Wednesday, April26, 2017 L-36.com


Marine Weather and Tides
Boswell's Corner, VA

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 6:15AMSunset 7:58PM Wednesday April 26, 2017 8:02 AM EDT (12:02 UTC) Moonrise 5:42AMMoonset 7:18PM 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
    EDIT      (on/off)   Help
ANZ536 Tidal Potomac From Indian Head To Cobb Island- 732 Am Edt Wed Apr 26 2017
Today..NW winds 5 kt. Waves less than 1 ft. A chance of showers this morning. Patchy fog this morning with vsby 1 to 3 nm.
Tonight..SE winds around 5 kt. Waves 1 ft. Patchy fog. Vsby 1 to 3 nm.
Thu..S winds 5 to 10 kt. Waves 1 ft. Patchy fog. Vsby 1 to 3 nm.
Thu night..S winds 5 to 10 kt. Waves 1 ft.
Fri..SW winds 5 to 10 kt. Waves 1 ft.
Fri night..S winds 5 to 10 kt. Waves 1 ft.
Sat..S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Sun..S winds 5 to 10 kt. Waves 1 ft. A chance of tstms. A chance of showers. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 732 Am Edt Wed Apr 26 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. Low pressure will weaken as it moves up the mid-atlantic coast through morning. The low will move off to our north and east through today and a cold front will approach from the west Thursday night before dissipating on Friday. A small craft advisory may be needed for portions of the waters Thursday afternoon into Thursday night.

7 Day Forecast for Marine Location Near Boswell's Corner, VA
   Hourly   EDIT   Help
location: 38.54, -77.48     debug


Area Discussion for - Baltimore, MD/Washington
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 klwx 260752
afdlwx
area forecast discussion
national weather service baltimore md/washington dc
352 am edt Wed apr 26 2017

Synopsis
Low pressure off of the DELMARVA will move northeastward away from
the mid-atlantic coast today. A cold front will approach the region
and weaken over the area Thursday night. A backdoor front may slide
into the area late Saturday into Sunday. A cold front will pass
through the region early next week.

Near term /until 6 pm this evening/
Vertically-stacked low that has been plaguing our weather the past
several days is currently analyzed over the DELMARVA coast. Low
clouds and some patchy drizzle/fog will remain through daybreak
today... With improvement expected from south-to-north through early
afternoon as low finally shifts off to the northeast. Primary
forecast challenge today will be timing when clouds break... And
subsequent high temperature forecast. Most confident in highs across
central va... Where clouds break early and insolation is strongest.

Expect highs in the u70s to near 80f across this region. Slightly
less confidence from the dc metro northward to the mason-dixon
line... Where clearing is expected near midday (dc) and then into the
afternoon (mason-dixon line). If clearing is slower (faster) then
highs would be lower (higher) across these areas.

Short term /6 pm this evening through Friday night/
Ridging develops over the area tonight... Leading to light winds and
relatively clear skies. With dewpoints in the u50s/l60s... Expect
lows near 60f... With the possibility of fog due to radiational
cooling.

Very warm with increasing humidity across the area Thursday as
southerly return flow strengthens ahead of a weak cold front. Front
will begin to washout as it approaches our area... Bringing the
possibility of showers/elevated thunderstorms to the higher terrain
late Thursday. Only a low chance that a shower or storm pushes east
of the blue ridge... As forecast thermodynamic profiles suggest
capping inversion would generally suppress convection.

Warm and humid weather continues Friday. Warm air aloft will lead to
a capping inversion near 800 mb that will likely suppress convection
across the much of the area... Especially with a lack of a focusing
mechanism. One exception could be across the higher terrain where an
isolated shower/thunderstorm could develop by late afternoon.

Though, poor mid-level lapse rates across this area would likely
limit parcel accelerations and prevent necessary ingredients for
lightning.

Long term /Saturday through Tuesday/
There is (unfortunately) tremendous spread in the weekend forecast.

The synoptic setup by that time will be for a warm (or backdoor
cool) front stretched east-west across the mid atlantic and the ohio
valley, to low pressure which will be in the southern plains. The
quandry is how far south will the front make it. The gfs, supported
by the GEFS mean and a number of its ensemble members, suggests
somewhere around southern pennsylvania or northern maryland... Which
would obviously keep the forecast area on the warm side of the
boundary. Some GEFS members are still further north than the mean.

