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 6:54AM||Sunset 4:47PM||Wednesday November 22, 2017 5:53 AM EST (10:53 UTC)||Moonrise 10:11AM||Moonset 8:16PM||Illumination 14%|
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|ANZ541 Choptank River To Cambridge Md And The Little Choptank River- 433 Am Est Wed Nov 22 2017 |
.small craft advisory in effect through late tonight...
Rest of the overnight..SW winds 10 kt. Waves 1 ft. Rain.
Today..NW winds 15 to 20 kt with gusts to 30 kt. Waves 2 to 3 ft. A chance of rain.
Tonight..N winds 10 to 15 kt. Gusts up to 25 kt until early morning. Waves 2 to 3 ft.
Thu..NW winds 5 to 10 kt. Waves 1 ft.
Thu night..W winds 5 to 10 kt. Waves 1 ft.
Fri..N winds around 5 kt...becoming S in the afternoon. Waves flat.
Fri night..S winds 5 to 10 kt. Waves 1 ft.
Sat..NW winds 10 to 15 kt. Waves 1 to 2 ft.
Sun..NW winds 10 to 15 kt. Waves 2 ft.
|ANZ500 433 Am Est Wed Nov 22 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front will pass through early this morning and high pressure will return for later today through early Friday. Another cold front will approach late Friday into Saturday before passing through Saturday night. High pressure will return for Sunday and Monday. A small craft advisory may be needed for the waters late Saturday and Sunday.
7 Day Forecast for Marine Location Near Choptank, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 220953|
area forecast discussion
national weather service mount holly nj
453 am est Wed nov 22 2017
A cold front will move across the area early this morning while
an area of low pressure moves northeastward offshore the mid
atlantic coast. High pressure will build toward the area
tonight, and control the weather Thursday and Friday. A cold
front is forecast to move across the area on Saturday while an
area of low pressure moves northeastward offshore the mid
atlantic coast. High pressure builds across the area Monday,
then offshore Tuesday.
Near term until 6 pm this evening
500 am update: two main bands of precipitation are occurring at
this time. The first is along and just offshore the new jersey
coast, with quite a bit of training going on (fortunately
offshore). Given that this has set up mostly off the coast, the
heaviest precipitation should remain there with this main band.
Totals in southern delaware and eastern new jersey have
generally been a quarter to a half inch (locally higher), with
is generally about two-thirds of what the consensus hi-res
guidance was showing up to this point. Nevertheless, with more
upstream precipitation, thinking totals of a half to three-
quarters of an inch in these areas is plausible, and the updated
qpf is not much different than the previous forecast.
The second band of showers is over and near chesapeake bay, and
this appears to be strongly associated with right-rear quadrant
jet dynamics as the 250-mb jet streak lifts into the northeast
this morning. This area of precipitation has had much better
success extending northward toward the mason-dixon line. Forward
trajectories take this precipitation generally along and
southeast of i-95 this morning, which seems to be well sampled
by the latest hrrr. The 06z NAM nest continues to look very
unrealistic with the evolution of the precipitation, and the
model has performed pretty badly with the event overall. Did not
incorporate it into the updated pops wx grids.
rain event is underway across the area, with an area of showers
moving through DELMARVA northeastward through eastern new
jersey early this morning. A few lightning strikes have already
been observed within the stronger convective cores, so the
models appear to be simulating the influx of buoyant air
reasonably well. Where the models continue to struggle is with
the lighter precipitation that may or may not develop on the
northwest fringe of the more convective showers. The recent hrrr
simulations suggest very little precip may occur west of
wilmington and philadelphia with a band of light rain developing
somewhere northeast of philadelphia (possibly as far west as
the lehigh valley, possibly as far east as not in pennsylvania
at all). The NAM nest provides little usable guidance, as it has
basically no clue regarding the convection occurring right now
southwest of atlantic city.
With the rapid growth of the precipitation still ongoing given
the continuing improvement of the synoptic-scale dynamics with
the approaching trough to the west phasing with a northeastward-
moving perturbation to the south, still quite difficult to
determine just how far west the precipitation will make it.
However, based on current trends (both radar and model), general
thinking is that i- 295 is going to be a reasonable
approximation to the sharp cutoff in QPF (maybe a little to the
east of there even). With the precipitation rates seen so far,
localized 1"+ totals are plausible southeast of a dover to
asbury park line. In fact, hourly accumulations in
central southern delaware are already nearing this threshold. To
the northwest, mere hundredths of an inch may occur in the
greater i-95 corridor (though confidence remains pretty low,
especially northeast of philly).
