Thursday, May25, 2017 L-36.com


Marine Weather and Tides
Mason Neck, VA

Version 3.4
What's New / NOTES
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 5:46AMSunset 8:24PM Thursday May 25, 2017 2:18 PM EDT (18:18 UTC) Moonrise 4:57AMMoonset 7:15PM Illumination 0% Phase: New Moon; Moon at 0 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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ANZ535 Tidal Potomac From Key Bridge To Indian Head- 132 Pm Edt Thu May 25 2017
.small craft advisory in effect from Friday morning through Friday afternoon...
This afternoon..S winds 10 kt. Waves 1 ft. Numerous showers and scattered tstms.
Tonight..W winds 10 kt. Waves 1 ft. Numerous showers and scattered tstms.
Fri..W winds 10 to 15 kt. Gusts up to 20 kt. Waves 1 ft.
Fri night..NW winds 5 to 10 kt. Gusts up to 20 kt in the evening. Waves 1 ft.
Sat..S winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Sat night..E winds around 5 kt. Waves 1 ft. A chance of showers and tstms.
Sun..SW winds around 5 kt. Waves 1 ft. A chance of tstms. A chance of showers.
Mon..W winds around 5 kt. Waves 1 ft. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 132 Pm Edt Thu May 25 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure and its associated cold front will move through the area this evening. High pressure will build overhead Friday through Friday night before moving off the mid-atlantic coast Saturday. A warm front will stall out near the waters later Saturday and Sunday before a stronger cold front moves through Monday.

7 Day Forecast for Marine Location Near Mason Neck, VA
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location: 38.65, -77.13     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 251436
afdlwx
area forecast discussion
national weather service baltimore md washington dc
1036 am edt Thu may 25 2017

Synopsis
Low pressure and associated cold front will move
through the area late today. Weak high pressure will return to
the area Friday night and Saturday. A warm front will stall
over the region Saturday night. A stronger cold front will cross
the region late Sunday night.

Near term through Friday
Vertically stacked low pressure will move through the ohio
valley today. An occluded front associated with the low will
move into our area... And surface low pressure will develop along
that boundary overhead. Latest guidance shows a theta E ridge
along and ahead of the occluded boundary. Modified klwx sounding
shows close to 1000 j kg of MLCAPE this afternoon along and
ahead of the occluded boundary. The upper-level low to our west
will be building overhead later this afternoon into this
evening. Popup showers and thunderstorms are expected over the
area. Shear profiles will be weakening during peak heating this
afternoon... But they should still be strong enough to elevate
the threat for severe thunderstorms mainly for locations near
and to the north of the occluded boundary. Those areas appear to
extend from eastern west virginia across northern virginia
toward the washington and baltimore metropolitan areas. Locally
damaging winds and large hail are the primary concerns. Low
clouds still have to dissipate by early this afternoon for the
severe threat to be elevated. Current thinking is that the
marine layer is shallow enough this morning for the clouds to
mix out... But will have to monitor satellite trends closely.

Due to recent rainfall... Any heavy rainfall from thunderstorms
does pose a threat for localized flash flooding. However... It
appears that any threat would be localized so confidence is too
low for a watch at this time.

Low pressure will move to the north this evening and convection
will come to an end. A closed upper low will move overhead this
evening and the chance for showers will persist overnight.

Remnants from the upper low will persist across the region
Friday however the Sun should peak out of the clouds by
afternoon. The chance for showers will persist across the
highlands through Friday afternoon. Temps will range from the
l70s across the highlands to the u70s across the low-lying areas
Friday.

Short term Friday night through Saturday
High pressure will briefly move into the mid-atlantic region fri
night-sat morning. A warm front is expected to approach the region
during this time and clouds will increase from west to east through
sat morning. The front will settle across the region by Sat night
and showers will return to the region by this time. Uncertainty
exists regarding onset of showers Saturday. At this
time... Showers will likely move into the region from west to
east through the afternoon.

Long term Saturday night through Wednesday
A warm front will stall over the region Saturday night and will
serve as focus for showers and t-storms. Latest euro shows a
strong signal for a t-storm complex to roll through the region
late Sat into Sat evening. Given stationary nature of front and
potential for training convection, heavy rainfall and possible
flash flooding appear the biggest threat. Exact timing with
convection as it is typically remains far from certain, but
guidance suggest Sat afternoon and evening will be the best
chance for active wx.

A stronger cdfnt will move through Sun night with more showers
and t-storms Sun afternoon and evening. Given lack of strong
instability, heavy rainfall appears the biggest threat.

Quieter and drier weather returns for next week as low pressure
exits the region and westerly flow establishes.

Aviation 15z Thursday through Monday
Low clouds will gradually lift into early this afternoon. Popup
showers and thunderstorms are expected this afternoon into this
evening. Some TS may produce hail and gusty winds. Activity
moves to the north tonight andVFR conditions tonight through
Saturday.

Possible complex of t-storms will roll through the area sat
evening with heavy rainfall the primary threat. Then, more
t-storms Sunday afternoon as cdfnt moves through the area with
heavy rainfall again the primary threat.

Marine
Low pressure has moved overhead this morning. A small craft
advisory remains in effect for middle portions of the bay and
the lower tidal potomac river through tonight. A cold front
will pass through the waters tonight. W-nw winds expected on the
waters Friday and a small craft advisory is in effect for all
waters Friday. The advisory may be needed into Friday night.

Dry conditions early on Saturday before periods of showers and
thunderstorms move through Saturday night into Monday as front
stalls and moves across our region. Winds will be below the sca
threshold Saturday into Monday.

Gradient winds should remain below SCA away from convection.

Mariners should remain ALERT to possible issuance of smw's as
t-storms are forecasted.

