Saturday, February24, 2018 L-36.com


Marine Weather and Tides
Brookmont, MD

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
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 6:45AMSunset 5:57PM Saturday February 24, 2018 10:47 AM EST (15:47 UTC) Moonrise 12:21PMMoonset 2:03AM Illumination 69% Phase: Waxing Gibbous; Moon at 9 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- 938 Am Est Sat Feb 24 2018
Rest of today..E winds 5 kt. Waves less than 1 ft. A chance of showers late this morning, then showers likely this afternoon. Areas of dense fog late this morning, then patchy fog this afternoon. Vsby 1 nm or less.
Tonight..E winds 5 kt. Waves less than 1 ft. Showers likely with patchy drizzle. Areas of fog. Vsby 1 to 3 nm.
Sun..SW winds 5 to 10 kt. Gusts up to 20 kt in the late morning and afternoon. Waves 1 ft. Showers likely. Patchy fog. Vsby 1 to 3 nm.
Sun night..NW winds 5 kt. Waves less than 1 ft. A chance of showers.
Mon..NW winds 5 kt. Waves less than 1 ft.
Mon night..NW winds around 5 kt. Waves 1 ft.
Tue..S winds around 5 kt. Waves 1 ft.
Wed..S winds around 5 kt. Waves 1 ft. A chance of showers through the night.
ANZ500 938 Am Est Sat Feb 24 2018
Synopsis for the tidal potomac and md portion of the chesapeake bay.. A boundary will remain just south of the waters through tonight before eventually moving to the north as a warm front on Sunday. A cold front will pass through from the west late Sunday into Sunday night. Small craft advisories may be needed for at least a portion of the waters on Sunday. High pressure will build over the waters for the first half of the upcoming work week.

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 241442
afdlwx
area forecast discussion
national weather service baltimore md washington dc
942 am est Sat feb 24 2018

Synopsis
A stationary boundary situated across our area will gradually lift
northward as a warm front through Sunday. A cold front will then
pass through from the west by Sunday evening, with high pressure
building in to the region through early next week.

Near term through tonight
Visibility is gradually starting to improve across the area, but
we remain solidly beneath a temperature inversion continuing to
be fed by north northeasterly winds. Dense fog advisory remains
in effect through 11 am, and some of the guidance hints we may
need to extend it longer for portions of the area (especially
near dc and waterways). Stay tuned.

The boundary is on the doorstep, as evidenced by S SW winds and
higher temps dewpoints at waynesboro (kw13) and sites just
south of the CWA in louisa and essex counties in virginia.

Meanwhile, an area of showers has spread across the northern cwa
this morning, dropping up to a half inch of rain. This is
followed by a lull, but another area of showers will push in
from the west late this morning and afternoon. I raised pops and
qpf in the south based on trends. The forecast update overall
leans heavily on the NAM nam nest for temps dewpoints, and on a
combination of NAM and hrrr for everything else. The incoming
rain and north winds should not allow the boundary to return
northward much, if at all, today, and if the NAM is correct, it
may even push a bit south.

Highs today range from the upper 40s near the mason-dixon line
(which could be optimistic) to the upper 60s in our far southern
cwa (which could be pessimistic). I expect very little movement
in temps tonight, with lows ranging from the mid 40s near the
mason-dixon to the mid upper 50s in the far southern cwa. Rain
chances continue throughout the night, along with a likely
resumption of low clouds and fog. Would be no surprise to need
another dense fog advisory.

Short term Sunday through Monday night
Come Sunday morning, a cold front will be moving eastward and
nearing the western portions of our cwa. The aforementioned warm
front will be lifting through and north of our area by Sunday
morning, allowing much warmer temperatures to prevail. High
temperatures will near 70 degrees for much of the area, with the
cooler middle to upper 60s over the northern third of the cwa.

Scattered shower activity Sunday morning will increase by midday as
the front nears from the west. With the warmer temperatures and
dewpoints creeping in to the lower 60s, along with frontogentical
forcing, a slight chance of thunderstorms is possible as the front
crosses the region by Sunday evening. Behind the front, clearing and
drying conditions will win out Sunday night, with temperatures still
above normal for late february, ranging from near 40 degrees to the
north west to around 50 degrees along our southern border.

High pressure will build in from the west as we kick off the work
week. The frontal boundary will linger along the carolina coast on
Monday, with the ECMWF indicating at least some rain chances for our
southern zones. As such, will keep chance pops for these areas on
Monday, but the majority of our CWA will remain dry. Weak CAA behind
the front on Monday will not prevent temperatures from reaching the
upper 50s on Monday, with lows Monday night cooler in to the 30s
area wide as CAA is a bit stronger and 850 temperatures reside at or
just below 0c. This is in response to a low mid level trough
swinging through the region Monday evening.

Long term Tuesday through Friday
The middle of the week will be quiet as high pressure will be
overhead. Tuesday will be the sunnier day; moisture will advance
Wednesday due to return flow warm advection as the center of the
high will move into the western atlantic. It remains to be seen if
there will be any showers. GFS pointing that way more than ecmwf.

Will back off pops for the period.

Have greater confidence that the end of the week will end on the wet
side, in spite of guidance timing organizational differences. (ecmwf
placing more emphasis on distinct southern stream shortwave energy
vs triple point from a well-defined northern stream system.) either
solution provides strong evidence of measurable precipitation, and
neither scenario suggests there will be type issues until the back
side (Friday night), when the QPF will be exiting.

Aviation 15z Saturday through Wednesday
Lifr ifr have been the rule at all terminals, but conditions are
slowly improving. Guidance remains pessimistic, especially at
dca bwi for improvement, but I do see at least a brief window
this afternoon before we likely fog back in tonight. Decent
chances of rain at all terminals, especially this afternoon and
tonight. Will be trying to refine those chances better for the
18z TAF package.

