Thursday, June20, 2019 L-36.com


Marine Weather and Tides
St. James, MD

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Sunrise 5:41AMSunset 8:43PM Thursday June 20, 2019 2:03 AM EDT (06:03 UTC) Moonrise 10:26PMMoonset 7:37AM Illumination 93% Phase: Waning Gibbous; Moon at 17 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- 138 Am Edt Thu Jun 20 2019
Overnight..S winds 5 kt. Waves less than 1 ft. A chance of showers. Patchy fog. Vsby 1 to 3 nm.
Thu..SW winds 5 to 10 kt. Gusts up to 20 kt in the late morning and afternoon. Waves 1 ft. Showers likely with a chance of tstms.
Thu night..W winds 10 kt. Waves 1 ft. A chance of showers and tstms.
Fri..NW winds 10 to 15 kt with gusts to 25 kt. Waves 1 ft.
Fri night..NW winds 10 to 15 kt with gusts to 20 kt...diminishing to 5 kt after midnight. Waves 1 ft.
Sat..NW winds 5 kt. Waves less than 1 ft.
Sat night..NW winds around 5 kt. Waves 1 ft or less.
Sun..SW winds around 5 kt. Waves 1 ft. A chance of showers and tstms through the night.
Mon..W winds around 5 kt. Waves 1 ft. A chance of showers and tstms. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 138 Am Edt Thu Jun 20 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A front will remain stalled north of the waters through tonight. Low pressure tracking to the northwest will sweep a cold front through the area late Thursday and Thursday night. High pressure nudging southward from canada will dominate over the waters through the weekend. Small craft advisories may be required Thursday night and Friday.


7 Day Forecast for Marine Location Near St. James, MD
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location: 39.59, -77.77     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 200146
afdlwx
area forecast discussion
national weather service baltimore md washington dc
946 pm edt Wed jun 19 2019

Synopsis
A stalled front will remain across pennsylvania into Thursday.

Low pressure crossing into ohio will bring a cold front into the
area late Thursday and Thursday night. Behind the cold front,
canadian high pressure will build southward over the region
Friday and into the weekend. This high will begin retreating
northward on Sunday as a warm front lifts toward the region
Sunday night.

Near term tonight
A stationary boundary resides across central and northern
pennsylvania this evening with a warm and moist southerly flow
dominating over the area. Despite the lack of a significant lifting
mechanism, scattered showers and isolated thunderstorms
continue this evening over mainly north central maryland, with
more isolated coverage being observed over southern maryland the
portions of central virginia. The showers and thunderstorms
that were able to form late this afternoon and evening are
feeding off the warm and moist environment in place with sultry
dewpoints in the low to middle 70s. The 00z iad sounding sampled
increasing moisture with a pwat of 1.80 inches and decent cape
of around 2500 j kg. While the steering flow aloft is a bit weaker
than previous days, it is strong enough to keep the storms
producing heavy rainfall moving. There are boundaries lurking
across north central maryland this evening, thanks to earlier
convection and the bay breeze marching inland, so the potential
for isolated instances of flooding with training showers storms
will remain over the next couple of hours.

Activity should wane by midnight as we move further away from
daytime heating and instability decreases. Partly to mostly
cloudy skies will remain overnight, with temperatures holding in
the middle 60s to lower 70s, and the humid conditions
persisting. Patchy fog will be possible towards morning,
especially over and near areas that received rainfall, as winds
go light and variable.

Short term Thursday through Friday night
An upper level trough will approach from the west Thursday.

It's associated surface low pressure and cold front will move
across our region later in the day into Thursday night. An
airmass change will finally take shape, but not before leaving
us in a chance for some nasty thunderstorms that could produce
damaging winds and large hail ahead of the system and front. Our
temperatures could very well reach the upper 80s to near 90 in
most places; thus, leading up to a descent amount of
instability. Throw in some good wind shear and the low-level
moisture in place, we could see some severe thunderstorms and
possible flooding in a few locations. Thunderstorm coverage
should reach the greatest potential later Thursday afternoon and
early evening, before tapering and ending by Thursday night.

As the surface low strengthens to the northeast, winds may gust
upwards of 35 mph by Friday afternoon, helping the overall
feeling of a refreshing change to the weather. Highs will only
be a bit cooler, with lower 80s common, but humidity will be
much lower, with dew points likely falling into the upper 50s.

Winds should die down as high pressure builds closer to the
region Friday night, and lows will drop much lower than recent
days, with 50s common in rural areas. One thing to watch Friday
night is the front, which will now be stalled to our south. A
weak wave may approach from the west late at night, which could
cause a few showers or a thunderstorm to develop or move into
west-central va late. However, odds of this remain low.

