Tuesday, March28, 2017 L-36.com


Marine Weather and Tides
Elkton, MD

Version 3.4
What's New / NOTES
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 6:50AMSunset 7:25PM Tuesday March 28, 2017 11:17 PM EDT (03:17 UTC) Moonrise 6:25AMMoonset 7:13PM Illumination 3% Phase: Waxing Crescent; Moon at 2 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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ANZ530 Chesapeake Bay North Of Pooles Island- 1031 Pm Edt Tue Mar 28 2017
.small craft advisory in effect from 6 am edt Wednesday through Wednesday afternoon...
Rest of tonight..N winds 5 to 10 kt. Waves 1 ft or less. A slight chance of showers. Patchy fog. Vsby 1 to 3 nm.
Wed..N winds 10 kt with gusts to 20 kt. Waves 1 ft.
Wed night..N winds 5 to 10 kt. Waves 1 ft.
Thu..N winds 5 to 10 kt...becoming E in the afternoon. Waves 1 ft.
Thu night..SE winds 5 to 10 kt. Waves 1 ft. A chance of rain.
Fri..SE winds 5 to 10 kt. Waves 1 ft. Rain.
Fri night..SE winds 5 to 10 kt. Waves 1 ft. Showers likely.
Sat..N winds 5 to 10 kt. Waves 1 ft. Showers likely in the morning.
Sun..NW winds 5 to 10 kt. Waves 1 ft.
ANZ500 1031 Pm Edt Tue Mar 28 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build into the waters for midweek, followed by a low pressure system moving towards the region on Friday. This system will exit the region Saturday. Small craft advisories are possible Thursday night through Saturday.

7 Day Forecast for Marine Location Near Elkton, MD
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location: 39.57, -75.85     debug


Area Discussion for - Philadelphia/Mount Holly, PA
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Fxus61 kphi 290140
afdphi
area forecast discussion
national weather service mount holly nj
940 pm edt Tue mar 28 2017

Synopsis
Surface low pressure offshore of the mid atlantic tonight will
drift into the open atlantic tomorrow. Canadian high pressure
builds into the northeast late Wednesday and Thursday. Low
pressure develops in the central u.S. On Thursday, moves east
into the mid- atlantic on Friday, and progresses offshore
Saturday. High pressure returns to the area by late in the
weekend. Another surface low may affect the region by the middle
of next week.

Near term /until 6 am Wednesday morning/
Weak low pressure has moved offshore of the mid-atlantic this
evening. Meanwhile, a cold front is pushing through central
ny/pa and will move across the area later tonight.

Areas of showers and drizzle continue across eastern
pennsylvania and most of new jersey. The DELMARVA is shower free
early this evening, but a few showers could still move across
the area over the next few hours. Along with the rain and
drizzle, there is also some patchy fog across the area, though
it is not very thick. These showers will continue to drift
eastward through this evening and begin to dissipate as the
surface low and mid-level trough/vorticity impulse slide east
of the area as well. However, until the cold front moves through
overnight and toward daybreak, there will continue to be cloudy
skies and some light fog.

Lows tonight will range from the mid and upper 30s across the
poconos and northern nj to the lower 40s for the rest of nj and
se pa, and in the mid to upper 40s in md/de.

Short term /6 am Wednesday morning through 6 pm Wednesday/
High pressure builds in from the north, bringing plenty of sunshine.

A slight downsloping flow will help moderate the temperatures, and
highs will top off in the mid 40s in the poconos, upper 50s across
northern nj and the lehigh valley, low 60s across central and
southern nj and SE pa, and in the mid to upper 60s in the
delmarva.

Long term /Wednesday night through Tuesday/
The long term period starts off quiet as a surface ridge axis
passes overhead Thursday morning. Surface flow becomes
northeasterly with time, and the cool/maritime origins of this
flow suggest Thursday may be a bit cooler than Wednesday,
especially if increasing cloudiness occurs early in the day.

This increased cloudiness would commence downstream of another
potent southern-stream vorticity maximum progressing eastward
from the central plains. Broad southerly low-level flow
amplifies downstream ridging in the eastern u.S., with
substantial warm advection in much of the midwest.

However, with the retreating surface high in eastern canada,
this is a favorable setup for cold air damming east of the
appalachians, particularly with the more southerly track of the
aforementioned vort max. As with the systems affecting the area
early this week, I think the models are overly aggressive
sweeping the baroclinic zone/associated warm front north through
the region Thursday night and Friday. Though the 12z GFS is a
bit of an outlier with the southern/slower track, the
disagreement in the midlevels between the 12z cmc/ecmwf do not
provide confidence enough to discard the GFS solution, which
would favor a somewhat colder scenario for our area (though the
gfs is itself switching winds to south way too fast in such a
setup). For temperatures, generally went somewhat below guidance
Thursday night and Friday, and my suspicion is that I am still
too warm during both periods.

