Thursday, June29, 2017 L-36.com


Marine Weather and Tides
Halfway, 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 5:44AMSunset 8:44PM Thursday June 29, 2017 12:01 PM EDT (16:01 UTC) Moonrise 10:56AMMoonset 11:47PM Illumination 30% 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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ANZ538 Patapsco River Including Baltimore Harbor- 1032 Am Edt Thu Jun 29 2017
.small craft advisory in effect through Friday evening...
Rest of today..S winds 10 kt with gusts to 20 kt. Waves 1 ft.
Tonight..S winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft.
Fri..S winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft.
Fri night..S winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft.
Sat..S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Sat night..SW winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms.
Sun..NW winds 5 kt. Waves flat. A chance of showers and tstms.
Mon..NW winds around 5 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 1032 Am Edt Thu Jun 29 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure east of the delmarva will move toward bermuda today allowing for southerly flow to remain through the weekend. Small craft advisories may be needed late Friday into early Saturday.

7 Day Forecast for Marine Location Near Halfway, MD
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location: 39.62, -77.79     debug


Area Discussion for - Baltimore, MD/Washington
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Fxus61 klwx 291341
afdlwx
area forecast discussion
national weather service baltimore md washington dc
941 am edt Thu jun 29 2017

Synopsis
High pressure will settle near bermuda today with hot and humid
conditions returning and persisting through at least the first
half of next week.

Near term until 6 pm this evening
High pressure continues to shift further offshore away from the
mid-atlantic... With a warming moistening southerly flow
strengthening. Highs this afternoon m u80s... Near normal for
late june.

While we kept forecast dry for now... Would not be be completely
surprised to see a stray shower (or brief thunderstorm) across
the higher terrain along west of the blue ridge during peak
afternoon heating. Any activity would be short-lived, very
localized, and would dissipate by mid-evening.

Short term 6 pm this evening through Saturday
Temperatures more typical for the end of june early july will
persist into Saturday. Outside of the higher elevations
temperatures will approach 90 both afternoons with lows near 70.

Precipitation chances will be slim in the next 48 hours -
perhaps some orographically induced showers thunderstorms Friday
afternoon evening, but the best chance will be Saturday
afternoon. Low pressure over ontario quebec with a cold front
dropping into ny state and a weak trough approaching the
mountains will serve as the focus for storms. Bufkit profiles
show a weak unidirectional wind field, so at this moment pulse
severe looks to be the worse case scenario.

With summer precipitation forecasting I am usually hesitant to
go beyond "chance" five periods out. Given we have been
advertising "likely" in the west as our surrounding offices, and
gfs is forecasting 70 pops i'll hold with the 60 pop Saturday
afternoon west of the blue ridge.

Long term Saturday night through Wednesday
Typical summertime conditions expected for late in the weekend and
into next week with daily chances for afternoon evening convection
and very warm temperatures.

A weakening frontal boundary that approaches Saturday will stall
near the region Saturday night into Sunday, keeping chances for
showers and thunderstorms in the forecast. This boundary will remain
near or just north of the area into next week, separating a
hot humid air mass to the south from a cooler canadian air mass to
the north. Thus there will be chances for isolated scattered
showers thunderstorms each day, but the vast majority of the time
should be dry.

Will show highs upper 80s to low 90s through the period for now,
with lows in the 60s 70s, but will be dependent on frontal
position.

Aviation 13z Thursday through Monday
Vfr conditions continue today through midday Saturday.

Showers thunderstorms will be possible Saturday afternoon,
especially at iad mrb cho.

MainlyVFR expected through at least Monday. Isolated-scattered
showers thunderstorms possible, so some brief reductions are
possible.

Marine
Southerly channeling ongoing on the chesapeake bay tidal
potomac - a sure sign of summer. While wind gusts have largely
been below SCA criteria thus far this morning... Expect winds to
increase to AOA sca threshold by afternoon as southerly flow
continues to strengthen.

This will likely reoccur Friday into Saturday with SCA possible.

Mainly sub-sca conditions expected Saturday night through Monday.

There is a chance for isolated-scattered showers thunderstorms each
afternoon and evening, which may contain locally gusty winds.

Lwx watches warnings advisories
Dc... None.

Md... None.

Va... None.

Wv... None.

Marine... Small craft advisory until 7 pm edt Friday for anz530>534-
537>541-543.

Small craft advisory until 11 am edt Friday for anz535-536-542.

Update... Mse
products... Woody! Mjm


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WASD2 - 8594900 - Washington, DC 66 mi43 min S 8 G 11 77°F 80°F1020 hPa
BLTM2 - 8574680 - Baltimore, MD 69 mi43 min WSW 6 G 14 80°F 77°F1019.8 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 72 mi43 min SW 8 G 11 79°F 1019.9 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD7 mi68 minSSW 910.00 miFair79°F59°F50%1020.2 hPa
Eastern WV Regional Airport/Shepherd Field, WV18 mi68 minVar 610.00 miFair80°F59°F49%1019 hPa

Wind History from HGR (wind in knots)
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Last 24hrW7SW7
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W3W4S3SW6S7S7S7SE6S9S6S7S5S5S8S7S6S6S10----S9S5
1 day agoW10
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NW13NW12NW6NW5NW4CalmCalmCalmCalmS4W4SE3E3SW4SW7SW6CalmCalm
2 days agoSW6W7SW10SW9SW7SW8SW6S9W7NW3W4W3CalmCalmW4SW3S3NW4CalmCalmW5W8NW8
G16
W9

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Thu -- 12:11 AM EDT     Moonset
Thu -- 01:25 AM EDT     3.28 feet High Tide
Thu -- 05:45 AM EDT     Sunrise
Thu -- 08:05 AM EDT     0.22 feet Low Tide
Thu -- 11:53 AM EDT     Moonrise
Thu -- 01:42 PM EDT     3.30 feet High Tide
Thu -- 08:35 PM EDT     0.07 feet Low Tide
Thu -- 08:37 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.93.23.22.82.11.50.90.50.20.41.22.12.83.23.32.92.41.71.10.50.20.10.61.5

Tide / Current Tables for Chain Bridge, Washington, D.C.
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Chain Bridge
Click for Map
Thu -- 12:11 AM EDT     Moonset
Thu -- 01:26 AM EDT     3.23 feet High Tide
Thu -- 05:45 AM EDT     Sunrise
Thu -- 08:07 AM EDT     0.24 feet Low Tide
Thu -- 11:53 AM EDT     Moonrise
Thu -- 01:44 PM EDT     3.25 feet High Tide
Thu -- 08:36 PM EDT     0.09 feet Low Tide
Thu -- 08:37 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.93.23.22.72.11.510.50.20.41.122.73.23.22.92.31.71.10.60.20.10.61.5

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 (12,3,4,5)
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Ground Weather Radar Station Sterling, VA
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weather_mapweather_map weather_map

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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.