With time, the precipitation will make a slow eastward jog
through the morning, with any lingering showers exiting the
coast around noon. Drying rapidly occurs for the rest of the
day, and cold-air advection begins in earnest as winds veer to
northwest and become gusty this afternoon. Models may be
underdoing cloud cover during the day, as mixing near the
surface and residual low-level moisture keep a scattered to
broken stratocumulus deck around. Trended the forecast more
pessimistic, but this is low confidence.
Temperatures will struggle to climb, though they may do so for
a time this morning as stronger cold-air advection trails the
wind shift. Forecast temperatures are heavily weighted to
met ecs mos, as the mav looked too warm.
Safe travels today.
Short term 6 pm this evening through 6 am Thursday
Upstream of the potent vort MAX moving through the region
today, a surface high will build into the appalachians
overnight. With clear skies and a decreasing surface pressure
gradient, temperatures will be much colder tonight. Forecast
lows are several degrees below seasonal averages, ranging from
around 20 in the southern poconos to around 30 in the urban
corridor and at the coast. Northwest winds will be decreasing
during the period, possibly becoming light and variable late.
The main uncertainty with the forecast is how quickly the winds
will die down, with the potential for some temperature error if
winds diminish faster than progged (i.E., it would be colder).
For now, I used a model blend, as I do not have much of a feel
for how quickly the winds decouple tonight. With the trend for
the past day being subtly slower with the incoming high (and
departing vort max), it may take a bit longer for the winds to
diminish than the models suggest.
Long term Thursday through Tuesday |
Fairly quiet weather is expected for most of the extended
period through next Tuesday, with a chance of isolated showers
High pressure is forecast to build across the area Thursday
into Friday and bring dry weather to the region. Temperatures
are forecast to be near or slightly below normal Thursday,
before warming back to near or slightly above normal Friday.
The high builds offshore Friday night in advance of an
approaching cold front coming through the area Saturday. Also,
an area of low pressure is forecast to be moving northeastward
offshore of the mid- atlantic coast on Saturday. This low is
currently expected to remain far enough offshore to not bring
major effects to the area Saturday. However, as the front moves
through Saturday there is a chance of isolated scattered showers
across the area. For Saturday night into Sunday, the low moves
farther to our northeast with high pressure to our west. This
will keep a strong northwest flow across the area Saturday night
and Sunday. It is possible that some isolated lake effect
showers could make their way across our area Saturday night into
Sunday in the northwest flow. Temperatures remain above normal
Saturday before the front moves through the area, but falls back
to near normal or slightly below for Sunday.
By Sunday night, high pressure begins to approach from the west
and the flow turns more northerly, cutting off the lake effect
showers potential across our area. The high pressure fully
builds across the area Monday, then pushes offshore by Tuesday.
This will bring dry weather back to the area early next week.
Temperatures are expected to be near normal or slightly below
for Monday, then warm back to above normal Tuesday as return
Aviation 10z Wednesday through Sunday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Through this morning... GenerallyVFR from kphl northwestward
with a few showers possible, but CIGS likely holding
predominantly above MVFR. For miv acy, brief sub-vfr conditions
(particularly cigs) are likely in heavier showers, which will
continue through around 15z with rapid progression offshore
thereafter. A sct-bkn deck around 3500-5000 feet may continue
through the morning across the area, with winds veering to
northwest and becoming gusty around noon (speeds 10-15 kts with
gusts to 25 kts). Confidence low to medium. Frequent updates to
the tafs are likely during this time frame.
This afternoon... Northwest winds continue, with a diminishing
trend after 21z.VFR conditions should continue. Confidence
Tonight...VFR with northwest winds continuing to diminish.
Thursday-Friday night...VFR expected. Westerly winds Thursday-
early Friday. Becoming southwest later Friday into Friday night.
Saturday-Sunday... GenerallyVFR. Isolated showers possible
which may occasionally lower conditions. Southwest winds early
Saturday, becoming northwest and gusting 20-25 knots Saturday
night into Sunday. Moderate confidence on showers and sub-vfr
conditions, high confidence on winds.
No changes to the small craft advisories this morning as
northwest winds will pick up late this morning and exceed
criteria easily this afternoon and evening. Seas will likely
hover around 5 feet through tonight, as well. Showers, possibly
with a couple lightning strikes, are expected through the
morning hours, before improvement this afternoon.
