Marine Weather and Tides
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.
|Sunrise 6:04AM||Sunset 7:59PM||Sunday April 30, 2017 10:55 AM EDT (14:55 UTC)||Moonrise 8:55AM||Moonset 11:41PM||Illumination 21%|
EDIT (on/off)  Help
|ANZ530 Chesapeake Bay North Of Pooles Island- 1049 Am Edt Sun Apr 30 2017 |
.small craft advisory in effect from Monday morning through Monday afternoon...
Rest of today..E winds 10 kt. Waves 1 ft.
Tonight..SE winds 10 to 15 kt. Waves 1 ft. Patchy fog. Vsby 1 to 3 nm.
Mon..S winds 10 to 15 kt with gusts to 25 kt. Waves 1 to 2 ft.
Mon night..SW winds 15 to 20 kt with gusts to 25 kt. Waves 2 ft. Showers likely with a chance of tstms.
Tue..SW winds 10 to 15 kt with gusts to 25 kt. Waves 1 to 2 ft.
Tue night..W winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft.
Wed..N winds 5 to 10 kt. Waves 1 ft or less.
Thu..SE winds 5 to 10 kt. Waves 1 ft. Showers. Winds and waves higher and visibilities lower in and near tstms.
|ANZ500 1049 Am Edt Sun Apr 30 2017 |
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A backdoor cold front will stall over the area today, and retreat northward tonight. A stronger cold front will approach from the west Monday before passing through Monday night. High pressure will build overhead Tuesday into Wednesday. Low pressure may impact the waters late in the week. A small craft advisory will likely be needed for the waters Monday night and Tuesday.
7 Day Forecast for Marine Location Near Fairlee, MDHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 301251|
area forecast discussion
national weather service mount holly nj
851 am edt Sun apr 30 2017
A front to our south today will lift northward tonight into Monday
morning as a warm front. A cold front is expected Monday night as an
area of low pressure moves into the great lakes region. This low
will drift northeastward across eastern canada through mid week.
Another low pressure system will lift out of the lower mississippi
valley towards the mid atlantic by late in the week.
Near term /until 6 pm this evening/
A cold front has pretty much cleared our area to the south early
this morning, with a northeast wind in its wake. Some short wave
energy tracking to our west is producing some showers and thunder
well to our west. However, a few showers may clip our far western
zones this morning. The remainder of the day is expected to be dry
with lots of cloud cover. Some drying however is trying to work in
from the north-northeast, but the clouds should dominate. Some
showers and thunderstorms may develop well to our west during
the afternoon, but they may dissipate as they approach our area.
Our region will be under a northeast to east flow today. This will
keep temperatures much cooler than they were on Saturday, with highs
expected to be about 20 degrees cooler. There will a more noticeable
breeze and even cooler temperatures along the coast.
A quick update was issued to adjust the temperature, dew point and
wind grids. The slight chance pops were removed for much of the
area, and thunder was also removed.
Short term /6 pm this evening through 6 am Monday/
The frontal boundary to our south is expected to begin lifting
northward as a warm front overnight tonight into Monday morning. As
the front begins to lift into our area after sunset and overnight, a
couple of short wave/vorticity impulses are forecast to move across
the area as well. Typically with a warm front lifting across the
area, we would expect fog to develop, and possibly become dense. But
with the short wave/vorticity impulse, there will be some lift
across the area and there is the potential for some showers to
develop. With this turbulent air and a steady enough of a breeze,
while there will likely be some fog develop, we do not have any
dense fog forecast at this time. Another possibility overnight in
addition to the light fog is for some patchy drizzle to form. This
would most likely be for the northern half of the area north of the
lifting warm front.
Long term /Monday through Saturday/
Monday... Increasing southerly flow is expected in advance of the
cold front Monday night. This will enhance the warm air
advection that will already be occuring in the wake of the warm
front tonight. Thus, expect temperatures to be 10 to 15 degrees
above normal, with highs generally in the 70s and low 80s.
