Friday, July28, 2017

Marine Weather and Tides
Arden on the Severn, MD

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
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.

Sunrise 6:02AMSunset 8:22PM Friday July 28, 2017 9:03 AM EDT (13:03 UTC) Moonrise 10:39AMMoonset 10:44PM Illumination 24% Phase: Waxing Crescent; Moon at 5 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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ANZ538 Patapsco River Including Baltimore Harbor- 731 Am Edt Fri Jul 28 2017
.small craft advisory in effect from Saturday morning through Saturday evening...
Today..E winds 5 kt. Waves less than 1 ft. Scattered showers with a chance of tstms this morning, then widespread showers with a chance of tstms this afternoon. Vsby 1 nm or less.
Tonight..NE winds 5 to 10 kt. Gusts up to 20 kt in the late evening and overnight. Waves 1 ft. Widespread showers with a chance of tstms. Vsby 1 nm or less.
Sat..N winds 10 to 15 kt with gusts to 25 kt. Waves 1 ft. Showers. Vsby 1 nm or less.
Sat night..N winds 10 to 15 kt with gusts to 25 kt. Waves 1 ft. A chance of showers.
Sun..N winds 10 kt. Waves 1 ft.
Sun night..N winds 5 to 10 kt. Waves 1 ft.
Mon..W winds around 5 kt. Waves 1 ft or less.
Tue..W winds 5 kt. Waves less than 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 731 Am Edt Fri Jul 28 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will approach the waters today and then intensify as it moves over the mid atlantic tonight. The low is expected to stall out over the delmarva peninsula Saturday into early Sunday before moving out to sea late Sunday into Monday. A small craft advisory may be needed Sunday into Monday. A gale warning may be needed for portions of the waters Saturday afternoon through Saturday night.

7 Day Forecast for Marine Location Near Arden on the Severn, MD
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location: 39.07, -76.58     debug

Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 280755
area forecast discussion
national weather service baltimore md washington dc
355 am edt Fri jul 28 2017

Upper-level low pressure system will intensify as it moves into the
area through tonight. The low will slowly pass through the area
Saturday before gradually moving away from the coast Saturday night
into Monday. High pressure is expected to build overhead early next

Near term through tonight
Active near-term forecast as potent compact upper- mid-level low
dives south from the great lakes and interacts with nearby frontal
boundary to induce cyclogenesis over the area. Strong
frontogenetical forcing amidst an anomalously moist (pwats surging
near 2 inches by afternoon evening) and modestly unstable airmass
will foster convective elements that are very efficient rainfall
producers... With heavy rainfall likely over a rather large area.

In coordination with NWS akq... Expanded the flash flood watch just a
bit further south into central va... As latest guidance suggests a
slight southward shift with the heaviest rainfall. Otherwise, watch
appears to be in good shape, with most guidance suggesting a belt
of heavy rainfall across the area near north of the surface low
track. Pwats near 2 inches suggest rainfall rates potentially
in excess of 2 inches per hour in the heaviest activity... With a
storm total of 2- 4+ inches possible over the watch area.

In terms of timing... Spotty shower and thunderstorm coverage through
early morning. Coverage expected to increase by afternoon, with the
heaviest rainfall expected from late afternoon into the overnight as
the surface low rides crosses the area as it traverses the frontal
boundary. While some areas may temporarily dry out early Saturday as
the area of precipitation near the surface shifts east of the area,
trowal precipitation (some of which may be of moderate intensity)
may shift south into parts of the area.

While hydro issues are the primary threat today... Some severe
thunderstorm potential does exist... With a marginal risk from spc.

The primary threat is isolated strong wind gusts due to modest
instability and relatively strong shear profiles.

Short term Saturday through Sunday night
Surface low remains east of the area Saturday with trowal
precipitation remaining over the area (some of which could be of
moderate intensity). Soils expected to be saturated over much of the
area... So while precipitation Saturday should be a bit lighter in
intensity... Any additional precipitation could exacerbate hydro

Cloud cover and nearby precipitation will keep temperatures in the
60s to l70s Saturday.

