Wednesday, August23, 2017

Marine Weather and Tides
Grasonville, 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 6:24AMSunset 7:48PM Wednesday August 23, 2017 4:21 AM EDT (08:21 UTC) Moonrise 7:19AMMoonset 8:08PM Illumination 1% Phase: Waxing Crescent; Moon at 1 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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ANZ540 Eastern Bay- 258 Am Edt Wed Aug 23 2017
.small craft advisory in effect until 5 am edt early this morning...
Overnight..SW winds 10 kt with gusts to 20 kt. Waves 2 ft. A chance of showers.
Wed..N winds 5 to 10 kt. Waves 1 ft.
Wed night..N winds 5 to 10 kt. Waves 1 ft.
Thu..NE winds 5 to 10 kt. Waves 1 ft.
Thu night..N winds around 5 kt. Waves 1 ft or less.
Fri..N winds 5 to 10 kt. Waves 1 ft.
Fri night..N winds 5 to 10 kt. Waves 1 ft.
Sat..NE winds 5 to 10 kt. Waves 1 ft.
Sun..NE winds 5 to 10 kt. Waves 1 ft.
ANZ500 258 Am Edt Wed Aug 23 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A cold front will cross the waters late tonight into early Wednesday. High pressure will return for the second half of the week.

7 Day Forecast for Marine Location Near Grasonville, MD
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location: 38.88, -76.25     debug

Area Discussion for - Philadelphia/Mount Holly, PA
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Fxus61 kphi 230746
area forecast discussion
national weather service mount holly nj
346 am edt Wed aug 23 2017

A cold front will slowly cross our region through the morning
hours before moving off shore late today. High pressure is then
expected to build towards the northeastern u.S. And remain over
our region into early next week. A low pressure system off the
east coast could affect our weather mid week next week.

Near term until 6 pm this evening
As of 3 am edt, the cold front is on the door step of SE and e
central pa. It has been making steady progress over the last 6
hours. Based on the observed trends, expect it to move into our
region within the next hour, and into the i-95 corridor by 6 am.

It will then likely slow its progress east thanks to increased
daytime mixing and may linger on the coastal plains (especially
southern delmarva) through mid day. Adjusted pops to keep a
mention of showers and thunderstorms along and ahead of where we
expect the front to be. Though shower activity has mostly
diminished for now, expect to see some additional development
ahead of the front near or after sunrise (though do not expect
as widespread coverage as what we saw overnight).

Mos guidance doesn't appear to be handling the front and the
effect on highs very well, so went with a blend of operational
models which show below normal highs along and west of the fall
line. Even for the eastern coastal plains which may stay in the
warm sector until just before peak heating, clouds could limit
highs through the day.

Short term 6 pm this evening through 6 am Thursday
Clearing skies and cold air advection will promote below normal
temperatures across the region. The one question will be if we
will see any fog development overnight. At this point, have not
mentioned it in the forecast as we should also see considerable
dry air advection behind the front.

Long term Thursday through Tuesday
500 mb: a -2sd trough begins the long term period in the great
lakes region, then weakens slightly as it moves into the
northeast Friday- Monday. Thereafter, we will monitor the
northeastward progress of what should be a split flow low of
tropical origins, having moved ashore along the gulf coast by
early next week.

Temperatures: calendar day averages Thursday... Near or slightly
below normal, then 2 to 6 degrees below normal daily Friday-

Forecast basis: a 50 50 blend of 12z 22 GFS nam MOS was used
Wednesday night-Thursday night, then the 12z 22 GFS mexmos was
applied Friday and thereafter the 15z 22 wpc d4-8 gridded
elements of MAX min t, 12 hr pop 6 hrly dew wind sky.

Thursday... Scattered light showers possible late Thursday in e
pa with considerable afternoon cloudiness.

Friday-Monday... High pressure shifts southeastward into the
great lakes Thursday through Saturday,then eastward into
southeastern canada northeast u.S. Sunday and Monday. This
expansive high will control our regional weather pattern across
the mid atlantic during this time. The trough aloft could result
in a shower north of i-78 Friday afternoon and there should be
considerable cloudiness at that time. Otherwise, for now, good
weather is predicted.

Tuesday... WAA overrunning clouds, if not rain, from a potential
tropical remnant moving northeastward from the gulf coast.

Aviation 08z Wednesday through Sunday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.

Once showers and low clouds move off shore later this morning,
expect mostlyVFR conditions for the remainder of the taf

A cold front will be moving through the region between 09 and
18z. Behind this cold front, expect northwesterly winds around
10kt with some higher gusts especially just behind the front.

After 00z, wind speeds should diminish below 10kt.


Thursday through Sunday...VFR. Generally light winds from the n
or nw, possibly becoming n-ne on Saturday and Sunday. Small
chance of a light shower vicinity kabe kttn krdg Thursday
afternoon and Friday afternoon.