Depending on how quickly the ridge moves further off shore and
how quickly the cold front approaches the region, we could start
to see showers and storms propagate into eastern pa late in the
Monday night... Cold front still on track to sweep through the
region late Monday night. Given the timing of the frontal
passage, low level lapse rates will be limited just ahead of the
front, which will limit instability (though there may still be
some surface based cape). However, 0-6km shear values will be
relatively high... On the order of 40 to 60 kt. This could lead
to a low cape/high shear set up for severe winds. However, this
is far from certain as if the inversion Monday night is stronger
than model soundings currently show, this could inhibit strong
winds mixing down to the surface altogether (similar to what we
saw with the storms last night). Additionally, precipitable
water values in the warm sector will be quite high. Expect the
threat for heavy downpours will be quite high, but the fast
storm motions should limit the flooding threat to poor drainage
Tuesday and Wednesday... In the wake of the cold front,
temperatures will be about 5 to 10 degrees lower, with highs
generally in the 60s and 70s. Models have trended faster with
the dry air advection behind the front, so I trimmed back on
the pops on Tuesday. It is looking mostly dry both days.
Thursday through Saturday... A warm front is expected to lift
north through the region Thursday or Thursday night. This will
be the start of the unsettled late week pattern. The biggest
question with this pattern is the evolution of the mid and upper
level low. The previous ECMWF showed the low becoming cutoff
over the lower mississippi valley. However, with the 00z run, it
has come closer to the GFS (which has stayed relatively
consistent with the last few runs). Both models depict the low
closing, deepening, and intensifying as it lifts northeast
through this period. However, there remain large differences in
the track and timing. For now, have stayed close to the previous
forecast and a consensus of guidance, with mostly medium chance
of precip, except Thursday night into Friday, with likely pops.
Aviation /13z Sunday through Thursday/
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Today...VFR ceilings around 4000 feet should lower to the 1500-2500
feet range through the day. Confidence is less than average as there
is some drier air to our north-northeast. Northeast winds mainly in
the 10-15 knot range, becoming easterly this afternoon.|
Tonight... MVFR ceilings are anticipated to lower to ifr this evening
(locally lifr overnight) as a warm front gradually shifts northward.
Some fog and drizzle should develop, however the extent of this is
less certain at this time. Visibilities are currently forecast to
lower into the 1-2sm range overnight. East to southeast winds mainly
Monday... Ifr/MVFR conditions should be present to start at most
terminals, then improving toVFR by late morning. South to southwest
winds increasing to near 15 knots, with gusts 20-25 knots in the
Monday night... Widespread MVFR or ifr conditions with thunderstorms
likely. An abrupt wind shift to westerly is expected with a cold
front Monday night.
Tuesday and Wednesday... MostlyVFR conditions expected.
Thursday... StartingVFR, but may lower to MVFR as showers and
thunderstorms start to move into the region.
A front has settled to our south and will stall today before
gradually shifting north tonight as a warm front. Northeast winds
will turn easterly through the day with gusts at times to around 20
North of the front tonight winds will remain easterly, but south of
the front the winds will become southerly. It is possible the front
may clear all of the waters during the overnight. While winds may
not reach advisory criteria, seas may begin building through the
night, but especially toward daybreak Monday. Overall, the
conditions are expected to be below advisory criteria through
Monday and Monday night... Building seas and increasing winds
are expected by Monday morning. Southerly gusts near or above 30
kt are possible Monday evening on the coastal waters. On the
delaware bay, there is a bit more uncertainty, but sca
conditions are possible.
Tuesday... Winds will shift to southwesterly and then westerly behind
a cold front expected early Tuesday. Gusts on Tuesday may linger
near 25 kt. Elevated seas may linger into Tuesday night.
Wednesday and Thursday... Winds and seas are expected to stay below
**record or number 2 warmest april on record**
presuming our forecast temps these last 30 hrs of april are
accurate, we are assured of a top 2 warmest april on record in
much of our forecast area. Sunday temps determine record or
Just below: april projected within the top april average temps,
the normal for april and the period of record (por).
This includes yesterdays (29th) high and low temperatures
through 4 pm.
Phl normal 54.0 por 1874
59.5 2017 projected warmest ever: still could slip .2 degrees.
abe normal 49.9 por 1922
56.8 projecting record and almost cant miss a record.
acy normal 51.7 por 1874
57.6 projecting record and almost cant miss.
