Wednesday, November14, 2018 L-36.com


Marine Weather and Tides
Alexandria, 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 6:49AMSunset 4:56PM Wednesday November 14, 2018 4:22 AM EST (09:22 UTC) Moonrise 12:37PMMoonset 10:56PM Illumination 38% Phase: Waxing Crescent; Moon at 6 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- 335 Am Est Wed Nov 14 2018
.small craft advisory in effect until 6 am est early this morning...
.small craft advisory in effect Thursday afternoon...
Rest of the overnight..NW winds 10 kt with gusts to 20 kt. Waves 1 ft.
Today..N winds 5 to 10 kt. Waves 1 ft.
Tonight..NE winds 5 to 10 kt. Waves 1 ft.
Thu..NE winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. Rain or sleet.
Thu night..NE winds 10 to 15 kt...becoming nw after midnight. Gusts up to 20 kt. Waves 1 ft. Rain.
Fri..NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft.
Fri night..W winds 5 to 10 kt. Waves 1 ft.
Sat..N winds around 5 kt. Waves 1 ft or less.
Sun..W winds around 5 kt. Waves flat.
ANZ500 335 Am Est Wed Nov 14 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build over new england through tonight as low pressure develops over the tennessee valley. This area of low pressure will lift up the east coast Thursday into Friday as the high pressure center moves offshore. Another area of high pressure will build in from the ohio valley for the weekend. Gale warnings may be needed Friday, and small craft advisories may be needed through early Saturday.


7 Day Forecast for Marine Location Near Alexandria, VA
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location: 38.83, -77.04     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 140901
afdlwx
area forecast discussion
national weather service baltimore md washington dc
401 am est Wed nov 14 2018

Synopsis
High pressure will build over new england through tonight as an
area of low pressure develops over the tennessee valley. This
area of low pressure will lift northward along the east coast
Thursday into Friday while the high pressure center moves
offshore. Another area of high pressure will build in from the
ohio valley over the weekend. A cold front will likely approach
from the great lakes early next week.

Near term through tonight
Latest surface analysis depicts a stalled front along the
southeast coast and high pressure over the corn belt. Clouds
continue to flood the region thanks to moisture being lifted
over the cooler air mass over our region, but no precipitation
is occurring in our region. Showers linger over southeastern
virginia and north carolina.

For today, some Sun will managed to reach the ground through the
high clouds, but overall, the theme of the day will be cloudier
versus sunnier. The clouds have kept temps elevated overnight
and this will likely allow temps to rise a bit more than we had
earlier anticipated, with low-mid 40s common, 30s in the cooler
spots. A gusty northwest wind will keep it feeling chilly.

Tonight, developing upper low to the southwest and surface low
near the southeast coast will start spreading moisture rapidly
northeastward. Clouds will thicken this evening, with
precipitation spreading across the region overnight. Thermal
profiles are highly questionable between the different models,
with a significant range of possibilities across the region.

Many areas are depicted with multiple p-types late tonight
depending on the model one is looking at, with the NAM being at
the colder end and the GFS towards the warm side. The ec is
overall colder too, though available resolution may not be
depicting small warm layers accurately. Thus, allow for sleet
and rain along and east of i-95 late tonight, with mainly sleet,
freezing rain and snow further west. Some areas could see a
quick thump of snow with several inches, even along i-95, if the
colder solutions are correct, while the warmer models suggest
little snow will fall anywhere in the forecast area. However, we
are confident that temps will settle below freezing west of i-95
thanks to cold air damming from the high building across
southeast canada, with slightly warmer temps likely closer to
the tidal waters. Winds will become north to northeast as the
cold air drains south.

Short term Thursday through Friday night
Strengthening low pressure rapidly moves northeast up the coast
on Thursday and Thursday night as upper low pushes northeast
toward us from the south-central us. Cold high pressure will
keep damming going over the western portions of the forecast
area, while some cold air erosion looks likely east of the blue
ridge. Thus, have sleet rain along and east of i-95
transitioning to plain rain through the day, with
snow sleet freezing rain between the blue ridge and i-95
changing to sleet freezing rain and then rain very late. From
the blue ridge west, cold air likely gets stuck, so keep temps
at or below freezing all day with snow sleet freezing rain
transitioning mainly to sleet freezing rain. Potential for
significant snow and ice exists, but as noted earlier, forecast
soundings differ significantly among the guidance. Strong warm
advection is partly at play here, which may mean the warm layer
is more potent than modeled by the colder guidance, though heavy
precip may tend to erode the warm layer more efficiently than
the warm guidance depicts. Bottom line is that in areas which
stay near or below freezing, the weather is likely to remain
hazardous through the day, but exactly what hazard will be the
worst is still a bit uncertain.

Given the heavy precip expected, snow could pile up quickly, and
freezing rain accumulation is also possibly significant. There
could even be an inch or two of pure sleet. Thus, expanded
winter storm watch a bit further north and east. Considered
adding a tier of advisories east of the watch with this package,
but given the highly uncertain progged temps both at and above
ground, it seemed prudent to wait one more shift.

