Saturday, April29, 2017 L-36.com


Marine Weather and Tides
Galesville, 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 6:07AMSunset 7:59PM Saturday April 29, 2017 7:12 AM EDT (11:12 UTC) Moonrise 8:00AMMoonset 10:41PM Illumination 12% Phase: Waxing Crescent; Moon at 3 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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ANZ532 Chesapeake Bay From Sandy Point To North Beach- 432 Am Edt Sat Apr 29 2017
Rest of the overnight..S winds 10 kt. Waves 1 ft. A slight chance of showers and tstms.
Today..SW winds 10 kt. Waves 1 ft. A chance of showers and tstms.
Tonight..S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Sun..SE winds 5 to 10 kt. Waves 1 ft.
Sun night..S winds 5 to 10 kt. Waves 1 ft.
Mon..S winds 10 to 15 kt with gusts to 20 kt. Waves 2 to 3 ft. A chance of showers and tstms.
Mon night..SW winds 10 to 15 kt with gusts to 20 kt. Waves 3 ft. Showers and tstms likely.
Tue..W winds 10 to 15 kt. Waves 1 to 2 ft. A chance of showers in the morning.
Wed..W winds 5 to 10 kt...becoming ne. Waves 1 ft. A chance of showers through the night. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 432 Am Edt Sat Apr 29 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A semi-stationary frontal boundary just north of the mason-dixon line will move south this afternoon and remain over the waters through early Sunday...before lifting north as a warm front late Sunday afternoon. A cold front will cross the mid-atlantic Monday night with canadian high pressure then building over the area through Wednesday. A small craft advisory is likely Monday into Tuesday.

7 Day Forecast for Marine Location Near Galesville, MD
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location: 38.85, -76.53     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 290747
afdlwx
area forecast discussion
national weather service baltimore md/washington dc
347 am edt Sat apr 29 2017

Synopsis
A frontal boundary just north of the mason-dixon line will move
south this afternoon and remain over the region through early
Sunday... Before lifting north as a warm front late Sunday afternoon.

A cold front will then cross the mid-atlantic late Monday. Weak low
pressure moves into the region Tuesday before a surface trough
develops Wednesday as strong low pressure develops over the
tennessee valley and heads towards the mid-atlantic Thursday and
Friday.

Near term /through tonight/
Latest surface analysis indicates that the warm front has return to
the northern reaches of the forecast area. South of the front not
only is it warmer, but its also more humid... With requisite amounts
of increased instability as well. Isentropic lift and copious shear
has been acting on this airmass discontinuity, and producing a swath
of showers and thunderstorms. East of the appalachians there is a
capping inversion in place, and thus the storms have mostly been
losing their root in the boundary layer. However, precipitation
has been overspreading the northern reaches of the forecast
area rather quickly, and have bumped pops up considerably
petersburg-metro dc northward through sunrise. This activity
will be raining itself out through dawn, but will leave behind
implications for the daytime hours.

There is ample ridging in place today, with plenty of warmth
supporting temps to rise to/above 90 degrees. In light of this heat,
mucape forecast to increase to 2000-3000 j/kg... Or higher... With
minimal cin. But, the northern portion of the forecast area will
first need to recover from the early morning rainfall. Have shaved a
degree or two off high temps across northern maryland and eastern
west virginia. In turn, this would provide a differential heating
boundary. Believe that would be enough in this volatile air mass for
late day showers/thunderstorms to develop. While heavy rain would be
primary threat (due to atypical precipitable water for late april),
would not rule out localized strong wind gusts or large hail in
taller storms (and thunderstorms today likely to be quite tall). Spc
concurs, placing the northern forecast area in marginal risk.

Thunderstorms will gradually decrease in coverage upon loss of
diurnal heating. However, there will be enough fuel lingering to
justify chance pops overnight.

Short term /Sunday through Monday night/
Similar considerations apply to Sunday's forecast, ie: the lingering
surface boundary and a warm/unstable air mass to its south. An
east/onshore flow across northeast maryland may provide a
stabilizing influence, and focus storms in the potomac highlands,
where terrain/upslope will provide another lifting mechanism. This
time, instability will wane with sunset. And, since flow will be
onshore, have no reason to dispute slightly cooler high temperatures
per superblend... Which still are about 10 degrees above normal.

On Monday, a deep low pressure system will work from the plains to
the great lakes, which will drag a cold front toward the forecast
area. Gfs/ecmwf timing is a little closer then previous, though
differences remain. Focus would be on the afternoon-evening hours.

