Tuesday, May21, 2019 L-36.com


Marine Weather and Tides
East Dennis, MA

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 5:14AMSunset 8:00PM Tuesday May 21, 2019 7:29 PM EDT (23:29 UTC) Moonrise 10:53PMMoonset 7:29AM Illumination 91% Phase: Waning Gibbous; Moon at 18 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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ANZ231 Cape Cod Bay- 716 Pm Edt Tue May 21 2019
.small craft advisory in effect through Wednesday morning...
Tonight..NW winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 4 ft.
Wed..N winds 15 to 20 kt, diminishing to 5 to 10 kt in the afternoon. Gusts up to 25 kt. Seas 2 to 4 ft.
Wed night..SW winds around 5 kt. Seas around 2 ft.
Thu..SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas around 2 ft.
Thu night..SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Showers likely with a chance of tstms.
Fri..NW winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 4 ft. A chance of showers.
Fri night..NE winds 10 to 15 kt with gusts up to 25 kt, diminishing to 5 to 10 kt after midnight. Seas 2 to 3 ft.
Sat..E winds 5 to 10 kt. Seas 2 to 3 ft.
Sat night..S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. A chance of showers.
Sun..SW winds 10 to 15 kt. Seas 2 to 3 ft. A chance of showers.
Sun night..W winds 5 to 10 kt. Seas around 2 ft. Winds and seas higher in and near tstms. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height.
ANZ200 716 Pm Edt Tue May 21 2019
Synopsis for massachusetts and rhode island coastal waters.. High pressure builds over new england tonight, then crests over the waters Wed into Wed night. The high shifts offshore Thu. Low pressure moves across northern new england Thu night dragging its associated cold front across the waters early on Fri. Gusty w/nw winds follow on Fri as high pressure builds over the waters through Sat. Low pressure moves east across soutehrn quebec Sat night dragging its associated cold front across the waters early on Sun. For information on possible hazardous weather beyond the 24-36 hour forecast period, please visit www.weather.gov/boston and follow the current hazards link above the map on the left.


7 Day Forecast for Marine Location Near East Dennis, MA
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location: 41.75, -70.16     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 212256
afdbox
area forecast discussion
national weather service boston norton ma
656 pm edt Tue may 21 2019

Synopsis
Dry and seasonable tonight. Continued seasonable, less wind on
Wednesday. Low pressure passes north of the region, with its
associated cold front bringing showers and isolated
thunderstorms late Thursday into Friday morning. Another brief
dry period late this week. Fast moving systems may bring
scattered showers Saturday night and late Monday, but the rest
of the holiday weekend will be dry.

Near term until 6 am Wednesday morning
7 pm update...

lingering northwest wind gusting to 34 kt in northern mass.

Expect these winds to diminish after sunset, but may linger in
the twilight hours. We will maintain the winds in NE mass for a
couple more hours, but otherwise continue with the forecast of
diminishing wind tonight. A thicker pach of clouds associated
with the upper cold pool has been moving southeast into essex co
mass and the north shore. This too should diminish with sunset.

Main change to the forecast is in clouds and wind early in the
night. Also adjusted temps (2-4f warmer) and dew points (2f
lower) based on observations. Ultimately everything comes out as
forecast.

Previous discussion...

winds relaxing across the interior while remaining brisk along the
coast. Near 1030 canadian high pressure wedging S as the storm exits
e. Winds turning n. Boundary layer decoupling is likely going to allow
winds to dissipate across interior S new england, however remaining
brisk with a continued gradient along the high terrain and coastline.

That being said, perhaps an opportunity for sheltered locations in
and around the ct and pioneer river valleys to radiate out beneath
mostly clear conditions and light winds. Could see lows down into
the upper 30s. Elsewhere in the 40s, warmest along the coast with
n gusts around 15 to 25 mph continuing into morning. Perhaps some
isolated to scattered low cloud rotating S across the CAPE and
islands behind the exiting storm center.

Short term 6 am Wednesday morning through Wednesday night
Wednesday ...

seasonable, dry day. High pressure in control with light winds which
should allow for developing sea-breezes around midday. Mixing again
to h8 where temperatures are just a tad warmer in comparison to today.

Add in light winds, abundant sunshine, leaning warmest guidance with
temperatures likely to over-achieve. Widespread highs in the low 70s
may be a sure bet, cooler along the coast with onshore winds. Scattered
mid to high level clouds late towards evening.

Wednesday night ...

a chance of scattered light showers into the W ct river valley towards
Thursday morning. Mid-high level clouds thickening and lowering towards
morning with enhancing isentropic upslope along the w-periphery of
departing high pressure ridge, now shifted SE of new england. Still
a measure of lingering dry air and subsidence inferred from forecast
model soundings, prefer to just keep up to chance pops in far W ma
and ct as there is some confidence of upslope precipitation along
the lifting warm front from the oh river valley to reach the surface,
albeit light, just a trace to a hundredth of outcomes by daybreak
Thursday.

