Friday, February22, 2019 L-36.com


Marine Weather and Tides
Arlington, VA

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 6:48AMSunset 5:54PM Friday February 22, 2019 11:22 AM EST (16:22 UTC) Moonrise 9:40PMMoonset 8:57AM Illumination 89% Phase: Waning Gibbous; Moon at 18 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- 937 Am Est Fri Feb 22 2019
Rest of today..N winds 5 kt. Waves less than 1 ft.
Tonight..NE winds around 5 kt. Waves 1 ft.
Sat..E winds around 5 kt. Waves 1 ft. Rain. Vsby 1 to 3 nm.
Sat night..SE winds around 5 kt. Waves 1 ft. Rain.
Sun..S winds 5 to 10 kt with gusts to 20 kt... Becoming W 15 to 20 kt with gusts to 30 kt in the afternoon. Waves 1 to 2 ft. Showers likely.
Sun night..W winds 10 to 15 kt. Gusts up to 30 kt... Diminishing to 20 kt after midnight. Waves 1 ft.
Mon..W winds 10 to 15 kt...becoming nw 5 kt after midnight. Waves 1 ft.
Tue..N winds 5 kt. Waves less than 1 ft.
ANZ500 937 Am Est Fri Feb 22 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A front will stall across the carolinas through tonight as high pressure builds to the north toward new england. Low pressure developing over the middle mississippi river valley will strengthen as it moves northeastward across the great lakes into canada this weekend. High pressure will build from the northern great plains toward the great lakes and eventually into the northeast through the first half of next week. Gale conditions are likely over the waters Sunday into Monday.


7 Day Forecast for Marine Location Near Arlington, VA
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location: 38.87, -77.06     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 221448
afdlwx
area forecast discussion
national weather service baltimore md washington dc
948 am est Fri feb 22 2019

Synopsis
A front will stall over the southeastern CONUS through tonight
as high pressure builds to the north toward new england. Low
pressure developing over the middle mississippi river valley
will strengthen as it moves northeastward across the great lakes
into canada this weekend. High pressure will build from the
northern great plains toward the great lakes and eventually into
the northeast through the first half of next week. Low pressure
developing over the tennessee valley could approach the region
during the middle of next week.

Near term through tonight
The dew point gradient is the best way to discern a subtle boundary
moving southward through central virginia and southern maryland
this morning. The main surface front temperature gradient is
draped across south carolina. Both of these boundaries will
sink southward and stall through this afternoon.

Plenty of high and mid-level clouds will remain overhead today
shortwave energy passes through in the westerly flow aloft and
the area remains in the right entrance of the jet. A northerly
flow will allow for dry conditions across most areas and it will
be seasonably chilly with highs in the upper 40s to lower 50s
for most locations. There may be enough overrunning for some
light rain, especially south of interstate 64 in central
virginia.

Short term Saturday through Sunday night
Surface high pressure will be building to the north over upstate new
york and into new england tonight (~1035 mb). This is an ideal spot
to lock in some cold air near the surface, but the antecedent
airmass isn't abundantly cold. Temperatures are expected to fall to
around freezing for elevations above 1500 feet tonight, and across
northern maryland, the eastern west virginia panhandle and
northwestern virginia.

Precipitation likely holds off until after daybreak Saturday, except
perhaps across west-central virginia, which should allow
temperatures to rise some. Still, freezing rain seems likely at
least across the ridgetops along and west of the blue ridge and into
western maryland, possibly the eastern west virginia panhandle
Saturday morning through about midday. This is as precipitation
develops in strengthening overrunning ahead of a deepening surface
low over the midwest.

Continued warm advection should push temperatures above freezing
Saturday afternoon, though some hi-res guidance like the 00z nam
nest wants to hold onto freezing temperatures over the ridges until
Saturday evening. Lower elevations should see all rain (except
perhaps over northern maryland near the pennsylvania border).

The latest guidance has trended southward a bit with the heaviest
precipitation amounts Saturday night, likely in part due to high
pressure to the north nosing some drier low-level air into the
region. Strong warm air advection may overcome this some, but the
best upper jet forcing is displaced to our northwest closer to the
parent surface low (likely to track over lake michigan Saturday
night). This could help keep rainfall amounts near or a little under
one inch, but even that could result in minor flooding given
saturated ground and recent snowmelt, particularly over eastern west
virginia this weekend.

There may be a few heavier showers along the approaching cold front
early Sunday morning. I could see the warm front never truly making
it fully through the area given the high to the north and the parent
low being so far west, but Sunday is still expected to be very mild
since appreciable cold air advection lags well behind the surface
front, and downsloping westerly flow compressional warming should
push highs well into the 60s. Winds will likely be very gusty Sunday
with a strong pressure gradient behind the front, possibly reaching
or exceeding advisory criteria (greater than 45 mph).

Long term Monday through Thursday
The weather pattern will be largely dominated by a broad trough
aloft across eastern north america and strong canadian high
pressure at the surface. As a result, temperatures will stay
cooler than normal and it will be much drier than it has been
lately. On Monday, a tight pressure gradient will still exist
over the region associated with a deep cyclone over atlantic
canada, but the winds will not be as strong like on Sunday, but
still windy nonetheless. Overall, fair weather is expected much
of next week but on the chilly side.

Aviation 15z Friday through Tuesday
MainlyVFR today. MVFR INVOF cho should lift late this morning.

