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 6:19AM||Sunset 7:58PM||Thursday August 17, 2017 1:38 PM EDT (17:38 UTC)||Moonrise 12:52AM||Moonset 3:36PM||Illumination 21%|
EDIT (on/off)  Help
|ANZ530 Chesapeake Bay North Of Pooles Island- 1103 Am Edt Thu Aug 17 2017 |
Rest of today..SE winds 5 to 10 kt. Waves 1 ft or less. A slight chance of showers. A slight chance of tstms this afternoon.
Tonight..S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Fri..S winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely.
Fri night..SW winds 5 to 10 kt. Waves 1 ft or less. A chance of showers and tstms.
Sat..W winds 5 to 10 kt. Waves 1 ft or less.
Sat night..W winds 5 kt. Waves less than 1 ft.
Sun..S winds around 5 kt. Waves flat.
Mon..S winds around 5 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 1103 Am Edt Thu Aug 17 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A warm front will pass through the area today before a cold front approaches Friday. The cold front will then pass through Friday night into early Saturday. High pressure will build to the north and west of the waters while a pressure trough will remain nearby for later Saturday and Sunday. The high pressure will shift offshore early next week.
7 Day Forecast for Marine Location Near George, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 171614|
area forecast discussion
national weather service mount holly nj
1214 pm edt Thu aug 17 2017
High pressure will move offshore today. A warm front will lift
northward towards the area this afternoon and then moves through the
area late tonight. A cold front will approach from the west on
Friday, pushing through the region Friday night into Saturday. High
pressure returns for Sunday through Tuesday. Another cold front will
arrive late Tuesday or Wednesday.
Near term until 6 pm this evening
A 1019 mb surface high centered over eastern ontario and
extending into western and central ny continues to lift to the
north and east today. Meanwhile, a diffuse stationary front runs
through the DELMARVA and into the southern tip of nj. This front
extends to the west, where it becomes a warm front associated
with low pressure moving into the western great lakes.
Mostly sunny skies will give way to a broken mid-deck this
A few pop-up showers, perhaps even an isolated thunderstorm, is
possible over the DELMARVA today as bay breezes develop and
interact with the aforementioned stationary boundary. Surface
dewpoints in the DELMARVA are in the low 70s and will creep up
during the day, so there could be a brief downpour, but
probabilities are low.
Warm and humid today with highs in the mid to upper 80s.
Dewpoints will generally be in the mid to upper 60s, except in
the delmarva, where dewpoints will be several degrees higher.
Short term 6 pm this evening through 6 am Friday
An area of low pressure will track east across the upper
midwest tonight. A warm front associated with the system is
expected to approach from the southwest this evening and then
lift northeastward through the forecast area overnight.
Models generally advertise a southerly low-level jet that
strengthens downstream of the midwest low tonight. Both
operational global models and hi-res cams indicate increasing
coverage of showers and storms overnight into early Friday
morning as the interaction between this low-level jet and
approaching warm front would yield forcing for ascent. Pops
increase to likely across NE pa and chance elsewhere by daybreak
Friday morning. However, capped thunderstorms at a slight
chance with only modest instability analyzed on model forecast
soundings and given the unfavorable time of day (diurnal min).
Pwats are forecast to increase to above 2 inches overnight, so
any storms that do develop could contain heavy downpours.
Increasing cloud cover tonight should keep temps elevated overnight
and limit the extent of fog development. Forecast lows range from
the mid 60s in the southern poconos to the mid 70s in the urban i-95
corridor and coastal locales.
Long term Friday through Wednesday
Friday looks like it could be a very active day across the forecast
area. The warm front should be north of the area by early Friday
with strong southerly flow behind it. This will bring an influx of
moisture to our area and we will see dewpoints rise back into the
low to mid 70s across the region. Instability will increase across
the area and the chances for thunderstorms will continue through out
the day. CAPE values range widely depending on the model but there
will be more than enough lift in place to sustain updrafts and the
development of thunderstorms. SPC has placed our region in a
marginal risk for severe storms with the main threat being damaging
What appears right not to be the greater threat for our area is
potentially heavy rainfall. While we have had a few days to dry out
across the majority of our area, there are still several spots that
have 3hr FFG values between 2-3 inches. Pwats will be in the 2-2.5
inch range and heavy rainfall will be possible in any storm that
develops. Wpc has included us in their day 2 excessive rainfall
outlook for Friday as the combination of high pwats, diurnal
heating, and the cold frontal passage has us primed for heavy
rainfall. Will not be issuing a watch at this time as the location
of heavy rainfall is difficult to pinpoint but the potential is
there for localized flash flooding. We have added the mention of
heavy rain into the grids.
The cold front will approach the region from the west on Friday,
crossing the region later Friday into Saturday. Ongoing showers and
thunderstorms with the potential for heavy rain will continue as the|
front crosses the area. Storms will end from the northwest to
southeast early Saturday morning. The front will slowly move
offshore through the day Saturday and really gets a good shove
offshore as a shortwave upper trough crosses through the region.
With the front not clearing the region early, it will prevent the
low level moisture from clearing out quickly so Saturday will remain
a little muggy even though the Sun should break through and be
overall a pretty nice day. As the upper trough pushes through later
Saturday, we should have some cooler and drier air make it into the
High pressure will build in for Sunday and a period of relatively
nice weather should continue for the start of the week with the high
shifting offshore on Monday. Another cold front will approach the
region from the west on Tuesday, crossing the area late Tuesday into
Wednesday. Additionally, a surface trough may develop in advance off
this next front and could serve as the focus for some convection to
Aviation 16z Thursday through Monday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
MainlyVFR expected for today and this evening with the better
chance for showers and storms this afternoon shifted to the
south of the TAF sites. Increasing chances for showers and
perhaps isolated embedded thunderstorms overnight tonight.
