Monday, November19, 2018 L-36.com


Marine Weather and Tides
Dahlgren Center, 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 6:53AMSunset 4:53PM Monday November 19, 2018 10:13 AM EST (15:13 UTC) Moonrise 3:12PMMoonset 2:49AM Illumination 88% Phase: Waxing Gibbous; Moon at 11 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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ANZ536 Tidal Potomac From Indian Head To Cobb Island- 636 Am Est Mon Nov 19 2018
.small craft advisory in effect from Tuesday morning through Tuesday afternoon...
Today..S winds 5 kt. Waves less than 1 ft.
Tonight..SW winds 5 kt. Waves less than 1 ft.
Tue..NW winds 5 to 10 kt with gusts to 20 kt. Waves 1 ft.
Tue night..NW winds 5 to 10 kt. Waves 1 ft.
Wed..W winds around 5 kt. Waves 1 ft.
Wed night..NW winds 5 to 10 kt. Waves 1 ft.
Thu..NE winds 5 to 10 kt. Waves 1 ft.
Fri..E winds around 5 kt. Waves 1 ft.
ANZ500 636 Am Est Mon Nov 19 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A weak area of low pressure north of the waters will pull off to the northeast today as a frontal boundary lingers nearby. Another wave of low pressure will move across the waters tonight as a cold front sweeps through on Tuesday. A more potent cold front will navigate across the waters late Wednesday and Wednesday night. Strong canadian high pressure will build over the waters for the remainder of the work week. Small craft advisories may be required for portions of the waters Wednesday afternoon through Thursday.


7 Day Forecast for Marine Location Near Dahlgren Center, VA
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location: 38.32, -77.03     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 191422
afdlwx
area forecast discussion
national weather service baltimore md washington dc
issued by national weather service mount holly nj
922 am est Mon nov 19 2018

Synopsis
A weak area of low pressure over the ohio valley will ride
along a stationary boundary situated near the mason dixon line
tonight, with a cold front crossing the area during the day on
Tuesday. Low pressure will move across the northern great lakes
on Wednesday, pushing a strong cold front through the region
Wednesday night. High pressure of canadian origin will build to
our north for the remainder of the work week before another
system threatens the area over the weekend.

Near term through tonight
Few changes made with the mid morning update. Fog is starting to
lift, though in some valleys, including frederick, visibility
below one mile continues. The trend for fog dissipating should
continue through the morning.

A weak area of low pressure is passing north of the mason dixon
line this morning riding along a stationary boundary oriented
southwest to northeast. Precipitation associated with this
should remain north of our region through the morning.

Another weak wave of low pressure near the ohio valley this
morning will track northeastward today, turning partly sunny
skies this morning to mostly cloudy by this afternoon and
evening. Have backed off a bit on precipitation chances this
afternoon for our northwestern zones, thinking much of the
region will remain dry today as cloud cover increases. Will keep
chance pops over the allegheny and potomac highlands, focused
mainly late this afternoon. Highs today will be near normal for
a change, ranging in the upper 40s to near 50 along the
northern western zones, to the upper 50s to near 60 degrees
across central virginia and southern maryland.

The area of low pressure will cross the northern third of the
cwa tonight, increasing shower chances. The best moisture
availability will remain north of the mason dixon, so will carry
chance pops along and north of the district, but thinking many
areas east of the blue ridge may very well end up on the dry
side. Highest chance for accumulating precip will be along the
alleghenies and potomac highlands, with rain snow showers mixing
late tonight along the western slopes. Lows tonight will range
from the lower 30s in the mountains to middle 40s in the metro
areas and near the bay.

Short term Tuesday through Tuesday night
A weak area of low pressure is passing north of the mason dixon
line this morning riding along a stationary boundary oriented
southwest to northeast. Essentially all the light shower
activity has remained to our north and will that will continue
to be the case this morning. Patchy fog has developed overnight,
with some locations dropping to near one mile at times in the
shenandoah valley and central virginia. Ample mid level clouds
continue to stream overhead thanks to weak WAA and a modest jet
aloft. Temperatures are ranging from the upper 20s in the
mountains to lower 40s in the city centers.

