Thursday, January17, 2019 L-36.com


Marine Weather and Tides
Chelsea, 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 7:08AMSunset 4:40PM Thursday January 17, 2019 4:18 AM EST (09:18 UTC) Moonrise 2:24PMMoonset 4:13AM Illumination 86% Phase: Waxing Gibbous; Moon at 11 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- 117 Am Est Thu Jan 17 2019
.small craft advisory in effect until 4 am est early this morning...
Rest of tonight..NW winds 5 to 10 kt with gusts up to 25 kt. Waves around 2 ft.
Thu..NW winds around 5 kt with gusts up to 20 kt, becoming ne in the afternoon. Waves around 2 ft.
Thu night..S winds around 5 kt. Waves 1 foot or less. A chance of snow.
Fri..S winds around 5 kt. Waves 1 foot or less. Snow likely. Vsby 1 to 3 nm.
Fri night..NW winds 5 to 10 kt with gusts up to 20 kt. Waves 1 foot or less.
Sat..N winds 5 to 10 kt. Waves 1 foot or less. A chance of snow. Vsby 1 to 3 nm.
Sat night..NE winds 5 to 10 kt, becoming E 10 to 15 kt after midnight. Gusts up to 25 kt. Waves 2 to 3 ft. Snow. Vsby 1 to 3 nm.
Sun..NE winds 15 to 20 kt with gusts up to 35 kt. Waves 2 to 4 ft. Rain, freezing rain and snow. Vsby 1 nm or less.
Sun night..NW winds 15 to 20 kt with gusts up to 35 kt. Waves around 2 ft. Snow likely, freezing rain and sleet. Vsby 1 to 3 nm.
Mon..NW winds 15 to 20 kt with gusts up to 30 kt. Waves around 2 ft.
Mon night..NW winds 10 to 15 kt with gusts up to 30 kt. Waves around 2 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 116 Am Est Thu Jan 17 2019
Synopsis for massachusetts and rhode island coastal waters.. High presume builds across the waters on Thursday. A wave of low pres lifts ne over southern new england on Fri bringing snow changing to rain, then is followed by dry high pres Fri night and Sat. A more potent low pres area will impact the waters Sat night and 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 Chelsea, MA
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location: 42.37, -71.06     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 170907
afdbox
area forecast discussion
national weather service boston norton ma
407 am est Thu jan 17 2019

Synopsis
Quiet weather today under high pressure. One weather system
slips past southern new england Friday, bringing a period of
snow changing to rain Thursday night and Friday. All eyes are on
a second storm that brings a mix of wintry weather for Saturday
night and Sunday. Arctic air returns for early next week.

Another weather system may bring rain and snow next Wednesday.

Near term until 6 pm this evening
The cold front has passed offshore this morning ushering in a
very dry airmass... Dewpoints across the region range from low
teens to near zero! Still seeing a few gusty spots but as high
pressure rapidly builds in we'll see these winds comes down
across the board by early morning. High pressure currently over
southern qc will cross into new york and then cross northern new
england today. Temperatures start very cold this morning,
especially in those locations with light winds that still have a
chance to radiate well before sunrise. This combined with caa
under high pressure will bring high temperatures down 10-15
degrees from the mild day we saw yesterday; highs top out in the
upper 20s.

Short term 6 pm this evening through 6 pm Friday
Thursday evening winds shift out of the east ahead of an
incoming warm front. As the high pressure moves offshore, a
shallow midlevel shortwave ushers a quick moving low pressure
south of the area which will bring light snow to the region
overnight. As the warm front approaches winds will turn out of
the south and snow starts over western ct and ma around 06z,
spreading east over the early morning hours. With low
temperatures in the teens and low 20s, we'll see light
accumulations of snow. Though light, it will have bad timing,
coming ahead of and during the Friday morning commute. Under a
split flow pattern, this shortwave does not have a good tap of
moisture with it, and models have been consistently backing off
on the QPF amounts with this system. Thus, snow amounts have
been lowered a bit this morning. Eventually this transitions to
rain for much of the coastal plain of ma and ri before precip
tapers off by late morning early afternoon. Currently looking at
snow totals of a half inch to an inch for most, with 1 to 2
inches possible in the high terrain of the interior. Take it
slow on the roads Friday morning as untreated surfaces will
become slick and hazardous. Temperatures warm into the upper 30s
and even the low 40s in coastal ma and ri, though there is
still some uncertainty on just how far north this warm air can
make it.

