Marine Weather and Tides
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.
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.
|Sunrise 7:04AM||Sunset 7:14PM||Monday March 19, 2018 6:32 AM EDT (10:32 UTC)||Moonrise 7:31AM||Moonset 8:31PM||Illumination 7%|
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|ANZ454 Coastal Waters From Cape May Nj To Cape Henlopen De Out 20 Nm- Coastal Waters From Cape Henlopen To Fenwick Island De Out 20 Nm- 619 Am Edt Mon Mar 19 2018 |
.gale warning in effect from Tuesday morning through Wednesday afternoon...
Today..SW winds 10 to 15 kt with gusts up to 20 kt, becoming nw 5 to 10 kt later this morning, then becoming ne early this afternoon, becoming E late. Seas 2 ft or less, then around 3 ft early this morning, then 2 ft or less late this morning and afternoon. SWell mainly from the se with a dominant period of 4 seconds.
Tonight..E winds 10 to 15 kt with gusts up to 20 kt, increasing to 15 to 20 kt with gusts up to 25 kt after midnight. Seas 2 ft or less, then 3 to 5 ft in the late evening and overnight. SWell mainly from the se with a dominant period of 9 seconds. A chance of rain after midnight. Rain late.
Tue..E winds 20 to 25 kt with gusts up to 35 kt, becoming ne 25 to 30 kt with gusts up to 45 kt in the late morning and afternoon. Seas 5 to 8 ft, building to 8 to 13 ft in the late morning and afternoon. SWell mainly from the E with a dominant period of 8 seconds. Rain.
Tue night..NE winds 25 to 30 kt with gusts up to 40 kt, increasing to 30 to 35 kt with gusts up to 45 kt late. Seas 9 to 13 ft dominant period 9 seconds. Rain likely.
Wed..NE winds 30 to 35 kt, becoming N 25 to 30 kt in the afternoon. Gusts up to 45 kt. Seas 9 to 13 ft. Rain, snow and sleet. Vsby 1 nm or less.
Wed night..N winds 20 to 25 kt with gusts up to 35 kt, becoming nw 15 to 20 kt with gusts up to 25 kt after midnight. Seas 7 to 10 ft. A chance of rain. Snow likely, mainly in the evening. Vsby 1 nm or less, increasing to 1 to 3 nm after midnight.
Thu..NW winds 10 to 15 kt. Seas 4 to 7 ft.
Thu night..NW winds 10 to 15 kt. Seas 3 to 5 ft.
Fri..NW winds 10 to 15 kt. Seas 3 to 4 ft.
Fri night..NW winds around 10 kt. Seas around 3 ft.
|ANZ400 619 Am Edt Mon Mar 19 2018 |
Synopsis for the coastal waters from sandy hook nj to fenwick island de and for delaware bay.. High pressure centered over south-central canada will extend southeastward into the mid-atlantic region through tonight. Low pressure will move eastward and emerge off the mid-atlantic coast Tuesday before shifting northeastward. A secondary low pressure system develops just off the mid-atlantic coast Tuesday night and tracks northeastward Wednesday into Thursday. High pressure builds in later Friday into Saturday, then low pressure tracks nearby Saturday night and Sunday.
7 Day Forecast for Marine Location Near Lewes, DEHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 190843|
area forecast discussion
national weather service mount holly nj
443 am edt Mon mar 19 2018
High pressure centered over south-central canada will extend
southeastward into the mid-atlantic region through tonight. Low
pressure will move eastward and emerge off the mid-atlantic coast
Tuesday before shifting northeastward. A secondary low pressure
system develops just off the mid-atlantic coast Tuesday night and
tracks northeastward Wednesday into Thursday. High pressure builds
in later Friday into Saturday, then low pressure tracks nearby
Saturday night and Sunday.
Near term until 6 pm this evening
An upper air analysis shows a closed low near northern new england,
a sharp trough in portions of the plains and some ridging in place
from the midwest southeastward. A 250 mb jet was positioned across
southern canada and across new england, with another segment from
the southern plains to off the coast of the carolinas. At the
surface, high pressure is parked over south-central canada with low
pressure in the southern plains. A weak front was draped from the
midwest to the eastern great lakes then into our area.