Drying out Sunday as low moves far enough to our east keeping
precipitation east of the area.

Long term Monday through Thursday
High pressure will be building across the mid atlantic for the
beginning of next week, providing an extended period of tranquil
weather. The only concern will be whether a cold front will drop
down into the area to provide a focus for showers thunderstorms
Thursday. There will be plenty of time to resolve that detail.

Temperatures will start the week mild-- almost cool-- for the last
day of july, and gradually warm through the week.

Aviation 08z Friday through Tuesday
Low pressure will approach the terminals today before moving
overhead and intensifying tonight. Widespread showers and
thunderstorms are expected to develop with locally heavy rain and
subsequent flight restrictions at times. Some storms may also
contain gusty winds. More rain is likely Saturday as the low stalls
out near the DELMARVA peninsula. Gusty north to northeast winds are
also possible during this time. Improving conditions Sunday as
surface low shifts well east of the area.

No aviation concerns anticipated under building high pressure.

Low pressure will approach the waters today before strengthening
overhead tonight. The low will likely stall out near the delmarva
peninsula Saturday through Saturday night. Gusty winds are possible
with the low nearby... Especially tonight through Saturday night.

Issued a small craft advisory with this package for tonight through
Saturday night for the bay and for the 2 3 of the tidal potomac for
the day Saturday. Gale force winds are possible Saturday
afternoon evening... Though probability of occurrence is currently
too low for a warning.

During afternoon mixing in the wake of low pressure, momentum
transfer may be sufficient for small craft gusts Monday. Aside from
that, no flags expected as high pressure builds.

A flash flood watch remains in effect this afternoon through
Saturday afternoon for the northern 2 3 of the forecast area.

Most likely rainfall amounts during this time will be around 2
to 4 inches (with locally higher amounts). This may cause
instances of flash flooding.

Pqpf from wpcs 70 member ensemble shows storm total precipitation of
1 3 5 inches at the 10 50 90th percentiles. Long-term nature of
the threat suggests that river flood risk could arise over the
weekend. Though, current mmefs guidance suggest any threat could
be localized... Particularly across the potomac river basin.

Tides coastal flooding
Water level departures starting to ease lower... A trend that's
likely to continue in light of anomalies of a half to 2 3rds of a
foot in the virginia waters. While onshore flow should be a
mitigating factor today, the duration of such winds will be minimal,
and will be followed by northerly blowouts. In the end, believe that
tides will reach action stage at worst today, and that would be for
vulnerable sections of the coastline such as straits point and
annapolis. This solution supported by not just etss but also snap-ex
ensemble guidance. Subsequent tide cycles should be unaffected.

Lwx watches warnings advisories
Dc... Flash flood watch from 2 pm edt this afternoon through
Saturday afternoon for dcz001.

Md... Flash flood watch from 2 pm edt this afternoon through
Saturday afternoon for mdz003>006-011-013-014-016>018-

Va... Flash flood watch from 2 pm edt this afternoon through
Saturday afternoon for vaz027>031-038>040-050>057-501-502-

Wv... Flash flood watch from 2 pm edt this afternoon through
Saturday afternoon for wvz050>053-055-501>504.

Marine... Small craft advisory from 5 am Saturday to 7 am edt Sunday for

Small craft advisory from 10 am to 7 pm edt Saturday for

Small craft advisory from 11 pm this evening to 7 am edt
Sunday for anz534-537-543.

