Tuesday, April25, 2017 L-36.com


Marine Weather and Tides
Cobb Island, 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 6:14AMSunset 7:56PM Tuesday April 25, 2017 2:28 PM EDT (18:28 UTC) Moonrise 5:00AMMoonset 6:02PM Illumination 0% Phase: New Moon; Moon at 29 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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ANZ537 Tidal Potomac From Cobb Island To Smith Point- 132 Pm Edt Tue Apr 25 2017
.small craft advisory in effect until midnight edt tonight...
This afternoon..E winds 10 to 15 kt. Gusts up to 30 kt... Diminishing to 20 kt late. Waves 4 ft. Rain and occasional drizzle.
Tonight..N winds 5 to 10 kt. Waves 2 ft. Rain likely. Patchy fog. Vsby 1 to 3 nm.
Wed..NW winds 5 to 10 kt. Waves 1 ft. A chance of rain. Patchy fog. Vsby 1 to 3 nm.
Wed night..S winds 5 kt. Waves less than 1 ft.
Thu..S winds 5 to 10 kt. Waves 1 ft.
Thu night..S winds 10 kt. Waves 1 to 2 ft.
Fri..S winds 5 to 10 kt. Waves 1 ft.
Sat..SW winds 5 to 10 kt. Waves 1 ft.
ANZ500 132 Pm Edt Tue Apr 25 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure weaken as it moves up the mid-atlantic coast through tonight. The low will move off to our north and east Wednesday and a cold front will approach from the west Thursday. The cold front will weaken and stall out nearby Thursday night and it will remain nearby through the weekend. A small craft advisory may be needed for portions of the waters Thursday into Thursday night.

7 Day Forecast for Marine Location Near Cobb Island, MD
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location: 38.22, -76.75     debug


Area Discussion for - Wakefield, VA
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Fxus61 kakq 251825
afdakq
area forecast discussion
national weather service wakefield va
225 pm edt Tue apr 25 2017

Synopsis
Low pressure tracks across the north carolina coastal plain
today... Then continues northeast along the mid atlantic coast
tonight and Wednesday. High pressure builds into the area
Thursday. A cold front stalls north of the region on Friday.

Near term /until 6 pm this evening/
Adjusted grids a bit this aftrn per crnt conditions. Dry slot
has quickly shut off pcpn in most areas but expect addntl shwrs
to develop as dytme heating combines with the upr level energy.

Kept thunder confined mainly along the coast and areas that has
seen sun. Temps range from the 60s nw... 70-75 se.

Pvs dscn:
tropical moisture plume and associated showers now lifting
north northwest as the system continue to wrap around the
upr level low to the south. Of note is the dry slot noted by
sct-bkn mid level clouds across NE nc/sern va. Still have the
upr level systm to deal with this afternoon so will continue
with the cat to likely pops for the next few hrs slowly ramping
down toward evening. Thunder chcs continue across the south and
east as the system tracks ne, especially in areas that do get
some partial sunshine. Highs arnd 60 NW to mid 70s se.

Short term /6 pm this evening through Thursday/
Upper/surface low pressure lifts along the mid-atlantic coast
this evening, and then north of the local waters late tonight.

Wrap around moisture keeps chance to likely pops across the
northeast local area through late tonight. Given the recent
rainfall and saturated soils, have included patchy fog across
much of the region. However, cloud cover and light winds will
limit the overall coverage. Lows tonight generally in the mid to
upper 50's.

Low pressure lifts along the northeast coast Wednesday as an
upper level ridge builds over the region. Thermal soundings
indicate mid level moisture trapped beneath a strong subsidence
inversion aloft, which will help keep clouds around through the
day. However, given the late april sun, anticipate several
breaks in the clouds inland. Soundings also indicate very little
mixing, but given height rises and warming low level
temps/thicknesses, forecast highs are generally in the mid to
upper 70's. Cooler along the coast. Mild Wednesday night under a
partly clear to mostly clear sky. Lows forecast in the upper
50's to low 60's.

Ridge axis slides offshore ahead of an approaching cold front
Thursday. Increasing return flow and 850mb temps around +14 to
+16c (around +1 standard deviation) result in warm (and dry)
conditions with highs generally in the 80's. Cooler along the
coast. Plenty of sunshine expected.

Long term /Thursday night through Monday/
Long term period will feature above normal temps with mainly dry wx.

