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 6:23AM||Sunset 7:51PM||Monday August 21, 2017 11:32 PM EDT (03:32 UTC)||Moonrise 5:06AM||Moonset 6:56PM||Illumination 0%|
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|ANZ540 Eastern Bay- 1031 Pm Edt Mon Aug 21 2017 |
.small craft advisory in effect until 6 am edt Tuesday...
.small craft advisory in effect from Tuesday afternoon through Tuesday evening...
Rest of tonight..S winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft. Isolated showers late this evening, then a slight chance of showers and tstms.
Tue..S winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft.
Tue night..SW winds 10 to 15 kt with gusts to 20 kt...becoming W 5 to 10 kt late. Waves 2 ft.
Wed..NW winds 5 to 10 kt. Waves 1 ft.
Wed night..N winds 5 to 10 kt. Waves 1 ft or less.
Thu..N winds 5 to 10 kt. Waves 1 ft.
Thu night..N winds 5 kt. Waves flat.
Fri..N winds 5 to 10 kt. Waves 1 ft.
Sat..NE winds 5 to 10 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 1031 Pm Edt Mon Aug 21 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will remain 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.
7 Day Forecast for Marine Location Near Cordova, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 220139|
area forecast discussion
national weather service mount holly nj
939 pm edt Mon aug 21 2017
High pressure will be centered in the western atlantic through
Tuesday. A warm front resides in eastern pennsylvania. A cold front
will approach from the west late Tuesday and slowly exit off the
coast on Wednesday. Canadian high pressure builds into the region on
Thursday and should to be the primary influence on our weather into
Near term until 6 am Tuesday morning
A subtle short wave slides across our area tonight and some
convection continues with it. The convection has struggled to
make much progress eastward across our forecast area this
evening, and the most unstable air is mainly west of i-95. While
some convection cannot be ruled out into the overnight hours
farther east, confidence is low on the extent of this. We
continue with some slight chance to chance pops for awhile
longer, but these do decrease through the overnight. Looks like
the main threat from any slower moving convection now is mainly
locally heavy rain.
The pops were adjusted based on radar trends, then these were
lowered overnight. The hourly temperature, dew point and wind
grids were adjusted with the latest observations then the lamp
guidance was blended in for the next few hours. Some local
temperatures dropped faster so far, especially where any rain
occurred and where less cloud cover has persisted. Otherwise,
some mid to high level clouds around however with plenty of low-
level moisture around some low clouds and or fog may develop.
The extent of this however at this time is of lower confidence.
Short term 6 am Tuesday morning through 6 pm Tuesday
Some changes were made with the 630 pm update. This was to slow
down the pop increase quite a bit eastward during the day.
While a few storms may initiate inland from the coast in the
afternoon, the majority of the guidance indicates we need to
wait for more organized convection incoming from the west later
in the afternoon. This is when the main forcing starts to
Otherwise, initially potentially more cloudiness and some fog may
start the day which would then scatter out as the low levels begin
to mix. Southerly flow will strengthen ahead of an approaching upper
trough and its attendant cold front, leading to warm moist advection
and heat indices to around 100 degrees for the urban corridor from
wilmington to philadelphia and trend then up to the nyc metro. A
heat advisory is valid from 1 pm through 8 pm Tuesday. The other
areas look to fall short of the advisory criteria.
Apart from the heat, there will be increasing chances of
thunderstorms toward evening as the upper trough approaches the
area, though the primary forcing for ascent and best chance for any
development will largely be to the north and west. At the moment,
some of the deterministic models seem a bit overdone with overall
convective coverage. Have sided more with higher resolution data
showing the best chance of thunderstorms over higher terrain in the
afternoon. Modest flow with veering profiles will once again support
the potential for strong to severe storms capable of damaging winds
and heavy rainfall toward late day.
Long term Tuesday night through Monday
500 mb: troughing in the great lakes region during midweek... Will
shift into the northeast Friday through this weekend.
Temperatures: the month of august so far has averaged within a degree
of normal except mount pocono where the monthly average was 2.5
degrees below. So... Calendar day averages should still be a few
degrees above normal Wednesday, then from from Thursday through next
Monday should average 2 to 6 degrees below normal on a daily basis.
Forecast basis: a 50 50 blend of 12z 21 GFS nam MOS was used
Tuesday night-Wednesday night, then, unless otherwise noted,
the 12z 21 GFS mexmos was applied Thursday and thereafter the
15z 21 wpc d4-8 gridded elements of MAX min t, 12 hr pop 6 hrly
dew wind sky.
Just tucking this in here... Since I didnt think this warranted
a climate section on its own...
abe 7.94" of rain so far in august ranks #12 when compared to
complete month of august totals at allentown, 13.47 in 2011 is
the record. Records date back to 1912 except we are missing
1920 and 1921.
