Marine Weather and Tides
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 5:41AM||Sunset 8:25PM||Monday May 29, 2017 5:07 PM EDT (21:07 UTC)||Moonrise 8:47AM||Moonset 11:14PM||Illumination 19%|
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|ANZ539 Chester River To Queenstown Md- 432 Pm Edt Mon May 29 2017 |
Rest of this afternoon..N winds 5 kt. Waves flat. A chance of showers with a slight chance of tstms.
Tonight..SE winds 5 to 10 kt. Waves 1 ft or less. Patchy fog. Vsby 1 to 3 nm.
Tue..SE winds 5 kt. Waves less than 1 ft. A chance of showers. Patchy fog. Vsby 1 to 3 nm.
Tue night..SW winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Wed..W winds 5 to 10 kt. Waves 1 ft or less.
Wed night..W winds 5 to 10 kt. Waves 1 ft.
Thu..SW winds 5 to 10 kt. Waves 1 ft or less.
Fri..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 432 Pm Edt Mon May 29 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A surface boundary will stall across the waters this afternoon and weaken by tonight. Another weak front will approach late Tuesday...also stalling and weakening. A third cold front will finally push through Wednesday night, with high pressure following on Thursday. A warm front will lift northward on Friday.
7 Day Forecast for Marine Location Near Kent Narrows, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 292008|
area forecast discussion
national weather service mount holly nj
408 pm edt Mon may 29 2017
A stationary front will remain to the south of the region early this
week while a surface trough persists from virginia northward through
central new york. The surface trough will advance as a weak
frontal boundary through the mid-atlantic Tuesday night, and a
secondary cold front will sweep through the northeast on
Wednesday. Another cold front will sag southward through the
midwest and northeast late this week into this weekend.
Near term until 6 pm this evening
The rest of the afternoon will feature plenty of clouds in most
areas. There are breaks developing across delmarva, and these could
expand N E into the forecast area for the next several hours.
Tonight, more low clouds and fog will be across the area as the low
level easterly flow continues. There may be some patchy drizzle at
times, but low confidence in this. Temperatures will remain
seasonably cool with readings dropping to the low mid 50s north
and upper 50s south east.
Short term 6 pm this evening through 6 am Tuesday
Tuesday morning will probably be a lot like this morning with
plenty of low clouds and areas of fog across the region. There
will be slow improvement during the day, probably faster than
today. Scattered showers will move in from the S W during the
afternoon. High temperatures Tuesday will most likely make it
into the low mid 70s south and mid upper 60s north.
Long term Tuesday through Monday
Main forecast concerns for the long-term period are
precipitation chances on Wednesday and a potentially more
impactful system or systems affecting the region this weekend.
The operational suite is faced with a low-predictability pattern
for the upcoming week. An omega block is projected to develop in
canada (high-amplitude ridging in central canada with deep
troughs to the east and west). Meanwhile, relatively low-
amplitude upper-level flow will become established over the
conterminous united states, albeit with perturbations generally
progressing from the southwest east-northeast to the ohio
valley great lakes regions through the period. As these
perturbations reach the midwest and downstream, phasing with
northern-stream perturbations digging from central canada may
occur, and it is the accuracy in the depiction of these phasing
processes that will determine how far from reality the
simulations will be.
Model analysis of dynamic tropopause plots suggests the GFS is
showing poor run-to-run consistency with the amplitude of the
central canada ridge and its subsequent evolution, with
interactions downstream with the potential vorticity anomaly in
eastern canada a notable source of variability. A comparison of
the 00z and 06z GFS simulations, for example, illustrates how
quickly the GFS runs off the consensus track. Meanwhile, there
are strong hints that the 12z cmc is exhibiting its westward
bias with deep longwave troughs, as it clearly becomes an
outlier with 500-mb heights by 12z Wednesday. However, as the
upper-level low rounds the base of the large-scale trough Friday
and Saturday in southeast canada, there is improved agreement
between it and the 12z ecmwf, whereas the 12z GFS once again
deviates from consensus considerably. For good measure, the 12z
cmc generates a surface low in the gulf of mexico late next
weekend... Moving northeastward to the mid-atlantic by early next
week, which has support from very few ensemble members of the
gefs or ecens. To say that the forecast is of low confidence
during the long-range period is hopefully an unnecessary
exercise at this point.
Forecast basis was a 40 20 20 20 blend of the 12z ECMWF 12z
gfs 09z SREF 12z NAM Wednesday, with replacement of the 12z nam
with the GFS ensemble mean Thursday onward and replacement of
the 12z GFS with the 12z cmc Friday onward. Further
modifications were made thereafter using statistical guidance
and to improve collaboration with surrounding offices.
