Monday, December10, 2018 L-36.com


Marine Weather and Tides
Boston, 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 7:01AMSunset 4:13PM Monday December 10, 2018 7:37 AM EST (12:37 UTC) Moonrise 10:39AMMoonset 8:15PM Illumination 9% 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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ANZ230 Boston Harbor- 716 Am Est Mon Dec 10 2018
Today..NW winds around 10 kt. Gusts up to 20 kt this morning. Waves 1 foot or less.
Tonight..N winds 5 to 10 kt. Waves 1 foot or less.
Tue..NW winds around 5 kt, becoming sw in the afternoon. Waves 1 foot or less.
Tue night..NW winds 5 to 10 kt. Waves 1 foot or less.
Wed..N winds 5 to 10 kt with gusts up to 20 kt. Waves around 2 ft.
Wed night..N winds 5 to 10 kt. Gusts up to 20 kt in the evening. Waves around 2 ft.
Thu..SW winds around 5 kt. Waves 1 foot or less.
Thu night..S winds 5 to 10 kt. Waves 1 foot or less.
Fri..S winds 5 to 10 kt. Waves 1 foot or less.
Fri night..SE winds 5 to 10 kt. Waves 1 foot or less. A chance of showers. 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 Mon Dec 10 2018
Synopsis for massachusetts and rhode island coastal waters.. A strengthening coastal low off the mid atlc coast will track well southeast of nantucket today, while high pres across quebec builds into northern new england. Light ocean effect showers and flurries are possible around midday into this afternoon across the waters E of cape cod and nantucket. Ocean effect snow bands will develop across the eastern massachusetts waters Tue night and Wed. High pres will cross the waters Thu before shifting E on Fri. 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 Boston, MA
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location: 42.36, -71.02     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 101214
afdbox
area forecast discussion
national weather service boston norton ma
714 am est Mon dec 10 2018

Synopsis
Another cold stretch of weather much of this week as
temperatures continue to average colder than normal through thu
with the coldest air Wed and thu. Mainly dry weather prevails
as well with the exception being potential scattered snow
showers or flurries late Tue night into Wed morning followed by
ocean effect snow showers Wed afternoon and night across the
outer cape. Temperatures moderate Friday ahead of an approaching
cold front that may result in rain Friday night into Saturday.

Near term until 6 pm this evening
7 am update...

dry cold frontal passage occurred during the predawn hours with
a wind shift to the nnw and a reinforcing surge of cold air
today. This wind shift has resulted in ocean effect clouds
streaming off the ocean into CAPE cod, as cold air is transported
on northerly winds over the relatively warm (40s) ocean waters.

Low level lapse rates may be steep enough to support some snow
showers flurries to impact the outer CAPE and possibly nantucket
today. Accumulations are not expected.

Otherwise dry weather prevails with below normal temps once
again as highs only climb into the mid and upper 30s, lower 30s
high terrain. Normal high should be in the upper 30s across the
high terrain to the lower 40s elsewhere.

Short term 6 pm this evening through 6 pm Tuesday
Tonight...

the northerly winds will linger across the mid and outer cape
as well as nantucket through around midnight, so could see the
ocean enhanced clouds linger as well. Otherwise, high pressure
remains in control with a frigid night in store. Expect
overnight lows to range from around 10-15 degrees across the
interior, ranging to the 20s along the immediate coast.

Tuesday...

a dry, nearly zonal mid level steering flow continues for
Tuesday. Clouds will linger across the mid and outer cape,
otherwise another mostly sunny and cold day elsewhere. Highs
will range from the upper 20s to around 30 across the higher
terrain to the upper 30s along the S coast.

However, noting the flow beginning to back to w-sw as a clipper
type system rides SE out of the great lakes. Looks like this
system will remain W of the region through Tuesday.

Long term Tuesday night through Sunday
335 am update...

highlights...

* noticeably colder Wed & Thu and blustery Wed afternoon evening
* ocean effect snow showers outer CAPE cod Wed afternoon & night
* milder Fri Sat Sun with threat of rain Fri night sat
Tuesday night into Wednesday morning...

offshore low tracking well southeast of the 40n 70w benchmark
tue evening, however an upstream strong northern stream short
wave exits the great lakes and ontario, tracking east into new
england. This high amplitude short wave induces an inverted
trough from the offshore cyclone westward into new england,
indicative of strong forcing for ascent. However limiting factor
is short duration of attending mid level moisture. Inspection
of time sections from both NAM and GFS bufkit reveal column
struggles to saturate including the dgz (-10c to -20c). This
should limit precip to widely scattered snow showers or just
flurries. Chilly day with 850 temps around -12c with model
soundings showing mixing almost to this layer.

