Tuesday, November21, 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 6:54AMSunset 4:44PM Tuesday November 21, 2017 5:08 AM EST (10:08 UTC) Moonrise 9:26AMMoonset 7:25PM Illumination 7% Phase: Waxing Crescent; Moon at 3 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- 405 Am Est Tue Nov 21 2017
.small craft advisory in effect through this evening...
.small craft advisory in effect from Wednesday morning through Wednesday afternoon...
Rest of the overnight..S winds 10 kt. Waves 1 ft.
Today..S winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft.
Tonight..SW winds 5 to 10 kt. Gusts up to 20 kt until early morning. Waves 1 ft. A chance of showers.
Wed..NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft.
Wed night..NW winds 5 to 10 kt. Waves 1 ft.
Thu..W winds 5 kt. Waves flat.
Thu night..W winds 5 kt. Waves flat.
Fri..SW winds 5 to 10 kt. Waves 1 ft or less.
Sat..W winds 5 to 10 kt. Waves 1 ft.
ANZ500 405 Am Est Tue Nov 21 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will move offshore through this afternoon. A cold front will pass through late tonight into early Wednesday morning. High pressure will return later Wednesday through early Friday, then another cold front will approach late Friday into Saturday. A small craft advisory will likely be needed for portions of the waters Wednesday night, and again Friday night through Saturday.

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 210852
afdphi
area forecast discussion
national weather service mount holly nj
352 am est Tue nov 21 2017

Synopsis
A cold front will cross the area Tuesday night and early Wednesday,
followed by high pressure into Saturday. Another cold front is
expected to cross the area Saturday night, with high pressure
anticipated for the first part of next week.

Wednesday... Lull in SCA conditions possible Wednesday morning.

Otherwise, winds shift to the NW and increase to 15-20 kt with 25-30
kt gusts.

Thursday through Friday... Sub-sca conditions expected.

Saturday and Sunday... SCA conditions are possible with the passage
of a strong cold front.

Near term until 6 pm this evening
Digging vort MAX in the upper midwest will continue southeastward
through the great lakes region today. Downstream, midlevel ridging
will amplify in response to low-level warm-air advection expanding
the atmospheric column. Predecessor perturbations in the flow will
progress through the east today, though these should have generally
minimal impacts on sensible weather other than increasing high
clouds, especially this afternoon. As the surface ridge to our south
continues offshore today, southwesterly flow will continue, getting
a boost from diabatic heating and a strong surface low moving
through ontario (aiding in an increased surface pressure gradient).

As such, expect breezy conditions again today, especially
along southeast of the urban corridor, as areas to the northwest
will be in somewhat of a surface col by afternoon.

Statistical guidance shows good agreement, but I suspect there is a
bit of a cool bias with temperatures today given the warming
profiles and the amplified ridging. Hard to go against good
agreement among the guidance, but I did nudge up temperatures a
degree or two in spots from the inherited forecast. It is quite
possible that philly reaches 60 today, with overall MAX temperatures
about 2-7 degrees above seasonal averages.

Short term 6 pm this evening through 6 am Wednesday
A perturbation over the southeast will lift northeastward during the
day, likely in vicinity of the carolinas by 21z. Precipitation
should break out near this vort max, with a surface wave likely
developing during the day near or off the coast of florida. This
southern-stream system will be affected strongly by the northern-
stream vort max, with some phasing likely to occur during the
overnight period, and rapid development northeastward progression of
the surface low near off the carolina coast. However, despite the
overall excellent agreement in the large-scale pattern, the NAM gfs
depictions of the southern-stream low leave some question marks. The
gfs looks a little on the fast progressive side, which is a typical
bias it exhibits in the short term. Comparison to the rgem suggests
it might be on the order of 3 hours too fast, and this difference
may be enough to keep the GFS too dry tonight. It will be critical
to watch the evolution of the southern-stream system today (and the
precipitation upscale feedback processes) to determine if the GFS is
keeping us too dry tonight.

Meanwhile, the NAM looks very similar to the rgem in the overall
evolution of the system tonight, but the NAM is simply drier than
the rgem (another bias observed on multiple occasions this season).

Based on this (and the GFS bias), I weighted guidance that was
slightly slower wetter (e.G., the NAM nest and the wrf-arw, along
with the rgem) somewhat higher. Also included some of the 00z ecmwf
with the QPF grids tonight, despite its coarser resolution, as it
seems to be doing a good job this fall depicting the cutoff of the
poleward side of the precipitation somewhat better than the NAM gfs
(likely because of its general slower deeper depictions of these
phasing systems).

The northern-stream upper-level jet streak will be in a favorable
position by night's end for rather deep ascent, but by this point,
the stronger lift will probably be offshore. Nevertheless, mesoscale
banding of the precipitation is clearly evident in most of the model
simulations tonight, and this does occur as far west as i-95 in most
of these simulations. This makes the QPF a challenge, since these
setups can be underdone in the models (both with precipitation rates
and the slow progression of these phenomena compared to the speed of
deep-layer flow). This was another reason I upped the QPF from the
previous forecast, but tempered to some degree versus the wettest
guidance (sref ecmwf).

