Marine Weather and Tides
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.
|Sunrise 5:37AM||Sunset 8:33PM||Monday June 18, 2018 12:14 AM EDT (04:14 UTC)||Moonrise 10:02AM||Moonset 11:43PM||Illumination 22%|
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|ANZ540 Eastern Bay- 1049 Pm Edt Sun Jun 17 2018 |
Rest of tonight..S winds 5 kt. Waves less than 1 ft.
Mon..S winds 5 to 10 kt. Waves 1 ft or less.
Mon night..SW winds 5 to 10 kt. Waves 1 ft.
Tue..NW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Tue night..NE winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Wed..NW winds 5 kt. Waves flat. Scattered showers and tstms.
Wed night..N winds around 5 kt. Waves 1 ft or less. Showers likely.
Thu..NE winds 5 kt. Waves less than 1 ft. Showers likely in the morning. A chance of showers.
Fri..SE winds 5 to 10 kt. Waves 1 ft. A chance of showers in the morning. A chance of showers through the night. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 1049 Pm Edt Sun Jun 17 2018 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will remain in the western atlantic through Monday. A cold front will approach from pennsylvania Tuesday, then stall over the waters during the middle and latter portion of the week.
7 Day Forecast for Marine Location Near Denton, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 180116|
area forecast discussion
national weather service mount holly nj
916 pm edt Sun jun 17 2018
High pressure will remain anchored over the southeast u.S. And
off the mid-atlantic coast through through Tuesday. A cold front
moves south through the area on Tuesday. This front will stall
south of the region through the end of the week. Several waves
of low pressure will develop on that boundary as high pressure
builds to the north.
Near term until 6 am Monday morning
Mid and high level cloudiness continues to stream southeast
across the area within a northwest flow aloft along the eastern
flank of an expansive ridge across much of the eastern us.
Given subsidence and lack of instability, do not expect any
The sea breeze that worked through the coastal plain earlier
has moistened the air mass, particularly across portions of
southern delaware and southeast new jersey, as evidenced in
higher dew points. As winds become light and variable later
tonight, there may be some patchy fog across this area, and
the current forecast conveys this.
A warm night is in store across much of the region with low
temperatures several degrees above normal.
high pressure remains offshore of the east coast tonight, with
a lee-side surface trough weakly affecting the area overnight as
well. Fair conditions are expected, with mostly clear skies for
much of the night, although some lower-mid level clouds may
develop late in the night for the southern half of the area.
Winds will likely become light and variable for many areas
tonight, and temperatures will cool overnight, although not as
cool as Saturday night. Dewpoints are expected to slightly
rebound through the night as well, so as temperatures drop near
the dewpoint, some areas of patchy fog may develop. We do not
expect significantly reduced visibilities at this time.
Short term 6 am Monday morning through 6 pm Monday
On Monday, high pressure remains offshore of the east coast,
keeping return flow across the area. This will allow for
temperatures to warm even more as dewpoints increase as well.
925 mb temperatures reach ~24-26, which would produce max
temperatures in the low to mid 90s for most of the area outside
of the higher elevations and areas right along the coast.
Temperatures this high, combined with dewpoints in the upper 60s
to lower 70s are expected to create very high heat index
values, with many locations reaching 100 degrees or more during
the afternoon. We have issued a heat advisory for eastern
pennsylvania, most of new jersey except the southern four
counties and the coastal strip, as well as new castle, de where
the criteria is 100 degrees heat index. The remainder of the
area has a heat index criteria of 105, which we expect to fall
short of. If dewpoints mix out more and are a degree or two
lower, we may fall just short of the advisory. However, since
this is the first very warm humid day of the summer, and it's
been rather cool recently and most people are not acclimated to
the heat yet, we decided the heat advisory was prudent.
A lee-side pre-frontal surface trough will reestablish itself
and strengthen across the east coast on Monday. Fair conditions
will remain across the area for most of the day, as there will
likely be enough of a capping inversion, and lack of any short
wave vorticity impulses early in the day, to prevent any showers
from developing. However, later in the afternoon toward
evening, a short wave vorticity impulse approaches from the
west. A line of showers and thunderstorms is expected to develop
to our northwest during the day and approach our area late in
the afternoon. Any precipitation may not actually reach the area
until later in the evening.
Long term Monday night through Sunday
A warm and humid night on tap Monday night with lows well in
the mid and upper 70s and surface dewpoints in the low 70s.
