Marine Weather and Tides
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.
|Sunrise 6:05AM||Sunset 7:51PM||Friday April 26, 2019 4:21 AM EDT (08:21 UTC)||Moonrise 1:04AM||Moonset 10:52AM||Illumination 57%|
7 Day Forecast for Marine Location Near Millbourne borough, PAHourly EDIT Help
Area Discussion for - Philadelphia/Mount Holly, PA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus61 kphi 260737|
area forecast discussion
national weather service mount holly nj
337 am edt Fri apr 26 2019
Low pressure will continue to track up the ohio valley toward the
eastern great lakes this morning. A warm front will gradually lift
northward and across our area through this morning. A strong cold
front will then cross our region late this afternoon through this
evening. Weak high pressure briefly moves in by late Saturday before
the next low pressure system crosses the area west to east on
Sunday. High pressure moves back in to start next week before the
next system moves in next Tuesday. A frontal boundary looks to then
stall in the general vicinity of the region through the remainder of
next week as additional waves move through along it.
Near term through tonight
Concern continues to increase for severe storms this afternoon and
A surface low in the midwest will continue northeastward today in
advance of a southern-stream vort MAX that is beginning to phase
with a digging northern-stream shortwave trough. Amplification and
negative tilting will continue through the morning as the large-
scale trough approaches the appalachians by midday. The mid-atlantic
will be at the nose of a potent midlevel jet streak vort MAX this
afternoon, with strongly difluent flow in the upper levels favorable
for substantial large-scale ascent along and in advance of a surging
cold front. A warm front will lift north through the northern mid-
atlantic today, with the warm sector likely making it through about
the southern two-thirds of the CWA or so by early afternoon.
Latest convection-allowing model guidance is suggestive of an
environment favorable for organized severe storms this afternoon.
Forecast soundings indicate backing surface flow as the large-scale
system and associated surface low to our northwest deepens within
the warm sector this afternoon. Hodographs are strongly indicative
of potential for rotating storms. Low-level storm-relative helicity
of 200-300 j kg is not out of the question in advance of the cold
front late this afternoon and this evening. In addition, several of
the hi-res models develop decent mixed-layer based instability (with
mitigating effects near the colder waters, as usual). The resulting
cape shear parameter space is adequate for tornadic supercells,
though the strong large-scale ascent may favor more of a quasi-
linear convective system (qlcs) with embedded transient rotating
storms. SPC has moved the slight risk northward to the philadelphia
Timing of the strongest convection looks to be in the 5 to 10 pm
time window. However, some of the hi-res guidance is indicating
predecessor quasi-discrete storms developing in advance of the
front qlcs during the afternoon. Should these develop, cannot rule
out strong to severe storms with these either, given the favorable
pre-frontal environment. Notably, some models depict little
convection aside from the qlcs, so this threat is much more
Storms will be capable of producing heavy rainfall as well, but the
storms will be progressive. The flooding threat looks somewhat
limited because of this, though should any training of storms occur,
an isolated instance of flash flooding may occur. The threat looks
too limited for a flash flood watch at this time.
Meanwhile, there are several other issues to contend with today,
including the showers moving through the area early this morning.
Some lightning has occurred on the south side of the precipitation,
where some marginal elevated instability has developed. Added slight
chances of thunder to the forecast early this morning, generally
from the i-276 i-195 corridors southward. Precipitation should
mainly be in the 0.1 to 0.4 inch range, generally from stevensville
to atlantic city northward, with this first batch. However,
additional rounds of showers isolated storms may occur through the
morning (as depicted by the hrrr NAM nest), so have maintained
fairly high pops through the morning.
Another question is just how far northward the warm front advances
today, with the NAM more pessimistic than the gfs. The NAM tends to
do better in these regimes, so have weighted the forecast position
and resultant winds temperatures strongly toward this guidance
today. This resulted in lowering MAX temps in the northern cwa
considerably, which seems reasonable given potential for a few
rounds of showers this morning anyway.
Finally, after cold-frontal passage this evening, winds will switch
to the west or northwest and become gusty. However, precipitation
should quickly end, except for the far north where northwest-flow
showers may linger through the night. Temperatures dew points will
drop behind the front, but temps may stay somewhat elevated owing to
the stronger winds. Kept the forecast close to continuity.