With the above in mind, brought pops up to chance generally urban
corridor southeastward and to likely southeast of a dover, de, to
sandy hook, nj, line. The timing of the precipitation looks to be
mainly after midnight, but there is some uncertainty here given the
discrepancies mentioned earlier. Amounts generally in the tenth to
quarter inch range along southeast of i-95 to potentially a half
inch near the coast, but confidence in these values is low because
of the uncertainty with the exact track of the precipitation. Also,
the cutoff of the precipitation will likely be sharper than I have
depicted in the grids (an inevitable result of precipitation
forecast uncertainty). Bottom line: large errors in the pops QPF are
possible tonight given the remaining model discrepancies.

Temperatures were generally a blend of met mav ecs mos, though I did
nudge temperatures up a little, in general given the increased
clouds and remaining low-level south southwest fetch. Looks like
temperatures will be too warm for non-liquid, non-freezing
precipitation anywhere in our CWA through daybreak.

One final note: given the strengthening dynamics aloft, strong lift
will aid in midlevel cooling possibly enough to generate some
marginal instability. Not totally out of the question to see a
couple lightning strikes, though the best chances are offshore.

Long term Wednesday through Monday
The extended period starts off with a cold front near or along the
coast Wednesday morning, moving east. Chillier air, normal for this
time of year, will move in behind this front. With ridging aloft
over the western u.S. And troughiness in the east, a seasonably cool
but mostly dry pattern is expected through most of the long term
period, with a chance of precipitation later Saturday and Sunday as
another cold front and associate deep upper level trough crosses the
mid-atlantic region.

The FROPA early Wednesday will trigger a few showers N W of phl. A
sfc low pressure is also forecast to develop off the nc sc coasts
with moisture spreading north ahead of it along the de nj coastal
areas. The highest pops continue over southern nj and delmarva,
counter to climo. Overnight temps should remain warm enough so that
all precip will be in liquid form. However a few showers may linger
past sunrise, and with cold advection behind the front a few snow
showers or flurries are possible in the poconos Wednesday morning.

The weather for Wed afternoon through Friday night will be dominated
by high pressure moving across the mid-atlantic region. Temperatures
will be a few degrees below normal on Thursday but should return to
near normal by Friday as the high shifts offshore and a more swly
flow develops. A cold front may push south in to ny state and new
england on Friday but probably will not affect our area to the south,
another fast-moving frontal system is forecast to push through our
area on Saturday. In part because of its fast movement it will not
be able to pick up much moisture. The current forecast continues
chance pops, higher N W of phl, but even this may be overdone.

Again, temps on Saturday appear to be warm enough to avoid any
frozen precip. However, the airmass behind this front seems to be
colder than the one mid-week, with strong low level cold advection
beginning Saturday night and continuing through the rest of the
weekend. This pattern of NW flow will favor lake effect snow with
some streamers possibly reaching the poconos and vicinity.

Aviation 09z Tuesday through Saturday
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.

Today...VFR with southwest winds 5 to 15 kts with occasional gusts
to 20 kts or so, especially from the i-95 corridor southeastward.

High confidence.

Tonight... Rapidly increasing clouds, likely to sub-vfr near the
coasts (kmiv and kacy most likely to see this). Showers should
spread from southwest to northeast through the area after 06z
Wednesday, mainly confined to the urban corridor southeastward. Sub-
vfr vsbys are likely with the heavier showers, but confidence on how
far inland the precipitation reaches is very low. Winds generally
southwest around or below 10 kts, with some veering to westerly
expected by daybreak. Medium confidence with winds; low confidence
with CIGS vsbys.

Outlook...

Wednesday... Rain possible south and east of i-95 early Wednesday
morning with MVFR or lower conditions... Then becomingVFR. Sw
winds 5-10 kt become NW Wednesday afternoon and increase to
10-20 kt.

Wednesday night and Thursday...VFR. NW winds gradually diminishing.

A storm system is currently expected to remain offshore. Forecast
confidence: medium to high.

Friday...VFR. NW winds 5-10 kt.

Saturday and Saturday night...VFR early... Then MVFR or lower
conditions possible in rain showers later in the day and at night.

Sw winds 10-15 kt.

Marine
Small craft advisory in effect for delaware bay and the delaware
atlantic coastal waters through today and for the new jersey coastal
waters through this evening as strong southwest winds
continue increase today. Winds should diminish overnight, especially
over delaware bay and the adjacent atlantic waters, though
confidence is not particularly high given the potentially brief
duration of these lighter winds.