Tuesday night and Wednesday: perturbations in primarily
southwesterly midlevel flow will provide a few chances for
showers and storms during this period, especially west of the
delaware river (where pops are highest during this period).
There may be some enhanced lift Tuesday night via right-entrance
region jet dynamics, but the strongest large-scale ascent looks
to be north west of the area. Additionally, the perturbations
within the flow are fairly weak, so precipitation coverage on
the south east fringe of the main jet looks generally scattered.
Model soundings suggest MUCAPE 500-1000 j kg during the period,
highest on Wednesday afternoon. With forced ascent via an
approaching cold front during the day and potential surface
heating in advance of the front, convective precipitation is the
likely mode (rather than stratiform). Shear profiles are
adequate for severe storms, but models suggest convective
coverage will be greatest west of the region (so timing of the
strongest ascent may not be ideal for our area). Nevertheless,
the well-mixed boundary layer profiles in model soundings
suggest gusty winds may be a threat with any storms that exist,
though any coverage of strong severe storms would be sparse.
On Thursday, a surface high will briefly build into the region,
which should make for a nice day. Forecast is dry with highs
near seasonal averages.
Things go downhill in time for the weekend. As the upper-level
low in the great lakes region and adjacent canada makes a move
eastward, perturbations will rotate quickly around it on its
southern fringe. This will promote periods of large-scale ascent
along a developing quasi-zonal baroclinic zone stretching from
the central plains to the mid-atlantic. A slow southward-
moving cold front will provide low-level convergence lift
necessary for several rounds of convection in its vicinity.
Operational models suggest two periods of increased potential
for our region. The first is Friday and Friday night as a
perturbation digs southeastward from the great lakes. The second|
is late Saturday through Sunday when a new upper low develops
and reloads the longwave trough in eastern north america. To
some degree, most operational guidance develops a reasonably
strong surface low along this baroclinic zone during the
weekend, moving it through the northeast mid-atlantic by late in
the weekend or early next week.
However, given the aforementioned lack of predictability of the
overall pattern, there is too much uncertainty to get too
specific with timing these perturbations right now. As such,
kept pops elevated but fairly uniform from Friday through
Sunday for the cwa, with storms a good bet at least once or
twice during this period. Pattern recognition suggests that both
severe weather and heavy rainfall are threats with this evolving
pattern, given the relatively fast upper-level flow and the
slow-moving nature of the cold front. In advance of the front,
return flow on the upstream side of a surface high in the
western atlantic will provide considerable moisture transport
and resultant instability to a large portion of the eastern u.S.
Though the details are far from clear, the overall model
consensus is suggesting the ingredients may be available for a
more substantial warm-season rain storm event. Stay tuned to
the latest forecasts.
Aviation 19z Monday through Saturday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Poor flying weather will continue across the area through Tuesday.
There is some drier air at the mid-levels trying to work into the
area from the S w, but whether it fully makes it to the area, and to
what effect it will have on any cig improvement is uncertain at this
time. We have cautiously indicated limited improvement in the S w
sites 20-22z. After that, it appears the the onshore flow will
continue and another period of low CIGS and some fog may occur again
tonight over most areas. Generally went along with the guidance with
regards to timing and flight categories. Slow improvement Tuesday
Tuesday night and Wednesday: a chance of showers and
thunderstorms, especially north west of kphl. Gusty erratic
winds and locally sub-vfr vsbys CIGS likely in proximity to
precipitation. Winds outside of storms generally southeast 5 to
15 kts becoming southwesterly by Wednesday afternoon,
potentially with a few gusts to 20 kts. Confidence average.
Wednesday night through Thursday night: storms rapidly diminish
or move out Wednesday evening.VFR conditions expected. Winds
primarily westerly 5 to 15 kts becoming southwesterly Thursday
night. Confidence above average.
Friday through Saturday: an elevated chance of showers storms.
GenerallyVFR conditions expected, but if more widespread
precipitation develops, sub-vfr conditions may occur at times.
Winds generally west or southwest 5 to 15 kts. Confidence below
We'll keep the SCA flag across the northern and central nj coastal
waters, and we will drop it across the delaware and southern nj
coastal waters. Seas did get to 5 ft across the SRN areas for a
little while earlier, but have not sustained at those levels.
We will also extend the expiration time into the evening for
several more hours. Scattered showers and areas of fog expected
Tuesday night through Thursday night: no marine headlines
anticipated. At least some chance of showers and storms Tuesday
night through Wednesday evening.
Friday through Saturday: advisory conditions are possible, as
wind gusts will approach 25 kts Friday and Friday night and seas
will become elevated through the period. A chance of storms at
times through the period.
the potential for the development of dangerous rip currents is
low for today and is expected to remain low tomorrow.
Tides coastal flooding
Tidal departures of around 1 foot are expected again tonight for
coastal areas of new jersey and delaware and areas along
delaware bay. These tidal departures would lead to another
round of minor coastal flooding for tonight's high tide.