Another weak wave of low pressure near the ohio valley this
morning will track northeastward today, turning partly sunny
skies this morning to mostly cloudy by this afternoon and
evening. Have backed off a bit on precipitation chances today
for our northwestern zones, thinking much of the region will
remain dry today as cloud cover increases. Will keep chance pops
over the allegheny and potomac highlands, focused mainly late
this afternoon. Highs today will be near normal for a change,
ranging in the upper 40s to near 50 along the northern western
zones, to the upper 50s to near 60 degrees across central
virginia and southern maryland.

The area of low pressure will cross the northern third of the
cwa tonight, increasing shower chances. The best moisture
availability will remain north of the mason dixon, so will carry
chance pops along and north of the district, but thinking many
areas east of the blue ridge may very well end up on the dry
side. Highest chance for accumulating precip will be along the
alleghenies and potomac highlands, with rain snow showers mixing
late tonight along the western slopes. Lows tonight will range
from the lower 30s in the mountains to middle 40s in the metro
areas and near the bay.

Long term Wednesday through Sunday
The long term starts out with a rather brutal but brief bout of
arctic air as a strong cold front slides south across the
region. The air behind this front is the coldest of the season
so far, with temps likely not getting far from the freezing mark
on thanksgiving day, and possibly reaching the teens in many
areas thanksgiving night. See the climate section below for a
few notes on how rare this cold spell might be, though the
midnight temperatures will affect this.

High pressure slides east into the atlantic Friday, and return
flow starts to bring milder air back north. A system will
already be approaching quickly, however, and it will be a race
between the returning warmer air and the precip. There is a
significant chance of some wintry weather at the onset Friday
night into Saturday as the storm moves in. Just how persistent
this wintry weather will be is yet to be determined, but anyone
with travel plans Friday night into Saturday should keep an eye
on evolving forecasts.

The low will likely pass us by Sunday and with a more pacific-
type air mass following it, the storm looks likely to do what
the system last week did... Nudge the coldest air back north of
the region and leave some more moderate temperatures over our
region for Sunday. Uncertainty regarding the timing of a system
quickly following on the first one's heals makes the forecast
for Sunday uncertain, but some rain is possible per the gfs, for
example. Other models, notably the ecmwf, allow for more of a
gap between the systems, which would make Sunday a fairly
decent travel day. Stay tuned...

Aviation 14z Monday through Friday
Widespread MVFR (and even ifr conditions at kmrb) will gradually
improve toVFR through the morning as the fog slowly dissipates.

This afternoon,VFR with dry conditions is expected at all the
terminals. A weak area of low pressure will passing along and
to the north of the terminals tonight, with mrb serving to see
the best chance of MVFR vis CIGS due to -shra, all other
terminals expected to remainVFR and mainly dry.

A cold front will cross the terminals on Tuesday with winds
shifting out of the northwest and becoming gusty to around 25
knots. A stronger but dry cold front will move through the
terminals late Wednesday into Wednesday night, maintaining gusty
northwest winds withVFR vis CIGS prevailing.

Vfr conditions expected Thursday and Friday as high pressure
builds in behind another cold front. Gusty NW winds may be an
issue, with gusts likely in the 20-30 knot range.

Marine
Sub SCA conditions expected through tonight as a weak area of
low pressure crosses the waters to the north. A cold front will
move through the waters on Tuesday with increasing northwesterly
breezes expected, thus an sca GOES into effect Tuesday morning
and persists for portions of the waters into Tuesday night. A
brief lull may be realized Wednesday morning over the waters as
the gradient weakens, however another strong cold front is
expected to sweep through the waters late Wednesday into
Wednesday night bringing solid SCA gusts over the marine
district.

Small craft advisories are likely Thursday and may continue into
Friday as another cold front slides across the region.

Climate
Unseasonably cold weather is looking increasingly likely to
briefly take hold of the region on thanksgiving. Daytime
temperatures are likely to stay in the 30s, and it could be the
coldest thanksgiving in over 20 years, depending on the readings
at midnight. Here are the benchmark readings to compare this
thanksgiving to:
washington dc area
year high elapsed
2017 47 1 year
2013 40 5 years
2000 38 18 years
1996 35 22 years
1930 30 88 years
the high has not been lower than 30 on thanksgiving since
official temperature record keeping began in 1872.