For Thu night/fri, deep swly flow continues across the eastern
seaboard as an upper-level ridge then builds in through the weekend
allowing for warm temps and dry wx as most of the energy aloft will
stay N and W of the local area. At most a 20% chance of a late day
shra/tstm Fri and sat. High temps Fri through Sun in the 80s,
pushing near 90 Sat and sun. Low temps in the mid/upr 60s.

Aviation /19z Tuesday through Sunday/
Low pressure continues to move northeast across the region this
afternoon before finally pushing offshore tonight. Widespread ifr
ceilings continue over mainly northern portions of the area,
including ric and sby, this afternoon. Closer to the center of low
pressure over southeast portions of the region, some temporary
clearing and mainlyVFR ceilings are anticipated. Radar trends have
shown diminishing coverage in rain showers this afternoon, but model
guidance continues to hint at the redevelopment of showers across
eastern portions of the area.

Stratus and widespread ifr ceilings are expected to redevelop
overnight as moisture wraps around the backside of the low pressure.

Guidance has also been persistent with the development of patchy fog
tonight and into tomorrow morning. Included MVFR visibilities for
tonight, but it is possible ifr visibilities may develop in a few
locations. Conditions will improve during the day on Wednesday,
returning toVFR Wednesday afternoon.

Light easterly flow is expected to continue through this afternoon
and evening. Winds will shift to the w/nw as the low departs the
area tonight and Wednesday. Winds remain light on Wednesday,
generally 5-10 knots.

Outlook: aviation conditions improve through the day on Wednesday
withVFR expected to return to the area. A shower or thunderstorm
will be possible during the day on Friday, but otherwise,VFR and
dry conditions should dominate the extended period.

Marine
Current analysis indicating sfc low pressure centered just s/sw of
cape hatteras, with e/ne flow ongoing across the local marine
area. Thus far, winds have been at SCA levels but have remained
below gale criteria. Pressure falls have not been that
significant and therefore will be relying on mixing the stronger
winds aloft to the surface. High res models depict a short
period with gale force gusts possible for the lower bay and
southern coastal waters through mid morning, with higher winds
lingering across the northern coastal waters into early aftn.

Overall, this event looks marginal but will maintain continuity
and keep the gale warning in effect through 10 am S to 1 pm n.

Sca headlines remain in effect for the upper james/york/rappahannock
rivers where gusts up to 30 kt are expected. Seas up to 8-12
ft, with a high surf advisory remaining in effect for 8-9 ft
waves in the surf zone. No cold air surge in the wake of this
system later today and tonight, so aside from high seas
lingering for the coastal waters/mouth of bay, expect rapidly
improving conditions later today and tonight. Seas should fall
off to below 5 ft later wed/wed night. Winds begin to shift to
the S thu/fri w/ sub-sca conditions to prevail.

Tides/coastal flooding
Current tidal departures are averaging around 1.5 to 1.75 feet
in the lower bay and southern coastal waters due to ongoing
onshore flow, while departures farther N are genly 1 ft or
less. Have raised coastal flood advisories for zones adjacent to
the lower bay/james/york river, as well as the va eastern
shore. This will be for the upcoming high tide later this
morning. More uncertainty exists farther N in the bay up the
coast and have continued with another round of statements for
these areas for now. Surprisingly, despite continued onshore
flow, currents data from CAPE henry channel shows that water has
been exiting the bay at the same rate that it has been coming
in/ i.E. Piling of water into the bay has been fairly minimal
so far. Estofs and cbofs data suggest this will change later
today through tonight with the potential for water to become
trapped in the bay and for eventual minor flooding for the
mid/upper bay by tonight. May need to raise a coastal flood
advisory later today for some of these locations, but did not do
this yet because of how the winds associated with this system
have genly underperformed so far.

Akq watches/warnings/advisories
Md... High surf advisory until 7 pm edt this evening for mdz025.

Nc... High surf advisory until 4 pm edt this afternoon for ncz102.

Va... High surf advisory until 4 pm edt this afternoon for vaz098.

High surf advisory until 7 pm edt this evening for vaz099-100.

Marine... Small craft advisory until 7 pm edt this evening for anz634.

Small craft advisory until 4 pm edt this afternoon for anz632.

Small craft advisory until 7 am edt Thursday for anz650-652-
654.