Short term Saturday
Main concern for Saturday is strong winds as the surface low
deepening to our north develops a strong pressure gradient across
the mid-atlantic during the day. The strongest winds should occur
during the morning, when bufkit soundings indicate potential for
gusts of 30 to 40 mph. Cannot rule out the need for an advisory, but
the current projections look a little shy of criteria.
Temperatures will be cool, as cold advection will take over across
the area. Additionally, some stratocumulus may develop during the
day as strong mixing occurs, especially in the northern cwa. With
this in mind, kept the forecast on the cold side of consensus.
Long term Saturday night through Thursday
Saturday night through Monday...
weak, transient surface ridge briefly moves in Saturday evening
before moving off to the east overnight as the next low pressure
system begins to approach from the west bringing increasing clouds
and the chance of some showers by Sunday morning over eastern pa.
This quick moving low will cut right across the heart of the cwa
Sunday bringing a period of some rain and showers. Since the low
will be quick moving with a relatively low amplitude upper level
wave it won't be able to tap into a lot of moisture and instability
so rain amounts won't be significant. Steadiest rain showers will be
near and north of the track of the low over northern portions of the
cwa along and north of the i-78 i-80 corridor. In fact areas south
of philly may not see much at all in the way of precip. Highs will
range from the upper 60s to mid 70s over the delmarva, SE pa and
central, southern nj to the low to mid 50s over the southern poconos
and NW nj. Also, as the low departs through the afternoon NW winds
should become fairly gusty.
Low pressure quickly departs Sunday night with high pressure then
building in through most of Monday bringing fair weather with
sunshine and seasonable temperatures to start the new week.
Monday night through Thursday...
in the big picture, the pattern looks to be dominated by an upper
level ridge over the SE CONUS with an upper level trough much of
central canada extending south toward the rocky mountain region.|
This will result in a continuing active weather pattern over the mid
atlantic region as a deep layer W SW flow dominates bringing
multiple disturbances through the region.
In terms of the details, the next low pressure system looks to move
through later Monday night into Tuesday as it cuts right across the
area along a frontal boundary. This will bring another round of some
rain and showers through the region with some thunderstorms possible
by Tuesday afternoon over southern portions of the area over SE pa,
the delmarva, and portions southern nj. Highs Tuesday look to
generally be in the 70s except a bit cooler right along the
immediate coast and over the southern poconos. Beyond this time,
forecast confidence decreases as models begin to diverge. GFS brings
in another system quickly on the heals of Tuesday's system for
Wednesday while the ECMWF holds this system off until Thursday as it
builds in a high briefly for Wednesday. In either case, main
baroclinic zone looks to be persist in the general vicinity of the
area so we keep in chance pops for showers through the remainder of
the long range. Temperatures look to be around or above average for
this time of year through the middle to end of next week.
Aviation 07z Friday through Tuesday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.
Rest of tonight... Conditions slowly deteriorating to MVFR and
possibly brief ifr, especially in areas of steadier showers.
Winds will be light and somewhat erratic, but should generally
favor an east or southeast direction. Moderate confidence.
Friday morning... Lingering sub-vfr to the north of a warm front,
with conditions expected to becomeVFR as the warm front moves
northward. To the north of the front, winds will be
predominantly easterly around 10 kts. To the south, a switch to
south or even southwest with gusts to 20 kts may occur.
Scattered showers should continue to the north of the front. The
front's timing is very low confidence, but expect passage
through ilg phl acy miv pne in the 14z to 17z time frame.
Passage at rdg abe ttn is even less certain.
Friday afternoon and evening... South to southwest winds should
increase to 10 to 15 kts with higher gusts as the warm front
continues slowly northward and or washes out, though this may be
slow to occur at rdg abe ttn. Scattered showers storms may
develop ahead of an approaching cold front, but the most
widespread convection will be with the front itself. Conditions
will quickly briefly deteriorate as a broken squall line moves
though, with lightning and strong erratic gusts possible. A
quick switch to west winds will occur as the squall line passes,
with gusty winds continuing thereafter. Timing of the line of
storms should be 21z to 00z from west to east, with quick
improvement toVFR thereafter. Moderate confidence.
Friday night...VFR with winds becoming northwest 10 to 15 kts
with higher gusts. High confidence.
Saturday...VFR with strong northwest winds 15 to 25 kts with
gusts 30 to 35 kts possible. High confidence.
Saturday night...VFR. West-northwest winds diminishing to 10
knots or less and even light and variable late.
Sunday... A period of MVFR or ifr conditions possible with some
showers especially near and north of phl, thenVFR at night.
