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 7:52PM||Sunday August 20, 2017 5:11 PM EDT (21:11 UTC)||Moonrise 3:56AM||Moonset 6:15PM||Illumination 2%|
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|ANZ530 Chesapeake Bay North Of Pooles Island- 432 Pm Edt Sun Aug 20 2017 |
Rest of this afternoon..NW winds 5 kt. Waves flat.
Tonight..SW winds around 5 kt. Waves flat.
Mon..S winds 5 to 10 kt. Waves 1 ft or less. A chance of showers and tstms.
Mon night..S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Tue..S winds 5 to 10 kt. Waves 1 ft.
Tue night..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Wed..N winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Thu..N winds 5 kt. Waves less than 1 ft. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 432 Pm Edt Sun Aug 20 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move offshore through tonight. A cold front will cross the waters late Tuesday night into early Wednesday. High pressure will return for the second half of the week. Small craft advisories will likely be needed Monday night through Wednesday night.
7 Day Forecast for Marine Location Near Cecilton, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 202012|
area forecast discussion
national weather service mount holly nj
412 pm edt Sun aug 20 2017
High pressure over the area moves offshore tonight, then slowly
drifts out to sea through Tuesday. A cold front approaches from
the west on Tuesday, then works its way across the region on
Wednesday. Canadian high pressure builds into the region late in
the week and into next weekend.
Near term until 6 am Monday morning
Relatively tranquil weather conditions will persist through
tonight as high pressure remains over the area. Scant cloud
cover and light and variable winds will lead to favorable
radiational cooling tonight, with temperatures falling to near
or within a few degrees of climatological normals. There may be
some patchy fog development towards daybreak, but with a
relatively dry air mass expect any development to be more
limited in nature.
Short term 6 am Monday morning through 6 pm Monday
As high pressure shifts offshore, flow will return to a more
southerly direction allowing warm moist advection through the
afternoon. Temperatures will be a few degrees higher than
Sunday, while humidity will markedly increase towards the
evening. There may be a chance for some showers and
thunderstorms as a short wave trough over the midwest moves
eastward, reaching the area by afternoon evening. One limiting
factor will be rather diffuse surface boundaries - with little
to no forecast convergence expected to focus or enhance
activity. As such, the best chance for any development will be
along higher terrain, mainly to the west of philadelphia.
Long term Monday night through Sunday
Some mid-level shortwave energy will pass through the region
Monday night. Onshore flow will usher a warm and humid airmass
into the region, as surface dewpoints will climb into the upper
60s to low 70s, and into the mid 70s across the DELMARVA and
extreme southern nj. This will result in isolated to scattered
showers and thunderstorms in the evening, gradually tapering off
after midnight. Patchy fog may form in the pre-dawn hours going
into Tuesday morning.
On Tuesday, low pressure over the great lakes will lift to the
northeast towards eastern canada. This will drag a cold front
through the great lakes and into the ohio valley late Tuesday.
Pre-frontal trough sets up ahead of the front, and that looks
to trigger afternoon and evening showers and thunderstorms.
Abundant low level moisture will be in place with dewpoints in
the low to mid 70s, and with several strong shortwaves out ahead
of the upper trough surface cold front, can expect some fairly
strong thunderstorms during the overnight hours Tuesday night
into Wednesday morning. Cold front works its way to the south
and east Wednesday through Wednesday evening, then becomes
nearly stationary over the mid-atlantic and DELMARVA for the end
of the week. Quite warm and humid for the first half of the
long term period, with highs in the upper 80s to low 90s on
Tuesday, then in the mid to upper 80s on Wednesday. MAX heat
index values on Tuesday look to be in the upper 90s for areas
along and south of the i-95 corridor, and around 100 for the
Several waves of low pressure may develop on this boundary, but
latest model guidance keeps those systems well offshore.
Canadian high pressure then builds in from the north and west
to close out the work week, with the center of the high
gradually passing north of the region on Saturday before moving
offshore on Sunday. Dry conditions expected for the end of the
week and into the weekend with temperatures running several
degrees below normal. Highs will top off in the upper 70s to
around 80 from Thursday through Sunday, and lows will drop into
the upper 50s to low 60s, except cooler up north.
Aviation 20z Sunday through Friday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Vfr conditions. There is a low chance of patchy fog development
towards daybreak tonight but with drier conditions expect any
development to be limited. Westerly winds through this afternoon|
will gradually become light southwesterly then light and
variable as high pressure shifts across the area.
By Monday, high pressure will shift offshore allowing southerly
flow to strengthen to around 5-10 kt through the afternoon.
Showers and thunderstorms will be possible by afternoon-evening,
mainly to the south and west of kphi.
Monday night... Sub-vfr conditions possible in scattered
shra tsra. Fog stratus also possible with sub-vfr conditions.
Tuesday... Morning fog stratus burns off, then predominantly
vfr. Scattered shra tsra develop late in the day and at night
with sub-vfr conditions.
Wednesday... Sub-vfr conditions in showers thunderstorms, which
taper off late in the day. A wind shift from S to NW likely late
in the day with the passage of a cold front.
Thursday through Friday...VFR and light winds.