Showers and thunderstorms develop on a pre-frontal trough ahead
of a cold front Monday evening, and then those storms will pass
through the region mainly after midnight Monday night. With
abundant low level moisture due to the high dewpoints, pwats
will approach 2.25", and can expect thunderstorms to produce
Cold front works its way south Monday night and Tuesday
morning, and should be through the poconos shortly after
daybreak Tuesday. Cooler air spills in behind the front. Highs
will generally top off in the low to mid 80s in the southern
poconos and into northern nj. Across southern nj, eastern md,
and delaware, however, hot and humid conditions continue, though
highs on Tuesday should be 1-3 degrees cooler than Monday. The
dewpoints will be higher, however, generally in the low 70s, and
this results in a heat index in the upper 90s to around 100.
Cold front continues to work its way south through the region
during the day, and showers and thunderstorms will continue to
develop with its passage. With CAPE values around 2000 j kg, and
a lifted index around -4c, there is enough energy for some
strong to severe thunderstorms. However, the bulk of the upper
level energy needed will remain well to the north. Best chances
for convection will be across delmarva, as a few mid-level
shortwaves dive into the region from the north and west. Going
into the afternoon, pops increase to likely across southern nj
Showers and thunderstorms taper off Tuesday evening with
passage of cold front. The airmass will stabilize over the
southern portions of the forecast area as that cooler and dryer
air filters southward.
From there, low confidence forecast for the rest of the week.
The cold front will become nearly stationary south of the
region, across the mid-atlantic, and several waves of low
pressure will develop to the west and ride along that boundary.
Meanwhile, high pressure builds to the north. Based on latest
guidance, it seems as if the southern half of the forecast area
could have a few rounds of precip into the end of the work week,
while the northern half could remain relatively dry. But it all|
depends on timing and placement of the high and of the
A stronger and more developed area of low pressure may move
into the region next weekend.
After Tuesday, highs will generally be within a few degrees of
normal, in the low to mid 80s.
Aviation 01z Monday through Friday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Tonight... MostlyVFR conditions will prevail through tonight.
Some patchy light fog may develop just before sunrise for a few
locations, but visibilities are expected to lower to only 3-6
Winds west-southwest around 5 knots becoming light and variable.
Monday... After any fog that does develop overnight dissipates
after sunrise,VFR conditions will continue through the day,
with increasing cloud cover during the afternoon. Southwest
winds are expected to increase during the day, and may become
gusty 15-20 knots during the afternoon.
A line of showers and thunderstorms will develop to our
northwest during the afternoon, but are not expected to make it
into our area until the evening hours or very late afternoon at
Monday night... MainlyVFR. Sub-vfr vsbys possible in patchy fog.
Scattered shra tsra, mainly from kphl north. Locally heavy rain
possible. SW winds less than 10 kt, turning W late.
Tuesday and Tuesday night... PredominatelyVFR, but shra tsra
will develop with passage of a cold front that could result in
heavy rain and sub-vfr conditions. Winds will shift from w-sw to
w-nw through the day at 10-15 kt with gusts up to 20 kt.
Wednesday through Friday...VFR likely, although it will depend
on how far the front stalls to our south. It may be located
close enough to the area to bring showers and brief sub-vfr
conditions to southern terminals.
Conditions expected to remain below advisory levels through
Monday, although winds may gust around 20 knots at times. Winds
above the surface are expected to increase to 25-30 knots, but
there should be enough of an inversion to prevent any of this
wind from mixing down to the surface.
Monday night... S-sw winds 15-20 kt. Inversion should be strong
enough to keep 25 kt gusts from mixing down Monday evening, then
winds diminish to 10-15 kt late. Scattered showers and
Tuesday... Cold front works its way south through the waters,
with scattered showers and thunderstorms across northern nj
coastal ocean waters, and showers and thunderstorms likely over
southern nj coastal waters, de coastal ocean waters, and de bay.
Winds shift from SW to NW through the day at around 15 kt with
gusts up to 20 kt. Generally sub-sca conditions outside of
Tuesday night through Friday... Winds and seas below SCA levels.
seas build to 2-3 feet on Monday with a dominant period of 7-8
seconds out of the southeast. South-southwest winds increase
Monday afternoon which may create locally enhanced rip current
risk, particularly where the flow has an onshore component, but
overall the risk for the development of dangerous rip currents
is low for the de and nj beaches.
Record-breaking heat may occur early this week, especially on
Monday. Current forecast high temperatures for Monday are within a
degree of their daily records at all of our first-order climate
sites except georgetown. Forecast high temperatures for atlantic
city on Tuesday are only a couple of degrees below its daily record.