Marine... Small craft advisory from 6 am Monday to 6 am edt Tuesday for
near term... Gorse/robertson
short term... Robertson
long term... Johnson/o'hara
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|
|TCBM2 - 8573364 - Tolchester Beach, MD||6 mi||43 min||ESE 8 G 12||71°F||63°F||1021 hPa|
|44043 - Patapsco, MD||14 mi||25 min||ENE 3.9 G 5.8||67°F||1021.3 hPa|
|44057 - Susquehanna, MD||18 mi||25 min||E 5.8 G 7.8||67°F||1021.1 hPa|
|FSNM2||18 mi||37 min||E 11 G 14||68°F||1020.7 hPa|
|FSKM2 - 8574728 - Francis Scott Key Bridge, MD||19 mi||37 min||ENE 8 G 9.9||68°F||1020.7 hPa|
|BLTM2 - 8574680 - Baltimore, MD||21 mi||37 min||ESE 11 G 13||69°F||65°F||1020.4 hPa|
|CPVM2||23 mi||37 min||69°F||63°F|
|44063 - Annapolis||26 mi||25 min||NE 3.9 G 5.8||70°F||1020.6 hPa|
|CHCM2 - 8573927 - Chesapeake City, MD||26 mi||37 min||E 6 G 11||70°F||63°F||1021.3 hPa|
|APAM2 - 8575512 - Annapolis, MD||26 mi||37 min||71°F||1020.3 hPa|
|TPLM2 - Thomas Point, MD||30 mi||55 min||E 14 G 15||69°F||61°F|
|DELD1 - 8551762 - Delaware City, DE||38 mi||37 min||ESE 8.9 G 11||66°F||62°F||1022 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||38 mi||37 min||70°F||62°F||1021.6 hPa|
|DRSD1 - Delaware Reserve, DE||42 mi||145 min||E 4.1||67°F||1022 hPa||59°F|
|SJSN4 - 8537121 - Ship John Shoal, NJ||43 mi||37 min||E 13 G 17||67°F||62°F||1021.5 hPa|
|BSLM2 - Chesapeake Bay, MD||45 mi||145 min||NNW 1||64°F||1020 hPa||62°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
|Phillips Army Air Field / Aberdeen, MD||12 mi||2 hrs||E 7||10.00 mi||Overcast||68°F||57°F||69%||1021.9 hPa|
|Baltimore / Martin, MD||13 mi||70 min||NNE 7||10.00 mi||Overcast||70°F||64°F||83%||1021.7 hPa|
|Baltimore, Inner Harbor, MD||22 mi||61 min||no data||mi||71°F||57°F||63%||1021.3 hPa|
|Bay Bridge Field, MD||23 mi||75 min||E 7||7.00 mi||Mostly Cloudy||73°F||62°F||69%||1020.7 hPa|
Wind History from APG (wind in knots)
|1 day ago||W||W||SW||SW||SW||SW||SW||S||S||Calm||Calm||Calm||Calm||Calm||Calm||Calm||Calm||W||SW||SW||SW||Calm||SW||SW|
|2 days ago||S||SE||S||SE||S||SW||SE||SE||S||S||S||S||SW||Calm||SW||SW||SW||SW||W||W||NW||SW||W||N |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Worton Creek entrance |
Click for Map
Sun -- 05:13 AM EDT 0.23 feet Low Tide
Sun -- 06:07 AM EDT Sunrise
Sun -- 09:55 AM EDT Moonrise
Sun -- 11:43 AM EDT 2.25 feet High Tide
Sun -- 07:08 PM EDT 0.30 feet Low Tide
Sun -- 07:57 PM EDT Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Baltimore Harbor Approach |
Click for Map
Sun -- 02:27 AM EDT -0.69 knots Max Ebb
Sun -- 05:08 AM EDT 0.00 knots Slack
Sun -- 06:08 AM EDT Sunrise
Sun -- 08:47 AM EDT 1.17 knots Max Flood
Sun -- 09:57 AM EDT Moonrise
Sun -- 12:14 PM EDT -0.00 knots Slack
Sun -- 03:32 PM EDT -1.10 knots Max Ebb
Sun -- 07:11 PM EDT 0.00 knots Slack
Sun -- 07:57 PM EDT Sunset
Sun -- 09:46 PM EDT 0.60 knots Max Flood
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 (10,2,3,4)(on/off)  Help
Ad by Google
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.