Long term Friday night through Wednesday
Big picture...

longwave scale continues to show ridge-west trough-east through the
long-term period, suggesting warm west and cold east. Shortwave
scale shows separate northern and southern streams Friday with
a weak shortwave racing through new england. The streams then
merge Saturday, although latest models show a little more
difficulty in the merge. Deep trough over the great lakes moves
east across new england Sunday night or Monday. The GFS and
ecmwf maintain cyclonic flow over the region through Tuesday.

Model fields are in general agreement through Saturday, and clearly
divergent later Monday through Wednesday. Confidence is moderate
Friday-Saturday and low Monday to Wednesday.

Concerns...

three periods of unsettled weather... Friday, Saturday night-Sunday,
and Wednesday. Cold dry or seasonably cold dry the remainder of the
period. Strong northwest wind gusts possible Sunday night and Monday
drawing unseasonably cold arctic air into southern new england.

Friday...

shallow northern stream shortwave in a split-stream flow regime
suggests only limited moisture amounts and weak lift. GFS cross
sections show deep moisture, but precipitable water values only a
little above normal. Consensus mslp fields show a surface low
tracking just south of our south coast, suggesting thermal fields
will support mainly snow, with a change to rain along the coast.

Temps aloft suggest MAX sfc temps in the afternoon in the 30s to low
40s. Clearing skies, diminishing wind, and dewpts in the teens and
low 20s suggest Friday night min temps in the teens and low 20s.

Saturday night and Sunday...

phased-stream flow brings higher moisture amounts to this system.

Cross sections again show deep moisture. Precip water values have
diminished a little, but still show values around 1 inch feeding
into southern and eastern parts of our area. These pw values are
well above normal in mid january.

Still uncertainty in this forecast as the models continue to shift.

Most confidence is in the ECMWF and allied models which have been
the most consistent in showing a center track along or near the
south coast. The GFS solution has shifted toward the ecmwf. This is
a colder solution, and supports more snow and ice in the forecast
than previously.

Based on this, the forecast starts with snow everywhere Saturday
night, then brings rain into the south coast by morning. Rain
spreads up to boston and the north shore Sunday, also across ri and
much of NRN ct. North of that zone will be a band of sleet freezing
rain in the interior... And snow in parts of northwest mass. Shifts
in the forecast storm path north and south will of course shift
these precipitation bands north and south.

Strong east winds will reach 35-50 mph speeds along the coast,
especially over CAPE cod and islands. Inland speeds will be more
like 25-35 mph.

Sunday night-Monday
the storm passes our area between 1 pm and 7 pm Sunday. Winds
will quickly shift out of the north and northwest. Strong
pressure gradient at the surface will generate strong sustained
winds, and cold advection will draw strong winds aloft down to
the surface with gusts of 25-40 mph possible. The combination of
wind and cold air will bring wind chills to single digits and
below zero Sunday night and Monday.

Wednesday...

another weather system moves up the ohio valley, spreading rain
and snow into southern new england Wednesday Wednesday night.

The upper flow favors the southern stream, but the day 7 time
period leaves much uncertainty.

Aviation 08z Thursday through Monday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Friday ... High confidence.

This morning...

vfr. Winds have switched to NW and will continue through the
morning, diminishing into Thursday.

Today and tonight...

mainlyVFR. Lowering CIGS through the overnight hours. Light winds
shift from NW to e-se through the evening. Snow approaches from
the southwest after 06z.

Kbos terminal... High confidence in taf.

Kbdl terminal... High confidence in taf.

Outlook Friday night through Monday ...

Friday night:VFR. Breezy.

Saturday:VFR. Chance sn.

Saturday night: mainly ifr, with areas MVFR possible. Windy
with gusts to 35 kt. Sn, fzra.

Sunday: mainly ifr, with local MVFR possible. Strong winds with
local gusts to 40 kt. Ra, fzra, pl, sn.

Sunday night:VFR. Windy with gusts to 35 kt. Chance sn, fzra
likely.

Martin luther king jr day: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 ...

high pressure builds over new england today, bringing lighter
winds to the waters. The high then moves off to the east
tonight. This will bring quieter boating weather to the waters.

An approaching weather system will spread snow and rain over the
waters after midnight Thursday night, with reduced vsbys by
morning.

Outlook Friday night through Monday ...

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

Saturday: winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of snow.

Saturday night: low risk for gale force winds with gusts up to
40 kt. Areas of rough seas. Snow likely, rain. Areas of
visibility 1 nm or less.

Sunday: moderate risk for gale force winds with gusts up to
45 kt. Rough seas up to 13 ft. Rain, freezing rain. Visibility
1 to 3 nm.