Through early this morning, quite the variability with temperatures
with some locales hanging onto a light wind which has slowed the
temperature drop thus far. Meanwhile, some areas have radiated quite
well. As a result, the temperatures needed to be reworked.
As we go through today, a weak surface front settles southeastward
and may simply dissipate. This occurs as high pressure centered just
south of hudson bay canada starts to build southeastward during the
day. This will begin to build into our area by the end of the day.
As this occurs, a strong short wave trough ejects eastward from the
plains and should be nearing the ohio valley by evening. There is
some downstream short wave energy moving through a confluence zone
over our region, and this combined with upper-level flow will lead
to some mainly high level clouds (more of this across the southern
zones with time). Given high pressure starting to build down from
the northwest, the low-level winds turn from the northeast today.
This should be fairly light overall and with enough heating
temperatures should warm a decent amount mainly from philadelphia on
southward. Since the flow is turning from the northeast, did not go
as mild as some of the guidance suggests and generally used a model
blend of 2 meter temperatures. The developing onshore flow will also
keep it cooler along the coast.
Short term 6 pm this evening through 6 am Tuesday
A rather complex setup begins to evolve tonight with a strong closed
low sitting near the canadian maritimes, meanwhile plenty of energy
shifts eastward and starts to interact. This will be setting the
stage for significant trough amplification in the east.
The main driver for tonight appears to be an incoming strong short
wave trough from the ohio valley. This combines with high pressure
still sitting just south of hudson bay canada, which gets a cold air
damming setup established. This will probably drive some low-level
drier air southward and be setting up shop especially along and
north of i-78. Meanwhile, increasing large scale lift augmented by
warm air advection and isentropic lift begins to arrive across our
southern zones toward daybreak Tuesday. This should allow for some
rain to develop from south to north, however the northern extent is
less certain although this may take some time to advance farther
north given enough dry air advection in the lower levels. We
therefore slowed down the northward increase in the pops. The
thermal profiles across the southern areas suggest the precipitation
starts as rain, however as the column cools enhanced by some
evaporative cooling suggests some snow and or sleet may occur. The
bulk of the precipitation is expected to be after this time frame,
therefore any snow sleet accumulations down across portions of the
southern areas are anticipated to be minimal.
As for the temperatures, we continued with a model blend of the 2
meter temperatures overall.
Long term Tuesday through Sunday
Complex storm system consisting of multiple coastal lows are
expected to impact the region on Tuesday and Wednesday. The
extent of the impacts are yet to be determined...
forecast models continue to exhibit poor run-to-run continuity
as they struggle to handle the complex interactions between the
train of shortwave troughs ejecting from western north america
(there are at least four distinct disturbances seen on water
vapor satellite imagery that will come into play).
There continues to be disagreement with the idea that the
midweek event will consist of two distinct waves of precip
(round 1 Tuesday-Tuesday night and round 2 Wednesday) with
enough separation distance between the two coastal lows to
allow for a break in the precip late Tuesday afternoon and
Round (1)- Tuesday and Tuesday night...
the latest trends point toward a favorable synoptic pattern for a
big winter snowstorm for our region. However, there are several
factors working against that notion at least for the first part of
(1) a high Sun angle in late march and marginally cold surface
temperatures (especially i-95, S e) will make it very difficult for
snow to accumulate effectively during the day time unless the rates
are moderate to heavy. Aside from the initial band of overrunning
precip that targets the southern half of the forecast region Tuesday
morning-early afternoon, the consensus from the 00z guidance is for
the precip to be light through Tuesday night.
(2) a key ingredient in this event in the position of the high,
which is forecast to be located over northern ontario and a bit
farther northwest than what is ideal for an all snow event,
especially along and S E of i-95. Consequentially, warm air aloft
wrapping cyclonically around the system should advance into the S e
portion of the region. This would imply mainly rain in SE pa, c S de
and E md (along and south of the delaware bay) through at least
Tuesday evening with a mix of rain sleet snow nosing close to
philadelphia (especially its S E suburbs).
