Monday, August21, 2017 L-36.com


Marine Weather and Tides
Trappe, 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 6:23AMSunset 7:51PM Monday August 21, 2017 9:42 PM EDT (01:42 UTC) Moonrise 5:06AMMoonset 6:56PM Illumination 0% Phase: New Moon; Moon at 29 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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ANZ541 Choptank River To Cambridge Md And The Little Choptank River- 859 Pm Edt Mon Aug 21 2017
.small craft advisory in effect until 6 am edt Tuesday...
.small craft advisory in effect from Tuesday afternoon through Tuesday evening...
Tonight..S winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft. A slight chance of showers and tstms.
Tue..S winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft.
Tue night..SW winds 10 to 15 kt with gusts to 20 kt...becoming W 5 to 10 kt late. Waves 2 ft.
Wed..NW winds 5 to 10 kt. Waves 1 ft.
Wed night..N winds 5 to 10 kt. Waves 1 ft.
Thu..N winds 5 to 10 kt. Waves 1 ft.
Thu night..N winds 5 to 10 kt. Waves 1 ft.
Fri..N winds 5 to 10 kt. Waves 1 ft.
Sat..NE winds 5 to 10 kt. Waves 1 ft. Winds and waves higher and visibilities lower in and near tstms.
ANZ500 859 Pm Edt Mon Aug 21 2017
Synopsis for the tidal potomac and md portion of the chesapeake bay.. High pressure will remain offshore through tonight. A cold front will cross the waters late Tuesday night into early Wednesday. High pressure will return for the second half of the week.

7 Day Forecast for Marine Location Near Trappe, MD
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location: 38.66, -76.08     debug


Area Discussion for - Philadelphia/Mount Holly, PA
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Fxus61 kphi 212238
afdphi
area forecast discussion
national weather service mount holly nj
638 pm edt Mon aug 21 2017

Synopsis
High pressure will be centered in the western atlantic through
Tuesday. A warm front resides in eastern pennsylvania. A cold front
will approach from the west late Tuesday and slowly exit off the
coast on Wednesday. Canadian high pressure builds into the region on
Thursday and should to be the primary influence on our weather into
next Monday.

Near term until 6 am Tuesday morning
A subtle short wave continues to approach from the west and
southwest. Some forcing with this feature combined with plenty of
instability is resulting in isolated to scattered convection across
the western areas. This activity has been slow to advance eastward,
however it is now into parts of berks county with more starting to
enter parts of the southern poconos. The more intense convection has
been on the western shore of chesapeake bay, however this has been
tending to weaken as it tries to slowly shift eastward. There is
modest deep-layer shear and combined with the instability, isolated
severe thunderstorms are possible through early this evening. The
main threat is locally damaging wind gusts especially with storms
that sustain a deeper stronger updraft and more vigorous multi-
clustered storms (hail cannot be ruled out as well). Slower storm
motion will result in locally heavy rainfall.

The pops were trimmed back westward for awhile given the slow
eastward movement to the convection thus far. The hourly
temperature, dew point and wind grids were adjusted with the latest
observations then the lamp guidance was blended in for the next few
hours.

After sunset and with the loss of diurnal heating, any ongoing
thunderstorms will gradually begin to decrease in intensity with
only perhaps isolated showers and thunderstorms continuing overnight.

Subsidence in the wake of the wave combined with increasing moisture
in low levels could support the development of some fog and stratus
overnight, particularly outside of the philadelphia metro.

Short term 6 am Tuesday morning through 6 pm Tuesday
Some changes were made with the 630 pm update. This was to slow
down the pop increase quite a bit eastward during the day.

While a few storms may initiate inland from the coast in the
afternoon, the majority of the guidance indicates we need to
wait for more organized convection incoming from the west later
in the afternoon. This is when the main forcing starts to
arrive.

Otherwise, initially potentially more cloudiness and some fog may
start the day which would then scatter out as the low levels begin
to mix. Southerly flow will strengthen ahead of an approaching upper
trough and its attendant cold front, leading to warm moist advection
and heat indices to around 100 degrees for the urban corridor from
wilmington to philadelphia and trend then up to the nyc metro. A
heat advisory is valid from 1 pm through 8 pm Tuesday. The other
areas look to fall short of the advisory criteria.

Apart from the heat, there will be increasing chances of
thunderstorms toward evening as the upper trough approaches the
area, though the primary forcing for ascent and best chance for any
development will largely be to the north and west. At the moment,
some of the deterministic models seem a bit overdone with overall
convective coverage. Have sided more with higher resolution data
showing the best chance of thunderstorms over higher terrain in the
afternoon. Modest flow with veering profiles will once again support
the potential for strong to severe storms capable of damaging winds
and heavy rainfall toward late day.

Long term Tuesday night through Monday
500 mb: troughing in the great lakes region during midweek... Will
shift into the northeast Friday through this weekend.

Temperatures: the month of august so far has averaged within a degree
of normal except mount pocono where the monthly average was 2.5
degrees below. So... Calendar day averages should still be a few
degrees above normal Wednesday, then from from Thursday through next
Monday should average 2 to 6 degrees below normal on a daily basis.

