Saturday, December16, 2017 L-36.com


Marine Weather and Tides
Charles, 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 7:16AMSunset 4:42PM Saturday December 16, 2017 11:50 AM EST (16:50 UTC) Moonrise 5:35AMMoonset 3:57PM Illumination 3% Phase: Waning Crescent; Moon at 28 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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ANZ530 Chesapeake Bay North Of Pooles Island- 1112 Am Est Sat Dec 16 2017
.small craft advisory in effect until 7 pm est this evening...
Rest of today..SW winds 15 kt with gusts to 20 kt. Waves 1 to 2 ft.
Tonight..W winds 10 to 15 kt with gusts to 20 kt... Becoming ne around 5 kt after midnight. Waves 1 ft or less.
Sun..SE winds 5 kt. Waves flat.
Sun night..S winds around 5 kt. Waves flat. A chance of showers.
Mon..W winds 5 kt. Waves less than 1 ft.
Mon night..SW winds 5 kt. Waves flat.
Tue..W winds 5 to 10 kt. Waves 1 ft.
Wed..NW winds 5 to 10 kt. Waves 1 ft.
ANZ500 1112 Am Est Sat Dec 16 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will build south of the waters through the weekend. A backdoor cold front will approach from the north Sunday, then return north as a warm front Monday.

7 Day Forecast for Marine Location Near Charles, MD
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location: 39.57, -75.97     debug


Area Discussion for - Philadelphia/Mount Holly, PA
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Fxus61 kphi 161637
afdphi
area forecast discussion
national weather service mount holly nj
1137 am est Sat dec 16 2017

Synopsis
A cold frontal boundary across the great lakes will move
southeastward through the region today and tonight. This front will
then comes back northward through the region as a warm front on
Sunday. Another cold front will then move through the region during
the middle of next week. To end next week, an area of low pressure
will track northeast into the great lakes bringing a warm front
through our region.

Near term until 6 pm this evening
1130 am update...

snow showers have been slow to start with radar indicating some
virga aloft across the southern poconos. The 12z model suite has
also delayed the onset. The 12z NAM and 15z rap have shifted the
qpf further north. As a result, have delayed the onset of light
snow showers into the 2-4 pm time frame generally in the
vicinityof i-80 in nj and carbon monroe counties of eastern
pa. Amounts across this area should range from a dusting to one
half of an inch. Cannot rule out isolated one inch amounts
across some of the higher terrain, with the higher snow ratios
in place. The snow showers should end early this evening.

The remainder of the forecast remains on track.

Previous discussion...

today, the attention turns to locations generally along and north of
interstate 80 for snow chances. No major changes to the previous
forecast with today's event. Another mid level shortwave trough will
approach our region through the day. In response, the cold front
currently over the great lakes will approach the region this
afternoon. Further, the right entrance region of an upper level jet
will be over the northern half of the region. As mentioned by the
previous shift, the best synoptic scale lift should stay north of
our region. However, models continue to indicate a ribbon of low
level frontogenesis across southern ny. This, combined with the
nearly saturated boundary layer and equivalent potential vorticity
values near or below 0 just south of the frontogenesis, indicates
there should be enough instability for some snow showers to progress
as far south as the i80 corridor. Moisture is limited, as is the
window of opportunity for any snow showers, so any accumulations are
expected to be less than an inch.

Further south, the combination of a building surface ridge over the
coastal plains and be further removed from any forcing, should keep
the area dry.

Forecast temperatures are below most guidance. The reason for this
is that models tend to have a warm bias the day after a fresh snow
pack. Thus, expect highs to range from the upper 20s in the southern
poconos and NW nj, to the lower 40s across delmarva.

Short term 6 pm this evening through 6 am Sunday
Overnight, the latest mid level short wave trough moves further away
from the region. The cold front should continue to slide south
through the region. However, by this point, models don't depict any
frontogenesis, but there should be subsidence thanks to the building
east coast ridge. Thus, expect the overnight period to be dry across
the region.

Undercut guidance considerably for overnight lows as models have had
a strong warm bias the last few nights. Though the snow pack may not
be much of an issue (much, if not all of it could melt during the
day today), clearing skies and light winds will promote radiational
cooling especially through the second half of the night.

Long term Sunday through Friday
Sunday through Monday night:
a wintry mix event is currently modeled across northern portions of
the region with moisture overruning a warm frontal boundary.

