Friday, December15, 2017 L-36.com


Marine Weather and Tides
Popponesset Island, MA

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 7:00AMSunset 4:13PM Friday December 15, 2017 8:58 AM EST (13:58 UTC) Moonrise 5:19AMMoonset 3:54PM Illumination 8% Phase: Waning Crescent; Moon at 27 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- 716 Am Est Fri Dec 15 2017
Today..W winds 5 to 10 kt, becoming sw this afternoon. Seas 2 to 3 ft. A slight chance of snow this afternoon.
Tonight..NW winds 5 to 10 kt, increasing to 15 to 20 kt with gusts up to 25 kt after midnight. Seas 2 to 3 ft. Snow. Vsby 1 nm or less.
Sat..W winds 15 to 20 kt with gusts up to 30 kt. Seas 3 to 4 ft.
Sat night..NW winds 15 to 20 kt with gusts up to 30 kt, diminishing to 10 to 15 kt with gusts up to 20 kt after midnight. Seas 2 to 4 ft.
Sun..NW winds 5 to 10 kt. Seas around 2 ft.
Sun night..W winds 5 to 10 kt. Seas 1 foot or less. A chance of snow. Vsby 1 to 3 nm.
Mon..SW winds 5 to 10 kt. Seas 1 foot or less. A chance of rain and snow. Vsby 1 to 3 nm.
Mon night..W winds 5 to 10 kt. Seas 1 foot or less.
Tue..SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. A chance of rain.
Tue night..W winds 15 to 20 kt with gusts up to 30 kt. Seas 3 to 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 716 Am Est Fri Dec 15 2017
Synopsis for massachusetts and rhode island coastal waters.. High pres moves offshore today. Low pres will develop off the mid atlc coast this afternoon and track well se of nantucket tonight. Another low will track to the north Sat dragging a cold front across the waters. High pressure builds over the waters on Sunday into Monday. 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 Popponesset Island, MA
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location: 41.59, -70.46     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 151201
afdbox
area forecast discussion
national weather service taunton ma
701 am est Fri dec 15 2017

Synopsis
High pressure will move offshore today but bring cold and dry
weather for most of the day today. Low pressure off the mid
atlc coast will track well southeast of nantucket but close
enough to bring a period of accumulating snow to the coastal
plain this evening, ending overnight. Expect dry but cold
conditions Saturday night into Sunday. Another round of light
snow or a wintry mix before changing to rain is possible early
next week. Cold and blustery conditions look to return around
mid week.

Near term until 2 pm this afternoon
645 am update...

noting bands of high clouds streaming eastward across the region
as seen on latest goes-16 (it's back but still prelim, non op)
fog product imagery. Temps have fallen back to the single digits
and teens with light variable or calm winds except w-nw winds at
about 5-10 kt across the higher inland terrain and along the
immediate E coast at 11z.

Near term forecast on track. Have updated to bring conditions
current.

Previous discussion...

high pres moves offshore this afternoon. Morning sunshine will
fade behind increasing clouds this afternoon. Developing low
pres emerging off the mid atlc coast this afternoon but it
should remain dry through sunset as deeper moisture still to the
south. Just a low risk for a few flurries or light snow
developing near the south coast around sunset. 925 mb temps -8
to -9c so another cold day with highs mostly mid-upper 20s with
some lower 30s outer CAPE islands.

Short term 2 pm this afternoon through 6 pm Saturday
*** a period of accumulating snow likely across ri and
southeast ma this evening ***
late today and tonight...

developing low pres off the mid atlc coast will be tracking ne
late today and this evening. Meanwhile, another digging
northern stream shortwave will be moving through the gt lakes
and into the northeast. How these two shortwaves interact will
determine how far north and west accumulating snow gets. Models
have trended stronger and more amplified with this northern
stream shortwave as it is becoming better sampled within the
upper air network. This allows the mid level flow to back enough
for deeper moisture to move further north and west into sne.

