occurring across the central southern waters ATTM and this
will continue overnight and Tuesday. Winds will remain mostly under
10 knots from the E or se.
sca conditions likely to persist over the waters with the
combination of swells from hurricane maria and occasional wind
gusts to 25 knots through at least Thursday night. By friay,
winds and seas are expected to begin subsiding, but there is a
renewed opportunity for SCA conditions over the weekend with
low pressure developing offshore.
a high risk for dangerous rip currents is expected for the rest of
today and into Tuesday.
The rip current risk remains high as long-period southeasterly
swells continue to build thanks to hurricane maria. Given the
observed rip currents this weekend along much of the nj de surf
zone, swimming is not recommended, especially in the absence of
lifeguards beach patrols.
The rip current fatality in long branch, nj on 9 23 brings the
total number to 8 this year - all in nj. This office has
compiled these statistics since 1998, and this is the greatest
number of fatalities in any one year, followed by 2008 with 6
Dangerous surf conditions will continue for much of the new
week. A high risk for the development of dangerous rip currents
is expected from Tuesday through at least Thursday. High surf
conditions and beach erosion likely to develop Tuesday and
High temperature records for today:
ged... 92(2010 and 1970)
Phi watches warnings advisories
Nj... High rip current risk through late tonight for njz014-024>026.
De... High rip current risk through late tonight for dez004.
Marine... Small craft advisory until 6 am edt Wednesday for anz452>455.
Small craft advisory for hazardous seas until 6 am edt
Wednesday for anz450-451.
near term... O'hara
short term... O'hara
long term... Franck
aviation... Franck o'hara
marine... Franck o'hara
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||52 min||ESE 1.9 G 2.9||78°F||77°F||1015.7 hPa|
|44043 - Patapsco, MD||8 mi||32 min||SE 9.7 G 12||81°F||1015.9 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||15 mi||52 min||SE 8 G 8||82°F||1015.1 hPa|
|CPVM2||17 mi||52 min||82°F||69°F|
|BLTM2 - 8574680 - Baltimore, MD||18 mi||52 min||S 1.9 G 4.1||82°F||80°F||1014.9 hPa|
|APAM2 - 8575512 - Annapolis, MD||20 mi||52 min||79°F||1014.9 hPa|
|44063 - Annapolis||20 mi||32 min||ESE 3.9 G 7.8||80°F||1014.8 hPa|
|TPLM2 - Thomas Point, MD||24 mi||82 min||E 4.1 G 4.1||81°F||77°F|
|44057 - Susquehanna, MD||25 mi||32 min||ESE 9.7 G 14||81°F||1015.8 hPa|
|CHCM2 - 8573927 - Chesapeake City, MD||32 mi||52 min||E 1.9 G 4.1||77°F||1016.3 hPa|
|BSLM2 - Chesapeake Bay, MD||38 mi||112 min||NE 1||81°F||1015 hPa||69°F|
|DELD1 - 8551762 - Delaware City, DE||43 mi||52 min||SSE 5.1 G 7||75°F||73°F||1016.3 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||43 mi||52 min||75°F||76°F||1015.9 hPa|
|DRSD1 - Delaware Reserve, DE||44 mi||112 min||E 4.1||74°F||1016 hPa||69°F|
|CA2 - 8571892 - Cambridge, MD||45 mi||52 min||78°F||80°F||1016.3 hPa|
|44062 - Gooses Reef, MD||46 mi||32 min||E 9.7 G 12||79°F||1016.2 hPa|
|WASD2 - 8594900 - Washington, DC||47 mi||52 min||SE 2.9 G 5.1||83°F||77°F||1015.4 hPa|
|SJSN4 - 8537121 - Ship John Shoal, NJ||47 mi||52 min||E 7 G 9.9||76°F||75°F||1015.8 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||97 min||N 0||10.00 mi||Partly Cloudy||84°F||71°F||66%||1015.9 hPa|
|Bay Bridge Field, MD||17 mi||42 min||ESE 4||10.00 mi||Fair||79°F||68°F||70%||1015.6 hPa|
|Phillips Army Air Field / Aberdeen, MD||18 mi||84 min||ESE 4||6.00 mi||Light Rain||77°F||72°F||85%||1015.9 hPa|
|Annapolis, United States Naval Academy, MD||20 mi||28 min||E 8||10.00 mi||Fair||82°F||72°F||72%||1015.7 hPa|
|Baltimore, Inner Harbor, MD||20 mi||28 min||no data||mi||84°F||68°F||59%||1015.4 hPa|
|Baltimore, Baltimore-Washington International Airport, MD||22 mi||28 min||SE 5||10.00 mi||Mostly Cloudy||80°F||68°F||67%||1015.2 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||Calm||NW||Calm||N||SE||S||SE||E||E||Calm|
|2 days ago||Calm||Calm||NW||NW||NW||Calm||Calm||Calm||Calm||W||W||Calm||Calm||W||NW||NW||N||NW||NW||N||NW||NW||NW||NW |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Tolchester Beach |
Click for Map
Mon -- 05:47 AM EDT 0.87 feet Low Tide
Mon -- 06:55 AM EDT Sunrise
Mon -- 11:01 AM EDT 1.53 feet High Tide
Mon -- 12:02 PM EDT Moonrise
Mon -- 05:08 PM EDT 0.65 feet Low Tide
Mon -- 06:56 PM EDT Sunset
Mon -- 10:26 PM EDT Moonset
Mon -- 11:50 PM EDT 1.99 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
Mon -- 12:30 AM EDT -0.00 knots Slack
Mon -- 03:40 AM EDT -0.84 knots Max Ebb
Mon -- 06:56 AM EDT Sunrise
Mon -- 07:07 AM EDT 0.00 knots Slack
Mon -- 09:46 AM EDT 0.53 knots Max Flood
Mon -- 12:02 PM EDT Moonrise
Mon -- 12:31 PM EDT -0.00 knots Slack
Mon -- 03:32 PM EDT -0.61 knots Max Ebb
Mon -- 06:22 PM EDT 0.00 knots Slack
Mon -- 06:57 PM EDT Sunset
Mon -- 09:54 PM EDT 0.89 knots Max Flood
Mon -- 10:27 PM EDT Moonset
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 (20,4,5,8)(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.