However, instability does not look nearly as strong as during the
weekend, but there still will be ample shear and favorable
timing for a few strong thunderstorms.

Long term /Tuesday through Friday/
Per the 29/00z gefs, the h5 low over the upper great lakes early
Tuesday lifts northeastward towards quebec, followed by slight
height rises through Thursday. On Thursday, a digging h5 trough
moves into the tennessee valley, and slowly makes it way towards the
northeast u.S.

The surface reflection of the upper levels reveal strong northwest
flow on Tuesday, followed by a saddle point in the surface pressure
field and stalled frontal boundary as low pressure develops in the
tennessee valley on Thursday and slowly makes its way to the
chesapeake bay region.

It should be noted that the deterministic 20/00z ECMWF has a closed
upper low for the thu/fri system as opposed to an open, albeit slow-
moving, wave per the 29/00z GEFS solution. This is to be expected
with the GEFS as the various solutions are damping out details of
the position of the upper low, and the 29/00z GFS deterministic has
a substantial, deep, cut h5 low. Both the 29/00z GFS and ECMWF seem
to be in harmony with similar solutions.

At this time, the sensible outcome of this strong low pressure
system looks to be a considerable, slow-moving nor'easter rainstorm
for the region in the Thursday-to-Friday timeframe.

Aviation /08z Saturday through Wednesday/
Showers and thunderstorms will be working across northern terminals
this morning. At this point, have been reserved in forecasting
restrictions, but did offer 06z tafs that were more pessimistic.

Will be monitoring activity and adjust as needed. Ifr likely within
thunderstorms, but direct strikes will be limited. Suspect a more
widespread MVFR possible.

Early morning activity likely to linger past daybreak before
breaking apart. Ample daytime heat will lead to scattered late day
thunderstorms, with local flight restrictions and gusty winds likely.

Areal coverage once again the mitigating factor.

Threat of flight restrictions will linger overnight/into Sunday
morning, with areas of fog possibly developing. Daytime Sunday will
carry a renewed thunderstorm risk, although areal coverage and
strength of storms potentially could be less.

A cold front will cross the terminals Monday afternoon/evening, with
yet another opportunity for thunderstorms/local AOB ifr.

PrimarilyVFR should prevail thuesday-Wednesday.

Marine
There will be several opportunities for thunderstorms this weekend,
each of which could carry locally strong wind gusts. Early this
morning will be the first round, although most of the winds likely
won't mix to the water. The same can't be said for late day Saturday
(today) into tonight, and again on Sunday. Finally, a cold front
will arrive Monday night.

In advance of the front, the gradient wind will increase from the
south. That will be the first chance at small craft advisories.

Marine warnings possible prior to that.

Northwest flow on Tuesday will likely bring small craft conditions
to the waters. As low pressure moves through the region in the
Thursday-to-Friday timeframe, additional small craft advisories may
be required.

Tides/coastal flooding
Water levels have retreated to near normal, with no complications
anticipated this weekend. That should be the case for much of the
week. By the end of the week though, a coastal low is likely to
cause elevated water levels once again.

Climate
The time periods to watch will be high temperatures today, and
warm overnight lows this weekend. Here are the record highs/warm
lows through the weekend:
washington dc...

Saturday 29 april... 91 (in 1974)/68 (in 1956)
Sunday 30 april... 92 (in 1942)/67 (in 1983)
bwi airport...

Saturday 29 april... 91 (in 1974)/67 (in 1956)
Sunday 30 april... 92 (in 1910)/63 (in 1983)
dulles airport..

Saturday 29 april... 87 (in 1996)/62 (in 1996)
Sunday 30 april... 86 (in 2007)/64 (in 1983)
also of note... The warmest night time low at dca in april is 69
degrees. That could be challenged tonight.

