Thursday, December13, 2018 L-36.com


Marine Weather and Tides
Dennis Port, 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 6:58AMSunset 4:12PM Thursday December 13, 2018 5:36 PM EST (22:36 UTC) Moonrise 12:21PMMoonset 11:05PM Illumination 38% Phase: Waxing Crescent; Moon at 6 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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ANZ232 Nantucket Sound- 336 Pm Est Thu Dec 13 2018
Tonight..SE winds 5 to 10 kt. Seas 1 foot or less.
Fri..SE winds 5 to 10 kt. Seas 1 foot or less.
Fri night..S winds 5 to 10 kt. Seas 1 foot or less, then around 2 ft after midnight. A chance of rain after midnight.
Sat..SW winds 5 to 10 kt, becoming N in the afternoon. Seas around 2 ft. A chance of rain.
Sat night..NE winds 10 to 15 kt with gusts up to 25 kt. Seas around 4 ft.
Sun..NE winds 10 to 15 kt, becoming E 15 to 20 kt in the afternoon. Gusts up to 30 kt. Seas around 5 ft. A chance of rain.
Sun night..NE winds 15 to 20 kt with gusts up to 25 kt. Seas around 5 ft. Rain likely in the evening, then showers likely after midnight.
Mon..N winds 15 to 20 kt, becoming nw 10 to 15 kt in the afternoon. Gusts up to 25 kt. Seas 4 to 5 ft. A chance of showers.
Mon night..NW winds 15 to 20 kt with gusts up to 30 kt. Seas 4 to 5 ft.
Tue..NW winds 20 to 25 kt with gusts up to 30 kt. Seas around 5 ft.
Tue night..NW winds 15 to 20 kt with gusts up to 30 kt. Seas around 5 ft. 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 336 Pm Est Thu Dec 13 2018
Synopsis for massachusetts and rhode island coastal waters.. High pres will shift E of the waters on Fri. A storm system will approach the waters from the sw Fri night and Sat, lifting slowly across the waters Sat night and Sun. High pres builds back towards the waters from the W on Tue into Wed. 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 Dennis Port, MA
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location: 41.65, -70.12     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 132039
afdbox
area forecast discussion
national weather service boston norton ma
339 pm est Thu dec 13 2018

Synopsis
High pressure moves east of new eng through Friday with a milder
southerly flow developing. A series of low pressure systems
tracking south of new england may bring a period of rain Friday
night into early Saturday and again Sunday into Sunday night,
with mixed precipitation ice possible in the interior. A cold
front sweeps across the region Monday followed by blustery and
cold weather Tuesday into Wednesday, with moderating
temperatures by Thursday.

Near term until 6 am Friday morning
Robust mid level low and shortwave moves across sne late
afternoon and evening before moving offshore. Forcing for
ascent is weaker than might be expected with an impulse this
strong due to subsidence from departing high pres. This
combined with limited moisture is resulting in only some light
snow and flurries focused across western new eng where better
moisture. As this mid level system moves offshore tonight, good
mid level drying moves in but low level moisture persists,
especially across the west. This may lead to some very light
snow or even a bit of freezing drizzle in western ma ct as the
snow growth region dries out. Any precip will be spotty and it's
possible it just remains dry. In eastern new eng where low level
moisture is less, partial clearing is possible overnight. Lows
will be mostly in the 20s.

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

high pres continues to move offshore with southerly flow
developing which brings milder air into sne. Still considerable
low level moisture below an inversion, especially west which
will result in mostly cloudy skies in western new eng where also
a low risk for spotty light rain or mixed precip. Sunshine in
eastern new eng will give way to increasing clouds in the
afternoon as moisture spreads east. Highs should range from
upper 30s to mid 40s, mildest across SE new eng.

Friday night...

split flow regime with northern stream trough across SE canada
and strong cut off over the SE conus. Confluent flow across new
eng will keep deeper moisture south of new eng. Some light rain
is expected Fri night, especially south of the pike but
steadier and heavier rainfall will remain to the south. Lows in
the 30s but steady or slowly rising temps expected overnight.

Long term Saturday through Thursday
* highlights...