(3) while areas farther N W of the city favor snow Tuesday and
Tuesday evening, precip amounts quickly taper off as there should be
a sharp cutoff on the northern edge of the precip shield.
Accordingly, snowfall accumulations are around an inch or less for
Tuesday; same for Tuesday night. The exception is the higher
elevations (above 400 ft) in SE pa and cecil county, md where 1-2"
of snowfall is possible each period. A winter weather advisory
may be needed for these areas.
Round (2)- Wednesday...
this is the period of greatest concern for a potentially significant
snowfall is Wednesday. This is also the period of greatest
uncertainty. The 00z ECMWF and UKMET have shifted considerably
toward a high-impact event with warning-level snowfall accumulations
and windy conditions as the second coastal low takes a track closer|
to the coast. The NAM and ggem showed a similar snowy scenario but
the latest 00z runs have backed off from that idea. The GFS is
somewhere in between but generally shows a minor event. There
continues to be a large spread among the gfs, ECMWF and gem ensemble
prediction systems. All this equates to is a high degree of
uncertainty. We've seen models trend northwest closer to the event
with several significant snows in recent years, so it's a bit
premature to rule out this scenario. Given the uncertainty, the
probabilistic snowfall graphics (available on our winter webpage)
provide much more value than any deterministic forecast. If the high-
end snowfall scenario were to verify, extensive tree damage and
power outages could occur once again.
A winter storm watch may eventually be needed.
High pressure builds in behind the storm later Thursday into Friday.
Cold (5-10 degrees below normal) and dry conditions would be
expected in this pattern.
Yet another storm system could impact the region next weekend.
There has not yet been a signal for coastal redevelopment with
this system, so the rain snow line would be determined by the
track of the primary low.
Aviation 09z Monday through Friday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Today...VFR with clouds mainly above 15,000 feet. Light variable to
light southwest winds, becoming northwest to north early this
morning, then northeasterly 5-10 knots.
Tonight...VFR as clouds increase and gradually lower, especially
near and south east of phl. East to northeast winds less than 10
Tuesday... Widespread MVFR ifr conditions likely from kphl kpne
southward. There is high uncertainty as you go farther north
toward abe regarding if snow will make it that far north with a
sharp cutoff in precip expected. For miv and acy, a considerable
amount of mixing of rain, snow and perhaps sleet is likely
while snow is favored farther northward toward phl. NE winds
10-20 kt with gusts 25-35 kt (higher end of range near the
coast). Moderate confidence.
Tuesday night through Wednesday night... Additional precip is
possible, mainly snow (except along the coast). Confidence in
precip occurring is high along the coast, but decreases farther
inland. MVFR or ifr conditions would be possible if snow
reaches the terminals. Gusty n-ne winds expected, especially
near the coast.
Thursday...VFR. NW winds gradually relax. High confidence.
Friday...VFR. NW winds. Moderate confidence.
The conditions are expected to be below small craft advisory
criteria today through the first half of tonight, then the southern
waters will see an increase in winds and seas late tonight (nearing
gale force gusts toward daybreak Tuesday). Otherwise, high pressure
extending southeastward from south-central canada through tonight
will turn the winds from southerly to north and northeast today and
Tuesday through Wednesday... The gale watch for the coastal
waters (except anz450) was upgraded to a gale warning. There is
a potential for gusts to peak near storm force off the S nj and
de coastal waters briefly during the day on Tuesday and again on
Wednesday. Capped gusts to 45 kt for now. The gale watch remains
in effect for the northernmost nj ocean waters with the onset of
gales delayed until Tuesday night. A gale watch was also issued
for the delaware bay from Tuesday afternoon through Wednesday
morning though there is greater uncertainty in winds reaching
gale force in the delaware bay than the coastal waters. Wave
heights in our southern coastal waters are forecast to build to
10-13 ft and to 6 to 10 ft for northern coastal ocean waters
late Tuesday into Wednesday. These wave heights were adjusted
several feet above wavewatch guidance given the model's low bias
in strong NE flow.