Forecast basis: a 50 50 blend of 12z 21 GFS nam MOS was used
Tuesday night-Wednesday night, then, unless otherwise noted,
the 12z 21 GFS mexmos was applied Thursday and thereafter the
15z 21 wpc d4-8 gridded elements of MAX min t, 12 hr pop 6 hrly
dew wind sky.

Just tucking this in here... Since I didnt think this warranted
a climate section on its own...

abe 7.94" of rain so far in august ranks #12 when compared to
complete month of august totals at allentown, 13.47 in 2011 is
the record. Records date back to 1912 except we are missing
1920 and 1921.

The dailies...

Tuesday night... Svr potential early in decent mlc of over
1000j more than adequate 0-6km bulk shear (near 45kt), pwat air
of 1.8 inches with residual showers overnight. Low temps about
9 to 12f above normal. The eastward sweep of svr should be
primarily i-78 north. Strong westerly flow at mid levels
(40-45kt 700-500mb) should drive a decent lines of showers and
tstms across the area as per the 15z hrrrx. Least likely area
for any tstms is probably southeast of phl across far S nj and
de. The 1703z d2 SPC outlook didn't change from the 06z vsn.

Wednesday... The cold front will likely slow down when it reaches
delmarva and perhaps eventually stall just south of the area
across southern va Wednesday afternoon. Accordingly, it is
looking more probable that the majority of the forecast area
dries out on Wednesday, especially north of the mason-dixon
line. The uk is pretty wet on Wednesday in the SE 1 2 of our
fcst area and... The ec looks pretty unstable. So... Opted for a
sref wetter blend to the 12z 21 ops pops... Which means continuity
with the mid shift fcst.

Wednesday night-Monday... High pressure over canada and the
great lakes region then starts to build southeastward toward the
area on Thursday. This expansive high should remain in control
through at least this weekend. The end result will be an
extended stretch of pleasant weather Thursday through Monday.

Highs in the upper 70s lower 80s and and lows ranging from the
50s to lower 60s are forecast each day and night (possibly some
upper 40s), respectively. While the forecast remains dry for
these four days, there looks to be increasing cloud cover
heading into the weekend and potentially a risk for an isolated
shower with 1) the approach of the upper trough and 2) light
onshore flow helping to moisten low-levels over time.

Aviation 00z Tuesday through Saturday
The following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.

Tonight... Any showers thunderstorms should end later this evening,
mostly impacting the kabe and krdg areas, otherwiseVFR. Some areas
of MVFR ifr conditions due to fog and or stratus may occur overnight
and toward daybreak. The extent of the low clouds and fog is of
lower confidence. Southerly winds 10 knots or less, becoming light
and variable at most terminals.

Tuesday... Sub-vfr conditions possible early for some areas due to
fog and or stratus, otherwiseVFR. Showers and thunderstorms are
expected to develop mainly to our west in the afternoon, however
these may approach krdg and kabe toward early evening. Light winds,
becoming southwest and increasing to 10-15 knots.

Outlook...

Tuesday night... Potential for MVFR or ifr restrictions with
showers and isolated storms. This activity should progress to
the east- southeast through the night.

Wednesday... Scattered showers and isolated thunderstorms mainly
for terminals S E of phl and earlier in the day. May start off
MVFR with lower CIGS but improvement toVFR is likely from NW to
se during the day. A wind shift from SW to NW can be expected
early in the day W fropa.

Wednesday night through Saturday...VFR and generally light
winds. Cannot rule out an isolated sprinkle each afternoon or
evening.

Marine
Winds and seas remain tranquil across the waters tonight in weak
southerly flow. Patchy fog development will be possible
overnight, but should dissipate shortly after sunrise. An
isolated shower or thunderstorm is also possible overnight.

Tuesday... SCA was issued for the atlantic coastal waters of nj
and de for late Tuesday afternoon and night. S-sw winds are expected
to strengthen late in the day to 15-25 kt. Some gusts to 30 kt are
possible mainly late in the day when the winds will be strongest.

Seas will build to 4-6 feet in response to the wind field.

Outlook...

Tuesday night... SCA continues for the atlantic coastal waters
of nj and de. S-sw winds with isolated gusts to 30 kt possible
mainly during the evening when the winds will be strongest. Seas
build to 4-6 feet in response to the wind field.

Wednesday... A wind shift from SW to w-nw should occur on Wednesday
behind a cold front. Winds will also decrease as well. There is
still a possibility that the SCA may need to be extended into
Wednesday morning if seas take a bit longer to subside below 5
ft.

Thursday through Saturday... Winds and seas below SCA criteria.

Rip currents...

a south to southwest wind will increase during the day Tuesday,
which will also allow the surf to increase some. Given a more
parallel wind to the coast overall, this should keep the rip current
risk reduced some. However, if a longer period swell becomes more
dominant then this would elevate the rip current risk more. Based on
this and in-house guidance, we will go with a moderate risk of rip
currents for Tuesday. This will be re-evaluated early Tuesday
morning.

Tides coastal flooding
Tides are expected to generally remain below coastal flooding
thresholds, but there may be a few localized areas of brief
minor flooding at times of high tide.

