Friday, June23, 2017 L-36.com


Marine Weather and Tides
Brookmont, MD

Version 3.4
What's New / NOTES
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
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.

Sunrise 5:42AMSunset 8:39PM Friday June 23, 2017 10:01 AM EDT (14:01 UTC) Moonrise 4:25AMMoonset 7:09PM Illumination 0% Phase: New Moon; Moon at 29 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- 731 Am Edt Fri Jun 23 2017
.small craft advisory in effect through Saturday afternoon...
Today..S winds 5 kt...becoming sw 15 kt with gusts to 25 kt late this morning and afternoon. Waves 1 ft. Widespread showers this morning, then scattered showers and tstms this afternoon.
Tonight..SW winds 10 to 15 kt. Gusts up to 25 kt... Diminishing to 20 kt in the late evening and overnight. Waves 1 ft. Showers with a chance of tstms. Vsby 1 nm or less.
Sat..W winds 10 kt with gusts to 20 kt. Waves 1 ft. Showers likely. Vsby 1 nm or less.
Sat night..NW winds 5 to 10 kt. Gusts up to 20 kt in the evening. Waves 1 ft.
Sun..W winds 5 to 10 kt. Waves 1 ft.
Sun night..NW winds 5 to 10 kt. Waves 1 ft.
Mon..NW winds around 5 kt. Waves 1 ft.
Tue..NW winds around 5 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 731 Am Edt Fri Jun 23 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will remain offshore today while a cold front slowly approaches from the northwest. The remnants of cindy will track along the front tonight, with the front finally pushing through on Saturday. A weak secondary front will cross Sunday before high pressure returns early next week. Small craft advisory conditions are possible Sunday.

7 Day Forecast for Marine Location Near Brookmont, MD
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location: 38.92, -77.1     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 230801
afdlwx
area forecast discussion
national weather service baltimore md washington dc
401 am edt Fri jun 23 2017

Synopsis
Tropical air will envelop the area today. A cold front will
cross the area late tonight into Saturday. High pressure will
return Sunday and persist through early next week.

Near term until 6 pm this evening
Lead shortwave trough is currently crossing the area. Most of
the forcing appears to be at this level along the leading edge
of precipitation, as rain is falling from a mid level cloud.

Lightning has not been observed so far, but there is just a
little elevated instability, so would not rule out a stray
rumble of thunder. Rainfall currently over nc is associated with
lower level forcing, though guidance suggests it will be in
non-uniform showers crossing during mid morning.

There may be a bit of a break during the midday hours due to
subsidence behind the trough, although there is enough evident
of a few showers to not remove pops entirely. There may be a
little insolation to help push temperatures well into the 80s.

However, the subsidence may also lead to a capping inversion and
thus make it difficult to initiate convection. Most guidance
has little to no convection during the afternoon hours, though
there are some hints there could be a lee trough which could
trigger a rogue storm. Mid- level energy may also clip the far
nw cwa. If something can break the cap, there will be plenty of
deep layer shear, so there is a conditional threat for severe
weather. Will have to monitor thermodynamic trends through the
morning to get a better handle on this potential. Based on this
forecast though, flooding looks like a low threat through the
day.

Short term 6 pm this evening through Sunday night
There is fairly good agreement between guidance of tracking the
remnant circulation of cindy across the central portion of the
cwa late tonight. That will represent the main chance of
moderate to heavy rainfall, though it's possible some lines of
storms could slowly drop south from pa during the evening and
prolong the issue over far NW sections of the area. Highest qpf
amounts will be to the northwest of the low track. Current
consensus still places this within the cwa, though some models
keep it to the northwest. The combination of uncertainty with
rain amounts today, along with where the axis of heaviest rain
tonight will be, gives low confidence on whether there will be
flash flood issues. However, the moisture-rich environment and
warm rain processes will be in play, so this situation will need
to be monitored closely. Current guidance also indicates stable
low levels tonight with meager instability, but winds aloft
will be very strong (with very high low level shear), so still
will not totally rule out an isolated instance of severe weather
just southeast of the low.