Synopsis... Mse
near term... Mse
short term... Mse
long term... Hts
aviation... Mse hts
marine... Mse hts
hydrology... Mse
tides coastal flooding... Hts

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
APAM2 - 8575512 - Annapolis, MD 8 mi45 min 79°F 1009.4 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 11 mi45 min E 8 G 9.9 76°F 1010 hPa
CPVM2 11 mi45 min 78°F 78°F
TPLM2 - Thomas Point, MD 14 mi63 min NE 2.9 G 4.1 78°F 81°F
BLTM2 - 8574680 - Baltimore, MD 14 mi45 min E 7 G 8 75°F 82°F1009.8 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 20 mi45 min E 5.1 G 7 75°F 82°F1010.5 hPa
BSLM2 - Chesapeake Bay, MD 21 mi153 min Calm 65°F 1010 hPa64°F
WASD2 - 8594900 - Washington, DC 27 mi45 min WNW 5.1 G 7 77°F 84°F1009.5 hPa
44061 - Upper Potomac, MD 31 mi45 min 76°F 1010.3 hPa
CA2 - 8571892 - Cambridge, MD 44 mi51 min 81°F 83°F1010.6 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 47 mi45 min WNW 2.9 G 5.1 78°F 1010.5 hPa

Wind History for Francis Scott Key Bridge NE Tower, MD
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1 day
2 days

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Annapolis, United States Naval Academy, MD8 mi69 minENE 47.00 miMostly Cloudy80°F79°F97%1010 hPa
Fort Meade / Tipton, MD10 mi75 minN 07.00 miOvercast72°F69°F94%1010.8 hPa
Baltimore, Baltimore-Washington International Airport, MD10 mi69 minNE 66.00 miFog/Mist77°F75°F94%1009.8 hPa
Bay Bridge Field, MD15 mi78 minENE 67.00 miFog/Mist77°F75°F94%1009.8 hPa
Baltimore, Inner Harbor, MD15 mi69 minno data mi77°F75°F94%1010.2 hPa
College Park Airport, MD19 mi75 minN 010.00 miOvercast74°F70°F89%1010.2 hPa
Baltimore / Martin, MD20 mi73 minN 010.00 miOvercast77°F75°F94%1010.5 hPa
Camp Springs / Andrews Air Force Base, MD23 mi65 minN 310.00 miMostly Cloudy77°F73°F89%1010.2 hPa

Wind History from NAK (wind in knots)
Last 24hr44SE10SE12S8S7S7SW6S8SE6SE5S7CalmCalmS3SE3CalmCalmCalmCalmE4NE4NE4NE5
1 day agoSE7E7SE5SE8SE7SE9SE7SE6SE7SE10SE17SE16SE16SE13SE12SE12SE11S8S4S7S86S6SW7
2 days agoNW9N11N5N8NW7NW5N5N4NE3N5NW7N4N6N5N5N6N6N4CalmN5E6E7E8E8

Tide / Current Tables for Cedar Point, Severn River, Maryland
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Cedar Point
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Fri -- 04:36 AM EDT     0.37 feet Low Tide
Fri -- 06:03 AM EDT     Sunrise
Fri -- 10:21 AM EDT     1.03 feet High Tide
Fri -- 11:39 AM EDT     Moonrise
Fri -- 05:05 PM EDT     0.24 feet Low Tide
Fri -- 08:21 PM EDT     Sunset
Fri -- 11:11 PM EDT     1.02 feet High Tide
Fri -- 11:44 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

Tide / Current Tables for Baltimore Harbor Approach, Maryland Current
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Baltimore Harbor Approach
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Fri -- 12:47 AM EDT     -0.00 knots Slack
Fri -- 03:39 AM EDT     -0.72 knots Max Ebb
Fri -- 06:02 AM EDT     Sunrise
Fri -- 06:34 AM EDT     0.00 knots Slack
Fri -- 09:37 AM EDT     0.77 knots Max Flood
Fri -- 11:38 AM EDT     Moonrise
Fri -- 12:34 PM EDT     -0.00 knots Slack
Fri -- 03:54 PM EDT     -0.95 knots Max Ebb
Fri -- 07:09 PM EDT     0.00 knots Slack
Fri -- 08:20 PM EDT     Sunset
Fri -- 10:23 PM EDT     0.92 knots Max Flood
Fri -- 11:43 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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

GOES Local Image of Mid-Atlantic    EDIT

Wind Forecast for Baltimore, MD/Washington (9,2,3,4)
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Ground Weather Radar Station Dover AFB, DE
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weather_mapweather_map weather_map

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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 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 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.