Sunday night: strong winds with gusts up to 35 kt. Rough seas
up to 13 ft. Chance of snow, chance of freezing spray, freezing
rain likely, chance of sleet.

Martin luther king jr day: strong winds with gusts up to 30 kt.

Rough seas up to 12 ft. Chance of snow, chance of freezing
spray.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory until 4 am est early this morning for
anz230>235-237.

Small craft advisory until 9 am est this morning for anz250.

Small craft advisory until 5 am est early this morning for
anz251.

Small craft advisory until 11 am est this morning for anz254.

Small craft advisory until 7 am est this morning for anz255-
256.

Synopsis... Wtb bw
near term... Bw
short term... Bw
long term... Wtb
aviation... Wtb bw
marine... Wtb bw


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 1 mi36 min 23°F 1025.2 hPa
44013 - BOSTON 16 NM East of Boston, MA 22 mi28 min NW 19 G 23 26°F 42°F4 ft1024.2 hPa (+3.6)12°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi74 min NNW 23 G 29 25°F 42°F3 ft1022.9 hPa
FOXR1 - 8454000 - Providence, RI 43 mi42 min N 8.9 G 12 27°F 41°F1024.5 hPa
PVDR1 44 mi36 min NNW 12 G 15 27°F 1025 hPa3°F
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi30 min NNW 9.9 G 14 29°F 1024.7 hPa
FRVM3 - 8447386 - Fall River, MA 46 mi42 min 29°F 38°F1024.8 hPa
FRXM3 47 mi36 min 29°F 14°F
IOSN3 - Isle of Shoals, NH 47 mi78 min WNW 25 G 27 19°F 1023.6 hPa (+3.8)-2°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi30 min NW 19 G 22 28°F 39°F1024.7 hPa
BGXN3 - Great Bay Reserve, NH 49 mi93 min W 8 17°F 1025 hPa-0°F

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi24 minNNW 1010.00 miFair23°F1°F40%1025.5 hPa
East Milton, MA11 mi22 minNW 9 G 18 mi20°F3°F50%1025.1 hPa
Norwood, Norwood Memorial Airport, MA14 mi25 minNW 1010.00 miFair26°F3°F38%1025.2 hPa
Laurence G Hanscom Field Airport, MA14 mi22 minNNW 810.00 miFair20°F3°F48%1027 hPa
Beverly, Beverly Municipal Airport, MA16 mi25 minNNW 810.00 miFair19°F0°F43%1025 hPa

Wind History from BOS (wind in knots)
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1 day agoW7NW10NW8NW11NW11NW8
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NW8N55W6NW7N7W10NW6N64CalmCalmSW4SW5S6SW6SW7SW9
2 days agoN11N11N12N10N13N10N10N10N11N6E6E4CalmCalmN4N3N5NW6NW6NW8NW8--NW7NW8

Tide / Current Tables for Charlestown Bridge, Charles River, Massachusetts
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Charlestown Bridge
Click for Map
Thu -- 01:09 AM EST     1.00 feet Low Tide
Thu -- 03:13 AM EST     Moonset
Thu -- 07:09 AM EST     Sunrise
Thu -- 07:24 AM EST     9.99 feet High Tide
Thu -- 01:24 PM EST     Moonrise
Thu -- 01:51 PM EST     0.27 feet Low Tide
Thu -- 04:39 PM EST     Sunset
Thu -- 08:01 PM EST     8.87 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.911.53.15.178.89.99.88.66.74.62.50.80.31.12.84.76.68.28.98.36.95.1

Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Thu -- 01:17 AM EST     0.00 knots Slack
Thu -- 03:12 AM EST     Moonset
Thu -- 03:29 AM EST     1.23 knots Max Flood
Thu -- 07:03 AM EST     -0.00 knots Slack
Thu -- 07:09 AM EST     Sunrise
Thu -- 10:41 AM EST     -1.18 knots Max Ebb
Thu -- 01:23 PM EST     Moonrise
Thu -- 01:52 PM EST     0.00 knots Slack
Thu -- 04:08 PM EST     1.17 knots Max Flood
Thu -- 04:38 PM EST     Sunset
Thu -- 07:35 PM EST     -0.00 knots Slack
Thu -- 11:02 PM EST     -1.07 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.8-0.30.71.21.21.10.70-0.6-0.9-1.1-1.2-1.1-0.80.10.91.21.110.4-0.3-0.7-1-1.1

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 (4,6,7,8)
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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.