Winds have dropped below 25 kt on the delaware bay, so the small
craft advisory has been cancelled for the bay. On the atlantic
coastal waters, waves and winds are diminishing, but there are
still some locations reporting SCA conditions, so will keep the
sca going for now. Once the winds and waves diminish this
morning, expect sub-sca conditions for the remainder of today
and tonight. For locations that still have southwesterly winds,
expect a wind shift to northwesterly by mid day as a cold front
moves through.


Thursday through Saturday... Winds and seas below SCA criteria.

Sunday... For no SCA headline but chance that northeast flow
will increase and cause hazardous seas to develop along the S nj
and de coasts Sunday (5 feet).

Rip currents...

Wednesday... At this point we are forecasting a low risk of rip
currents today as earlier elevated seas are diminishing quickly.

Phi watches warnings advisories
Pa... None.

Nj... None.

De... None.

Md... None.

Marine... Small craft advisory until 6 am edt early this morning for

Synopsis... Johnson
near term... Johnson
short term... Johnson
long term... Drag
aviation... Drag johnson
marine... Drag johnson

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
TPLM2 - Thomas Point, MD 10 mi81 min W 6 G 6 81°F 81°F
CPVM2 11 mi51 min 80°F 74°F
44063 - Annapolis 12 mi41 min NNW 5.8 G 5.8
APAM2 - 8575512 - Annapolis, MD 14 mi51 min 79°F 1008.6 hPa
44043 - Patapsco, MD 20 mi41 min W 7.8 G 9.7 80°F 1009.5 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 23 mi51 min WNW 5.1 G 7 79°F 83°F1009.3 hPa
CA2 - 8571892 - Cambridge, MD 23 mi51 min 80°F 83°F1010.1 hPa
44062 - Gooses Reef, MD 24 mi41 min WSW 5.8 G 9.7 82°F 1009.8 hPa
BSLM2 - Chesapeake Bay, MD 25 mi111 min Calm 76°F 1009 hPa72°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 28 mi51 min WSW 8 G 9.9 78°F 1008.8 hPa
BLTM2 - 8574680 - Baltimore, MD 32 mi51 min WSW 4.1 G 6 77°F 84°F1008.6 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 34 mi51 min NW 8 G 8.9 80°F 1010 hPa
SLIM2 - 8577330 - Solomons Island, MD 40 mi51 min NW 5.1 G 7 81°F 82°F
WASD2 - 8594900 - Washington, DC 41 mi51 min WNW 1.9 G 2.9 80°F 83°F1009 hPa
DRSD1 - Delaware Reserve, DE 45 mi111 min W 1.9 79°F 1010 hPa75°F
BISM2 - 8571421 - Bishops Head, MD 47 mi51 min SW 17 G 20 82°F 82°F1009.1 hPa
44057 - Susquehanna, MD 47 mi41 min SW 5.8 G 5.8 78°F 1008.9 hPa

Wind History for Cambridge, MD
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1 day
2 days

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Bay Bridge Field, MD8 mi36 minWNW 410.00 miFair79°F71°F79%1009.1 hPa
Easton / Newman Field, MD11 mi22 minWNW 310.00 miFair80°F73°F81%1010.5 hPa
Annapolis, United States Naval Academy, MD14 mi87 minW 310.00 miFair81°F73°F79%1009.1 hPa

Wind History from W29 (wind in knots)
Last 24hrS8S7SW4SW4S9S8S8SW8S5SW9S9S9S10S13
1 day agoCalmSE3CalmCalmS4SE5SE8SE10S8S11
2 days agoNW3N6N6N6N7N8N8N8N6N3N5N4NW3CalmSE4CalmCalmCalmCalmCalmCalmCalmCalmCalm

Tide / Current Tables for Claiborne, Eastern Bay, Maryland
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Click for Map
Wed -- 05:50 AM EDT     1.91 feet High Tide
Wed -- 06:26 AM EDT     Sunrise
Wed -- 08:19 AM EDT     Moonrise
Wed -- 12:43 PM EDT     0.42 feet Low Tide
Wed -- 06:15 PM EDT     1.66 feet High Tide
Wed -- 07:48 PM EDT     Sunset
Wed -- 09:08 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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Wed -- 12:40 AM EDT     -0.87 knots Max Ebb
Wed -- 03:35 AM EDT     0.00 knots Slack
Wed -- 06:26 AM EDT     Sunrise
Wed -- 06:50 AM EDT     1.03 knots Max Flood
Wed -- 08:19 AM EDT     Moonrise
Wed -- 10:00 AM EDT     -0.00 knots Slack
Wed -- 01:11 PM EDT     -1.05 knots Max Ebb
Wed -- 04:25 PM EDT     0.00 knots Slack
Wed -- 07:26 PM EDT     0.93 knots Max Flood
Wed -- 07:48 PM EDT     Sunset
Wed -- 09:09 PM EDT     Moonset
Wed -- 10:32 PM EDT     -0.00 knots Slack
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 Philadelphia/Mount Holly, PA (4,6,7,8)
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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.