Overall, this system will be weakening as it comes northeast into
our region. Through this event, thermal profiles look to support
mainly rain across the philadelphia area and locations to the south,
while locations further north have modeled soudings which would
yield a mixture of snow and freezing rain. This is noted in a warm
nose advecting northeast at about 925 mb throughout Sunday night
with 925 mb temperatures rising to between 1 and 2c with surface
temperatures near or below freezing. QPF does look light and under
1 10th of an inch on most models and ensembles at this time.

Generally opted temperatures Sunday toward the modeled two meter
temperatures then incorporating some of the met mav ECMWF temperature
guidance Monday and Monday night. Temperatures should rise into the
40's for most of us with lows Monday night in the 30's.

Tuesday and Tuesday night:
our region will be between a high pressure offshore and an
approaching cold front from the west. This will result in southerly
winds and warming temperatures. Enough moisture and lift could be
present ahead of the front for some scattered rain showers. However,
the signal for precipitation is noisy on the various ensembles and
fairly limited so we will maintain slight to low chance pops. Right
now the temperature forecast is on the warmer end of the ensemble
envelope with highs well into the 50's, nighttime temperatures should
fall back into the 30's.

Wednesday through Thursday night:
after the frontal passage, we return to northwest flow with cold
air advection into the region. Another period of gusty winds is not
out of the question. With high pressure building in both days should
be mostly sunny. Right now the wind direction off the lakes looks
unfavorable for any increase in clouds or snow showers up in the
southern poconos. Bufkit analysis shows the potential for some gusts
from the west at around 20 mph Wednesday afternoon. High
temperatures should fall back into the 40's with lows in the 20's,
opted to go on the cooler end of the ensemble guidance given the
cold air advection into the region.

Friday and Friday night:
a warm frontal boundary lifts northward across the region as a low
pressure system tracks into the great lakes. Another surge of
southerly flow will come into the region leading toward a moderating
trend with temperatures. This warm front will also bring some
showers with it.

Longer term:
a quick look into christmas week does still provide the chance of a
white christmas with an active weather pattern that looks to turn
colder thanks to a epo which is falling several standard deviations
below normal. The - epo will discharge cold from ak southeast into
the united states just before christmas. However, the colder air can
dive into the western united states first leading to warmer
conditions and a typical ridge in la-ninas over the southeastern
united states. Exactly how this plays out is still outside the
forecast window and a lot of possibilities are in play. Be mindful
of any weather information you see about christmas can still change
quite a bit over the next few days.

Aviation 18z Saturday through Thursday
The following discussion is for kphl, kpne, kttn, kabe, krdg,
kilg, kmiv, kacy and surrounding areas.

Today...VFR. There is a small chance that snow showers along
and north of i80 this afternoon, could move as far south as
kabe. If this happens, there could be brief MVFR conditions.

However, this is very unlikely so have not included it in the
taf. Winds generally out of the west around 10 kt with gusts
up to 20 kt. High confidence.

Tonight...VFR conditions are expected overnight. A cold front moving
through by 06z will result in northerly or northwesterly winds, but
speeds should be 10kt or less. After 06z, winds will likely become
light and variable. High confidence.

Outlook...

Sunday:VFR, winds under 10 knots. High confidence.

Sunday night: sub-vfr possible with patchy light rain, mixed
precipitation possible at kabe, kttn and krdg. Winds under 10
knots. Moderate confidence.

Monday and Monday night: mainlyVFR, winds generally under 10
knots. Moderate confidence.

Tuesday through Wednesday:VFR. An isolated shower can not be ruled
out on Tuesday. Southwest wind gusts around 15 knots then shifting
to northwest and increasing to 20 knots on Wednesday. High
confidence.

Marine
1130 am update...

after a brief lull this morning, winds will increase again this
afternoon across the nj coastal waters and de bay. Across the de
coastal waters, winds have subsided, and if this trend continues,
plan on dropping the SCA by 18z. Elsewhere, the SCA continues as
posted.

Previous discussion...

winds gusting above 25 kt are expected on all the waters
through at least the morning hours. On the delaware bay and
delaware and southern new jersey coastal waters, winds may drop
below small craft advisory earlier than previously expected,
possibly as early as this afternoon. However, I did not have
enough confidence to change the end time on the small craft
advisory.

On the northern and central new jersey coastal waters, though there
may be a brief lull in the winds late this afternoon, wind gusts
above 25 kt are possible behind a cold front this evening.