The implications of this are most important for the southern
poconos and sussex county, nj, where precipitation will likely
begin Thursday night and temperatures will once again flirt with
the freezing mark. Model guidance is at least somewhat
suggestive of a wintry mix of precipitation in this region, and
thermal profiles suggest the presence of a warm nose, which may
mean that freezing rain and/or sleet would be possible. For now,
kept things simple with a mix of rain and snow in this area
(particularly with surface temperatures forecast slightly above
freezing), but later shifts may need to include mention of sleet
or freezing rain in this region. By some time on Friday,
temperatures are expected to warm here enough for precipitation
to be all rain, but given lackluster performance with models
this winter scouring out this cold air in an accurate manner,
current forecast may be overly optimistic (at least Friday
morning).

A sustained southerly low-level fetch downstream of the surface
low moving through the region on Friday brings pwats > 1.0 inch
(approaching 1.25 inches) to central/southern portions of the
cwa. With aid of upper-level jet coupling, substantial
differential cyclonic vorticity advection, and considerable low-
level isentropic ascent, widespread rain should develop on
Friday and continue through Friday night as the low approaches
the mid-atlantic coast. QPF looks quite decent, with widespread
0.5-1.5 inch totals possible (and perhaps more, if some
simulations verify). The potential for storms seems limited at
this time, given the cwa's position generally along/north of the
surface low track. However, if the warm sector is able to move
more poleward than currently forecast, convection may also be a
consideration (particularly for delmarva).

The surface low is expected to move offshore by Saturday, but
wraparound showers may still occur, particularly north of the
mason-dixon line. Only gradually lowered pops late Friday night
and Saturday given this possibility. Winds will switch to the
north, but temperatures may actually be a little warmer than
Friday's readings given greater potential for sunshine, subtle
downsloping, and boundary-layer mixing. However, not sold on the
very warm mexmos readings at this point given the origins of the
upstream surface high.

Sunday and Monday should generally be dry as upstream ridging
moves through the region. Temperatures will be near to slightly
above seasonal averages.

Another in a series of southern-stream systems is projected to
move into the ohio/tennessee valleys by early next week. With
increased large-scale ascent downstream of the attendant surface
low, precipitation will probably break out Monday night and
Tuesday across the area. This low's track would be farther to
the west, which suggests this system will be warmer, giving our
region greater potential for convection. Did not add thunder to
the grids at this point given track/timing uncertainties, but
think this is a good bet given relatively decent agreement among
the model suite. Models suggest a reinforcing system may
approach the area midweek, keeping the QPF train chugging.

Aviation /02z Wednesday through Sunday/
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.

Tonight... MVFR/ifr conditions with scattered showers and fog
early. Sub-vfr cigs/vsbys will continue for much of tonight in
fog after showers depart. Improvement toVFR not until prior to
daybreak Wednesday.VFR conditions will prevail through the day
Wednesday.

North- northeast winds around 5 knots are expected to become
northwest overnight, and increase through daybreak. Winds will
become gusty during the day Wednesday.

Outlook...

Wednesday night through Thursday night...VFR with generally
light winds. Confidence well above average.

Friday through Saturday... Sub-vfr conditions likely, with
lowered CIGS and vsbys and periods of rain. East or southeast
winds Friday around 10 kts becoming northerly and potentially
gusty on Saturday. Confidence average.

Saturday night and Sunday...VFR with north or northwest winds
around 10 kts with at least some potential for gusts to 20 kts.

Confidence average.

Marine
Vsby reductions possible in showers and fog tonight, with
improvements not until well after midnight. Unlimited vsbys expected
on Wednesday. Sub-sca conditions tonight through Wednesday, but some
gusts to 20 kt possible Wednesday morning/early afternoon, mainly on
the ocean.

Outlook...

Wednesday night... Marginal small craft advisory conditions
possible, especially off the new jersey coast.

Thursday and Thursday night... Sub-advisory conditions expected.

Friday through Saturday... Marginal advisory conditions possible.

Rain likely.

Saturday night and Sunday... Sub-advisory conditions expected.

Tides/coastal flooding
Though astronomical tides will be gradually diminishing through the
week now that we are past the new moon, the threat of minor tidal
flooding along the nj and de atlantic coasts increases late in the
week. This is a result of a low pressure system bringing a prolonged
period of on shore flow. The tide of most concern at this point is
the high tide on Friday evening/late Friday night. By this tide
cycle, it will take a surge of 0.8 to 1.0 feet to reach minor
flooding thresholds, which is possible but still uncertain (it
will be dependent on how quickly the on shore flow develops and
how strong it will be by then). At least one source of guidance
shows water levels reaching minor tidal flooding thresholds with
the Thursday evening/night high tide, but that seems unlikely
as the latest forecast depicts onshore flow either developing
right around or just after the time of that high tide.