Light and variable winds becoming southerly near 10 knots, then
nw 10-15 with gusts 20-25 knots by late day into Sunday evening.
Monday and Tuesday... MainlyVFR, however some showers are possible
late Monday and Tuesday. East and southeast winds up to 10
knots Monday, then becoming west-southwest Tuesday.
Sub-advisory conditions are occurring on the waters at this time,
but as a warm front lifts northward today, winds will become
southerly and increase, likely nearing exceeding advisory criteria
by this afternoon. Seas will also build to around above 5 feet late
in the day. A small craft advisory is in effect for the atlantic
waters from 1 to 6 pm today. Advisory conditions are not expected on
delaware bay this afternoon. Occasional showers and isolated storms
are expected today, with some erratic winds waves to be expected in
This evening, a cold front will move through the waters, with
showers storms likely in its vicinity. Strong wind gusts are
probable with the stronger storms. Winds will quickly switch to west
or northwest behind the front (along with storms quickly departing),
and models are indicating potential for some gale-force gusts
overnight into Saturday morning. Have issued a gale watch for the
waters for this time frame.
Saturday night... West to northwest winds continuing to diminish
below SCA levels through Saturday evening with seas also
continuing to subside below 5 feet.
Sunday and Monday... Winds and seas may increase to small craft
advisory criteria for a time late Sunday into Sunday night,
otherwise the conditions should be below advisory criteria.
Tuesday... The conditions are anticipated to be below small craft
Phi watches warnings advisories
Marine... Small craft advisory from 1 pm this afternoon to 6 pm edt
Saturday for anz452>455.
Small craft advisory from 4 pm this afternoon to 6 pm edt
Saturday for anz450-451.
Small craft advisory from 10 pm this evening to 6 pm edt
Saturday for anz430-431.
near term... Cms
short term... Cms
long term... Fitzsimmons
aviation... Cms fitzsimmons
marine... Cms fitzsimmons
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|
|PHBP1 - 8545240 - Philadelphia, PA||3 mi||34 min||55°F||58°F||1008.7 hPa|
|BDSP1||6 mi||34 min||53°F||60°F||1009.5 hPa|
|MRCP1 - 8540433 - Marcus Hook, PA||16 mi||40 min||56°F||60°F||1008.3 hPa|
|BDRN4 - 8539094 - Burlington, Delaware River, NJ||18 mi||46 min||ESE 4.1 G 4.1||54°F||58°F||1009.7 hPa|
|NBLP1 - 8548989 - Newbold, PA||26 mi||34 min||E 4.1 G 5.1||54°F||59°F||1010.3 hPa|
|DELD1 - 8551762 - Delaware City, DE||34 mi||40 min||NE 9.9 G 11||56°F||60°F||1007.8 hPa|
|RDYD1 - 8551910 - Reedy Point, DE||35 mi||40 min||1007.3 hPa|
|CHCM2 - 8573927 - Chesapeake City, MD||45 mi||40 min||E 8 G 9.9||56°F||65°F||1007.9 hPa|
|SJSN4 - 8537121 - Ship John Shoal, NJ||46 mi||34 min||ENE 8.9 G 11||57°F||63°F||1007.7 hPa|
Wind History for Philadelphia, PA(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Philadelphia, Philadelphia International Airport, PA||6 mi||28 min||NE 5||8.00 mi||Light Rain||54°F||51°F||90%||1009 hPa|
|Philadelphia, Northeast Philadelphia Airport, PA||12 mi||28 min||E 4||5.00 mi||Light Rain Fog/Mist||55°F||51°F||87%||1010 hPa|
|Philadelphia - Wings Field Airport, PA||13 mi||47 min||N 0||5.00 mi||Mostly Cloudy||52°F||51°F||100%||1010.8 hPa|
|Mount Holly, South Jersey Regional Airport, NJ||18 mi||28 min||N 4||4.00 mi||Rain Fog/Mist||52°F||50°F||93%||1009.5 hPa|
Wind History from PHL (wind in knots)
|1 day ago||W||W||NW||W||NW||W||NW||W||NW|
|2 days ago||SW||SW||W||W||NW||S||NW||SW||W||SW||SW||SW||SW||SW||S||S||S||S||S||SW||S||SW||SW||SW |
EDIT Weekend mode (on/off) (on/off)  Help One Week of Data
EDIT (on/off)  Help One Week of Data
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.
Link to Loop
Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for Philadelphia/Mount Holly, PA (4,6,7,8)(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.