- light to moderate rain possible Saturday
- skirting offshore storm system Sunday - Sunday night
- cold and dry Monday through Thursday
- another storm system possible late week
overview and model preferences...

unsettled sensible wx is mainly on the front end of the long
term. A N stream wave currently off the W pacific will rapidly
move E across the conus. It is the interaction with S stream
cutoff is the big question mark. Most of the guidance favors a
very late phasing of these two features, with the N stream wave
becoming dominant as the trof axis negatively tilts and orients
toward newfoundland-labrador. This late timing will still lead
to coastal cyclogenesis, but mainly to the s, with current
ensemble clustering favoring near or just SE of the 40 70
benchmark Sun night. Should the track remain this suppressed,
strong convection near the low center and within the developing
trowal will likely usurp much of the available moisture across
new england. The timing of the cyclogenesis is key, and given
the spread, there is still some uncertainty that will have to be
overcome once the pacific wave moves onshore and becomes better
sampled. Following the arctic push from the N stream wave early
next week, the remainder of the week is defined by zonal,
confluent flow as remnant ridging is slowly suppressed by a
strong W pacific jet and trof deepening. This should yield a
period of mainly quiet and moderating conditions. Given the
uncertainty early, will lean most heavily on ensemble means with
this forecast update.

Details...

sat and Sat night...

initial overrunning ahead of the S stream cutoff sets up along
a frontal boundary stalled from the DELMARVA to S of long
island. Strong suppression by +1025mb high to the N should keep
the bulk of the precipitation along the S tier. Echo previous
forecaster that at least some chance pops are warranted for this
risk. Antecedent airmass is generally warm enough for p-type to
be all rain by onset early daytime sat. Highs will reach the
mid-upper 40s with a spot 50. Overnight mins mainly in the 30s.

Sun and mon...

again will be monitoring complex upper lvl PV interactions and
coastal low pres development during the day on sun. At this
time, mid lvl moisture wrapping will lead to pwats reaching near
1.00in across S new england however the strongest dynamic
forcing will be co-located with the cyclogenesis, which is why
the track will ultimately determine how significant the outcome
will be. Noting in mass fields there is modest indication of
cold air damming from high pres to the ne, but again lower lvl
airmass looks to be mainly above freezing as any precipitation
develops. Highest risk for p-type issues will be NW ma.

Conditions dissipate Sun night into early Mon as cold front
associated with the arctic wave approaches, leading to mid and
lower lvl subsidence between offshore cyclone and the cold front
itself, so expect gradually improving conditions during the day
on mon. Temperatures, near seasonal until late mon, at which
point cold advection will begin.

Mon night into Tue night...

strong caa, expected along with rapid pres rises and tightening
pres gradient Tue morning. This will lead to blustery cold
conditions as the core of the arctic influenced wave pivots
across the region. In fact, with Tue highs struggling toe reach
the low-mid 30s, wind chill values (with gusts 20-30 mph likely)
will dip into the teens and low 20s. These values will also
likely be the ambient min temps Tue night as the floor drops out
with widening dewpoint depressions. Column does show enough
lingering moisture Mon night for a few shsn as the CAA develops.

Wed into thu...

high pres under confluence aloft with mainly quiet conditions
and gradual moderation of the airmass temps warming back to near
seasonal normals.

Aviation 21z Thursday through Tuesday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Friday night ...

through 00z...

areas of MVFR ifr in light snow across western ma and ct
valley, otherwiseVFR cigs.

Tonight... Moderate confidence.

MVFR CIGS across western ma and ct with a low risk for some very
light snow or fzdz. OtherwiseVFR with partial clearing SE new
eng.

Friday... Moderate confidence.

MVFR CIGS across much of the interior, especially western new
eng. MainlyVFR CIGS SE new eng.

Friday night... Moderate confidence.

Areas of MVFR ifr cigs. Chance of light rain.

Kbos terminal... High confidence in taf.

Kbdl terminal... High confidence in taf.

Outlook Saturday through Tuesday ...

Saturday through Saturday night: mainlyVFR, with local ifr
possible very late. Breezy. Slight chance ra.

Sunday through Sunday night: mainly MVFR, with areas ifr
possible. Breezy. Chance shra, chance shsn.

Monday and Monday night: mainlyVFR. Windy with areas gusts to
30 kt.

Tuesday:VFR. Windy with gusts to 30 kt.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Friday night ... High confidence.

Tranquil boating conditions to prevail through Friday night as
high pres slowly drifts east of the waters. Winds below 20 kt
and seas below 5 ft. Chance of light rain Fri night.