While the sfc low is tracking southeast of the benchmark,
inverted trough extends back to the NW into sne assocd with
approaching northern stream trough. Models showing large scale
synoptic forcing ahead of the shortwave along with favorable
upper jet dynamics within the left exit region of 170 kt upper
jet. Cross sections indicate a period of modest omega within
the dgz this evening, especially across SE new eng. Given the
deep moisture in place, expect a period of light to moderate
snow across much of ri and SE ma this evening where snowfall
of 1-3 inches is expected with a low risk for a few 4 inch
amounts near the south coast and CAPE cod if trough is more
amplified. Onset of the snow will be 5-8 pm so part of the
evening commute may be impacted. Will let next forecast team
examine the 12z model suite to decide whether an advisory is
necessary. Expect light snow to extend north across much of sne
but amounts will be limited to less than an inch in the distant
interior.

This will be a progressive system and snow will be exiting se
new eng coast after midnight.

Saturday...

another northern stream shortwave will bring a reinforcing shot
of cold air and blustery wnw winds to sne. 850 mb temps -12c
support highs from upper 20s to mid 30s with a mix of Sun clouds
and wind gusts to 30 mph expected. Mainly dry weather is
expected other than a few flurries in western ma as lake effect
snow showers try to spill over the berkshires.

Long term Saturday night through Thursday
Overview...

overall steering pattern across the lower 48 transitions to
relatively flat mid level flow, which remains progressive even
as a long wave trough digs across the western states late this
weekend, then trends toward the southern stream as it slowly
moves along in the flow. The northern stream remains
progressive, with cold temps continuing into early next week.

Another h5 trough moves ashore across the pacific NW tue
night wed, with rather good agreement amongst the 00z model
suite. While this moves east through late next week, appears
that rising h5 heights as the return SW flow may bring somewhat
milder temps to eastern areas toward the end of the period.

Models and ensembles continue to show weak short waves moving
across the region in the fast flow aloft, with timing issues
coming into play starting early next week as model solution
spread increases. Also noting some ptype issues as the mid level
pattern tries to transition back to near or slightly above
normal temps toward the middle of next week.

Details...

Saturday night and Sunday...

as h5 short wave shifts offshore Sat night, will see any
leftover precip exit as well. Leftover NW low level jet up to
h85 will push offshore. However, will see gusty winds linger sat
evening, up to 25-30 kt. Good low level lapse rates, on order
8-9c km mainly across central and eastern areas which will allow
for good mixing. The lapse rates will drop off between 03z-06z
as the low level jet also moves offshore, so winds will drop off
rather quickly by around midnight. Skies will be mostly clear
as temps drop to the single digits and teens, except the upper
teens to lower 20s along the immediate coast.

Large high pressure, extending from quebec down the eastern
seaboard, will move across the region late Sat night and Sunday.

Light w-nw winds will become variable as ridge axis crosses the
during Sunday. Mid and high clouds start to stream across the
region Sunday afternoon. It will be another chilly day, with
temps remaining below freezing across the interior, reaching to
lower-mid 30s along the immediate coast.

Sunday night into Monday...

some question about next approaching system from the ohio
valley during this timeframe. Both the ggem and ECMWF were
pretty robust with the development of overrunning precip, while
the GFS and NAM keeps the mid level energy rather diffuse in the
nearly zonal flow.

Went along with an overall model blend, which has precip
developing overnight Sun night and continuing into Monday.

Should see some light snow break out, but overall this is
another moisture starved system with QPF amounts generally less
than 0.1 inches, which yields an inch or less of snow as it
mixes with or changes to rain before ending across eastern
areas. Have most of the precip pushing offshore Mon afternoon,
though timing is in question due to model solution spread with
this system.

Monday night through Tuesday night...

another short wave moves along in the zonal flow, but again
more questions about whether there is enough energy and moisture
to bring another round of precipitation during this time. Could
also see ptype issues with this system as low and mid level
winds appear to back to s-sw as long wave trough starts to dig
across the northern plains states, with possibly a wintry mix
developing late Mon night into early Tue before changing to rain
during tue. Current forecast suggests temps will actually rise
during the day, with highs running around 5 degrees above
seasonal normals.

