Friday, July21, 2017

Marine Weather and Tides
Arnold, 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 5:56AMSunset 8:28PM Friday July 21, 2017 12:43 AM EDT (04:43 UTC) Moonrise 3:04AMMoonset 5:51PM Illumination 7% Phase: Waning Crescent; Moon at 27 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- 1031 Pm Edt Thu Jul 20 2017
Rest of tonight..W winds 5 kt. Waves less than 1 ft.
Fri..W winds 5 kt. Waves flat.
Fri night..N winds around 5 kt. Waves flat. A chance of showers and tstms.
Sat..SE winds 5 kt. Waves flat. A chance of showers and tstms.
Sat night..SW winds around 5 kt. Waves flat. A chance of showers and tstms.
Sun..SW winds 5 to 10 kt. Waves 1 ft or less. A chance of showers and tstms.
Sun night..W winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Mon..NW winds 5 kt. Waves less than 1 ft. A chance of showers and tstms in the morning.
Tue..N winds 5 to 10 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1031 Pm Edt Thu Jul 20 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Light flow is expected with high pressure to the south through the weekend. Tranquil weather expected although daily scattered Thunderstorms are expected in the afternoon and evening mainly Saturday and Sunday.

7 Day Forecast for Marine Location Near Arnold, MD
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location: 39.03, -76.53     debug

Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 210104
area forecast discussion
national weather service baltimore md washington dc
904 pm edt Thu jul 20 2017

Weak high pressure will remain over the region
through tonight, followed by the potential for weak
disturbances Friday through Sunday. An upper level trough of low
pressure will move over the northeastern us early in the new

Near term through Friday
Very warm and humid this evening across the mid-atlantic region.

The 8pm ob at dca came in with 91 77 with a south wind and heat
index of 105. Warm and humid conditions will continue overnight
with temps only dropping into the 70s and low 80s in the metros
and near the bay.

Showers and thunderstorms have been approaching the region from
pa and the ohio valley this evening. Activity has been
weakening as nocturnal inversions set-up. Showers will likely
enter the potomac highlands and northern md tonight but
dissipate as they move further south. Most areas will be dry

A heat advisory is in effect for much of the region east of the
blue ridge from 10am-8pm Friday. Heat indices around 105 are
forecast to occur with dewpts climbing into the low 70s. Temps
in the mid to upper 90s expected by afternoon.

For tomorrow, models don't indicate much change in maxt so
temperatures will be as hot as they are today. Moisture might be
a little higher with 850 mb and sfc dewpoints progged much
higher than today. Heat advisories will likely be needed again
for most of the area similar to today.

Showers and thunderstorms expected to form across the
appalachian mtns Friday afternoon and move eastward into the
evening. Shear is still minimal however instability will be high
due to the high dewpts. Isolated thunderstorms may become
strong to severe.

Short term Friday night through Saturday night
Potentially active convective day Saturday afternoon and
evening. Both GFS and ECMWF show an MCS over the lower great lks
moving sewd across the fcst area Sat afternoon and evening. As
always with summertime convection, details especially with
respect to timing are very uncertain this far out. Continued hot
and humid with heat advisories still likely to be needed.

Long term Sunday through Thursday
Upper level energy from the west will set up a trough of low
pressure on the leeside of the appalachians Sunday into Sunday
night. Additional showers and thunderstorms could form along this
trough but could mainly be isolated to scattered. Highs will reach
the middle to upper 90s.

A cold front will approach the region Monday before pushing across
the region Monday night. Showers and thunderstorms will develop
along and ahead of this front. Highs will reach the 90s again.

The front could stall just to our south Tuesday, allowing for a
couple of showers or a thunderstorm to develop.

High pressure will build in from the west and northwest Tuesday
night through Thursday. Temperatures will be nearly 10 degrees
cooler than previous days with a comfortable relative humidity.

Aviation 01z Friday through Tuesday
Hot and hazy next few days. Sct-nmrs t-storms mainly sat.

MVFR to ifr conditions possible with showers and thunderstorms
Sunday through Monday night. Winds southwest becoming west-northwest
5 to 10 knots Sunday into Sunday night. Winds northwest becoming
southwest 5 to 10 knots Monday and Monday night.

Potential for showers and thunderstorms Fri night and
Saturday and again Sun which may require special marine

No marine hazards expected Sunday through Monday night. Winds
southwest 10 knots Sunday and Sunday night. Winds southwest 5 to 10
knots Monday and Monday night.

Late july is climatologically the warmest time of the year,
just like six months from now is the coldest time. How has the
heat of 2017 compared with heat waves (up to now) in other
years? I chose "consecutive days that reached 90 and above" as
the criteria.

At dca there have been two times this summer with stretches of
six consecutive days - beginning june 29 and again july 10. In
terms of ranking (going back to 1871) these are #47 and 48. #1
(18 consecutive days) occurred 145 years ago - beginning
6 27 1872!
for baltimore there were also six consecutive days beginning
june 29, which puts it in 36th place. #1 was 13 consecutive days
beginning 7 3 1993.

The all-time record for june-aug: for baltimore 25 consecutive
days beginning 7 12 1995. For dc there have been two periods of
21 consecutive days - beginning 7 29 1988 and 7 25 1980.