Outlook Saturday through Tuesday ...

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

Chance of rain.

Saturday night through Sunday night: moderate risk for small
craft advisory winds with gusts up to 30 kt. Rough seas up to 10
ft. Chance of rain showers.

Monday: low risk for small craft advisory winds with gusts up
to 25 kt. Rough seas up to 9 ft. Chance of rain showers.

Monday night into Tuesday: strong winds with gusts up to 30 kt.

Rough seas up to 9 ft. Slight chance of snow showers. Local
visibility 1 to 3 nm.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... None.

Synopsis... Kjc doody
near term... Kjc
short term... Kjc
long term... Doody
aviation... Kjc doody
marine... Kjc doody


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44020 - NANTUCKET SOUND 14 mi26 min ESE 5.8 G 9.7 35°F 40°F1034.4 hPa23°F
44090 17 mi36 min 43°F1 ft
WAXM3 - Waquoit Bay Reserve, MA 22 mi51 min 1 33°F 1034 hPa23°F
NTKM3 - 8449130 - Nantucket Island, MA 25 mi36 min E 4.1 G 5.1 35°F 37°F1034.4 hPa (+1.3)
BZBM3 - 8447930 - Woods Hole, MA 30 mi36 min 35°F 40°F1034.1 hPa (+1.2)
44018 - SE Cape Cod 30NM East of Nantucket, MA 38 mi46 min SE 3.9 G 7.8 33°F 3 ft1034.6 hPa (+0.7)19°F

Wind History for Nantucket Island, MA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chatham, Chatham Municipal Airport, MA8 mi44 minN 010.00 miMostly Cloudy34°F21°F61%1035 hPa
Hyannis, Barnstable Municipal-Boardman Airport, MA9 mi40 minN 010.00 miMostly Cloudy33°F21°F64%1034.2 hPa
Otis Air National Guard Base, MA21 mi41 minE 310.00 miOvercast30°F21°F69%1034.5 hPa

Wind History from CQX (wind in knots)
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Last 24hrNW6NW66N734CalmCalmCalmN3NW3CalmNW4NW4CalmE3E7E7SE4SE4S3E4NE4Calm
1 day agoNW3CalmNW3CalmCalmCalmNW3CalmCalmCalmCalm5NW9
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2 days agoCalmCalmNW3NW3CalmCalmCalmCalmCalmCalmNW3NW4NW4NW3CalmCalmCalmS4S64SW5SW3CalmCalm

Tide / Current Tables for Dennis Port, Nantucket Sound, Massachusetts
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Dennis Port
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Thu -- 04:10 AM EST     3.15 feet High Tide
Thu -- 06:58 AM EST     Sunrise
Thu -- 09:41 AM EST     0.62 feet Low Tide
Thu -- 11:21 AM EST     Moonrise
Thu -- 04:10 PM EST     Sunset
Thu -- 04:17 PM EST     3.35 feet High Tide
Thu -- 10:05 PM EST     Moonset
Thu -- 10:13 PM EST     0.32 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.21.82.42.93.132.51.91.30.70.60.91.422.63.13.33.22.82.11.40.70.30.4

Tide / Current Tables for Pollock Rip Channel, Massachusetts Current
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Pollock Rip Channel
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Thu -- 01:27 AM EST     -0.00 knots Slack
Thu -- 04:05 AM EST     -1.60 knots Max Ebb
Thu -- 06:57 AM EST     Sunrise
Thu -- 07:17 AM EST     0.00 knots Slack
Thu -- 10:34 AM EST     1.65 knots Max Flood
Thu -- 11:20 AM EST     Moonrise
Thu -- 01:39 PM EST     -0.00 knots Slack
Thu -- 04:10 PM EST     Sunset
Thu -- 04:17 PM EST     -1.61 knots Max Ebb
Thu -- 07:25 PM EST     0.00 knots Slack
Thu -- 10:05 PM EST     Moonset
Thu -- 10:57 PM EST     1.95 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.40.5-0.6-1.3-1.6-1.4-1-0.20.61.31.61.61.30.6-0.3-1.2-1.6-1.5-1.1-0.40.51.31.82

Weather Map and Satellite Images
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Wind Forecast for Boston, MA (17,4,5,8)
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Ground Weather Radar Station Boston, MA
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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.