Tides coastal flooding
Combination of high astronomical tides due to a new moon and
onshore flow will result in minor coastal flooding possibly
moderate flooding at straits point today and tonight. Advisories
have been extended through late this afternoon and evenings tide
cycle and a coastal flood watch is in effect for straits point
for late tonights high tide. Straight etss suggests more
westerly flow and negative anomalies preventing most other areas
from reaching moderate.

Lwx watches warnings advisories
Dc... Coastal flood advisory until 11 pm edt this evening for dcz001.

Md... Coastal flood advisory until 8 pm edt this evening for mdz014-
018.

Coastal flood advisory until 6 pm edt this evening for mdz016.

Coastal flood watch late tonight for mdz017.

Coastal flood advisory until 2 am edt Friday for mdz017.

Coastal flood advisory until noon edt today for mdz508.

Va... Coastal flood advisory until 6 pm edt this evening for vaz057.

Coastal flood advisory until 11 pm edt this evening for vaz054.

Wv... None.

Marine... Small craft advisory until 6 pm edt Friday for anz532>534-537-
540>543.

Small craft advisory until 11 am edt this morning for anz530-
531-538-539.

Small craft advisory from 6 am to 6 pm edt Friday for anz530-
531-535-536-538-539.

Synopsis... Lfr
near term... Bjl hsk
short term... Hsk
long term... Lfr
aviation... Bjl hsk lfr
marine... Bjl hsk lfr
tides coastal flooding... Lfr bjl


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44061 - Upper Potomac, MD 11 mi60 min WSW 9.7 G 9.7 65°F 67°F999.1 hPa
WASD2 - 8594900 - Washington, DC 16 mi60 min WSW 4.1 G 8.9 69°F 68°F998.6 hPa
NCDV2 23 mi60 min WSW 6 G 8.9 71°F 67°F998.3 hPa
BSLM2 - Chesapeake Bay, MD 24 mi168 min WSW 7 62°F 999 hPa58°F
44062 - Gooses Reef, MD 38 mi48 min W 9.7 G 12 70°F 999.9 hPa
TPLM2 - Thomas Point, MD 41 mi78 min WSW 6 G 6 67°F 64°F
APAM2 - 8575512 - Annapolis, MD 41 mi60 min 71°F 998.5 hPa
44063 - Annapolis 42 mi48 min W 5.8 G 9.7 68°F 998.7 hPa
SLIM2 - 8577330 - Solomons Island, MD 43 mi60 min WSW 5.1 G 7 73°F 66°F
COVM2 - 8577018 - Cove Point LNG Pier, MD 43 mi60 min W 11 G 14 72°F 999.8 hPa
CPVM2 46 mi60 min 69°F 65°F
PPTM2 - 8578240 - Piney Point, MD 48 mi60 min NNW 1.9 G 4.1

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Belvoir, VA6 mi20 minSSE 810.00 miMostly Cloudy69°F60°F73%999.6 hPa
Quantico Marine Corps Airfield - Turner Field, VA13 mi22 minSSE 610.00 miMostly Cloudy71°F63°F76%999.3 hPa
Washington/Reagan National Airport, DC, VA15 mi26 minS 910.00 miMostly Cloudy69°F62°F78%999.3 hPa
Camp Springs / Andrews Air Force Base, MD19 mi80 minSSW 1010.00 miMostly Cloudy68°F62°F81%999.9 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA21 mi22 minSSW 410.00 miOvercast71°F60°F68%999.9 hPa
Stafford, Stafford Regional Airport, VA24 mi23 minSSW 510.00 miMostly Cloudy70°F62°F77%1000.3 hPa

Wind History from DAA (wind in knots)
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Last 24hrE5SE6SE6E4SE4E6SE9SE8SE7SE5E4E4CalmE5E4E3CalmNW4NW3CalmSW4W5--S8
1 day agoCalmCalmE3E4SE3CalmCalmCalmCalmCalmNW3CalmCalmCalmCalmCalmCalmCalmCalmCalmSE3SE8SE6Calm
2 days agoCalmS3SE5S4S3CalmCalmNW3CalmCalmCalmNW4NW4NW5CalmCalmCalmN3CalmCalmE3E3CalmSE3

Tide / Current Tables for Gunston Cove, Virginia
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Gunston Cove
Click for Map
Thu -- 01:43 AM EDT     0.10 feet Low Tide
Thu -- 05:49 AM EDT     Sunrise
Thu -- 05:57 AM EDT     Moonrise
Thu -- 07:34 AM EDT     2.72 feet High Tide
Thu -- 02:42 PM EDT     -0.02 feet Low Tide
Thu -- 03:46 PM EDT     New Moon
Thu -- 08:13 PM EDT     2.31 feet High Tide
Thu -- 08:14 PM EDT     Moonset
Thu -- 08:22 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.40.20.10.30.91.72.32.72.72.41.81.30.80.40.1-00.30.91.62.12.32.21.81.2

Tide / Current Tables for Riverview, Potomac River, Maryland
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Riverview
Click for Map
Thu -- 02:04 AM EDT     0.16 feet Low Tide
Thu -- 05:48 AM EDT     Sunrise
Thu -- 05:56 AM EDT     Moonrise
Thu -- 07:54 AM EDT     3.44 feet High Tide
Thu -- 03:04 PM EDT     0.00 feet Low Tide
Thu -- 03:46 PM EDT     New Moon
Thu -- 08:14 PM EDT     Moonset
Thu -- 08:22 PM EDT     Sunset
Thu -- 08:32 PM EDT     2.91 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.70.30.20.30.91.82.73.33.43.22.51.81.20.70.200.20.91.82.52.92.92.41.8

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 (14,3,4,5)
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Ground Weather Radar Station Sterling, VA
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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.