Wednesday evening and overnight...

strong CAA behind departing northern stream short wave. 850 mb
temps lower to -12c to -14c and 925 mb temps -10c to -12c across
the region. So highs only 30-35 Wed aftn expected but will feel
considerably colder with gusty north winds 15-25 mph providing
wind chills in the 20s. These gusty north winds advecting a cold
airmass over the relatively warm ocean waters will generate
ocean effect snows (oes) from about hyannis eastward. Given ssts
near shore still relatively warm around +6c to +7c, this will
support steep low level lapse rates with delta-t on the order of
approaching 20 degs. This typically is the instability
threshold for the beginning of accumulating ocean effect snows.

Nam bufkit at chh has ocean induced capes up to 700 j kg with
normalized CAPE greater than 0.20 inches. This should be
sufficient for minor snow accumulations, say a coating to
perhaps up to 2 inches in a few locations. Winds drop off after
midnight so should see some improvement then. Cold night as 1034
mb high crest over the region. Thus ideal radiational cooling
and will follow the coldest guidance accordingly.

Thursday...

not as windy as Wed as 1034 mb high crest over the region.

Therefore light winds. However subsidence inversion will
preclude cold morning temps from modifying much. Thus a chilly
thu. Dry weather prevails.

Friday, Saturday and Sunday...

milder temps Fri as northern stream jet lifts northward and
high pres moves offshore, promoting onshore flow into southern
new england. Seasonably warm with highs in the 40s fri.

Thereafter forecast becomes highly uncertain from Fri night into
Sunday. Ensembles and deterministic guidance have all trended
away from streams merging with now an unphased scenario this
period along with southern stream being more dominant. However
individual members from both the 00z GEFS and eps really exhibit
large spread with many members dry this weekend while other
members are very wet. Thus highly uncertain weekend forecast.

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

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Tuesday ... High confidence.

12z update...

MVFR CIGS impact CAPE cod and islands today as well as the high
terrain of northern and western ma. OtherwiseVFR prevails with
modest nnw winds and dry weather.

Earlier discussion below.

===============================================================
tonight and Tuesday...

vfr. CIGS linger across the mid and outer CAPE nantucket
tonight, then may linger on the outer CAPE into Tuesday. N
winds tonight will diminish as they shift to e-se early tue,
then light w-sw by midday tue.

Kbos terminal... High confidence in taf.

Kbdl terminal... High confidence in taf.

Outlook Tuesday night through Friday ...

Tuesday night:VFR.

Wednesday through Wednesday night:VFR. Breezy. MVFR in snow
showers likely across the outer cape.

Thursday:VFR.

Thursday night: mainlyVFR, with local MVFR possible.

Friday:VFR. Breezy.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Tuesday ... High confidence.

Through today...

winds and seas have lowered below small craft criteria on the
outer waters so have ended the small craft headlines.

Winds have shifted to n-nw over the last few hours with the
passing cold front, which will lie across CAPE cod and near the
s coast by late this morning. With another batch of cold air
moving in, will see gusts up to around 20 kt. May see a few
brief gusts up to 25 kt mainly across the southern outer waters
this afternoon. Seas 4 ft or less.

Ocean enhanced clouds will develop across most of the eastern
waters during this morning, with the best chance across portions
of the mid and outer cape, and continue through this afternoon
as the northerly winds bring another batch of colder air. May
see some brief visibility restrictions E of CAPE cod in ocean
effect rain and snow showers around midday through the
afternoon.

Tonight...

winds slowly diminish as they become n-ne. Gusts up to 20 kt
possible across the eastern outer waters this evening. Any
leftover rain and or snow showers will dissipate this evening as
the northerly winds diminish. Otherwise, good visibility. Seas
around 2 to 4 feet away from the coast.

Tuesday...

high pressure moves offshore as another weak low quickly
approaches from the w. Winds diminish as they shift to s-sw.

Seas continue at 4 ft or less.

Outlook Tuesday night through Friday ...