Will see the strong low pushing NE across the great lakes into
quebec. Attendant cold front should push through, bringing a
return to colder temps Tue night.

Wednesday and Thursday...

blustery and cold conditions return Wed as the strong low will
exit into the maritimes. May see some snow showers develop in
the w-nw flow, possibly lake effect induced, moving across the e
slopes of the berkshires. May also see ocean effect snow
showers develop offshore.

High pres will push eastward Wed night and thu, with winds
diminishing and temps close to or slightly below seasonal
normals.

Aviation 12z Friday through Tuesday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday ...

today... High confidence.

Vfr through most of the day. Some late day MVFR CIGS developing
near the south coast after 19z with chc -sn.

Tonight...

high confidence in a period of snow with ifr impacts developing
across ri SE ma this evening. Localized lifr in moderate snow
possible near the south coast. Accums 1-3 inches. Northern and
western extent of the snow still uncertain, but it will likely
reach bdl-orh-bos for a short time with brief MVFR possible and
a coating to less than an inch. Snow exiting SE new eng coast
around 06z with improving conditions toVFR thereafter.

Increasing NW winds along the coast 08z-12z with gusts to 25
kt.

Saturday... High confidence.

Vfr with sct-bkn 050-080 developing. Wnw gusts to 25 kt.

Kbos terminal... Moderate confidence. Period of light snow with
MVFR conditions this evening. Brief ifr vsbys possible.

Kbdl terminal... Moderate confidence. Period of light snow with
MVFR conditions this evening. Low risk for brief ifr vsbys
outlook Saturday night through Tuesday ...

Saturday night:VFR. Breezy.

Sunday:VFR.

Sunday night: mainly MVFR, with areasVFR possible. Chance sn.

Monday: mainly MVFR, with areasVFR possible. Chance sn, slight
chance ra.

Monday night: mainlyVFR, with local MVFR possible. Slight
chance fzra, slight chance sn.

Tuesday: mainly MVFR, with local ifr possible. Breezy. Chance
ra, chance fzra, chance sn.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday ... High confidence.

Today...

w-nw winds 10-15 kt shifting to SW this afternoon. Seas below
sca. Vsbys may lower in light snow south coastal waters late in
the day.

Tonight...

increasing NW winds developing after midnight as coastal low
moves offshore. Gusts to 25-30 kt expected late tonight. Vsbys
reduced in developing snow this evening, especially south
coastal waters, improving after midnight.

Saturday...

sca conditions with wnw gusts to 30 kt with low risk for
marginal gale force gusts over southern waters.

Outlook Saturday night through Tuesday ...

Saturday night: low risk for small craft advisory winds with
gusts up to 30 kt. Local rough seas.

Sunday: winds less than 25 kt.

Sunday night through Monday: winds less than 25 kt. Chance of
rain, chance of snow.

Monday night: winds less than 25 kt. Slight chance of rain.

Tuesday: low risk for small craft advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft. Chance of rain.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... None.

Synopsis... Kjc evt
near term... Kjc evt
short term... Kjc
long term... Evt
aviation... Kjc evt
marine... Kjc evt