Even where precip is mainly rain, the hazard of heavy rain and
potential flooding will exist. See the hydro section below for
more details.

The surface low quickly lifts northeast of the region later
Thursday night into early Friday, but with some wraparound
moisture associated with the passing upper low, rain could
briefly change back to snow sleet before ending. Temps will
likely be fairly steady Thursday night.

Friday into Friday night, the system heads further away and we
have a comparatively mild westerly flow settling across the
region. Temps will actually be noticeably milder on Friday after
the clouds break, with temps making a run at 50. Lows Friday
night will be chilly again, with temps near or below freezing -
however, with high pressure in nominal control, it should be
dry.

Long term Saturday through Tuesday
Largely zonal flow aloft over the eastern CONUS will scoot an
area of high pressure at the surface over the mid-atlantic over
the weekend. Temperatures are expected to be several degrees
below normal with dry weather during this time.

A modest mid-level shortwave and associated surface cold front
are progged to approach from the great lakes and cross the area
early Monday. Model QPF output is pretty light if at all, but
given the upper jet dynamics believe some light precip is
plausible.

Another cool area of high pressure looks poised to settle over
the area Tuesday into Wednesday of next week, but with longwave
troughing becoming more firmly entrenched over the eastern
conus, can't rule out that another weak system sneaks toward our
area by the middle portion of next week.

Aviation 09z Wednesday through Sunday
Vfr thru today and most of tonight, then considerable decline in
conditions late tonight into Thursday. Mainly rain expected at
dca, with more of a mix of rain ice snow at the other
terminals... Mrb is likely to be the snowiest and iciest of
them, however. CIGS and vis also likely to be significantly
restricted on Thursday, even where it is just plain rain. Low
level wind shear also looks likely.

Conditions improve later Friday night withVFR returning Friday
as the system pulls away. Conditions continueVFR Friday night.

MainlyVFR expected over the weekend in NW flow.

Marine
High pressure sliding to the northwest will provide dry
conditions with winds gusting 20-25 knots from the northwest to
north today. Winds shift more northeasterly Thursday and
increase potentially to 35 knots, with gales now up for the
central bay and potentially being needed for all waters later
Thursday night into Friday. Rain and fog, perhaps also some
sleet, are hazards Thursday as well, though the weather will
clear on Friday.

Some gustiness on NW flow may require SCA early Saturday before
winds go light as high pressure builds overhead.

Hydrology
A plume of 1.5+ inch pws will be advecting toward the mid-
atlantic Thursday on an anomalously strong 850 hpa easterly jet.

Though pws likely stay around 1-1.25 directly overhead, the
very strong low- level moisture advection coupled with strong
mid and upper jet dynamics will result in widespread moderate to
heavy precipitation. In the i-95 corridor where precipitation
is expected to fall as mainly liquid (and where 6-hr FFG is less
than 1.5 inches), some isolated minor areal flooding instances
could arise. This may ultimately necessitate the need for a
flood watch in future forecast updates, with generally 1-2" qpf
seeming increasingly likely.

Tides coastal flooding
Increasing onshore flow Wednesday night into Thursday ahead of
an approaching coastal low will cause tidal anomalies to
increase. Although tides will be near astronomical minimums,
minor flooding is still possible for at least some areas along
the tidal potomac river and western shore of the chesapeake bay.

Climate
Here are the current rankings for wettest year on record
(through november 13th):
washington dc area (dca)
1. 61.33 inches (1889)
2. 60.83 inches (2003)
3. 60.09 inches (1878)
4. 58.17 inches (1886)
5. 57.54 inches (1948)
6. 57.38 inches (2018)
7. 54.29 inches (1937)
weather records for the washington dc area have been kept at
what is now ronald reagan washington national airport (dca)
since 1945. Precipitation records observed downtown extend the
period of record back to 1871.

Baltimore md area (bwi)
1. 62.66 inches (2003)
2. 62.35 inches (1889)
3. 61.68 inches (2018)
4. 58.98 inches (1979)
weather records for the baltimore md area have been kept at
what is now baltimore-washington international thurgood marshall
airport (bwi) since 1950. Precipitation records observed
downtown extend the period of record back to 1871.

Dulles va area (iad)
1. 65.67 inches (2003)
2. 59.05 inches (1972)
3. 58.09 inches (1996)
4. 57.65 inches (2018)
5. 55.43 inches (1979)
weather records have been kept at what is now washington dulles
international airport (iad) since 1960.

Note: all climate data are considered preliminary until
reviewed by the national centers for environmental information
(ncei).

Lwx watches warnings advisories
Dc... None.

Md... Winter storm watch from late tonight through late Thursday
night for mdz003-501-502.

Va... Winter storm watch from late tonight through late Thursday
night for vaz025-503-504-508.

Winter storm watch from late tonight through late Thursday
night for vaz026>031-507.