Cigs expected to lower to ifr by late Saturday as a warm front
slowly approaches from the south, with rain overspreading the
area Saturday afternoon. Some freezing rain is possible near mrb
Saturday morning, if precipitation moves in quickly enough
while temperatures are still near or below freezing. Winds will
generally be N to NE AOB 10 kts.

Vfr likely returns by Sunday afternoon with gusty W winds 35+
kts.

Still windy on Monday with gusts likely in the 25-35 kt range.

Winds diminish further on Tue but still breezy with gusts in
the 15-25 kt range.

Marine
High pressure will continue to build from the north and winds
should remain below SCA criteria for most of the time through
Saturday night.

Rain is expected to overspread the waters Saturday into Saturday
night as the aforementioned boundary returns north as a warm front.

Whether or not the warm front makes it through the waters before a
cold front approaches from the west by Sunday morning remains to be
seen, but there is moderately high confidence in gale force winds
later Sunday into Sunday night in westerly flow behind the
front.

Marginal gales will still be possible on mon. Otherwise, strong
sca conditions mon-mon evening. SCA conditions possible again on
tue and wed.

Hydrology
Given recent snowmelt and saturated ground, three quarters of an
inch to around an inch of rain may be enough to result in minor
flooding issues this weekend, particularly over eastern west
virginia. The overall trend has been for slightly less rain, but not
so much less to completely avoid a flood threat. Despite the
slightly lower QPF totals in the 00z model suite, mmefs still
indicates >50% chance of minor flood at several river forecast
points later this weekend.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Bjl lfr
near term... Bjl dhof
short term... Dhof
long term... Lfr
aviation... Bjl lfr dhof
marine... Bjl lfr dhof
hydrology... Dhof


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 2 mi35 min N 4.1 G 7
BSLM2 - Chesapeake Bay, MD 20 mi113 min N 1 43°F 1029 hPa40°F
APAM2 - 8575512 - Annapolis, MD 32 mi35 min 44°F 1029.1 hPa
TPLM2 - Thomas Point, MD 33 mi23 min N 8 G 8.9 42°F 38°F1030.3 hPa (+1.3)29°F
BLTM2 - 8574680 - Baltimore, MD 37 mi41 min NNE 8 G 11 44°F 38°F1029.2 hPa
CPVM2 37 mi35 min 40°F 36°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 37 mi35 min NE 7 G 8 43°F 1029.6 hPa
FSNM2 37 mi41 min N 8 G 9.9 44°F 1029.2 hPa
NCDV2 38 mi41 min NE 1.9 G 4.1 49°F 41°F1028.8 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 48 mi35 min N 6 G 7 40°F
TCBM2 - 8573364 - Tolchester Beach, MD 49 mi35 min NNE 4.1 G 5.1 42°F 40°F1029.8 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA2 mi31 minN 710.00 miOvercast48°F30°F50%1030 hPa
Camp Springs / Andrews Air Force Base, MD10 mi87 minNNW 610.00 miPartly Cloudy45°F30°F58%1029.9 hPa
College Park Airport, MD11 mi40 minN 010.00 miFair45°F27°F51%1029.5 hPa
Fort Belvoir, VA12 mi27 minNW 410.00 miA Few Clouds48°F27°F45%1030.1 hPa
Gaithersburg - Montgomery County Airport, MD21 mi27 minVar 510.00 miPartly Cloudy44°F28°F53%1032.9 hPa
Fort Meade / Tipton, MD22 mi41 minN 410.00 miFair43°F28°F57%1030.1 hPa
Washington/Dulles International Airport, DC, VA22 mi31 minNNW 710.00 miOvercast44°F27°F51%1029.9 hPa

Wind History from DCA (wind in knots)
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Last 24hrE3CalmSE3N3554NW7N4CalmN9N7N7W4N9NW8S4S5SW3CalmN7N6N7N7
1 day agoE9NE7SE8E5SE4CalmNE6N5N4E6N5N3N5NW6CalmCalmSW4SW4SW4CalmW3SW6CalmE3
2 days agoN7N10NW10NW10NW6N5NW7W6NW9N6N3E7SE3SE5SE5E5E6E9SE5SE3SE7E6E6NE5

Tide / Current Tables for Washington, D.C.
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Washington
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Fri -- 04:46 AM EST     -0.45 feet Low Tide
Fri -- 06:50 AM EST     Sunrise
Fri -- 08:56 AM EST     Moonset
Fri -- 10:02 AM EST     3.19 feet High Tide
Fri -- 05:14 PM EST     -0.46 feet Low Tide
Fri -- 05:53 PM EST     Sunset
Fri -- 09:40 PM EST     Moonrise
Fri -- 10:30 PM EST     3.09 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.11.40.70.1-0.3-0.401.12.22.93.232.41.710.4-0.1-0.4-0.30.51.72.633

Tide / Current Tables for Fort Washington, Maryland
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Fort Washington
Click for Map
Fri -- 04:14 AM EST     -0.40 feet Low Tide
Fri -- 06:50 AM EST     Sunrise
Fri -- 08:56 AM EST     Moonset
Fri -- 09:55 AM EST     2.80 feet High Tide
Fri -- 04:42 PM EST     -0.41 feet Low Tide
Fri -- 05:53 PM EST     Sunset
Fri -- 09:40 PM EST     Moonrise
Fri -- 10:23 PM EST     2.72 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.710.4-0.1-0.4-0.30.41.32.12.62.82.521.30.70.1-0.3-0.400.81.72.42.72.6

Weather Map and Satellite Images
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GOES Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Wind Forecast for Baltimore, MD/Washington (11,2,3,4)
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Ground Weather Radar Station Sterling, VA
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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.