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
WAXM3 - Waquoit Bay Reserve, MA 3 mi133 min Calm 16°F 1019 hPa7°F
BZBM3 - 8447930 - Woods Hole, MA 12 mi40 min 24°F 41°F1019.2 hPa
44020 - NANTUCKET SOUND 18 mi68 min NW 9.7 G 12 23°F 42°F1 ft1019.1 hPa (+1.3)11°F
44090 19 mi28 min 46°F2 ft
NTKM3 - 8449130 - Nantucket Island, MA 29 mi40 min NW 4.1 G 6 25°F 38°F1019.5 hPa
BUZM3 - Buzzards Bay, MA 33 mi58 min N 2.9 G 4.1 23°F 1020 hPa (+0.7)
FRVM3 - 8447386 - Fall River, MA 38 mi46 min 21°F 40°F1019.4 hPa
FRXM3 39 mi40 min 22°F 10°F
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 39 mi40 min WNW 4.1 G 6 22°F 1018.6 hPa
PRUR1 45 mi40 min 21°F 13°F
NWPR1 - 8452660 - Newport, RI 46 mi40 min SW 5.1 G 6 20°F 40°F1019.5 hPa
NAXR1 - Narragansett Bay Reserve, RI 47 mi133 min WSW 4.1 16°F 999 hPa8°F
PTCR1 - 8452951 - Potter Cove, Prudence Island, RI 47 mi46 min W 2.9 G 5.1 19°F 1019.5 hPa
CPTR1 - 8452944 - Conimicut Light, RI 48 mi40 min WSW 6 G 7 18°F 40°F1019.4 hPa

Wind History for Nantucket Island, MA
(wind in knots)    EDIT      (on/off)   Help
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Last
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N9
G12
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G14
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G16
NW9
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G14
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W14
G25
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G28
W13
G24
W10
G30
W17
G26
W15
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G24
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W7
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NE6
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SE6
G12
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G24
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W12
G19

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Otis Air National Guard Base, MA6 mi63 minN 010.00 miFair14°F6°F73%1019 hPa
Hyannis, Barnstable Municipal-Boardman Airport, MA11 mi62 minN 010.00 miFair17°F8°F68%1018.6 hPa
Marthas Vineyard Airport, MA15 mi65 minN 010.00 miFair7°F5°F91%1019.3 hPa

Wind History from FMH (wind in knots)
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Last 24hrNW4NW8NW9
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W6W13
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W14W9
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W9W9W8W6W5W3NW4NW3
1 day agoW21
G27
W23W22
G35
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G34
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G31
W24
G36
W18
G33
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W14W6NW5N35N5
G11
2 days agoSE14SE10SE14
G22
SE13
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SE12SE11
G17
SE11
G20
SE8W3SE3SW5W7W9W13
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W14W9
G14
W9W13W12
G22
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W16
G23
W13
G25
W20
G26
W17
G26

Tide / Current Tables for Poponesset Island, Poponesset Bay, Nantucket Sound, Massachusetts
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Poponesset Island
Click for Map
Fri -- 04:18 AM EST     Moonrise
Fri -- 04:37 AM EST     0.20 feet Low Tide
Fri -- 07:01 AM EST     Sunrise
Fri -- 11:08 AM EST     2.41 feet High Tide
Fri -- 02:54 PM EST     Moonset
Fri -- 04:12 PM EST     Sunset
Fri -- 05:15 PM EST     0.05 feet Low Tide
Fri -- 11:41 PM EST     2.18 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
21.71.20.60.30.20.40.81.31.92.32.42.321.50.90.30.10.10.40.81.41.82.1

Tide / Current Tables for Cape Cod Canal, Massachusetts Current
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Cape Cod Canal
Click for Map
Fri -- 01:03 AM EST     0.06 knots Slack
Fri -- 04:18 AM EST     Moonrise
Fri -- 04:22 AM EST     4.07 knots Max Flood
Fri -- 07:02 AM EST     Sunrise
Fri -- 07:23 AM EST     -0.07 knots Slack
Fri -- 10:13 AM EST     -4.36 knots Max Ebb
Fri -- 01:32 PM EST     0.19 knots Slack
Fri -- 02:54 PM EST     Moonset
Fri -- 04:12 PM EST     Sunset
Fri -- 04:52 PM EST     4.14 knots Max Flood
Fri -- 07:55 PM EST     -0.12 knots Slack
Fri -- 10:37 PM EST     -4.21 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-2.9-0.72.83.7443.52-2.5-3.9-4.3-4.2-3.5-2.223.444.13.93-0.9-3.3-4.1-4.2

Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of Northeast    EDIT
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Wind Forecast for Boston, MA (8,2,3,4)
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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.