Lwx watches warnings advisories
Dc... Heat advisory from 10 am to 8 pm edt Friday for dcz001.

Md... Heat advisory from 10 am to 8 pm edt Friday for mdz011-013-014-

Va... Heat advisory from 10 am to 8 pm edt Friday for vaz037>039-

Wv... None.

Marine... None.

Synopsis... Lfr
near term... Hsk lfr
short term... Lfr
long term... Klw
aviation... Lfr klw
marine... Lfr klw
climate... Woody! Hsk

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
APAM2 - 8575512 - Annapolis, MD 4 mi43 min 85°F 1012.8 hPa (+0.6)
44063 - Annapolis 6 mi33 min W 3.9 G 3.9 85°F 1 ft1013.9 hPa
CPVM2 8 mi43 min 84°F 79°F
TPLM2 - Thomas Point, MD 10 mi43 min SSW 11 G 12 84°F 82°F
44043 - Patapsco, MD 11 mi33 min SW 7.8 G 9.7 85°F 1 ft1013.6 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 13 mi43 min W 7 G 8 87°F 1013 hPa (+0.4)
BLTM2 - 8574680 - Baltimore, MD 17 mi43 min WNW 1.9 G 5.1 89°F 88°F1012.8 hPa (+0.5)
BSLM2 - Chesapeake Bay, MD 20 mi133 min Calm 79°F 1013 hPa75°F
TCBM2 - 8573364 - Tolchester Beach, MD 20 mi43 min S 4.1 G 6 84°F 88°F1013.4 hPa (+0.4)
WASD2 - 8594900 - Washington, DC 28 mi43 min SSW 5.1 G 5.1 86°F 87°F1013 hPa (+0.6)
44062 - Gooses Reef, MD 33 mi33 min SSW 9.7 G 12 85°F 1 ft1014.1 hPa
CA2 - 8571892 - Cambridge, MD 40 mi43 min 83°F 87°F1014.3 hPa (+0.3)
44057 - Susquehanna, MD 43 mi33 min W 1.9 G 3.9 85°F 1012.8 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 44 mi43 min SW 14 G 17 84°F 1014 hPa (+0.0)
SLIM2 - 8577330 - Solomons Island, MD 49 mi43 min SW 11 G 13 84°F 85°F

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, MD4 mi1.8 hrsSSW 49.00 miPartly Cloudy85°F77°F77%1013.3 hPa
Bay Bridge Field, MD11 mi58 minSSW 410.00 miPartly Cloudy84°F75°F74%1013.2 hPa
Fort Meade / Tipton, MD13 mi55 minN 010.00 miFair77°F71°F83%1014.2 hPa
Baltimore, Baltimore-Washington International Airport, MD13 mi49 minW 610.00 miOvercast85°F73°F68%1013.2 hPa
Baltimore, Inner Harbor, MD18 mi1.8 hrsno data mi91°F72°F54%1012.9 hPa
College Park Airport, MD21 mi55 minN 010.00 miPartly Cloudy83°F73°F73%1013.2 hPa
Baltimore / Martin, MD22 mi46 minS 310.00 miPartly Cloudy86°F78°F79%1013.5 hPa
Camp Springs / Andrews Air Force Base, MD23 mi45 minSSW 610.00 miMostly Cloudy83°F72°F72%1013.9 hPa

Wind History from NAK (wind in knots)
Last 24hrCalmCalmW4N5NE3CalmCalmCalmN5N3NE3SE7SE74S8SE8S8S7S5S5CalmCalmSW4Calm
1 day agoS3S4CalmCalmCalmCalmS33CalmN4CalmSE7SE8SE8SE10SE11SE9S8S7S7S4S4CalmCalm
2 days agoS5S3CalmS4S4S4S4CalmCalmSE8SE8SE8SE9S8S9S7SE6S6S8S9S10S8S5S5

Tide / Current Tables for Brewer Point, Maryland
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Brewer Point
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Fri -- 04:04 AM EDT     Moonrise
Fri -- 04:19 AM EDT     1.52 feet High Tide
Fri -- 05:57 AM EDT     Sunrise
Fri -- 11:45 AM EDT     0.34 feet Low Tide
Fri -- 04:26 PM EDT     0.89 feet High Tide
Fri -- 06:50 PM EDT     Moonset
Fri -- 08:27 PM EDT     Sunset
Fri -- 10:26 PM EDT     0.15 feet Low Tide
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 -- 03:40 AM EDT     1.25 knots Max Flood
Fri -- 04:03 AM EDT     Moonrise
Fri -- 05:56 AM EDT     Sunrise
Fri -- 07:16 AM EDT     -0.00 knots Slack
Fri -- 10:31 AM EDT     -1.05 knots Max Ebb
Fri -- 02:12 PM EDT     0.00 knots Slack
Fri -- 04:31 PM EDT     0.48 knots Max Flood
Fri -- 06:49 PM EDT     Moonset
Fri -- 06:56 PM EDT     -0.00 knots Slack
Fri -- 08:26 PM EDT     Sunset
Fri -- 10:02 PM EDT     -0.73 knots Max Ebb
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 (0,6,7,8)
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Ground Weather Radar Station Dover AFB, DE
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weather_mapweather_map weather_map

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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.