Below are the daily high temperature records for Monday, june 18 and
Tuesday, june 19 at our first-order climate sites:
daily high temperature records: (f)
june 18 MAX temp june 19 MAX temp
station record (year set) record (year set)
------- ---------------- ----------------
allentown, pa 95 (1957) 95 (1994)
atlantic city (pomona), nj 95 (1944, 2014) 96 (1993, 1994)
georgetown, de 97 (1957, 2014) 96 (1952)
mount pocono, pa 88 (1957) 86 (1905, 1929)
philadelphia, pa 96 (1957) 100 (1994)
reading, pa 97 (1957) 95 (1905, 1929)
trenton, nj 96 (1865, 1957) 94 (1929)
wilmington, de 95 (1894, 1957) 100 (1994)
Phi watches warnings advisories
Pa... Heat advisory from noon to 8 pm edt Monday for paz054-055-
Nj... Heat advisory from noon to 8 pm edt Monday for njz001-007>010-
De... Heat advisory from noon to 8 pm edt Monday for dez001.
near term... Lf robertson
short term... Robertson
long term... Mps
aviation... Lf robertson mps
marine... Lf robertson 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|
|DRSD1 - Delaware Reserve, DE||25 mi||104 min||SSE 1.9||71°F||1019 hPa||71°F|
|CA2 - 8571892 - Cambridge, MD||25 mi||44 min||76°F||80°F||1019.6 hPa|
|CPVM2||31 mi||44 min||76°F||74°F|
|TCBM2 - 8573364 - Tolchester Beach, MD||32 mi||44 min||SSE 4.1 G 7||77°F||78°F||1018.2 hPa|
|TPLM2 - Thomas Point, MD||32 mi||74 min||S 11 G 11||78°F||76°F||1019.3 hPa (+0.9)||75°F|
|44063 - Annapolis||33 mi||34 min||SSW 7.8 G 9.7||77°F||1018.3 hPa|
|APAM2 - 8575512 - Annapolis, MD||35 mi||44 min||79°F||1017.6 hPa|
|44062 - Gooses Reef, MD||38 mi||34 min||S 9.7 G 12||77°F||1018.5 hPa|
|LWSD1 - 8557380 - Lewes, DE||38 mi||44 min||S 4.1 G 7||72°F||69°F||1018.8 hPa|
|BRND1 - 8555889 - Brandywine Shoal Light, DE||39 mi||44 min||S 15 G 15||71°F||1019.2 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||44 mi||44 min||S 8.9 G 11||79°F||1017.7 hPa|
|FSNM2||44 mi||56 min||S 8.9 G 16||80°F||1017.8 hPa|
|COVM2 - 8577018 - Cove Point LNG Pier, MD||44 mi||44 min||S 14 G 15||76°F||1018.7 hPa|
|CHCM2 - 8573927 - Chesapeake City, MD||45 mi||44 min||SSW 1.9 G 4.1||75°F||77°F||1018.4 hPa|
|CMAN4 - 8536110 - Cape May, NJ||47 mi||44 min||SSE 5.1 G 8||70°F||72°F||1018.6 hPa|
|BISM2 - 8571421 - Bishops Head, MD||47 mi||44 min||SE 6 G 8||75°F||83°F||1019 hPa|
|BSLM2 - Chesapeake Bay, MD||47 mi||104 min||SSE 2.9||74°F||1018 hPa||71°F|
|BLTM2 - 8574680 - Baltimore, MD||48 mi||44 min||SSW 1.9 G 5.1||79°F||76°F||1017.7 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||49 mi||44 min||73°F||75°F||1017.7 hPa|
Wind History for Cambridge, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Easton / Newman Field, MD||14 mi||25 min||S 4||10.00 mi||Fair||78°F||67°F||71%||1019.6 hPa|
Wind History from ESN (wind in knots)
|1 day ago||Calm||Calm||Calm||Calm||Calm||Calm||Calm||W||NW||NW||NW||NW||W||W||W||SW||W||SW||S||Calm||SW||Calm||Calm||Calm|
|2 days ago||W||NW||NW||N||Calm||Calm||Calm||N||N||N||N||NW||NW|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
Click for Map
Mon -- 12:04 AM EDT Moonset
Mon -- 05:25 AM EDT 0.82 feet Low Tide
Mon -- 05:37 AM EDT Sunrise
Mon -- 11:02 AM EDT Moonrise
Mon -- 11:26 AM EDT 3.72 feet High Tide
Mon -- 06:54 PM EDT 0.65 feet Low Tide
Mon -- 08:31 PM EDT Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
Click for Map
Mon -- 12:04 AM EDT Moonset
Mon -- 12:14 AM EDT 3.19 feet High Tide
Mon -- 05:37 AM EDT Sunrise
Mon -- 06:11 AM EDT 0.94 feet Low Tide
Mon -- 11:02 AM EDT Moonrise
Mon -- 12:31 PM EDT 4.26 feet High Tide
Mon -- 07:40 PM EDT 0.74 feet Low Tide
Mon -- 08:31 PM EDT Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  HelpWeather Map
GOES Local Image of EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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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.