Equipment
Knel appears to be reading 10f too warm the past several days.

Phi watches/warnings/advisories
Pa... None.

Nj... None.

De... None.

Md... None.

Marine... None.

Synopsis... Cms
near term... Robertson/mps
short term... Mps
long term... Cms
aviation... Cms/robertson/mps
marine... Cms/mps
tides/coastal flooding...

equipment...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
CHCM2 - 8573927 - Chesapeake City, MD 4 mi47 min N 1.9 G 5.1 53°F 48°F1013.2 hPa
DELD1 - 8551762 - Delaware City, DE 14 mi47 min N 4.1 G 7 47°F 45°F1013.7 hPa
RDYD1 - 8551910 - Reedy Point, DE 15 mi47 min 49°F 45°F1013.3 hPa
MRCP1 - 8540433 - Marcus Hook, PA 28 mi47 min 50°F 1013.3 hPa
SJSN4 - 8537121 - Ship John Shoal, NJ 31 mi47 min 49°F 45°F1013 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 32 mi47 min NNE 4.1 G 5.1 55°F 48°F1014.1 hPa
DRSD1 - Delaware Reserve, DE 40 mi62 min NNW 2.9 53°F 1013 hPa53°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 43 mi47 min NNW 7 G 8 60°F 1013.8 hPa
FSNM2 43 mi47 min N 7 G 8.9 60°F 1013.4 hPa
BLTM2 - 8574680 - Baltimore, MD 44 mi47 min N 9.9 G 14 60°F 48°F1013.4 hPa
PHBP1 - 8545240 - Philadelphia, PA 45 mi47 min 48°F 44°F1013.5 hPa
CPVM2 49 mi47 min 50°F 50°F

Wind History for Chesapeake City, MD
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Wilmington, New Castle County Airport, DE15 mi26 minN 410.00 miOvercast51°F50°F96%1014 hPa
Phillips Army Air Field / Aberdeen, MD18 mi79 minNNE 410.00 miMostly Cloudy55°F52°F92%1013.8 hPa

Wind History from ILG (wind in knots)
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Last 24hrNE7NE5NE7NE5NE6NE5NE7NE7N11NE13E9NE8E8NE12E7NE5N5N6NE6N6N10N7N10N4
1 day agoNE8E8E9E6E7E7E5NE3CalmSE3N3CalmCalmW6SW8SW7SW8SW5CalmCalmE4E5NE6E4
2 days agoNE10
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Tide / Current Tables for Old Frenchtown Wharf, Maryland
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Old Frenchtown Wharf
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Tue -- 04:32 AM EDT     0.21 feet Low Tide
Tue -- 06:53 AM EDT     Sunrise
Tue -- 07:25 AM EDT     Moonrise
Tue -- 10:32 AM EDT     3.03 feet High Tide
Tue -- 05:09 PM EDT     -0.06 feet Low Tide
Tue -- 07:23 PM EDT     Sunset
Tue -- 08:12 PM EDT     Moonset
Tue -- 11:04 PM EDT     2.67 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.21.71.10.60.30.20.61.21.92.6332.621.30.70.2-0.10.10.51.21.92.52.7

Tide / Current Tables for Chesapeake and Delaware Canal, Maryland/Delaware Current
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Chesapeake and Delaware Canal
Click for Map
Tue -- 01:33 AM EDT     -2.11 knots Max Ebb
Tue -- 04:46 AM EDT     0.08 knots Slack
Tue -- 06:53 AM EDT     Sunrise
Tue -- 07:25 AM EDT     Moonrise
Tue -- 08:10 AM EDT     2.26 knots Max Flood
Tue -- 11:00 AM EDT     -0.08 knots Slack
Tue -- 02:02 PM EDT     -2.05 knots Max Ebb
Tue -- 05:14 PM EDT     0.08 knots Slack
Tue -- 07:23 PM EDT     Sunset
Tue -- 08:12 PM EDT     Moonset
Tue -- 08:30 PM EDT     2.11 knots Max Flood
Tue -- 11:02 PM EDT     -0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-1.7-2.1-2.1-1.8-1.20.61.422.32.11.50.1-1.4-1.9-2-1.9-1.4-0.61.11.72.12.11.60.3

Weather Map and Satellite Images
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Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Mid-Atlantic    EDIT
Geos

Wind Forecast for Philadelphia/Mount Holly, PA (23,6,7,8)
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Ground Weather Radar Station Dover AFB, DE
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weather_mapweather_map weather_map

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Disclaimer:
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.