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 8:34PM||Wednesday June 20, 2018 9:38 AM EDT (13:38 UTC)||Moonrise 12:16PM||Moonset 12:17AM||Illumination 46%|
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|ANZ539 Chester River To Queenstown Md- 731 Am Edt Wed Jun 20 2018 |
Today..SE winds 5 kt. Waves less than 1 ft. Isolated showers and tstms this afternoon.
Tonight..W winds 5 to 10 kt. Waves 1 ft. Showers and tstms likely. Vsby 1 to 3 nm.
Thu..N winds 5 to 10 kt. Waves 1 ft.
Thu night..NE winds 5 kt. Waves less than 1 ft.
Fri..E winds 5 to 10 kt. Waves 1 ft. A chance of showers.
Fri night..E winds 10 kt. Waves 1 ft. Showers likely.
Sat..S winds 10 to 15 kt...becoming W 5 to 10 kt. Waves 1 to 2 ft. Showers and tstms likely.
Sun..NW winds 5 to 10 kt. Waves 1 ft. A chance of tstms. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 731 Am Edt Wed Jun 20 2018 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will track from west virginia east over the waters along a stalled front through tonight. The front will then drop farther south Thursday as high pressure briefly builds from the ohio valley to new england. The front will then return north as a warm front Friday night into Saturday as the high moves offshore and low pressure moves from the midwest to the great lakes. A small craft advisory may be needed for a portion of the waters Friday into Saturday.
7 Day Forecast for Marine Location Near Greensboro, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 200800|
area forecast discussion
national weather service mount holly nj
400 am edt Wed jun 20 2018
Low pressure over the ohio valley today and its associated fronts
will traverse the region tonight. Canadian high pressure moves
into the area Thursday into Friday. Low pressure moving from the
eastern great lakes into northern new england will lift a warm
through the region on Saturday, followed by a cold frontal
passage Saturday night. A sprawling area of canadian high
pressure builds into the area Sunday through Tuesday.
Near term until 6 pm this evening
A west-east oriented front was nearly stationary over the ohio
valley, potomac basin, and DELMARVA region. This boundary was rather
diffuse but there was a north-south moisture gradient evident near
the front with surface dewpoints in 70s to the south and 50s to the
north. Farther west along the front, a weak area of low pressure was
forming over the midwest. This surface low will track eastward
today, reaching the SW pa-e wv-w md border late in the day. Light s-
sw winds ahead of this low will allow the front to lift northward
into SE pa and c nj this afternoon.
The models have been rather persistent with the development of low
clouds and or fog over the lower DELMARVA and nearshore waters
overnight, which has occurred. With light southeasterly flow just to
the east of a low-level trough axis, expect this area of stratus and
fog to expand gradually into S de and far S nj early this morning
before dissipating mid to late morning. Following variable sky cover
elsewhere across the area to start, the trend will be for increasing
clouds as the day progresses.
Following a dry morning, showers will likely start to overspread ne
pa and NW nj late in the afternoon. An isolated pop-up shower or
storm cannot be ruled out in the de-nj coastal plain during peak
heating this afternoon where higher dewpoints and instability will
High temperatures will generally be in the 70s north of the warm
front (ne pa and NW nj) and near the coast, and low to mid 80s
Short term 6 pm this evening through 6 am Thursday
Low pressure is expected to track eastward near the mason-dixon line
tonight. Meanwhile, high pressure centered along the quebec-ontario
border will build southeastward.
Northerly flow around the surging high and southerly flow just
downstream of the surface low and attendant low- mid-level shortwave
trough will strengthen convergence and lead to frontogenesis near
the front. This will set the stage for a rainy night across much of
the area. With pwats approaching 2", modest instability to enhance
convective updrafts, and a focus for enhanced lift along and north
of the front, there is a potential for a band of heavy rainfall to
develop mainly during the overnight in similar fashion to what
happened on the night of june 10-11. However, both the synoptic- and
mesoscale dynamics do not appear to quite as robust and stationary
tonight as it was during the flash flood event in SE pa and S nj ten
days ago. After coordination with surrounding offices and wpc, we
opted to hold off on a flash flood watch at this point. Although
there is some uncertainty regarding where this potentially narrow
band of heavy rain sets up, the best guess would be somewhere
between i-78 and the mason-dixon line. Locally heavy rainfall
amounts of 2-3" are not out of the question. Depending on where this
heavy rain falls, the response can vary between minor poor drainage
flooding and flash flooding with the greatest risk for the latter
type being if it falls over urban areas.
Long term Thursday through Tuesday
Highlights include lingering showers on Thursday due to a slow
moving cold front, especially southeast of i-95. More substantial
precipitation is likely late Friday into Saturday, with a chance of
thunderstorms. There is another chance of showers on Sunday, with a
drying trend taking hold for the early part of next week. While an
onshore at times will make for cooler temperatures down the shore,
for the remainder of the area, temperatures at or slightly above
normal through the period.