Long term Thursday through Tuesday
Big picture...

upper flow continues to feature a ridge over the eastern usa, upper
trough closed low over the western usa, and the "battle zone"
between the two over northwest mexico and the plains. Meanwhile the
northern stream flows from northern canada to the prairies and
then east to the maritimes.

Two shortwaves eject from the western trough, moving around the edge
of the eastern ridge and across new england. Model consensus would
bring them through on Thursday night and Saturday night. A shortwave
in the northern stream drops south to the great lakes, then
moves east across new england early next week.

With the building heights associated with the upper ridge, expect
temperatures during the forecast period to be near seasonable
Thursday-Friday and warmer over the weekend. Normal highs are
currently mid 60s to low 70s, normal lows around 50.

Good agreement on model mass and thermal fields through Saturday,
then some diverging early next week. Timing of shortwaves can be a
variable that adds uncertainty to a forecast. Overall, moderate
confidence in the forecast.

Concerns...

Thursday-Friday...

surface high pressure shifts offshore Thursday with developing south
flow. This should bring increased moisture to the column... Pw values
climb to near 1.25 inches during the morning. Question is... How much
lift will be generated with the high so close to us. We will show
diminishing morning showers, mainly in ct. Dry weather in the
afternoon with mixing to around 925 mb. This taps 925 mb temps of
13c-15c, which supports MAX temps in the mid 60s to low 70s.

As noted above, the first of three shortwaves is expected to move
through during Thursday night. This will drive a surface low and
cold front from the great lakes across new england. Weak cold
advection aloft but favorable jet dynamics as a 130-kt jet feeds
southeast from canada and places southern new england in the left
exit region. Stability parameters are favorable for thunder... Totals
at 48-50, mid-level lapse rates 6 to 6.5c km, LI around 0... But
doesn't look severe at this time.

The shortwave and surface systems move off to the east on Friday.

Could be leftover showers during the morning, but the trend will be
for drying and clearing, especially in the afternoon. With colder
temps aloft, expect a deeper mixed layer... Possibly to 850 mb. Temps
in the layer reach 7-8c and should support MAX sfc temps in the
lower 70s. Winds in the mixed layer will be nnw about 25 kt, so
expect gusts of 25-30 mph in the afternoon.

Saturday through Tuesday...

shortwaves cross new england Saturday night and Monday, times
approximate. Pw values are forecast around 1.5 inches Saturday night
and 1.25 inches Monday, both above seasonal norms and Saturday night
much above. Convective parameters are marginal but may support
thunder especially with the Saturday night system. Therefore we
expect showers with each passage, possibly some thunder. The
mixed layer shrinks and expands over this period, but temps in
the layer generally support sfc highs in the 70s. Dew points
will be in the upper 40s and 50s, trending lower through the 40s
Tuesday... So we expect min temps mainly in the 50s.

Aviation 00z Wednesday through Sunday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Wednesday night ... High confidence.

Tonight ...

vfr. Bkn070 over NE mass 00z-02z, but trend everywhere is toward
skc. NW winds gusting 30-35 kt early but diminishing after
sunset.

Wednesday ... VFR. Skc. Few 040. N winds diminishing becoming
light allowing for onshore sea-breezes to develop 16-18z and
push well inland towards evening. Sct mid-high CIGS by sunset.

Wednesday night ...

sct mid-high CIGS becoming bkn, lowering towards low-endVFR. S
winds prevailing. Chance -shra for W ct valley terminals by morning.

Kbos terminal...

n winds diminishing, forecast sea-breeze around 18z Wednesday.

Kbdl terminal...

high confidence in taf.

Outlook Thursday through Sunday ...

Thursday:VFR. Breezy. Slight chance shra, isolated tsra.

Thursday night: MVFR ifr conditions possible. Breezy. Chance
shra, slight chance tsra, patchy br.

Friday: mainlyVFR, with local MVFR possible. Breezy. Slight
chance shra.

Friday night: mainlyVFR, with local ifr possible. Breezy.

Patchy br.

Saturday:VFR. Slight chance shra.

Saturday night: mainly MVFR, with local ifr possible. Chance
shra, slight chance tsra.

Sunday: mainlyVFR, with local MVFR possible.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Wednesday night ... High confidence.

Tonight ...

winds have been holding up right up to sunset... We will extend
the gale warning for boston harbor and mass ipswich bays to 10
pm. Small craft advisory for the remaining waters.

Continue the trend of diminishing wind during the night, from
25-35 kt early to 15-25 kt after midnight. Expect the headlines
will drop off zone-by-zone with this trend overnight.

Wednesday into Wednesday night ...

high pressure building into the waters allowing both winds and seas
to subside. Will see the conclusion of small craft headlines. Light
winds into midday, will see the development of onshore winds. S winds
prevailing over all waters by evening and overnight.