Low will be exiting quickly Saturday morning, taking the
heavier rain with it. However, the other player in all this --
the cold front -- does not look like it will completely push to
the southeast until later in the afternoon. Have maintained
chances for showers and storms east of i-95. Drying will
continue to advect in overnight, leading to less muggy lows.

A secondary cold front will drop through the area Sunday,
although it should remain precipitation-free. Highs will fall
back into the lower to mid 80s, with lows Sunday night in the
mid 50s to lower 60s.

Long term Monday through Thursday
The weather will feel more like late may than late june for
at least the first half of next week as a trough of upper level
low pressure settles over the region and a surface high sets up
to the west, funnelling cooler and less humid canadian air
across our region. Temperatures will be several degrees below
normal, with highs in the 70s to lower 80s and lows in the 50s
to lower 60s. By this time of year, normal highs are in the mid-
upper 80s and normal lows are in the mid-upper 60s.

A weak cold front crossing the area, reinforcing the cooler and
drier air, may spark off a shower or t-storm late Monday into
early Tuesday. Otherwise, the period looks generally dry.

The trough will swing east of the region late in the week and
the surface high will return to a more typical bermuda-high
position, allowing warmer and more humid air to start returning
to the region.

Aviation 08z Friday through Tuesday
Leading edge of rainfall associated with upper trough is not
currently posing any restrictions. There may be a brief period
of MVFR CIGS and additional showers working north during early
to mid morning. HoweverVFR conditions are expected by late
morning and will persist through the afternoon, though SW winds
may gust to 20 kt. Thunderstorm development this afternoon is
conditional this afternoon with a cap in place. Guidance has
little to no coverage, so will limit mention. Main restrictions
will come tonight as remnants of cindy cross the area. MVFR to
possibly ifr will occur late tonight, but exit quickly Saturday
morning. Cold front may not clear the area until afternoon,
though chance of additional showers storms is low.

Second cold front will cross on Sunday with little to no
impact.

Vfr expected Monday and Tuesday. An isolated shower or
thunderstorm can't be ruled out late Monday into early Tuesday
with a weak cold front, but odds are low.

Marine
Winds beginning to increase a bit over the open waters early
this morning, though will increase in earnest later this morning
once showers clear and mixing can increase SCA remains in
effect. Any thunderstorms this afternoon should be isolated. May
be a lull in the winds tonight, but will increase south of the
low track of the remnants of cindy. Have extended the sca
through Saturday as cold front pushes through the area, although
winds may decrease by mid afternoon as gradient weakens. Second
cold front will cross on Sunday and winds may marginally reach
sca levels.

A weak cold front crossing the area late Monday into early
Tuesday could boost winds up to SCA levels. An isolated shower
or thunderstorm is also possible with this front.

Hydrology
Highest QPF still looks to remain across the NW parts of the
area where 1-2 inches total will be possible. However, there is
still considerable uncertainty, especially since preceding
events may underproduce, and thunderstorms could produce local
variations. With areal averages spread out over the period,
mmefs continues to indicate no potential of mainstem river
flooding. The main concern will be flash flooding in any areas
which receive repeated and or prolonged periods of heavy rain.

Again, that would be the mountains, primarily tonight into
Saturday morning.

Tides coastal flooding
Water levels remain near astronomical normals. While an increase
is anticipated through Friday, flow will remain southwest. As
such, flooding is not likely. However, caution action stages
will be reached today, and any small deviation could bring the
sensitive spots to minor.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory from 10 am this morning to 6 pm edt
Saturday for anz530-531-535-536-538>540.

Small craft advisory until 6 pm edt Saturday for anz532>534-
537-541>543.