Synoptically, a cyclonic flow associated with a northern stream
trough pulls away from the region on Thursday. Meanwhile, a closed
low over the middle mississippi valley will eject northeastward into
the eastern great lakes by Friday. This sets the stage for a deep
layer southwest flow Friday night into Saturday, until the shortwave
associated with the aforementioned low moves across the region. But
the longwave trough remains to our west until at least Sunday, and
will be followed by broad mid-level ridging on Monday and Tuesday.
Thursday... The guidance is in good agreement on weak low pressure
developing along a cold front across southern de md, slowing the
forward progress of this boundary. In addition, there is sufficient
instability for thunder, but weak shear will preclude the potential
for stronger thunderstorms. With the boundary providing a source of
lift, precipitable water values near 2.0 inches, and slow cell
motions, heavy downpours are likely across de md and far southern
nj, with the potential for poor drainage flooding. Elsewhere, a
chance of showers into the afternoon south of an i-95 to i-195 line.
North of this area, a more pleasant day is in store with increasing
Thursday night... A dry night is expected with brief ridging aloft.
In spite of the recent rainfall, winds should be elevated enough
to preclude the development of fog, and this is also supported by
model algorithms. But cannot rule out limited fog in the more
sheltered locations of the lehigh valley and southern poconos.
Friday... Onshore flow develops between high pressure south of nova
scotia and a northward advancing warm front to our south. This will
promote an overunning regime, but with high pressure providing a
source of dry low-level air, the question is just how fast does the|
column saturate? The GFS is the most progressive in bringing precip
across the region during the day, while the remainder of the model
suite holds off until Friday night. For now, increased pops across
extreme southeast pa and de to slight chance and the eastern shore
of md to chance. With the proximity of the warm front and increasing
instability, inserted a slight chance of thunder across the eastern
shore of md during the afternoon and evening.
Friday night through Saturday night... A deep layer southwesterly
flow will setup out ahead of the next shortwave, with precipitable
water values again increasing to around 2.0 inches. Expect strong
isentropic lift just north of the warm front to produce widespread
rainfall Friday night, which will be heavy at times, leading to the
potential for poor drainage flooding. By Saturday, much of the area
will be within the warm sector, and our attention turns to the
potential for convection with the approaching cold front. During the
afternoon and evening, surface based CAPE increases to 2000 j kg and
bulk shear reaches 50 kts. But lapse rates may be weak and a large
amount of mid-level dry air may work in, limiting both convective
potential and coverage. In any event, there is the potential
for strong winds with thunderstorms that develop.
Sunday through Tuesday... A chance of lingering showers and
isolated thunder on Sunday. Then a return to fair weather for
Monday and Tuesday.
Aviation 08z Wednesday through Sunday
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
This morning... Low clouds and fog has developed over the lower
delmarva and nearshore waters. This may expand northward into acy
and possibly miv toward daybreak. Low-end MVFR or ifr conditions
would develop if this occurs. Farther N W toward the i-95 terminals,
expectVFR. Light N winds will become NE after sunrise and then se
This afternoon... Increasing clouds butVFR is favored. Shra may
overspread abe (lesser chances farther south) mid to late afternoon.
Se winds 5-10 kt will become s-sw.
Tonight... Shra start to overspread the area this evening. This
activity may become widespread and moderate to heavy at times
overnight, resulting in MVFR to locally ifr vsby restriction. Cigs
may lower to MVFR late this evening and then to near MVFR-ifr
thresholds overnight. Winds will be light and variable.
Thursday and Thursday night... MVFR ceilings at acy and miv, with
northeast wind gusts up to 20 mph. Elsewhere,VFR. Medium confidence.
Friday... PredominantlyVFR. Cannot rule out brief MVFR ceilings in
shra. Easterly wind gusts up to 20 mph, especially acy and phl.
Friday night... Low clouds and fog will lead MVFR, with ifr possible,
especially late. Easterly wind gusts up to 20 mph. Low confidence.
Saturday... Conditions gradually improving to MVFR, withVFR possible
by afternoon, especially i-95 corridor terminals. But shra and tsra
will lead to brief ceiling visibility restrictions. Southwest winds.
Saturday night... A return to low clouds and fog with MVFR, and even
ifr possible. Winds shifting to the northwest. Low confidence.
Sunday... Low clouds and fog will dissipate with a return toVFR.
Winds west-southwest. Medium confidence.