Baltimore md area
year high elapsed
2017 44 1 year
2013 38 5 years
2000 37 18 years
1996 33 22 years
1930 31 88 years
the high has not been lower than 31 on thanksgiving since
official temperature record keeping began in 1872.

Rainfall totals continue to creep upward, with baltimore setting
the annual record already. Here are the current rankings for
wettest year on record (through november 18th):
washington dc area (dca)
1. 61.33 inches (1889)
2. 60.83 inches (2003)
3. 60.09 inches (1878)
4. 58.58 inches (2018)
5. 58.17 inches (1886)
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. 63.18 inches (2018)
2. 62.66 inches (2003)
3. 62.35 inches (1889)
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. 59.17 inches (2018)
3. 59.05 inches (1972)
4. 58.09 inches (1996)
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... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Bkf
near term... Bkf 99
short term... Bkf
long term... Rcm
aviation... Bkf rcm 99
marine... Bkf rcm
climate...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
NCDV2 0 mi43 min WSW 1 G 1.9 48°F 48°F1019.6 hPa
PPTM2 - 8578240 - Piney Point, MD 29 mi67 min W 2.9 G 4.1
SLIM2 - 8577330 - Solomons Island, MD 31 mi43 min SW 4.1 G 6 50°F 52°F1020.2 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 35 mi43 min SSW 7 G 8 48°F 1020.9 hPa
BSLM2 - Chesapeake Bay, MD 36 mi103 min SSE 1 38°F 1020 hPa38°F
44062 - Gooses Reef, MD 36 mi43 min 49°F 1020.6 hPa
LWTV2 - 8635750 - Lewisetta, VA 37 mi43 min WSW 5.1 G 7 50°F 49°F1020.4 hPa
WASD2 - 8594900 - Washington, DC 38 mi43 min S 2.9 G 2.9 45°F 46°F1020.3 hPa
44042 - Potomac, MD 42 mi43 min W 5.8 G 7.8 48°F 1020 hPa

Wind History for Piney Point, MD
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Quantico Marine Corps Airfield - Turner Field, VA19 mi17 minS 410.00 miMostly Cloudy46°F44°F93%1020.5 hPa
Fredericksburg, Shannon Airport, VA23 mi38 minN 010.00 miFair45°F44°F100%1020 hPa

Wind History from NYG (wind in knots)
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Last 24hrSW4S4S4CalmS3S4S4CalmCalmCalmNW3NW6NW4CalmW4CalmNW4W3CalmNW3NW5CalmS3S4
1 day agoNE94N4E7E5E5NE4CalmNW5NW5NW5NW7NW5NW7NW6NW5NW7NW6NW7NW6NW5NW4NW3SW3
2 days agoW5W7W6W10W9W6W8CalmNW5NW6E7W3NW4NW7NW7NW6NW8W7NW6NW5N7N6NE5N6

Tide / Current Tables for Dahlgren, Upper Machodoc Creek, Virginia
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Dahlgren
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Mon -- 02:49 AM EST     Moonset
Mon -- 05:48 AM EST     -0.00 feet Low Tide
Mon -- 06:53 AM EST     Sunrise
Mon -- 11:52 AM EST     1.59 feet High Tide
Mon -- 03:11 PM EST     Moonrise
Mon -- 04:52 PM EST     Sunset
Mon -- 06:17 PM EST     0.01 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.51.310.60.30.100.10.50.91.21.51.61.51.20.80.50.200.10.30.71.11.4

Tide / Current Tables for Colonial Beach, Potomac River, Virginia
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Colonial Beach
Click for Map
Mon -- 02:48 AM EST     Moonset
Mon -- 05:21 AM EST     0.02 feet Low Tide
Mon -- 06:53 AM EST     Sunrise
Mon -- 11:25 AM EST     1.58 feet High Tide
Mon -- 03:11 PM EST     Moonrise
Mon -- 04:52 PM EST     Sunset
Mon -- 05:51 PM EST     0.03 feet Low Tide
Mon -- 11:44 PM EST     1.51 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.41.10.80.50.200.10.30.611.41.61.61.410.70.30.100.20.50.91.21.5

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 (10,2,3,4)
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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.