Tuesday night... Svr potential early in decent mlc of over
1000j more than adequate 0-6km bulk shear (near 45kt), pwat air
of 1.8 inches with residual showers overnight. Low temps about
9 to 12f above normal. The eastward sweep of svr should be
primarily i-78 north. Strong westerly flow at mid levels
(40-45kt 700-500mb) should drive a decent lines of showers and
tstms across the area as per the 15z hrrrx. Least likely area
for any tstms is probably southeast of phl across far S nj and
de. The 1703z d2 SPC outlook didn't change from the 06z vsn.
Wednesday... The cold front will likely slow down when it reaches
delmarva and perhaps eventually stall just south of the area
across southern va Wednesday afternoon. Accordingly, it is
looking more probable that the majority of the forecast area
dries out on Wednesday, especially north of the mason-dixon
line. The uk is pretty wet on Wednesday in the SE 1 2 of our
fcst area and... The ec looks pretty unstable. So... Opted for a
sref wetter blend to the 12z 21 ops pops... Which means continuity
with the mid shift fcst.|
Wednesday night-Monday... High pressure over canada and the
great lakes region then starts to build southeastward toward the
area on Thursday. This expansive high should remain in control
through at least this weekend. The end result will be an
extended stretch of pleasant weather Thursday through Monday.
Highs in the upper 70s lower 80s and and lows ranging from the
50s to lower 60s are forecast each day and night (possibly some
upper 40s), respectively. While the forecast remains dry for
these four days, there looks to be increasing cloud cover
heading into the weekend and potentially a risk for an isolated
shower with 1) the approach of the upper trough and 2) light
onshore flow helping to moisten low-levels over time.
Aviation 02z Tuesday through Saturday
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Rest of tonight... Some lingering showers thunderstorms mainly
west of kphl should weaken dissipate overnight. However, an
isolated shower or storm cannot be ruled out overnight. Mainly
vfr, although some localized MVFR this evening. Some areas of
MVFR ifr conditions due to fog and or stratus may then occur
overnight and toward daybreak. The extent of the low clouds and
fog is of lower confidence. Southerly winds less than 10 knots,
becoming light and variable at most terminals.
Tuesday... Sub-vfr conditions possible early for some areas due
to fog and or stratus, otherwiseVFR. Showers and thunderstorms
are expected to develop to our west in the afternoon, however
these may approach krdg and kabe toward early evening. Light
winds, becoming southwest and increasing to 10-15 knots (local
gusts up to 20 knots possible in the afternoon).
Tuesday night... Potential for MVFR or ifr restrictions with
showers and isolated storms. This activity should progress to
the east- southeast through the night.
Wednesday... Scattered showers and isolated thunderstorms mainly
for terminals S E of phl and earlier in the day. May start off
MVFR with lower CIGS but improvement toVFR is likely from NW to
se during the day. A wind shift from SW to NW can be expected
early in the day W fropa.
Wednesday night through Saturday...VFR and generally light
winds. Cannot rule out an isolated sprinkle each afternoon or
Winds and seas remain tranquil across the waters tonight in weak
southerly flow. Patchy fog development is possible overnight.
An isolated shower or thunderstorm is also possible overnight.
Tuesday... SCA for the atlantic coastal waters of nj and de
starting mid afternoon. S-sw winds are expected to strengthen
late in the day to 15-25 kt. Some gusts to 30 kt are possible
mainly late in the day when the winds will be strongest. Seas
will build to 4-6 feet in response to the wind field.
Tuesday night... SCA continues for the atlantic coastal waters
of nj and de. S-sw winds with isolated gusts to 30 kt possible
mainly during the evening when the winds will be strongest. Seas
build to 4-6 feet in response to the wind field.
Wednesday... A wind shift from SW to w-nw should occur on Wednesday
behind a cold front. Winds will also decrease as well. There is
still a possibility that the SCA may need to be extended into
Wednesday morning if seas take a bit longer to subside below 5
Thursday through Saturday... Winds and seas below SCA criteria.
a south to southwest wind will increase during the day Tuesday,
which will also allow the surf to increase some. Given a more
parallel wind to the coast overall, this should keep the rip current
risk reduced some. However, if a longer period swell becomes more
dominant then this may elevate the rip current risk more. Based
on this and in-house guidance, we went with a moderate risk of
rip currents for Tuesday. This will be re-evaluated early Tuesday
Phi watches warnings advisories
Pa... Heat advisory from 1 pm to 8 pm edt Tuesday for paz070-071-102-
Nj... Heat advisory from 1 pm to 8 pm edt Tuesday for njz010-012-015-
De... Heat advisory from 1 pm to 8 pm edt Tuesday for dez001.