Synopsis... Rcm
near term... Ads
short term... Ads
long term... Rcm
aviation... Ads rcm
marine... Ads rcm
hydrology... Ads
tides coastal flooding... Hts rcm


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 5 mi43 min SSW 9.9 G 12 76°F 82°F1010.2 hPa
44061 - Upper Potomac, MD 10 mi43 min W 16 G 18 72°F 82°F1010.7 hPa
BSLM2 - Chesapeake Bay, MD 23 mi151 min SSE 5.1 68°F 1012 hPa67°F
APAM2 - 8575512 - Annapolis, MD 33 mi43 min 76°F 1010.5 hPa
44063 - Annapolis 35 mi31 min SW 12 G 16 75°F 1010.9 hPa
TPLM2 - Thomas Point, MD 35 mi61 min SSW 18 G 20 74°F 78°F
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 37 mi43 min S 8.9 G 11 74°F 1010.4 hPa
BLTM2 - 8574680 - Baltimore, MD 37 mi43 min SW 4.1 G 8 74°F 82°F1010.2 hPa
FSNM2 37 mi43 min SSW 7 G 13 73°F 1010.6 hPa
CPVM2 38 mi43 min 75°F 74°F
44043 - Patapsco, MD 41 mi31 min SSW 16 G 21 75°F 1011.2 hPa
NCDV2 42 mi43 min SSW 8 G 13 76°F 80°F1010.7 hPa
44062 - Gooses Reef, MD 44 mi31 min WSW 16 G 19 76°F 1012.5 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Washington/Reagan National Airport, DC, VA6 mi69 minS 1110.00 miOvercast75°F73°F94%1011 hPa
College Park Airport, MD10 mi68 minS 310.00 miOvercast73°F70°F90%1010.8 hPa
Fort Belvoir, VA14 mi63 minS 710.00 miMostly Cloudy75°F71°F89%1011.4 hPa
Camp Springs / Andrews Air Force Base, MD14 mi63 minSSW 13 G 1710.00 miOvercast73°F70°F93%1011.6 hPa
Gaithersburg - Montgomery County Airport, MD17 mi65 minSSW 510.00 miOvercast73°F70°F90%1013.5 hPa
Washington/Dulles International Airport, DC, VA19 mi69 minSSW 810.00 miOvercast73°F70°F90%1010.5 hPa
Fort Meade / Tipton, MD21 mi70 minSSW 510.00 miOvercast72°F69°F94%1011.8 hPa

Wind History from DCA (wind in knots)
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Last 24hrS7S7S8NW8SW8SW10W8SW11S7SW8S8SW7SW7S6S7S6SW7SW9S8SW9SW10S10S11S11
1 day agoS6S10S9SW7W10W14
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SW10SW7S7S3S6SW63SW3S6SW5NW3CalmE3S4S3
2 days agoSW6W7W8--W8SW10
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Tide / Current Tables for Chain Bridge, one mile below, Washington, D.C.
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Chain Bridge
Click for Map
Fri -- 02:25 AM EDT     0.14 feet Low Tide
Fri -- 05:25 AM EDT     Moonrise
Fri -- 05:43 AM EDT     Sunrise
Fri -- 08:10 AM EDT     3.81 feet High Tide
Fri -- 03:28 PM EDT     -0.04 feet Low Tide
Fri -- 08:09 PM EDT     Moonset
Fri -- 08:37 PM EDT     Sunset
Fri -- 08:51 PM EDT     3.19 feet High Tide
Fri -- 10:32 PM EDT     New Moon
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.90.40.20.20.71.72.83.53.83.632.31.60.90.4000.61.62.533.22.92.2

Tide / Current Tables for Reagan National Airport, Washington, D.C.
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Reagan National Airport
Click for Map
Fri -- 02:15 AM EDT     0.13 feet Low Tide
Fri -- 05:25 AM EDT     Moonrise
Fri -- 05:43 AM EDT     Sunrise
Fri -- 07:59 AM EDT     3.99 feet High Tide
Fri -- 03:16 PM EDT     -0.07 feet Low Tide
Fri -- 08:08 PM EDT     Moonset
Fri -- 08:37 PM EDT     Sunset
Fri -- 08:39 PM EDT     3.36 feet High Tide
Fri -- 10:32 PM EDT     New Moon
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.80.40.10.20.923.13.843.732.21.50.90.3-00.10.81.92.83.33.32.92.2

Weather Map and Satellite Images
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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 (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.