Phi watches warnings advisories
Pa... Heat advisory from 1 pm to 8 pm edt Tuesday for paz070-071-102-
104-106.

Nj... Heat advisory from 1 pm to 8 pm edt Tuesday for njz010-012-015-
017>019.

De... Heat advisory from 1 pm to 8 pm edt Tuesday for dez001.

Md... None.

Marine... Small craft advisory from 3 pm Tuesday to 6 am edt Wednesday
for anz450>455.

Synopsis... Drag
near term... Di spigna gorse
short term... Di spigna gorse
long term... Drag
aviation... Drag gorse
marine... Drag di spigna
tides coastal flooding...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
CA2 - 8571892 - Cambridge, MD 6 mi43 min 80°F 83°F1021.3 hPa (-0.0)
44062 - Gooses Reef, MD 19 mi33 min SSW 7.8 G 9.7 81°F 1 ft1020.9 hPa
COVM2 - 8577018 - Cove Point LNG Pier, MD 24 mi43 min SSW 11 G 13 81°F 1021 hPa (+0.5)
TPLM2 - Thomas Point, MD 25 mi43 min SW 9.9 G 9.9 80°F 81°F
CPVM2 28 mi43 min 81°F 77°F
44063 - Annapolis 29 mi33 min S 3.9 G 3.9 1 ft
BISM2 - 8571421 - Bishops Head, MD 30 mi43 min S 9.9 G 12 82°F 83°F1020.7 hPa (-0.0)
SLIM2 - 8577330 - Solomons Island, MD 31 mi43 min W 1.9 G 6 79°F 83°F
APAM2 - 8575512 - Annapolis, MD 31 mi43 min 79°F 1019.6 hPa (+0.6)
BSLM2 - Chesapeake Bay, MD 34 mi133 min WSW 1.9 76°F 1020 hPa70°F
44043 - Patapsco, MD 38 mi33 min SW 7.8 G 9.7 80°F 1020.2 hPa
TCBM2 - 8573364 - Tolchester Beach, MD 39 mi43 min SSE 2.9 G 4.1 78°F 82°F1020.4 hPa (+0.3)
PPTM2 - 8578240 - Piney Point, MD 44 mi43 min SSW 4.1 G 5.1
DRSD1 - Delaware Reserve, DE 45 mi133 min S 4.1 79°F 1020 hPa74°F
44042 - Potomac, MD 45 mi33 min S 7.8 G 12 82°F 1 ft1020 hPa
FSKM2 - 8574728 - Francis Scott Key Bridge, MD 45 mi43 min SSW 5.1 G 6 77°F 1019.8 hPa (-0.0)

Wind History for Cambridge, MD
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Cambridge-Dorchester Airport, MD9 mi53 minN 010.00 miFair79°F73°F84%1020.7 hPa

Wind History from CGE (wind in knots)
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Last 24hrCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmSE4SE5S66
G13
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G19
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G15
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1 day agoCalmCalmNW8CalmCalmCalmCalmCalmCalmN6N8N7N5N5N6N7NW7N6N63CalmCalmCalmCalm
2 days agoCalmCalmCalmCalmCalmSE3CalmCalmCalmCalmNW4NW5N7
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Tide / Current Tables for Oxford, Tred Avon River, Maryland
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Oxford
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Mon -- 03:52 AM EDT     2.60 feet High Tide
Mon -- 06:06 AM EDT     Moonrise
Mon -- 06:24 AM EDT     Sunrise
Mon -- 11:06 AM EDT     0.58 feet Low Tide
Mon -- 02:31 PM EDT     New Moon
Mon -- 04:07 PM EDT     1.95 feet High Tide
Mon -- 07:50 PM EDT     Sunset
Mon -- 07:56 PM EDT     Moonset
Mon -- 10:33 PM EDT     0.44 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.11.62.12.52.62.52.21.81.410.70.60.711.41.81.91.91.61.30.90.60.50.5

Tide / Current Tables for Cove Point (1.1 mi. NE of), Maryland Current
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Cove Point (1.1 mi. NE of)
Click for Map
Mon -- 02:31 AM EDT     0.80 knots Max Flood
Mon -- 06:04 AM EDT     -0.00 knots Slack
Mon -- 06:07 AM EDT     Moonrise
Mon -- 06:25 AM EDT     Sunrise
Mon -- 09:25 AM EDT     -0.77 knots Max Ebb
Mon -- 12:34 PM EDT     0.00 knots Slack
Mon -- 02:31 PM EDT     New Moon
Mon -- 03:13 PM EDT     0.54 knots Max Flood
Mon -- 06:19 PM EDT     -0.00 knots Slack
Mon -- 07:50 PM EDT     Sunset
Mon -- 07:56 PM EDT     Moonset
Mon -- 09:31 PM EDT     -0.59 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.30.60.80.80.60.40-0.3-0.6-0.8-0.7-0.5-0.20.10.40.50.50.30.1-0.2-0.4-0.6-0.6-0.4

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 (21,6,7,8)
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Ground Weather Radar Station Dover AFB, DE
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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.