Marine... Small craft advisory from 3 pm Tuesday to 6 am edt Wednesday
near term... Di spigna gorse
short term... Di spigna gorse
long term... Drag
aviation... Drag gorse
marine... Drag di spigna
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||17 mi||45 min||80°F||78°F|
|TPLM2 - Thomas Point, MD||18 mi||33 min||SSW 9.9 G 11||79°F||81°F|
|44063 - Annapolis||19 mi||33 min||SSE 5.8 G 7.8||82°F|
|APAM2 - 8575512 - Annapolis, MD||21 mi||45 min||78°F||1019.5 hPa|
|44043 - Patapsco, MD||23 mi||33 min||SSW 9.7 G 14||79°F||81°F||1019.9 hPa (+0.0)|
|CA2 - 8571892 - Cambridge, MD||23 mi||45 min||79°F||83°F||1021.3 hPa|
|TCBM2 - 8573364 - Tolchester Beach, MD||23 mi||45 min||S 4.1 G 6||77°F||82°F||1019.9 hPa|
|44062 - Gooses Reef, MD||29 mi||33 min||SSW 7.8 G 7.8||80°F||81°F||1 ft||1020.9 hPa (+0.3)|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||32 mi||45 min||S 8 G 9.9||77°F||1019.5 hPa|
|BSLM2 - Chesapeake Bay, MD||33 mi||123 min||SW 1||71°F||1020 hPa||69°F|
|BLTM2 - 8574680 - Baltimore, MD||36 mi||45 min||SW 1.9 G 4.1||76°F||84°F||1019.5 hPa|
|DRSD1 - Delaware Reserve, DE||37 mi||123 min||SSE 1.9||76°F||1021 hPa||74°F|
|COVM2 - 8577018 - Cove Point LNG Pier, MD||38 mi||45 min||SSW 6 G 8||79°F||1021.1 hPa|
|44057 - Susquehanna, MD||44 mi||33 min||SW 3.9 G 3.9||79°F||81°F||1019.5 hPa (-0.3)|
|SLIM2 - 8577330 - Solomons Island, MD||44 mi||51 min||S 4.1 G 5.1||79°F||83°F|
|CHCM2 - 8573927 - Chesapeake City, MD||46 mi||51 min||S 1.9 G 5.1||76°F||84°F||1020 hPa|
|SJSN4 - 8537121 - Ship John Shoal, NJ||47 mi||45 min||S 8.9 G 9.9||79°F||80°F||1019.8 hPa|
|BISM2 - 8571421 - Bishops Head, MD||47 mi||45 min||S 12 G 16||82°F||82°F||1020.9 hPa|
|WASD2 - 8594900 - Washington, DC||49 mi||45 min||SSW 4.1 G 5.1||78°F||83°F||1019.5 hPa|
Wind History for Tolchester Beach, MD(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Easton / Newman Field, MD||7 mi||34 min||SSW 3||10.00 mi||Fair||78°F||73°F||86%||1021.7 hPa|
|Bay Bridge Field, MD||13 mi||48 min||SSW 4||10.00 mi||Fair||77°F||73°F||89%||1020 hPa|
|Annapolis, United States Naval Academy, MD||21 mi||39 min||S 3||8.00 mi||Fair||78°F||75°F||93%||1020.1 hPa|
Wind History from ESN (wind in knots)
|1 day ago||SW||Calm||Calm||Calm||Calm||Calm||Calm||Calm|
|2 days ago||SW||W||Calm||Calm||NW||Calm||Calm||N |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Wye Landing |
Click for Map
Mon -- 04:52 AM EDT 2.41 feet High Tide
Mon -- 06:05 AM EDT Moonrise
Mon -- 06:23 AM EDT Sunrise
Mon -- 12:15 PM EDT 0.52 feet Low Tide
Mon -- 02:31 PM EDT New Moon
Mon -- 05:07 PM EDT 1.81 feet High Tide
Mon -- 07:50 PM EDT Sunset
Mon -- 07:56 PM EDT Moonset
Mon -- 11:42 PM EDT 0.40 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Baltimore Harbor Approach |
Click for Map
Mon -- 01:42 AM EDT 0.00 knots Slack
Mon -- 05:11 AM EDT 1.15 knots Max Flood
Mon -- 06:06 AM EDT Moonrise
Mon -- 06:24 AM EDT Sunrise
Mon -- 08:31 AM EDT -0.00 knots Slack
Mon -- 11:43 AM EDT -1.08 knots Max Ebb
Mon -- 02:31 PM EDT New Moon
Mon -- 03:06 PM EDT 0.00 knots Slack
Mon -- 05:53 PM EDT 0.79 knots Max Flood
Mon -- 07:51 PM EDT Sunset
Mon -- 07:57 PM EDT Moonset
Mon -- 08:46 PM EDT -0.00 knots Slack
Mon -- 11:47 PM EDT -0.85 knots Max Ebb
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 (23,6,7,8)(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.