Tuesday night: winds less than 25 kt. Areas of seas approaching
5 ft. Local visibility 1 to 3 nm.

Wednesday: low risk for small craft advisory winds with gusts
up to 25 kt. Low risk of gale force northerly winds. Seas up to
5 ft. Chance of snow showers. Visibility 1 to 3 nm.

Wednesday night: winds less than 25 kt. Low risk of gale force
northerly winds during the evening, then diminishing after
midnight. Areas of rough seas. Slight chance of snow showers.

Local visibility 1 to 3 nm.

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

Thursday night: winds less than 25 kt. Areas of seas
approaching 5 ft. Slight chance of rain showers. Local
visibility 1 to 3 nm.

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

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... None.

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


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 2 mi38 min 29°F 1018.5 hPa (-0.0)
44013 - BOSTON 16 NM East of Boston, MA 20 mi48 min N 19 G 23 34°F 46°F2 ft1017.6 hPa (+0.5)24°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 27 mi94 min NNW 14 G 18 32°F 45°F2 ft1016.8 hPa
FOXR1 - 8454000 - Providence, RI 43 mi44 min N 8 G 11 29°F 42°F1018.1 hPa
PVDR1 44 mi38 min NNW 7 G 9.9 29°F 1018.6 hPa (+0.5)19°F
FRVM3 - 8447386 - Fall River, MA 46 mi44 min 26°F 43°F1018.6 hPa
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi38 min N 4.1 G 5.1 26°F 1018.5 hPa (+0.4)
IOSN3 - Isle of Shoals, NH 47 mi38 min NNW 15 G 16 30°F 1017.8 hPa (+0.6)22°F
FRXM3 47 mi38 min 26°F 18°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi44 min NNW 14 G 16 31°F 41°F1018.3 hPa
44018 - SE Cape Cod 30NM East of Nantucket, MA 48 mi48 min N 16 G 19 36°F 3 ft1017.2 hPa (+0.0)23°F
BGXN3 - Great Bay Reserve, NH 49 mi53 min ENE 1 16°F 15°F

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA1 mi44 minNW 1010.00 miA Few Clouds30°F17°F58%1018.5 hPa
East Milton, MA11 mi42 minNNW 11 mi22°F16°F78%1018.7 hPa
Norwood, Norwood Memorial Airport, MA14 mi45 minN 010.00 miFair19°F15°F84%1018.6 hPa
Laurence G Hanscom Field Airport, MA16 mi42 minN 010.00 miFair16°F10°F80%1020.2 hPa
Beverly, Beverly Municipal Airport, MA16 mi45 minWNW 310.00 miFair22°F14°F71%1018 hPa

Wind History from BOS (wind in knots)
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Tide / Current Tables for Charlestown, Charles River, Massachusetts
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Charlestown
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Mon -- 12:54 AM EST     9.26 feet High Tide
Mon -- 06:48 AM EST     1.01 feet Low Tide
Mon -- 07:02 AM EST     Sunrise
Mon -- 09:38 AM EST     Moonrise
Mon -- 12:57 PM EST     10.28 feet High Tide
Mon -- 04:11 PM EST     Sunset
Mon -- 07:16 PM EST     Moonset
Mon -- 07:22 PM EST     0.02 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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8.89.38.67.25.33.21.5123.75.889.710.39.68.163.61.40.10.31.63.45.5

Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Mon -- 12:30 AM EST     -0.00 knots Slack
Mon -- 04:49 AM EST     -1.10 knots Max Ebb
Mon -- 06:53 AM EST     0.00 knots Slack
Mon -- 07:01 AM EST     Sunrise
Mon -- 09:38 AM EST     Moonrise
Mon -- 10:05 AM EST     1.12 knots Max Flood
Mon -- 12:40 PM EST     -0.00 knots Slack
Mon -- 04:11 PM EST     Sunset
Mon -- 05:11 PM EST     -1.20 knots Max Ebb
Mon -- 07:15 PM EST     Moonset
Mon -- 07:23 PM EST     0.00 knots Slack
Mon -- 10:37 PM EST     1.08 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.3-0.2-0.6-0.9-1-1.1-0.80.10.91.11.110.4-0.2-0.6-1-1.1-1.2-1.1-0.40.511.11.1

Weather Map and Satellite Images
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GOES Local Image of Northeast    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 (7,2,3,4)
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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.