The coastal flood advisory remains in effect.
Phi watches warnings advisories
Nj... Coastal flood advisory from 10 pm this evening to 4 am edt
Tuesday for njz012>014-020>027.
De... Coastal flood advisory from 10 pm this evening to 4 am edt
Tuesday for dez002>004.
Marine... Small craft advisory until 11 pm edt this evening for
near term... O'hara
short term... O'hara
long term... Cms
aviation... Cms o'hara
marine... Cms o'hara
tides coastal flooding... Cms iovino
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|
|CPVM2||8 mi||49 min||72°F||67°F|
|TPLM2 - Thomas Point, MD||11 mi||67 min||E 8 G 8.9||71°F||67°F|
|44063 - Annapolis||11 mi||37 min||NE 1.9 G 1.9||70°F||1013.9 hPa|
|APAM2 - 8575512 - Annapolis, MD||12 mi||49 min||71°F||1013.3 hPa|
|44043 - Patapsco, MD||15 mi||37 min||NNE 1.9 G 1.9||69°F||1014.6 hPa|
|TCBM2 - 8573364 - Tolchester Beach, MD||17 mi||49 min||ESE 6 G 8.9||73°F||67°F||1014 hPa|
|FSNM2||23 mi||49 min||ESE 9.9 G 11||69°F||1013.6 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||23 mi||49 min||SE 7 G 9.9||68°F||1013.7 hPa|
|BLTM2 - 8574680 - Baltimore, MD||27 mi||49 min||S 6 G 8.9||72°F||68°F||1013.3 hPa|
|BSLM2 - Chesapeake Bay, MD||28 mi||157 min||E 6||77°F||1013 hPa||66°F|
|CA2 - 8571892 - Cambridge, MD||29 mi||55 min||75°F||73°F|
|44062 - Gooses Reef, MD||30 mi||37 min||WSW 3.9 G 3.9||71°F||1014.5 hPa|
|44057 - Susquehanna, MD||40 mi||37 min||E 7.8 G 9.7||67°F||1014.4 hPa|
|COVM2 - 8577018 - Cove Point LNG Pier, MD||40 mi||49 min||S 8 G 8.9||71°F||1014.1 hPa|
|WASD2 - 8594900 - Washington, DC||41 mi||49 min||NNW 8 G 11||83°F||67°F||1012.7 hPa|
|DRSD1 - Delaware Reserve, DE||44 mi||157 min||E 1.9||62°F||1015 hPa||62°F|
|CHCM2 - 8573927 - Chesapeake City, MD||45 mi||55 min||E 5.1 G 7||66°F||68°F||1015.4 hPa|
|SLIM2 - 8577330 - Solomons Island, MD||46 mi||49 min||SE 8 G 8.9||72°F||70°F|
Wind History for Tolchester Beach, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Bay Bridge Field, MD||4 mi||77 min||E 4||10.00 mi||Fair||75°F||62°F||65%||1013.9 hPa|
|Annapolis, United States Naval Academy, MD||12 mi||73 min||SE 7||10.00 mi||Fair||74°F||69°F||85%||1014 hPa|
|Easton / Newman Field, MD||15 mi||77 min||ENE 4||10.00 mi||Partly Cloudy||77°F||64°F||65%||1015.2 hPa|
Wind History from W29 (wind in knots)
|1 day ago||N||NE||NE||SE||NE||E||Calm||Calm||Calm||Calm||Calm||SE||E||Calm||NE||E||E||E||E||SE||SE||SE||SE||SE|
|2 days ago||NW|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Kent Island Narrows |
Click for Map
Mon -- 02:15 AM EDT 0.32 feet Low Tide
Mon -- 05:42 AM EDT Sunrise
Mon -- 08:35 AM EDT 2.16 feet High Tide
Mon -- 09:47 AM EDT Moonrise
Mon -- 04:09 PM EDT 0.33 feet Low Tide
Mon -- 08:22 PM EDT Sunset
Mon -- 09:11 PM EDT 1.46 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 -- 02:10 AM EDT -0.68 knots Max Ebb
Mon -- 04:48 AM EDT 0.00 knots Slack
Mon -- 05:42 AM EDT Sunrise
Mon -- 08:27 AM EDT 1.18 knots Max Flood
Mon -- 09:47 AM EDT Moonrise
Mon -- 11:50 AM EDT -0.00 knots Slack
Mon -- 03:12 PM EDT -1.16 knots Max Ebb
Mon -- 06:49 PM EDT 0.00 knots Slack
Mon -- 08:23 PM EDT Sunset
Mon -- 09:30 PM EDT 0.68 knots Max Flood
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 (17,4,5,8)(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.