Thursday-Saturday... Sub small craft advisory conditions
expected, although seas may be around 4 feet Thursday before
Saturday night-Sunday... Small craft advisory conditions likely
behind cold frontal passage.
The kdox radar remains out of service. Replacement parts are
expected to arrive on Wednesday, november 22nd.
Phi watches warnings advisories
Marine... Small craft advisory until 6 am est Thursday for anz450>455.
Small craft advisory from noon today to midnight est tonight
near term... Cms
short term... Cms
long term... Robertson
aviation... Cms robertson
marine... Cms robertson
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|
|CA2 - 8571892 - Cambridge, MD||10 mi||53 min||54°F||50°F||1014.5 hPa (-1.0)|
|44062 - Gooses Reef, MD||26 mi||43 min||SSW 5.8 G 7.8||54°F||1 ft||1013.8 hPa|
|TPLM2 - Thomas Point, MD||30 mi||53 min||S 7 G 7||54°F||53°F|
|COVM2 - 8577018 - Cove Point LNG Pier, MD||30 mi||53 min||W 9.9 G 12||54°F||1014 hPa (-1.4)|
|BISM2 - 8571421 - Bishops Head, MD||32 mi||53 min||W 14 G 15||55°F||49°F||1013.5 hPa (-2.5)|
|CPVM2||32 mi||53 min||54°F||49°F|
|44063 - Annapolis||33 mi||43 min||S 5.8 G 5.8||53°F||1011.6 hPa|
|APAM2 - 8575512 - Annapolis, MD||35 mi||53 min||53°F||1012 hPa (-2.1)|
|SLIM2 - 8577330 - Solomons Island, MD||36 mi||53 min||WSW 6 G 8.9||54°F||54°F||1013.1 hPa (-1.1)|
|DRSD1 - Delaware Reserve, DE||39 mi||83 min||S 1||53°F||1013 hPa||53°F|
|44043 - Patapsco, MD||40 mi||43 min||WSW 1.9 G 3.9||51°F||1 ft||1013.4 hPa|
|TCBM2 - 8573364 - Tolchester Beach, MD||40 mi||53 min||S 7 G 13||53°F||49°F||1012.6 hPa (-2.0)|
|BSLM2 - Chesapeake Bay, MD||41 mi||83 min||SSE 4.1||49°F||1013 hPa||48°F|
|LWSD1 - 8557380 - Lewes, DE||45 mi||53 min||SW 6 G 8.9||57°F||52°F||1012.9 hPa (-1.8)|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||48 mi||53 min||WNW 1.9 G 2.9||53°F||1012.8 hPa (-1.4)|
|BRND1 - 8555889 - Brandywine Shoal Light, DE||49 mi||53 min||SSW 15 G 17||56°F||1013.1 hPa (-2.6)|
|44042 - Potomac, MD||49 mi||43 min||WNW 9.7 G 12||54°F||1 ft||1013 hPa|
|PPTM2 - 8578240 - Piney Point, MD||49 mi||53 min||WNW 8 G 8.9|
Wind History for Cambridge, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Cambridge-Dorchester Airport, MD||11 mi||68 min||Var 3||10.00 mi||Overcast||55°F||53°F||94%||1012.9 hPa|
|Easton / Newman Field, MD||11 mi||57 min||W 5||5.00 mi||Fog/Mist||54°F||52°F||95%||1014.6 hPa|
Wind History from ESN (wind in knots)
|1 day ago||NW||NW||NW|
|2 days ago||NW|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
Click for Map
Wed -- 02:05 AM EST 0.46 feet Low Tide
Wed -- 06:34 AM EST 1.30 feet High Tide
Wed -- 06:53 AM EST Sunrise
Wed -- 10:11 AM EST Moonrise
Wed -- 12:38 PM EST 0.08 feet Low Tide
Wed -- 04:45 PM EST Sunset
Wed -- 07:08 PM EST 2.13 feet High Tide
Wed -- 08:16 PM EST Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Dover Bridge |
Click for Map
Wed -- 03:09 AM EST 0.49 feet Low Tide
Wed -- 06:54 AM EST Sunrise
Wed -- 08:09 AM EST 1.38 feet High Tide
Wed -- 10:11 AM EST Moonrise
Wed -- 01:43 PM EST 0.09 feet Low Tide
Wed -- 04:45 PM EST Sunset
Wed -- 08:16 PM EST Moonset
Wed -- 08:43 PM EST 2.25 feet High Tide
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 (5,6,7,8)(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.