Long term Saturday through Wednesday
A upper level ridge over the central plains will slowly shift
eastward toward our region this weekend. High pressure will remain
over our area through early Sunday afternoon. Temperatures will
remain mild in the mid to upper 70s on Saturday. A warm front will
move through our area on Sunday leading to winds becoming southerly.

The southerly flow will lead to increasing temperatures and moisture
on Sunday due to warm air advection.

The warm front will move to our north and a west to southwesterly
flow will continue to advect warm and moist air into our region. Day
time temperatures are forecast to rise up into the upper 80s to mid
90s on Monday with dewpoints in the low to mid 70s. These high temps
and dewpoints will create instability in our region on Monday which
could lead to the formation of showers and thunderstorms.

Temperatures will remain elevated on Tuesday in the upper 80s but a
westerly flow will help keep dew point temperatures down which
should help limit instability . There will be continued potential
for shower and thunderstorms to form during the afternoon periods on
Tuesday.

Aviation 01z Thursday through Monday
MVFR vis CIGS possible over the next couple of hours at
dca bwi mtn as scattered showers and isolated thunderstorms move
off to the north northeast. As showers storms wane by around
04z, MVFR vis will be possible towards morning with patchy fog,
potentially impacting cho mrb bwi mtn where rainfall was
received today and winds go light.

PredominateVFR conditions expected Thursday, with showers and
t-storms posing a threat of subVFR conditions during the
afternoon and evening hours. A cold front passing through the
terminals Thursday night will bring a return toVFR conditions
Friday, though gusty northwest winds may exceed 30 knots at
times.

Mostly clear skies are expected Saturday through Sunday with winds
mainly out of the north becoming southerly Sunday afternoon.VFR
conditions expected at this time for the weekend

Marine
Winds below SCA levels through Thursday morning, although a
gusty thunderstorm this evening could impact the northern
chesapeake bay waters.

Southerly flow picks up ahead of an approaching cold front
Thursday afternoon. This may result in marginal SCA conditions,
but confidence is currently low, so have held off on issuing
sca.

Strong (for late june) northwest flow behind cold front on
Friday will lead to widespread SCA gusts, potentially has high
as 30 knots or so. Winds should diminish Friday night.

High pressure expected this weekend over the waters with winds out
of the north. Winds expected to remain below 18 knots over the
waters and small craft advisories are not expected at this time.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... None.

Synopsis... Bkf klw
near term... Bkf
short term... Klw
long term... Jmg
aviation... Bkf klw jmg
marine... Bkf klw jmg


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 63 mi51 min S 8 G 8.9 77°F 78°F1004.7 hPa
BLTM2 - 8574680 - Baltimore, MD 67 mi51 min S 1 G 5.1 75°F 78°F1004.1 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 71 mi45 min SSW 7 G 8 76°F 1004.6 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD9 mi70 minESE 410.00 miFair74°F71°F91%1005 hPa
Eastern WV Regional Airport/Shepherd Field, WV17 mi70 minSE 310.00 miFair71°F68°F90%1003.9 hPa
Frederick Municipal Airport, MD24 mi83 minN 010.00 miMostly Cloudy73°F71°F94%1005.8 hPa

Wind History from HGR (wind in knots)
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Last 24hrCalmCalmNW3CalmCalmCalmCalmSW3S5SW3SW5S4S7S10S11S5S6S4SE5E5E5W3SE4Calm
1 day agoE4NW4E4E4NW3CalmS3W6SW7SW6W8
G17
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Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Thu -- 05:42 AM EDT     Sunrise
Thu -- 05:45 AM EDT     0.43 feet Low Tide
Thu -- 08:36 AM EDT     Moonset
Thu -- 11:29 AM EDT     3.34 feet High Tide
Thu -- 06:32 PM EDT     0.29 feet Low Tide
Thu -- 08:37 PM EDT     Sunset
Thu -- 11:21 PM EDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.92.51.91.30.80.50.40.81.52.433.33.32.92.31.71.10.70.40.30.81.62.32.8

Tide / Current Tables for Chain Bridge, one mile below, D.C.
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Chain Bridge
Click for Map
Thu -- 05:40 AM EDT     0.43 feet Low Tide
Thu -- 05:42 AM EDT     Sunrise
Thu -- 08:36 AM EDT     Moonset
Thu -- 11:24 AM EDT     3.34 feet High Tide
Thu -- 06:27 PM EDT     0.29 feet Low Tide
Thu -- 08:36 PM EDT     Sunset
Thu -- 11:21 PM EDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.92.41.81.20.80.50.40.81.62.433.33.32.82.21.61.10.60.30.40.81.62.32.8

Weather Map and Satellite Images
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GOES Local Image of    EDIT
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Wind Forecast for Baltimore, MD/Washington (2,6,7,8)
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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.