Lwx watches/warnings/advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Lee
near term... Hts
short term... Hts
long term... Lee
aviation... Hts
marine... Hts/lee
tides/coastal flooding... Hts
climate... Hts


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
TPLM2 - Thomas Point, MD 6 mi72 min S 16 G 17 67°F 60°F
44063 - Annapolis 9 mi42 min SSW 14 G 18 68°F 1014.8 hPa
APAM2 - 8575512 - Annapolis, MD 10 mi54 min 70°F 1014.5 hPa
BSLM2 - Chesapeake Bay, MD 11 mi162 min W 4.1 68°F 1017 hPa65°F
CPVM2 13 mi54 min 66°F 66°F
44062 - Gooses Reef, MD 21 mi42 min WSW 14 G 14 68°F 1016.3 hPa
44043 - Patapsco, MD 22 mi42 min S 9.7 G 12 66°F 1015.3 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 25 mi54 min SSW 8.9 G 12 73°F 1014.2 hPa
FSNM2 25 mi54 min SSW 8 G 13 73°F 1014.2 hPa
WASD2 - 8594900 - Washington, DC 26 mi54 min S 8 G 11 71°F 67°F1015.2 hPa
BLTM2 - 8574680 - Baltimore, MD 29 mi54 min W 2.9 G 5.1 72°F 65°F1014.2 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 29 mi54 min SSW 11 G 17 71°F 63°F1015 hPa
CA2 - 8571892 - Cambridge, MD 31 mi60 min 71°F 65°F
COVM2 - 8577018 - Cove Point LNG Pier, MD 32 mi54 min WSW 16 G 20 74°F 1017.5 hPa
SLIM2 - 8577330 - Solomons Island, MD 37 mi54 min SW 13 G 16 71°F 62°F
NCDV2 45 mi60 min SSW 8.9 G 11 74°F 68°F1016.5 hPa
PPTM2 - 8578240 - Piney Point, MD 49 mi54 min WSW 4.1 G 4.1

Wind History for Francis Scott Key Bridge NE Tower, MD
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Annapolis, United States Naval Academy, MD9 mi78 minS 67.00 miFair72°F71°F97%1015.2 hPa
Bay Bridge Field, MD14 mi32 minS 117.00 miFog/Mist72°F68°F88%1015.2 hPa
Camp Springs / Andrews Air Force Base, MD18 mi74 minS 1010.00 miFair69°F66°F90%1016.4 hPa
Fort Meade / Tipton, MD21 mi33 minSW 65.00 miFair64°F62°F94%1016.3 hPa
College Park Airport, MD23 mi31 minS 510.00 miFair71°F65°F83%1015.9 hPa

Wind History from ADW (wind in knots)
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Last 24hrSW4NW7NW5W4SW5W5CalmS6SW6SW7S5S7SE9SE7S5S7S7S9S6S6W7SW5S10SW11
1 day agoE5E5S4S5SW8S10S11S9S13S14S14S10S7S8S9SW11SW13SW6SW9SW10SW6SW4W7SW4
2 days agoNW6NW7NW7NW6N7N7N5NW4NW5N5NE4E6SE5SE4SE3SE3CalmSE3CalmSE5SE3CalmCalm--

Tide / Current Tables for Shady Side, West River, Maryland
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Shady Side
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Sat -- 01:18 AM EDT     0.12 feet Low Tide
Sat -- 06:10 AM EDT     Sunrise
Sat -- 07:39 AM EDT     1.60 feet High Tide
Sat -- 09:00 AM EDT     Moonrise
Sat -- 03:10 PM EDT     0.18 feet Low Tide
Sat -- 07:56 PM EDT     Sunset
Sat -- 08:10 PM EDT     1.00 feet High Tide
Sat -- 11:41 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.20.10.20.30.611.31.61.61.51.210.70.40.30.20.20.40.70.9110.80.6

Tide / Current Tables for Baltimore Harbor Approach, Maryland Current
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Baltimore Harbor Approach
Click for Map
Sat -- 01:35 AM EDT     -0.74 knots Max Ebb
Sat -- 04:17 AM EDT     0.00 knots Slack
Sat -- 06:09 AM EDT     Sunrise
Sat -- 07:56 AM EDT     1.24 knots Max Flood
Sat -- 08:59 AM EDT     Moonrise
Sat -- 11:22 AM EDT     -0.00 knots Slack
Sat -- 02:40 PM EDT     -1.14 knots Max Ebb
Sat -- 06:17 PM EDT     0.00 knots Slack
Sat -- 07:56 PM EDT     Sunset
Sat -- 08:50 PM EDT     0.61 knots Max Flood
Sat -- 11:32 PM EDT     -0.00 knots Slack
Sat -- 11:41 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.5-0.7-0.7-0.5-0.10.30.81.11.21.10.70.2-0.3-0.8-1.1-1.1-0.9-0.6-0.10.30.50.60.50.2

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 Baltimore, MD/Washington (7,2,3,4)
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Ground Weather Radar Station Dover AFB, DE
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weather_mapweather_map weather_map

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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.