A cold front will move through the terminals Sunday afternoon, with
plentiful rain chances and ifr lifr vis CIGS continuing ahead of it.

Southwesterly breezes at around 10 knots, gusting to near 20 knots
during the day on Sunday, will shift out of the northwest Sunday
night and fall to less than 10 knots in the wake of the frontal
passage. Conditions should improve to MVFRVFR Sunday night, and
back toVFR through Monday night as high pressure moves in from the
west. Exception to this on Monday would be cho, where some residual
shower activity is possible as the aforementioned boundary lingers
well to our south. This could result in periods of subVFR
conditions there.

Outlook for Tuesday and Wednesday...

vfr conditions expected at this time due to high pressure.

Marine
No advisories expected through tonight for our waters as winds will
remain light as a stationary boundary to our south starts to lift
northward as warm front. As a cold front approaches from the west on
Sunday, winds will pick up and become gusty out of the south
southwest Sunday morning, with SCA conditions looking possible
through much of the day on Sunday until the front passes through
our waters. The frontal passage may bring with it a gusty line
of showers, with a slight chance of thunderstorms as well. High
pressure will then build in to the region behind the front
through Monday night, delivering lighter winds across our
waters, and sub SCA conditions.

Outlook for Monday through Wednesday...

winds will remain below small craft advisory thresholds due to high
pressure. Southerly flow will increase late Wed in the wake of the
high.

Lwx watches warnings advisories
Dc... Dense fog advisory until 11 am est this morning for dcz001.

Md... Dense fog advisory until 11 am est this morning for mdz003>006-
011-013-014-016>018-503>508.

Va... Dense fog advisory until 11 am est this morning for vaz040-
051>054-501-502-505-506.

Wv... Dense fog advisory until 11 am est this morning for wvz052-053.

Marine... None.

Synopsis... Bkf
near term... Je
short term... Bkf
long term... Hts
aviation... Je bkf hts
marine... Je bkf hts


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 5 mi48 min ENE 1.9 G 4.1 50°F 48°F1021.8 hPa (+0.7)
APAM2 - 8575512 - Annapolis, MD 33 mi48 min 47°F 1021.3 hPa (+0.0)
TPLM2 - Thomas Point, MD 35 mi48 min NNE 6 G 7 45°F 43°F
FSNM2 37 mi48 min NE 4.1 G 6 46°F 1021.7 hPa (+0.5)
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 37 mi48 min NE 4.1 G 5.1 46°F 1022.2 hPa (+0.4)
BLTM2 - 8574680 - Baltimore, MD 37 mi48 min E 1.9 G 2.9 47°F 44°F1021.8 hPa (+0.8)
CPVM2 38 mi48 min 44°F 44°F
NCDV2 42 mi48 min E 4.1 G 5.1 51°F 46°F1020.4 hPa (+0.0)
44062 - Gooses Reef, MD 44 mi38 min SE 3.9 G 5.8 45°F 1028.7 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 mi56 minNNE 60.25 miFog51°F51°F100%1021.8 hPa
College Park Airport, MD10 mi70 minN 03.00 miOvercast48°F48°F99%1021.7 hPa
Fort Belvoir, VA14 mi52 minNE 35.00 miFog/Mist52°F51°F100%1021.7 hPa
Camp Springs / Andrews Air Force Base, MD14 mi1.8 hrsENE 30.25 miFog50°F50°F100%1022.1 hPa
Gaithersburg - Montgomery County Airport, MD17 mi52 minVar 38.00 miOvercast48°F46°F96%1025.5 hPa
Washington/Dulles International Airport, DC, VA19 mi56 minENE 62.00 miFog/Mist50°F50°F100%1021.1 hPa
Fort Meade / Tipton, MD21 mi72 minNE 30.25 miOvercast46°F46°F100%1022.7 hPa

Wind History from DCA (wind in knots)
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Last 24hrE6CalmCalmS6S6S5S5S6S6S5S5S6S3S4S5CalmCalmCalmCalmN5E4NE3NE5NE6
1 day agoNE6E8E9SE10NE5N11NE12NE12NE18NE14E11NE12NE10E11E7NE9E6NE8E4NE7E5E6E4E5
2 days agoS15
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S10SW11S9S83SW4N3N5N8NE11NE14NE12NE12NE8NE12NE13NE12

Tide / Current Tables for Chain Bridge, one mile below, Washington, D.C.
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Chain Bridge
Click for Map
Sat -- 02:03 AM EST     Moonset
Sat -- 02:39 AM EST     2.64 feet High Tide
Sat -- 06:47 AM EST     Sunrise
Sat -- 08:59 AM EST     0.05 feet Low Tide
Sat -- 12:21 PM EST     Moonrise
Sat -- 02:55 PM EST     3.06 feet High Tide
Sat -- 05:55 PM EST     Sunset
Sat -- 10:18 PM EST     0.10 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.52.22.62.62.31.71.10.50.20.10.20.61.52.42.93.12.82.31.71.10.60.30.10.2

Tide / Current Tables for Reagan National Airport, Washington, D.C.
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Reagan National Airport
Click for Map
Sat -- 02:03 AM EST     Moonset
Sat -- 02:25 AM EST     2.71 feet High Tide
Sat -- 06:47 AM EST     Sunrise
Sat -- 08:48 AM EST     0.11 feet Low Tide
Sat -- 12:20 PM EST     Moonrise
Sat -- 02:41 PM EST     3.15 feet High Tide
Sat -- 05:55 PM EST     Sunset
Sat -- 10:08 PM EST     0.15 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.72.42.72.62.31.710.50.20.10.30.81.72.63.13.12.82.31.61.10.60.30.20.3

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.