Saturday, August17, 2019 L-36.com


Marine Weather and Tides
Mercersburg, PA

Version 3.4
NOTICE
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 6:23AMSunset 8:06PM Saturday August 17, 2019 8:39 PM EDT (00:39 UTC) Moonrise 8:32PMMoonset 7:12AM Illumination 94% 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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ANZ538 Patapsco River Including Baltimore Harbor- 736 Pm Edt Sat Aug 17 2019
Tonight..S winds 5 kt. Waves flat. Isolated showers and tstms this evening.
Sun..S winds 5 to 10 kt. Waves 1 ft or less. Scattered showers and tstms.
Sun night..S winds 5 to 10 kt. Waves 1 ft.
Mon..S winds 5 kt. Waves flat.
Mon night..SW winds 5 kt. Waves flat.
Tue..SW winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Tue night..S winds 5 kt. Waves less than 1 ft. A chance of showers and tstms.
Wed..SW winds 5 kt. Waves less than 1 ft. A chance of tstms. A chance of showers.
Thu..NW winds 5 kt. Waves less than 1 ft. Showers likely with a chance of tstms, then a chance of showers after midnight. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 736 Pm Edt Sat Aug 17 2019
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure over the atlantic will control the weather pattern through Monday. A trough will build near the waters for Tuesday and Wednesday. Small craft advisories may be needed for portions of the waters Wednesday.


7 Day Forecast for Marine Location Near Mercersburg , PA
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location: 39.79, -77.93     debug


Area Discussion for - State College, PA
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Fxus61 kctp 172350
afdctp
area forecast discussion
national weather service state college pa
750 pm edt Sat aug 17 2019

Synopsis
Very warm and humid conditions will persist through into early
next week, and a trough of low pressure will keep the mention of
mainly afternoon and evening showers and thunderstorms in the
forecast.

Near term until 6 am Sunday morning
Waning band of convection noted along southern edge of shortwave
in vicinity of i-80 at 23z. Passage of shortwave, combined with
nocturnal cooling, should cause lingering showers storms to
taper off between 23z-03z, affecting mainly counties along and
just south of i-80.

Next shortwave and associated surface warm front my clip the
northwest part of the forecast area with a few late night
showers. Otherwise, the main concern will be developing valley
fog. The areas most likely to see fog will be northern pa and
areas east of the susq river, where rain fell today.

It will be another muggy mid summer night with lows ranging
from the mid 60s over the north to lower 70s se.

Short term 6 am Sunday morning through 6 pm Sunday
Scattered, diurnally-driven convection is expected Sunday.

Moderate capes in the 1000-2000 j kg range could support a few
strong storms, but fairly weak 0-6km shear suggests little risk
of organized severe weather. Sunday's high temps will be a deg
or 2 warmer than those of today. Highs will range from around 80
along the ny border to the lower 90s along the mason-dixon
line. The combination of heat and humidity will drive heat
indices into the mid 90s over the lower susq valley for a few
hours Sunday afternoon.

Long term Sunday night through Saturday
Hot and humid Monday with heat indices near 100 for much central
pa in the valleys. Scattered afternoon and evening showers and
thunderstorms may knock some temps down but it will feel muggy.

Active summer pattern with best chances for storms in the late
afternoon and lesser chances overnight through midweek. So
rounds of showers and thunderstorms likely Tuesday and Wednesday
as a weak coldfront drops down across pa. Another coldfront
will move through Wednesday night and Thursday. More showers and
thunderstorms with this front but behind it will finally bring
a change in the pattern with cooler drier weather for Friday and
Saturday under high pressure.

Aviation 00z Sunday through Thursday
00z tafs sent.

Still a strong storm just east of ipt and one near the office
here. Storms could produce gusty winds to around 35 to 40 mph
for another hour or so.

Another storm north of pit.

Late afternoon discussion below.

Updated the tafs here, minor adjustments for storms on radar and
current and fcst winds.

Main area for storms will be acros northern pa. Moisture good
for storms across the far southeast, but support is well to the
north for the storms.

Earlier discussion below.

WidespreadVFR is in place, except where the showers storms are
affecting individual airfields. This will continue into the
evening before patchy fog and low clouds redevelop late, lasting
through the sunrise hours. Expect continued improvement toVFR
conditions once again by late morning Sunday.

Outlook
Mon-wed... Rounds of showers thunderstorms possible, mainly in
the afternoon early evening hours. Late night and early morning
fog low clouds.

Thu... MainlyVFR behind a cold front.

Ctp watches warnings advisories
None.

Synopsis... La corte
near term... Fitzgerald
short term... Fitzgerald la corte
long term... Watson steinbugl
aviation... La corte martin


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BLTM2 - 8574680 - Baltimore, MD 80 mi70 min WSW 1.9 G 4.1 86°F 83°F1013.9 hPa
WASD2 - 8594900 - Washington, DC 80 mi70 min S 5.1 G 6
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 84 mi70 min W 1 G 1.9 85°F 1014.3 hPa

Wind History for Washington, DC
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hagerstown, Washington County Regional Airport, MD12 mi1.8 hrsS 810.00 miFair89°F66°F47%1014.8 hPa

Link to 5 minute data for KHGR

Wind History from HGR (wind in knots)
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Last 24hr--SE4SE3------CalmNW3--NW4CalmW3--4Calm5SW8S63S6S7SW8S8S3
1 day agoSE4Calm--E3NW4W6------CalmCalm------S9S6SW5SE10SE4--S8--SE9SE3
2 days agoN3NE6NE3CalmN4N5N5N3NW4CalmN4CalmCalmCalmNW5S5CalmSE6S12S12SE9S8--SE5

Tide / Current Tables for Chain Bridge, D.C.
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Chain Bridge
Click for Map
Sat -- 04:56 AM EDT     0.44 feet Low Tide
Sat -- 06:23 AM EDT     Sunrise
Sat -- 08:09 AM EDT     Moonset
Sat -- 10:40 AM EDT     3.25 feet High Tide
Sat -- 05:24 PM EDT     0.36 feet Low Tide
Sat -- 08:00 PM EDT     Sunset
Sat -- 09:27 PM EDT     Moonrise
Sat -- 11:05 PM EDT     3.10 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.621.40.90.60.40.71.32.22.83.23.22.92.31.71.10.70.40.40.91.72.52.93.1

Tide / Current Tables for Chain Bridge, one mile below, D.C.
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Chain Bridge
Click for Map
Sat -- 04:51 AM EDT     0.44 feet Low Tide
Sat -- 06:23 AM EDT     Sunrise
Sat -- 08:09 AM EDT     Moonset
Sat -- 10:35 AM EDT     3.25 feet High Tide
Sat -- 05:19 PM EDT     0.36 feet Low Tide
Sat -- 08:00 PM EDT     Sunset
Sat -- 09:27 PM EDT     Moonrise
Sat -- 11:00 PM EDT     3.10 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.621.40.90.60.40.71.42.22.93.23.22.82.21.610.60.40.411.82.52.93.1

Weather Map and Satellite Images
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wmap_A
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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for State College, PA (20,4,5,8)
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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.