Local temporary restrictions to ifr possible if heavier showers
or storms directly impact a terminal.
Light and variable winds this morning will become sely and then sly
this afternoon and tonight between 4 and 9 kt.
Friday... Fog possible early morning. Sub-vfr conditions in showers
Saturday... MVFR or lower conditions early in showers and
thunderstorms. Conditions are expected to improve toVFR by Saturday
the afternoon, may take longer at kmiv and kacy as they remain
closer to the boundary.
Sunday and Monday... MainlyVFR conditions expected.
Winds and seas below SCA criteria today and tonight. Seas should
hover around 3 feet through the period (lower in delaware bay).
Friday... Mainly sub-small craft advisory conditions expected.
Guidance shows that the gradient will tighten up and southerly winds
will gust between 20-25 knots on Friday, mainly during the afternoon
and evening. Additionally, seas will rise but are expected to remain
below 5 feet. Showers and thunderstorms possible Friday through
early Saturday, with locally higher seas and winds.
Saturday thru Monday... Sub-small craft advisory conditions expected
on the area waters through Monday.
buoy observations indicate that the longer-period (8-9 seconds)
southeasterly swells generated by hurricane gert have
diminished to around 3 ft. With improving conditions today
compared to yesterday, the risk for dangerous rip currents will
be lowered, but still in moderate category.
Phi watches warnings advisories
near term... Klein mps
short term... Klein
long term... Meola
aviation... Klein meola mps
marine... Klein meola 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|
|TCBM2 - 8573364 - Tolchester Beach, MD||6 mi||50 min||N 4.1 G 7||81°F||80°F||1016.3 hPa|
|44043 - Patapsco, MD||14 mi||38 min||S 7.8 G 7.8||81°F||82°F||1016.9 hPa (-0.8)|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||17 mi||50 min||ESE 13 G 14||81°F||1015.7 hPa|
|44057 - Susquehanna, MD||18 mi||38 min||ENE 1.9 G 1.9||83°F||84°F||1016.2 hPa (-1.1)|
|BLTM2 - 8574680 - Baltimore, MD||19 mi||50 min||S 9.9 G 12||82°F||82°F||1015.4 hPa|
|CPVM2||23 mi||50 min||82°F||77°F|
|44063 - Annapolis||26 mi||38 min||S 9.7 G 14||81°F||81°F||1 ft||1015.8 hPa (-0.9)|
|APAM2 - 8575512 - Annapolis, MD||26 mi||50 min||85°F||1015.5 hPa|
|CHCM2 - 8573927 - Chesapeake City, MD||27 mi||56 min||E 5.1 G 7||84°F||81°F||1016.8 hPa|
|TPLM2 - Thomas Point, MD||30 mi||38 min||S 8 G 8||80°F||80°F|
|DELD1 - 8551762 - Delaware City, DE||39 mi||50 min||SE 5.1 G 6||82°F||78°F||1016.7 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||39 mi||50 min||86°F||81°F||1016.3 hPa|
|DRSD1 - Delaware Reserve, DE||44 mi||68 min||E 5.1||83°F||1017 hPa||73°F|
|BSLM2 - Chesapeake Bay, MD||44 mi||128 min||SE 6||79°F||1016 hPa||70°F|
|SJSN4 - 8537121 - Ship John Shoal, NJ||45 mi||50 min||SE 9.9 G 12||78°F||79°F||1016.5 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||11 mi||1.9 hrs||ESE 4||6.00 mi||Partly Cloudy with Haze||84°F||78°F||84%||1016.9 hPa|
|Phillips Army Air Field / Aberdeen, MD||12 mi||1.7 hrs||SE 5||10.00 mi||Partly Cloudy||83°F||72°F||72%||1017.2 hPa|
|Baltimore, Inner Harbor, MD||21 mi||44 min||no data||mi||86°F||75°F||70%||1015.8 hPa|
|Bay Bridge Field, MD||23 mi||53 min||SSE 8||7.00 mi||Partly Cloudy||88°F||71°F||59%||1016.3 hPa|
Wind History from MTN (wind in knots)
|1 day ago||Calm||N||N||Calm||N||Calm||NE||Calm||Calm||Calm||Calm||Calm||W||Calm||Calm||Calm||Calm||Calm||Calm||Calm||W||Calm||Calm||SE|
|2 days ago||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||NW||Calm||E||SE||E||Calm||Calm||Calm||Calm||Calm||NW||N||Calm||SE||E |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Pooles Island |
Click for Map
Thu -- 01:52 AM EDT Moonrise
Thu -- 04:00 AM EDT 2.22 feet High Tide
Thu -- 06:20 AM EDT Sunrise
Thu -- 11:23 AM EDT 0.70 feet Low Tide
Thu -- 04:02 PM EDT 1.40 feet High Tide
Thu -- 04:36 PM EDT Moonset
Thu -- 07:57 PM EDT Sunset
Thu -- 10:03 PM EDT 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
Thu -- 01:28 AM EDT 1.07 knots Max Flood
Thu -- 01:53 AM EDT Moonrise
Thu -- 05:06 AM EDT -0.00 knots Slack
Thu -- 06:20 AM EDT Sunrise
Thu -- 08:19 AM EDT -0.85 knots Max Ebb
Thu -- 11:58 AM EDT 0.00 knots Slack
Thu -- 02:16 PM EDT 0.39 knots Max Flood
Thu -- 04:35 PM EDT Moonset
Thu -- 04:37 PM EDT -0.00 knots Slack
Thu -- 07:51 PM EDT -0.66 knots Max Ebb
Thu -- 07:57 PM EDT Sunset
Thu -- 10:40 PM EDT 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 (13,3,4,5)(on/off)  Help
Ad by Google
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.