The ecmwf, on the other hand, represents the furthest south of the
ensemble spread, although some GEFS members support it, too. Based
on this solution, the forecast area will be impacted by a backdoor
front, which would drop temperatures by around 10 degrees, most
notably across the northern portion of the forecast area. Will seek
some sort of middle ground, although will still favor warmer
solutions until forecast mean comes into some sort of consensus.

By Sunday, it seems apparent that we will be under the influence of
a backdoor front. The only question here will be how cool will it
get. Errors from the Saturday forecast will only multiply, so will
not deviate from the model blend at this time.

There are precip implications to the above, as warmer weather will
yield greater instability, and the presence of a surface boundary
potentially could yield thunderstorm development. Will be keeping
the Saturday forecast as chance showers/thunderstorms. Am thinking
it may be dubious for storms to have a chance on Sunday (they'd be
shunted to the south instead). Will utilize showers instead.

Either way, by Monday the front would be dragged north of the area
again as low pressure intensifies and heads toward the great lakes.

That would pave the way for a late Monday or Monday night cold
frontal passage.

Aviation /08z Wednesday through Sunday/
Low cigs/vis will cause ifr (to at times MVFR) conditions across
much of the area through daybreak... With clearing (and a return to
vfr) expected from south to north through the morning into midday.

Vfr expected by afternoon at all TAF sites. Sub-vfr could return
tonight as fog develops over the area (especially across the ne).

Vfr returns during the day Thursday. Cold front approaches the area
late Thursday with the chance for isolated showers/thunderstorms.

Dry Friday withVFR conditions.

There is a large degree of uncertainty in the weekend forecast, as a
frontal boundary will be meandering around the area. Showers and
thunderstorms will be likely, but areal coverage will be a question.

If the front does make it south of the terminals, then there will be
the opportunity for low clouds to work inland. Lots of opportunities
for flight restrictions, but details unclear at this time.

Marine
Light winds expected today/tonight as low pressure continues to move
away from the area. Strengthening southerly flow Thursday ahead of a
cold front could lead to low-end SCA wind gusts. Low confidence
precludes issuance of SCA at this time range. Light winds and dry
weather expected Friday.

A front likely will be meandering across the waters. As a result,
the pressure gradient likely to not be strong. Direction of winds
unclear, dependent upon what happens with the front. If the front
does sink south, then a northeast wind may pick up Saturday
night.

Tides/coastal flooding
Elevated water levels continue, but departures are not as high as
last evening. Have cancelled the coastal flood advisory for calvert
county, as tides have come in an inch or two under minor threshold.

Straits point definitively above minor, so that advisory in good
shape. The theme of water levels hovering around the minor threshold
will be working north, which does reduce confidence. Have opted to
issue a coastal flood advisory for anne arundel county nonetheless.

No action north of there.

On the potomac, the advisory for alexandria and southwest washington
dc seems to be on track. However, base on what's happening
downriver, am not completely sold on this outcome.

The overnight tide cycle is the higher of the two astronomically.

Since these forecasts are right at threshold, that will be the only
cycle of concern. Will need to monitor trends for tomorrow
night/Thursday morning, and perhaps again Friday morning.

Lwx watches/warnings/advisories
Dc... Coastal flood advisory until noon edt today for dcz001.

Md... Coastal flood advisory until 8 am edt this morning for mdz014.

Coastal flood advisory until 6 am edt early this morning for
mdz017.

Va... Coastal flood advisory until noon edt today for vaz054.

Wv... None.

Marine... None.