Wv... Winter storm watch from late tonight through late Thursday
night for wvz050>053-055-501>506.

Marine... Small craft advisory until 6 pm est this evening for anz532-
539-540-542.

Small craft advisory from midnight tonight to 6 pm est
Thursday for anz532-539-540-542.

Small craft advisory until 6 pm est Thursday for anz533-541.

Small craft advisory until noon est Thursday for anz534-537-
543.

Gale warning from noon to 6 pm est Thursday for anz534-537-543.

Small craft advisory until noon est today for anz530-531-538.

Small craft advisory from 6 am to 6 pm est Thursday for anz530-
531-538.

Small craft advisory until 6 am est early this morning for
anz535-536.

Small craft advisory from noon to 6 pm est Thursday for anz535-
536.

Synopsis... Dhof
near term... Rcm
short term... Rcm
long term... Dhof
aviation... Rcm dhof
marine... Rcm dhof
hydrology... Dhof
tides coastal flooding... Dhof
climate... Dhof


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 3 mi35 min NNW 8.9 G 15 41°F 51°F1027.2 hPa
BSLM2 - Chesapeake Bay, MD 18 mi113 min NW 5.1 41°F 1026 hPa29°F
TPLM2 - Thomas Point, MD 32 mi23 min NW 14 G 15 41°F 52°F1027.5 hPa (+1.7)23°F
APAM2 - 8575512 - Annapolis, MD 32 mi35 min 42°F 1026.2 hPa
44063 - Annapolis 33 mi29 min NNW 12 G 16 41°F 52°F1026.9 hPa
NCDV2 35 mi35 min N 7 G 9.9 1026.4 hPa
CPVM2 36 mi35 min 42°F 30°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 38 mi35 min WNW 14 G 18 41°F 1026.3 hPa
44062 - Gooses Reef, MD 38 mi33 min 44°F 1026.4 hPa
FSNM2 38 mi35 min NW 14 G 19 40°F 1025.9 hPa
BLTM2 - 8574680 - Baltimore, MD 39 mi35 min N 7 G 12 1026.1 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 46 mi35 min NNW 14 G 19 43°F 1026.7 hPa
SLIM2 - 8577330 - Solomons Island, MD 47 mi35 min NNW 14 G 20 43°F 55°F1026 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 minNNW 1010.00 miMostly Cloudy41°F24°F51%1027.3 hPa
Camp Springs / Andrews Air Force Base, MD9 mi27 minNW 910.00 miFair39°F23°F52%1027.3 hPa
Fort Belvoir, VA10 mi27 minNW 710.00 miFair41°F30°F66%1027.4 hPa
College Park Airport, MD12 mi41 minN 010.00 miFair38°F26°F62%1026.7 hPa
Fort Meade / Tipton, MD23 mi41 minNW 610.00 miFair37°F26°F65%1027.4 hPa
Washington/Dulles International Airport, DC, VA24 mi31 minN 1010.00 miOvercast38°F25°F60%1027.2 hPa
Gaithersburg - Montgomery County Airport, MD24 mi27 minNW 810.00 miFair36°F23°F59%1030.1 hPa

Wind History from DCA (wind in knots)
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Last 24hrNW10NW12NW12N12NW12NW11NW13NW11NW8NW14
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1 day agoCalmCalmCalmS4S5CalmS3S5S6SE5S4SW4CalmE5E6E3E4NE4NE5NE7NE9N8N9N8
2 days agoN6N6N63NW5N34E3SE3S4S6S7SW6S6SW5S3SW3CalmSW4SW3SW4CalmCalmCalm

Tide / Current Tables for Bellevue, D.C.
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Bellevue
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Wed -- 12:25 AM EST     2.86 feet High Tide
Wed -- 06:49 AM EST     Sunrise
Wed -- 07:22 AM EST     0.33 feet Low Tide
Wed -- 12:36 PM EST     Moonrise
Wed -- 01:09 PM EST     2.59 feet High Tide
Wed -- 04:55 PM EST     Sunset
Wed -- 07:12 PM EST     0.35 feet Low Tide
Wed -- 10:56 PM EST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.82.82.51.91.40.90.50.40.40.81.52.12.42.62.521.40.90.50.40.40.81.52.2

Tide / Current Tables for Benning Bridge, D.C.
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Benning Bridge
Click for Map
Wed -- 12:40 AM EST     2.97 feet High Tide
Wed -- 06:49 AM EST     Sunrise
Wed -- 07:36 AM EST     0.35 feet Low Tide
Wed -- 12:36 PM EST     Moonrise
Wed -- 01:24 PM EST     2.69 feet High Tide
Wed -- 04:54 PM EST     Sunset
Wed -- 07:26 PM EST     0.38 feet Low Tide
Wed -- 10:56 PM EST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.932.72.21.610.60.40.40.71.422.52.72.62.21.71.10.60.40.40.71.42.1

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 (4,6,7,8)
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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.