Winds and seas remain tranquil across the waters through Monday
as high pressure gradually shifts offshore. Seas will remain
two feet or less through Monday afternoon, with a few 3 foot
seas possible off the northern nj coast by evening as southerly
winds begin to strengthen.
Monday night... Winds and seas below SCA thresholds.
Tuesday... SCA possible late afternoon and night with S winds
increasing to around 25 kt ahead of cold front. Building seas
to 4-6 ft are forecast for the atlantic coastal waters.
Wednesday... Winds should decrease to below 25 kt but sca
conditions may continue into the morning as it may take longer
for seas in the coastal waters to drop below 5 ft.
Thursday through Friday... No marine hazards expected.
Winds will be northwest this afternoon before turning to the
southwest this evening. The overall risk for today looks to be
low at both the delaware beaches and the new jersey shore but
with a more southwesterly flow developing a few of the more
prone locations, like lbi, may see a slightly increased risk
through this evening.
The outlook for tomorrow is continued low risk. However, this
will be reevaluated later this evening as factors such as wind
direction, new moon, and an increasing period will be increasing
the risk, but not sure yet if it will be moderate tomorrow.
Tides coastal flooding
Minor coastal flooding is possible at the high tide Monday
evening. With high pressure offshore, onshore will winds
develop, and this will coincide with relatively high
astronomical tides due to a new moon. Latest guidance is showing
water levels just touching minor coastal flooding thresholds.
Phi watches warnings advisories
near term... 99
short term... 99
long term... Mps
aviation... Mps 99
marine... Johnson mps 99
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|
|CHCM2 - 8573927 - Chesapeake City, MD||6 mi||42 min||WNW 5.1 G 7||82°F||83°F||1019.5 hPa|
|44057 - Susquehanna, MD||12 mi||32 min||N 5.8 G 7.8||82°F||1019.4 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||17 mi||42 min||83°F||82°F||1018.8 hPa|
|DELD1 - 8551762 - Delaware City, DE||17 mi||42 min||WNW 6 G 8.9||83°F||79°F||1019.1 hPa|
|TCBM2 - 8573364 - Tolchester Beach, MD||26 mi||42 min||W 1 G 1.9||82°F||82°F||1019.8 hPa|
|SJSN4 - 8537121 - Ship John Shoal, NJ||28 mi||42 min||NW 6 G 8.9||81°F||80°F||1018.8 hPa|
|MRCP1 - 8540433 - Marcus Hook, PA||34 mi||42 min||84°F||1018.6 hPa|
|DRSD1 - Delaware Reserve, DE||34 mi||102 min||W 4.1||83°F||1019 hPa||63°F|
|44043 - Patapsco, MD||35 mi||32 min||ESE 1.9 G 3.9||81°F||1020.4 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||39 mi||42 min||SE 6 G 8||81°F||1019.2 hPa|
|BLTM2 - 8574680 - Baltimore, MD||40 mi||42 min||N 1.9 G 8.9||85°F||82°F||1018.8 hPa|
|CPVM2||42 mi||42 min||81°F||64°F|
|44063 - Annapolis||46 mi||32 min||NW 3.9 G 5.8|
|APAM2 - 8575512 - Annapolis, MD||46 mi||42 min||81°F||1019 hPa|
|TPLM2 - Thomas Point, MD||49 mi||72 min||E 2.9 G 2.9||80°F||81°F|
Wind History for Chesapeake City, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Phillips Army Air Field / Aberdeen, MD||16 mi||74 min||NNW 4||10.00 mi||Fair||83°F||61°F||48%||1019.9 hPa|
|Wilmington, New Castle County Airport, DE||21 mi||21 min||W 10||10.00 mi||Fair||84°F||62°F||48%||1019.3 hPa|
Wind History from APG (wind in knots)
|1 day ago||S||NW||NE||S||Calm||Calm||S||W||W||W||W||W||Calm||Calm||W||NW||NW||Calm||NW||W||SW||N||W||W|
|2 days ago||E||S||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||S||S||S||S||S||SW||SW||SW||SW||S||S||S||S |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Old Town Point Wharf |
Click for Map
Sun -- 02:24 AM EDT 0.57 feet Low Tide
Sun -- 04:56 AM EDT Moonrise
Sun -- 06:21 AM EDT Sunrise
Sun -- 09:19 AM EDT 3.86 feet High Tide
Sun -- 04:12 PM EDT 0.90 feet Low Tide
Sun -- 07:14 PM EDT Moonset
Sun -- 07:52 PM EDT Sunset
Sun -- 09:30 PM EDT 2.69 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Chesapeake and Delaware Canal |
Click for Map
Sun -- 03:47 AM EDT 0.02 knots Slack
Sun -- 04:55 AM EDT Moonrise
Sun -- 06:20 AM EDT Sunrise
Sun -- 06:35 AM EDT 2.35 knots Max Flood
Sun -- 10:18 AM EDT -0.09 knots Slack
Sun -- 12:35 PM EDT -1.64 knots Max Ebb
Sun -- 03:50 PM EDT 0.08 knots Slack
Sun -- 06:39 PM EDT 2.05 knots Max Flood
Sun -- 07:14 PM EDT Moonset
Sun -- 07:51 PM EDT Sunset
Sun -- 09:16 PM EDT -0.04 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 (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.