Wednesday night and Thursday... SCA conditions likely.
Friday... Sub-sca conditions expected.
Tides coastal flooding
An extended period of strong northeasterly winds are expected
to occur from late tonight through Wednesday with two coastal
storms tracking south and east of the region. Positive tidal
anomalies will increase with each successive high tide as water
piles up along the coast. The threat for coastal flooding looks
to develop as early as the Tuesday evening high tide along the
nj- de coast and continue through the Wednesday night high tide.
The degree of coastal flooding will depend on the track and
strength of both coastal lows, which is still uncertain
especially with with the second one Tuesday night into
Wednesday. Etss, estofs and other tidal prediction guidance from
stevens flood advisory system indicate minor to possibly low-
end moderate coastal flooding is most likely.
Phi watches warnings advisories
Marine... Gale warning from 6 am Tuesday to 6 pm edt Wednesday for
Gale watch from Tuesday evening through Wednesday afternoon
Gale warning from noon Tuesday to 6 pm edt Wednesday for
Gale watch from Tuesday afternoon through Wednesday afternoon
near term... Gorse
short term... Gorse
long term... Klein
aviation... Gorse klein
marine... Gorse klein
tides coastal flooding...
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|
|LWSD1 - 8557380 - Lewes, DE||0 mi||45 min||SW 8 G 12||38°F||42°F||1012.2 hPa|
|BRND1 - 8555889 - Brandywine Shoal Light, DE||14 mi||51 min||WSW 20 G 22||40°F||1012.3 hPa|
|CMAN4 - 8536110 - Cape May, NJ||16 mi||45 min||WSW 14 G 16||40°F||40°F||1011.7 hPa|
|DRSD1 - Delaware Reserve, DE||27 mi||123 min||Calm||31°F||1012 hPa||30°F|
|OCIM2 - 8570283 - Ocean City Inlet, MD||31 mi||45 min||WSW 7 G 8||40°F||42°F||1013.2 hPa|
|44009 - DELAWARE BAY 26 NM Southeast of Cape May, NJ||31 mi||43 min||SW 14 G 16||42°F||41°F||3 ft||1012.7 hPa (-0.9)||39°F|
Wind History for Lewes, DE(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Georgetown - Delaware Coastal Airport, DE||14 mi||39 min||SW 4||10.00 mi||Fair||34°F||30°F||89%||1012.7 hPa|
|Wildwood, Cape May County Airport, NJ||20 mi||38 min||W 7||10.00 mi||Fair||39°F||33°F||79%||1012.8 hPa|
Wind History from GED (wind in knots)
|1 day ago||Calm||Calm||W||NW|
|2 days ago||W||W||W||NW|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
Click for Map
Mon -- 04:26 AM EDT -0.34 feet Low Tide
Mon -- 07:05 AM EDT Sunrise
Mon -- 08:30 AM EDT Moonrise
Mon -- 10:47 AM EDT 4.52 feet High Tide
Mon -- 04:44 PM EDT -0.30 feet Low Tide
Mon -- 07:11 PM EDT Sunset
Mon -- 09:31 PM EDT Moonset
Mon -- 11:05 PM EDT 4.66 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Delaware Bay Entrance |
Click for Map
Mon -- 03:23 AM EDT -1.51 knots Max Ebb
Mon -- 06:07 AM EDT 0.00 knots Slack
Mon -- 07:05 AM EDT Sunrise
Mon -- 08:30 AM EDT Moonrise
Mon -- 09:05 AM EDT 1.57 knots Max Flood
Mon -- 12:13 PM EDT -0.00 knots Slack
Mon -- 03:37 PM EDT -1.52 knots Max Ebb
Mon -- 06:21 PM EDT 0.00 knots Slack
Mon -- 07:11 PM EDT Sunset
Mon -- 09:21 PM EDT 1.65 knots Max Flood
Mon -- 09:31 PM EDT Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  HelpWeather Map
GOES Local Image of Mid-Atlantic 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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Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for Philadelphia/Mount Holly, PA (6,6,7,8)(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.