Showers should spread northeastward overnight (generally after
midnight), with localized restrictions possible. Expect erratic
gusts and locally very choppy seas in vicinity to showers. A
lightning strike or two is not out of the question, though the
probability is too low for inclusion in the forecast at this point.

Outlook...

Wednesday... Lull in SCA conditions possible Wednesday morning.

Otherwise, winds shift to the NW and increase to 15-20 kt with 25-30
kt gusts.

Thursday through Friday... Sub-sca conditions expected.

Saturday and Sunday... SCA conditions are possible with the passage
of a strong cold front.

Phi watches warnings advisories
Pa... None.

Nj... None.

De... None.

Md... None.

Marine... Small craft advisory until 1 am est Wednesday for anz450>453.

Small craft advisory until 7 pm est this evening for anz454-
455.

Small craft advisory until 7 pm est this evening for anz430-
431.

Synopsis... Miketta
near term... Cms
short term... Cms
long term... Miketta
aviation... Cms miketta
marine... Cms miketta


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44057 - Susquehanna, MD 6 mi38 min SW 5.8 G 7.8 46°F 1020.1 hPa
CHCM2 - 8573927 - Chesapeake City, MD 9 mi56 min Calm G 1.9 35°F 46°F1020.4 hPa
DELD1 - 8551762 - Delaware City, DE 20 mi50 min SSW 2.9 G 7 43°F 45°F1020.2 hPa
RDYD1 - 8551910 - Reedy Point, DE 21 mi50 min 40°F 48°F1019.8 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 29 mi50 min S 7 G 11 47°F 48°F1020.4 hPa
MRCP1 - 8540433 - Marcus Hook, PA 34 mi56 min 43°F 53°F1019.8 hPa
44043 - Patapsco, MD 36 mi38 min SSW 14 G 16 46°F 1020.9 hPa
SJSN4 - 8537121 - Ship John Shoal, NJ 36 mi50 min SSW 15 G 17 44°F 51°F1020.6 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 38 mi50 min SSW 5.1 G 6 41°F 1020.2 hPa
BLTM2 - 8574680 - Baltimore, MD 38 mi56 min SW 1 G 2.9 40°F 54°F1019.9 hPa
DRSD1 - Delaware Reserve, DE 44 mi98 min S 4.1 38°F 1022 hPa33°F
CPVM2 45 mi50 min 48°F 33°F
44063 - Annapolis 49 mi38 min S 14 G 16 46°F 1020.2 hPa
APAM2 - 8575512 - Annapolis, MD 49 mi50 min 44°F 1019.9 hPa

Wind History for Chesapeake City, MD
(wind in knots)    EDIT      (on/off)   Help
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Phillips Army Air Field / Aberdeen, MD13 mi70 minSW 710.00 miFair40°F31°F72%1020.6 hPa
Wilmington, New Castle County Airport, DE21 mi17 minNW 310.00 miFair33°F28°F82%1020.6 hPa

Wind History from APG (wind in knots)
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Last 24hrW7W7SW4NW8W13
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W9SW5SW4W4CalmCalmCalmCalmCalmW3W6SW7SW7
1 day agoSW9W18
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W9W6W4W7W8W8W9W8W6
2 days agoCalmCalmSE3S3S7S5S7S11S6S8S8S9S8S7S10SW9S16
G22
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SW14SW11S16
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G23

Tide / Current Tables for Charlestown, Northeast River, Chesapeake Bay, Maryland
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Charlestown
Click for Map
Tue -- 06:55 AM EST     Sunrise
Tue -- 07:10 AM EST     0.54 feet Low Tide
Tue -- 09:25 AM EST     Moonrise
Tue -- 11:42 AM EST     1.57 feet High Tide
Tue -- 04:44 PM EST     Sunset
Tue -- 05:45 PM EST     0.04 feet Low Tide
Tue -- 07:24 PM EST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.62.52.11.71.30.90.70.50.60.91.21.51.61.41.10.70.30.100.20.61.21.82.3

Tide / Current Tables for Chesapeake and Delaware Canal, Maryland/Delaware Current
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Chesapeake and Delaware Canal
Click for Map
Tue -- 02:21 AM EST     -1.55 knots Max Ebb
Tue -- 05:14 AM EST     0.04 knots Slack
Tue -- 06:54 AM EST     Sunrise
Tue -- 08:34 AM EST     1.84 knots Max Flood
Tue -- 09:24 AM EST     Moonrise
Tue -- 10:49 AM EST     -0.01 knots Slack
Tue -- 02:25 PM EST     -2.20 knots Max Ebb
Tue -- 04:43 PM EST     Sunset
Tue -- 06:07 PM EST     0.07 knots Slack
Tue -- 07:24 PM EST     Moonset
Tue -- 09:17 PM EST     2.18 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.1-1.2-1.5-1.5-1.1-0.50.81.41.81.81.3-0.6-1.5-1.9-2.2-2.2-1.8-1.3-0.41.21.92.22.11.6

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 (5,6,7,8)
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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.