Winds and seas below SCA criteria today and tonight. Periods of
moderate to locally heavy rain and thunderstorms are likely late
winds and seas may reach SCA levels Thursday night as low pressure
develops offshore. The pressure gradient between high pressure to
the north and an approaching warm front to the south likely leads to
continued SCA winds seas Friday and Friday night. As the warm front
moves across the waters, a brisk southwest flow promotes SCA level
seas through at least Saturday. A return to more tranquil, sub-sca
boating conditions is expected Sunday into early next week.
a low risk for the development of dangerous rip currents is expected
today at the nj and de beaches.
Phi watches warnings advisories
near term... Klein
short term... Klein
long term... Lf
aviation... Klein lf
marine... Klein lf
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||22 mi||128 min||Calm||75°F||1012 hPa||75°F|
|TCBM2 - 8573364 - Tolchester Beach, MD||28 mi||50 min||NNE 2.9 G 4.1||75°F||78°F||1012.3 hPa|
|CA2 - 8571892 - Cambridge, MD||30 mi||50 min||75°F||81°F||1012.8 hPa|
|CPVM2||30 mi||50 min||75°F||59°F|
|TPLM2 - Thomas Point, MD||33 mi||98 min||NNE 9.9 G 9.9||73°F||76°F||1012.7 hPa (+0.8)||60°F|
|44063 - Annapolis||33 mi||38 min||NE 5.8 G 7.8||74°F||76°F||1 ft||1012.4 hPa (+0.5)|
|APAM2 - 8575512 - Annapolis, MD||35 mi||50 min||1011.6 hPa|
|BRND1 - 8555889 - Brandywine Shoal Light, DE||37 mi||50 min||ESE 7 G 8||74°F||1012.2 hPa|
|CHCM2 - 8573927 - Chesapeake City, MD||38 mi||50 min||E 4.1 G 6||74°F||79°F||1012.2 hPa|
|LWSD1 - 8557380 - Lewes, DE||39 mi||56 min||ESE 6 G 8||75°F||71°F||1011.7 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||41 mi||50 min||NNE 4.1 G 5.1||74°F||1011.9 hPa|
|FSNM2||41 mi||50 min||NE 4.1 G 5.1||74°F||1011.9 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||43 mi||50 min||74°F||76°F||1011.3 hPa|
|44062 - Gooses Reef, MD||43 mi||38 min||ENE 5.8 G 7.8||75°F||77°F||1 ft||1012.9 hPa (+1.1)|
|DELD1 - 8551762 - Delaware City, DE||44 mi||50 min||NNW 1.9 G 5.1||74°F||72°F||1012 hPa|
|BLTM2 - 8574680 - Baltimore, MD||45 mi||50 min||ENE 4.1 G 5.1||78°F||1011.8 hPa|
|CMAN4 - 8536110 - Cape May, NJ||46 mi||50 min||E 6 G 8||75°F||72°F||1011.3 hPa|
|COVM2 - 8577018 - Cove Point LNG Pier, MD||49 mi||50 min||NE 5.1 G 6||75°F||1012.4 hPa|
|BSLM2 - Chesapeake Bay, MD||49 mi||128 min||Calm||58°F||1012 hPa||57°F|
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||17 mi||50 min||N 0||10.00 mi||A Few Clouds||77°F||69°F||79%||1013.2 hPa|
|Dover Air Force Base, DE||22 mi||42 min||SE 4||10.00 mi||Mostly Cloudy||75°F||72°F||90%||1012.1 hPa|
Wind History from ESN (wind in knots)
|1 day ago||Calm||W||SW||SW||SW||SW||SW||SW||SW||SW||SW||SW||SW||SW||SW||SW||SW||W||W||SW||W||W||W|
|2 days ago||Calm||Calm||S||E||Calm||SW||SW||W||W||Calm||E||SE||SE||S||S||S||Calm||S||Calm||Calm||Calm||Calm||Calm||Calm|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
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Wed -- 01:17 AM EDT Moonset
Wed -- 02:17 AM EDT 3.54 feet High Tide
Wed -- 05:37 AM EDT Sunrise
Wed -- 06:52 AM EDT First Quarter
Wed -- 08:41 AM EDT 1.24 feet Low Tide
Wed -- 01:15 PM EDT Moonrise
Wed -- 02:24 PM EDT 3.64 feet High Tide
Wed -- 08:32 PM EDT Sunset
Wed -- 09:16 PM EDT 0.75 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
Click for Map
Wed -- 01:12 AM EDT 3.09 feet High Tide
Wed -- 01:17 AM EDT Moonset
Wed -- 05:38 AM EDT Sunrise
Wed -- 06:52 AM EDT First Quarter
Wed -- 07:55 AM EDT 1.08 feet Low Tide
Wed -- 01:15 PM EDT Moonrise
Wed -- 01:19 PM EDT 3.18 feet High Tide
Wed -- 08:30 PM EDT 0.65 feet Low Tide
Wed -- 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 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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Wind Forecast for Philadelphia/Mount Holly, PA (9,2,3,4)(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.