Outlook Thursday through Sunday ...

Thursday: winds less than 25 kt. Seas 3 feet or less. Slight
chance of rain showers.

Thursday night: winds less than 25 kt. Local rough seas. Chance
of rain showers, slight chance of thunderstorms.

Friday: low risk for small craft advisory winds with gusts up
to 25 kt. Local rough seas. Slight chance of rain showers.

Friday night: winds less than 25 kt. Areas of seas approaching
5 ft.

Saturday: winds less than 25 kt. Seas locally approaching 5 ft.

Saturday night: winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of rain showers.

Sunday: winds less than 25 kt. Areas of seas approaching 5 ft.

Slight chance of rain showers.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory until 11 pm edt this evening for
anz232>235-237.

Gale warning until 10 pm edt this evening for anz230-251.

Small craft advisory until 11 am edt Wednesday for anz231.

Small craft advisory until 10 pm edt this evening for anz236.

Small craft advisory until 2 pm edt Wednesday for anz250-255.

Small craft advisory until 5 pm edt Wednesday for anz254.

Small craft advisory until 8 am edt Wednesday for anz256.

Synopsis... Wtb sipprell
near term... Wtb sipprell
short term... Sipprell
long term... Wtb
aviation... Wtb sipprell
marine... Wtb sipprell


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44090 11 mi30 min 52°F4 ft
44020 - NANTUCKET SOUND 19 mi40 min NNW 18 G 23 55°F1 ft1010 hPa
WAXM3 - Waquoit Bay Reserve, MA 23 mi105 min NW 9.9 69°F 1009 hPa36°F
BZBM3 - 8447930 - Woods Hole, MA 31 mi42 min 65°F 57°F1010.4 hPa
44018 - SE Cape Cod 30NM East of Nantucket, MA 32 mi40 min NW 19 G 23 56°F 3 ft1009.9 hPa (+2.7)41°F
NTKM3 - 8449130 - Nantucket Island, MA 32 mi42 min NNW 4.1 G 6 63°F 60°F1010.7 hPa
44013 - BOSTON 16 NM East of Boston, MA 49 mi40 min NW 16 G 18 57°F 51°F4 ft1010.3 hPa (+3.4)43°F

Wind History for Nantucket Island, MA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hyannis, Barnstable Municipal-Boardman Airport, MA8 mi2.6 hrsN 9 G 1610.00 miFair68°F39°F36%1008.4 hPa
Chatham, Chatham Municipal Airport, MA10 mi2.6 hrsNW 10 G 1810.00 miFair67°F37°F35%1009.1 hPa
Provincetown Municipal Airport, MA18 mi2.6 hrsNW 16 G 2010.00 miFair63°F44°F50%1009 hPa
Otis Air National Guard Base, MA20 mi1.9 hrsNW 1410.00 miFair68°F35°F30%1009.1 hPa

Wind History from HYA (wind in knots)
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2 days agoS533S3E3SE3S3S4S4S5S3S5S6S7
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Tide / Current Tables for South Yarmouth, Bass River, Nantucket Sound, Massachusetts (2)
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South Yarmouth
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Tue -- 03:11 AM EDT     3.25 feet High Tide
Tue -- 05:16 AM EDT     Sunrise
Tue -- 07:29 AM EDT     Moonset
Tue -- 09:33 AM EDT     -0.22 feet Low Tide
Tue -- 03:50 PM EDT     2.84 feet High Tide
Tue -- 07:59 PM EDT     Sunset
Tue -- 09:42 PM EDT     0.18 feet Low Tide
Tue -- 10:52 PM EDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.62.333.23.12.721.20.4-0.1-0.20.20.81.52.22.72.82.62.11.50.80.30.20.5

Tide / Current Tables for Pollock Rip Channel, Massachusetts Current
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Pollock Rip Channel
Click for Map
Tue -- 02:28 AM EDT     -1.86 knots Max Ebb
Tue -- 05:15 AM EDT     Sunrise
Tue -- 05:35 AM EDT     0.00 knots Slack
Tue -- 07:28 AM EDT     Moonset
Tue -- 09:09 AM EDT     2.23 knots Max Flood
Tue -- 12:17 PM EDT     -0.00 knots Slack
Tue -- 03:01 PM EDT     -1.73 knots Max Ebb
Tue -- 06:08 PM EDT     0.00 knots Slack
Tue -- 07:58 PM EDT     Sunset
Tue -- 09:29 PM EDT     1.84 knots Max Flood
Tue -- 10:51 PM EDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.4-1.3-1.8-1.8-1.4-0.60.41.322.22.11.40.3-0.8-1.5-1.7-1.5-1-0.10.81.51.81.81.4

Weather Map and Satellite Images
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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.
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Wind Forecast for Boston, MA (19,4,5,8)
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Ground Weather Radar Station Boston, MA
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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.