Small craft advisory until 7 pm edt Wednesday for anz656-658.

Synopsis... Alb/mpr/sam
near term... Mpr
short term... Sam
long term... Mas
aviation... Ajb
marine... Lkb/mas
tides/coastal flooding...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
PPTM2 - 8578240 - Piney Point, MD 13 mi40 min ENE 13 G 15
NCDV2 17 mi40 min NE 5.1 G 8.9 61°F 61°F1005.9 hPa
SLIM2 - 8577330 - Solomons Island, MD 17 mi46 min NE 13 G 19 61°F 60°F
LWTV2 - 8635750 - Lewisetta, VA 22 mi40 min E 12 G 15 62°F 60°F1005.4 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 23 mi40 min E 15 G 18 60°F 1007.3 hPa
44042 - Potomac, MD 26 mi28 min ENE 12 G 14 62°F 59°F2 ft1004.9 hPa (+0.0)
44062 - Gooses Reef, MD 29 mi28 min E 14 G 18 60°F 52°F2 ft1007.9 hPa (-1.0)
BISM2 - 8571421 - Bishops Head, MD 38 mi40 min E 13 G 15 63°F 59°F1006.4 hPa
BSLM2 - Chesapeake Bay, MD 39 mi118 min NNE 6 54°F 1008 hPa53°F
CA2 - 8571892 - Cambridge, MD 44 mi46 min 61°F 61°F
WASD2 - 8594900 - Washington, DC 47 mi40 min NNE 4.1 G 11 59°F 65°F1007.9 hPa

Wind History for Piney Point, MD
(wind in knots)    EDIT      (on/off)   Help
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G26
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E8
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NE6
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
St Marys County Airport, MD12 mi47 minNE 77.00 miOvercast59°F57°F94%1007.1 hPa
St. Inigoes, Webster Field, Naval Electronic Systems Engineering Activity, MD18 mi35 minNE 12 G 2110.00 miOvercast62°F61°F96%1005.6 hPa
Patuxent River, Naval Air Station, MD19 mi36 minENE 1510.00 miLight Drizzle61°F61°F100%1006.1 hPa

Wind History from NUI (wind in knots)
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Last 24hrNE12
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1 day agoNE8NE4N3N3CalmE4E5E5E5E5NE5NE4NE7NE8NE9NE7
G17
NE75NE9NE11NE11
G19
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2 days agoN7NE5N663NE8NE4Calm34NE6NE33NE7NE7NE5NE7N6NE64NE5N75N5

Tide / Current Tables for Colton's Point, Potomac River, Maryland
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Colton's Point
Click for Map
Tue -- 02:08 AM EDT     2.30 feet High Tide
Tue -- 05:59 AM EDT     Moonrise
Tue -- 06:17 AM EDT     Sunrise
Tue -- 08:25 AM EDT     0.08 feet Low Tide
Tue -- 02:39 PM EDT     2.09 feet High Tide
Tue -- 07:02 PM EDT     Moonset
Tue -- 07:52 PM EDT     Sunset
Tue -- 08:29 PM EDT     0.11 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.92.22.32.21.71.20.70.30.10.10.40.91.41.82.12.11.81.30.80.40.10.10.40.9

Tide / Current Tables for Point Patience, 0.1 mile southwest of, Maryland Current
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Point Patience
Click for MapFlood direction 315 true
Ebb direction 145 true

Tue -- 01:30 AM EDT     -0.00 knots Slack
Tue -- 05:26 AM EDT     -1.00 knots Max Ebb
Tue -- 05:58 AM EDT     Moonrise
Tue -- 06:16 AM EDT     Sunrise
Tue -- 09:40 AM EDT     0.00 knots Slack
Tue -- 11:20 AM EDT     0.43 knots Max Flood
Tue -- 01:34 PM EDT     -0.00 knots Slack
Tue -- 05:20 PM EDT     -0.81 knots Max Ebb
Tue -- 07:01 PM EDT     Moonset
Tue -- 07:52 PM EDT     Sunset
Tue -- 09:05 PM EDT     0.00 knots Slack
Tue -- 11:28 PM EDT     0.70 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.50.2-0.2-0.6-0.8-1-1-0.8-0.6-0.20.10.40.40.2-0.1-0.4-0.7-0.8-0.8-0.6-0.4-00.40.7

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 Wakefield, VA (14,3,4,5)
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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.