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


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
NCDV2 28 mi51 min NNW 6 G 8 58°F 61°F1006.3 hPa
WASD2 - 8594900 - Washington, DC 33 mi45 min NNW 5.1 G 8 59°F 64°F1006.6 hPa
44062 - Gooses Reef, MD 56 mi33 min NW 9.7 G 12 58°F 1007.1 hPa

Wind History for Washington, DC
(wind in knots)    EDIT      (on/off)   Help
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
Last
24hr
NE4
G9
NE3
G11
NE4
G15
NE8
G16
N6
G11
NE5
G12
NE5
G9
NE3
G10
E3
G13
NE4
G7
NE6
G11
NE1
G7
NE2
G10
NE4
G11
N4
G10
N3
G8
N4
N4
N3
N4
G11
N3
G6
N6
N8
N4
G11
1 day
ago
NE3
G7
NE5
G12
NE2
G10
NE4
G9
NE4
G10
NE1
G7
NE3
G7
N3
G7
NE2
G7
N2
G8
N1
G4
NE2
G9
NE3
G12
N4
G9
NE3
G6
NE3
G8
NE1
G5
NE2
G6
NE4
G10
NE2
G8
NE4
G10
NE2
G8
2 days
ago
NE3
G10
NE4
G9
NE2
G6
S1
G4
S3
G6
NE3
SE4
G9
S3
G8
SE5
G8
SE4
SE3
E1
E2
E1
NE2
E3
E2
E2
NE2
SE1
NE2
G5
NE4
G9

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Quantico Marine Corps Airfield - Turner Field, VA10 mi67 minNNW 710.00 miOvercast58°F57°F97%1007.4 hPa
Stafford, Stafford Regional Airport, VA10 mi68 minNNW 75.00 miFog/Mist56°F56°F100%1008.5 hPa
Manassas, Manassas Regional Airport/Harry P. Davis Field, VA13 mi67 minNNW 57.00 mi57°F55°F93%1008.5 hPa
Warrenton-Fauquier Airport, VA13 mi68 minNNW 610.00 miOvercast58°F53°F85%1007.4 hPa
Fredericksburg, Shannon Airport, VA19 mi68 minNNW 310.00 miOvercast58°F58°F100%1006.8 hPa
Culpeper, Culpeper County Airport, VA20 mi68 minN 410.00 miPartly Cloudy56°F55°F97%1007.8 hPa
Fort Belvoir, VA21 mi65 minNW 69.00 miOvercast58°F55°F91%1007.1 hPa

Wind History from RMN (wind in knots)
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
Last 24hrN10
G14
N14
G19
N11
G17
NE10
G19
NE11NE9
G15
NE8
G15
NE8NE6N6N7N5N5N4N8N7N6N5NW8N8N6N5NW6N6
1 day agoN7N8NE6N7N7NE9
G15
NE6N7N7N3NE5NE6N7N4NE4NE5NE6NE7NE5NE9
G15
N4N6N8N7
2 days agoN6NE6NE5CalmNE7NE7E5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmNE5NE6NE7

Tide / Current Tables for Aquia Creek, Virginia
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Aquia Creek
Click for Map
Wed -- 12:23 AM EDT     -0.04 feet Low Tide
Wed -- 06:18 AM EDT     Sunrise
Wed -- 06:24 AM EDT     1.68 feet High Tide
Wed -- 06:41 AM EDT     Moonrise
Wed -- 08:18 AM EDT     New Moon
Wed -- 01:08 PM EDT     -0.10 feet Low Tide
Wed -- 06:48 PM EDT     1.24 feet High Tide
Wed -- 07:56 PM EDT     Sunset
Wed -- 08:16 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-000.30.81.21.51.71.61.410.70.40.1-0.100.40.711.21.21.10.80.50.3

Tide / Current Tables for Quantico Creek, Virginia
   EDIT      (on/off)   Help   One Week of Data
Quantico Creek
Click for Map
Wed -- 01:06 AM EDT     0.07 feet Low Tide
Wed -- 06:17 AM EDT     Sunrise
Wed -- 06:41 AM EDT     Moonrise
Wed -- 07:22 AM EDT     1.87 feet High Tide
Wed -- 08:18 AM EDT     New Moon
Wed -- 01:55 PM EDT     0.00 feet Low Tide
Wed -- 07:56 PM EDT     Sunset
Wed -- 07:56 PM EDT     1.66 feet High Tide
Wed -- 08:16 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.20.10.10.40.91.41.71.91.81.51.10.70.40.100.10.50.91.31.61.71.51.10.7

Weather Map and Satellite Images
       (on/off)   Help
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 (8,2,3,4)
      (on/off)   Help

Ground Weather Radar Station Sterling, VA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.