Outlook...

the main period for concern is northwesterly winds Wednesday
afternoon which may approach or briefly exceed 25 knots which may
warrant an sca. Data is indicating seas stay below five feet
throughout the outlook period. High confidence.

Phi watches warnings advisories
Pa... None.

Nj... None.

De... None.

Md... None.

Marine... Small craft advisory until 1 am est Sunday for anz450>455.

Small craft advisory until 6 pm est this evening for anz430-
431.

Synopsis... Gaines
near term... Franck johnson
short term... Johnson
long term... Gaines
aviation... Franck gaines johnson
marine... Franck gaines johnson


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
CHCM2 - 8573927 - Chesapeake City, MD 9 mi164 min S 5.1 G 6 31°F 37°F1020.9 hPa
DELD1 - 8551762 - Delaware City, DE 20 mi50 min WSW 8 G 9.9 35°F 37°F1019.8 hPa (-0.4)
RDYD1 - 8551910 - Reedy Point, DE 21 mi62 min 35°F 40°F1019.6 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 29 mi158 min SW 16 G 18 35°F 37°F1020.9 hPa
MRCP1 - 8540433 - Marcus Hook, PA 34 mi164 min 29°F 40°F1019.7 hPa
FSNM2 38 mi50 min SW 7 G 13 38°F 1019.8 hPa (+0.0)
BLTM2 - 8574680 - Baltimore, MD 38 mi158 min W 1.9 G 5.1 32°F 45°F1020.5 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 38 mi56 min SW 14 G 18 37°F 1020.3 hPa
DRSD1 - Delaware Reserve, DE 44 mi140 min SSW 4.1 31°F 1021 hPa30°F
CPVM2 45 mi50 min 40°F 22°F
APAM2 - 8575512 - Annapolis, MD 49 mi158 min 34°F 1020.7 hPa

Wind History for Chesapeake City, MD
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Phillips Army Air Field / Aberdeen, MD13 mi1.9 hrsWSW 610.00 miPartly Cloudy0°F0°F%1021.3 hPa
Wilmington, New Castle County Airport, DE21 mi59 minSW 1010.00 miA Few Clouds36°F26°F67%1020.1 hPa

Wind History from APG (wind in knots)
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Last 24hr----CalmCalm--CalmCalmCalmCalmCalmCalmW3W3W5W3W4W4W3CalmCalmW4W6W6SW12
1 day agoNW7NW8NW9CalmNW8CalmNW4CalmCalmCalmN3N6N4----------------------
2 days agoW13
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W11W8
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W5CalmCalmCalmSW11SW7CalmSE3SE3CalmCalmCalmSW5W5W5W8W8NW10
G19
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Tide / Current Tables for Charlestown, Northeast River, Chesapeake Bay, Maryland
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Charlestown
Click for Map
Sat -- 04:01 AM EST     0.17 feet Low Tide
Sat -- 05:33 AM EST     Moonrise
Sat -- 07:18 AM EST     Sunrise
Sat -- 08:31 AM EST     1.31 feet High Tide
Sat -- 03:00 PM EST     -0.41 feet Low Tide
Sat -- 03:56 PM EST     Moonset
Sat -- 04:41 PM EST     Sunset
Sat -- 09:34 PM EST     2.23 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.410.60.30.20.30.611.31.31.10.70.3-0-0.3-0.4-0.30.10.71.41.92.22.22

Tide / Current Tables for Chesapeake and Delaware Canal, Maryland/Delaware Current
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Chesapeake and Delaware Canal
Click for Map
Sat -- 02:26 AM EST     0.00 knots Slack
Sat -- 05:12 AM EST     2.01 knots Max Flood
Sat -- 05:33 AM EST     Moonrise
Sat -- 07:17 AM EST     Sunrise
Sat -- 07:56 AM EST     -0.08 knots Slack
Sat -- 11:20 AM EST     -2.23 knots Max Ebb
Sat -- 03:17 PM EST     0.05 knots Slack
Sat -- 03:56 PM EST     Moonset
Sat -- 04:40 PM EST     Sunset
Sat -- 05:57 PM EST     2.21 knots Max Flood
Sat -- 09:36 PM EST     -0.01 knots Slack
Sat -- 11:52 PM EST     -1.56 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-1.5-1.2-0.811.721.91.4-0.4-1.4-2-2.2-2.2-1.9-1.6-0.81.322.221.61-0.8-1.4

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 Philadelphia/Mount Holly, PA (11,2,3,4)
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Ground Weather Radar Station Dover AFB, DE
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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.