Tuesday, December18, 2018 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 7:07AMSunset 4:15PM Tuesday December 18, 2018 6:15 AM EST (11:15 UTC) Moonrise 2:43PMMoonset 3:13AM Illumination 83% 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- 355 Am Est Tue Dec 18 2018
.gale warning in effect through this evening...
Today..NW winds 20 to 25 kt with gusts up to 40 kt. Waves around 2 ft, except up to 5 ft at the outer harbor entrance.
Tonight..NW winds 15 to 20 kt, diminishing to 10 to 15 kt after midnight. Gusts up to 35 kt. Waves around 2 ft.
Wed..W winds 5 to 10 kt. Gusts up to 20 kt in the morning. Waves around 2 ft in the morning, then 1 foot or less.
Wed night..SW winds 5 to 10 kt. Waves 1 foot or less.
Thu..SW winds 5 to 10 kt. Waves 1 foot or less.
Thu night..SE winds 5 to 10 kt. Gusts up to 20 kt after midnight. Waves 1 foot or less, then around 2 ft after midnight. Rain after midnight.
Fri..SE winds 15 to 20 kt with gusts up to 30 kt. Waves around 3 ft. Rain. Vsby 1 to 3 nm in the morning.
Fri night..S winds 10 to 15 kt. Gusts up to 20 kt in the evening. Waves around 3 ft. Rain, mainly in the evening.
Sat..SW winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft. A chance of rain in the morning.
Sat night..W winds around 15 kt with gusts up to 25 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 355 Am Est Tue Dec 18 2018
Synopsis for massachusetts and rhode island coastal waters.. NW gales on the waters today, will diminish tonight into Wed as high pres crests over the waters. This high pres will shift offshore late Wed into Thu, resulting in sw winds and moderating temperatures. A storm system will approach srn new england from the sw Fri and Fri night, which will bring a slug of rain along with unseasonably muggy conditions. 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 180809
afdbox
area forecast discussion
national weather service boston norton ma
309 am est Tue dec 18 2018

Synopsis
High pressure approaches from the west bringing drier weather.

Expect windy and much colder conditions tonight and Tuesday with
bitter wind chill values. High pressure will bring dry
conditions at mid week, with a moderating temperature trend for
Thursday. Strong low pressure will pass west of the region
Thursday night into early next weekend, bringing rain that will
fall heavily at times especially during Friday. Colder
temperatures then return early next week.

Near term until 6 pm this evening
A vigorous mid level shortwave will move farther away from our
region early this morning. This feature combined with the
leading edge of some significantly colder air generated some
quick-moving snow squalls. The last of these snow squalls
should move out to sea by 4 am, although a few snow showers may
linger until about 7 am.

Winds will dramatically increase with the squalls, then are
likely to remain elevated through much of this morning.

Strongest wind gusts will be this morning, with a gradual
decline after noon. Have already seen wind gusts just shy of
wind advisory criteria with the snow squalls, an indicator of
the strength of the pressure gradient. Will keep the wind
advisory in place for this morning along the coast.

High temperatures will be significantly lower than Monday, by
about 10 degrees region-wide.

Short term 6 pm this evening through 6 pm Wednesday
High pressure will be our dominant weather feature tonight into
Wednesday. Winds will continue to diminish through this period,
and be more from the W than nw. Dry weather expected through
this period.

Very cold conditions tonight, with low temperatures in the
single digits above zero and teens common away from the
immediate coast. With some sunshine Wednesday and warm air
advection beginning, high temperatures recover some, but will
remain below normal.

Long term Wednesday night through Monday
Big picture...

Thursday shows ridges over the western atlantic and the rockies,
while a deep trough digs over the mississippi valley. Closed low in
the base of the deep trough will sweep up the east coast Friday and
across new england Saturday. The flow over the usa then becomes more
zonal, with an embedded shortwave moving through early in the week.

Mass field show good agreement through Friday and possibly Saturday.

Mslp fields show the surface low taking an inside track through
ny pa Friday. All show the zonal upper flow Sunday-Monday, but with
different timing for the movement of the shortwave. Thermal fields
are similar through Friday with h850 temperatures in the mid teens
briefly moving up across our area Friday.

Concerns...

Thursday-Friday...

as noted, the midwest deep trough ejects up the eastern usa Thursday
night and Friday, crossing new england Saturday. The atlantic high
should keep enough low level dry air to keep the weather dry during
the day Thursday.

Deep moisture moves in Thursday night with pw values forecast to 1
inch all the way to the white mtns while values of 1.5 inches reach
the south coast. As per the SPC sounding climatology, even the 1
inch values are at the upper end of what is expected in mid
december while 1.5 inches would be at or near record levels.

South to southeast flow builds Thursday night with 65 to 85 knot
winds forecast at 850 mb and winds near 35 knot forecast at 1000 mb.

The former actually suggests surface winds could gust to 45 knots.

Bufkit soundings show abv freezing air to at least 800 mb. Based on
this and the expected storm track through new york, expect southern
new england will have rain developing Thursday night, especially
after midnight, and continuing through Friday. Rainfall should total
at least 1-2 inches with potential for some higher amounts.

Potential for winds at advisory levels, especially in
eastern central mass and ri.

Rest of the period...

dry. Height contours at 500 mb are forecast above normal Wednesday
night through Saturday, then seasonable or a little below on Sunday
and Monday. This would mean above normal temperatures late this
week, trending to seasonably cold temps early next week.

Aviation 08z Tuesday through Saturday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Wednesday ... High confidence.

Today... VFR. Windy with gusts to 30-35 kt, possibly up to 40 kt
along the east coast of ma.

Tonight... VFR. NW wind gusts 25-30 kt early, diminishing to
less than 20 kt after midnight.

Wednesday...VFR.

Kbos terminal... High confidence in taf.

Kbdl terminal... High confidence in taf. Moderate risk for a
brief snow squall before 06z, which may coat the ground in
spots. Runways mainly should be wet.

Outlook Wednesday night through Saturday ...

Wednesday night through Thursday:VFR.

Thursday night: mainly MVFR. Breezy. Ra.

Friday: mainly ifr, with areas MVFR possible. Windy with gusts
to 35 kt. Ra, patchy br.

Friday night: mainly ifr, with areas MVFR possible. Windy with
local gusts to 30 kt. Ra, patchy br.

Saturday: mainly MVFR, with local ifr possible. Windy with
local gusts to 30 kt. Chance ra.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Wednesday ... High confidence.

Nw gales expected today due to frequent gusts. These gusts
diminish tonight into Wednesday. Rough seas also anticipated,
which will take longer to subside across the eastern and
southern outer coastal waters of ma and ri. Seas continue to
subside Wednesday.

Significantly colder air will move across the waters today into
tonight. With the gusty winds and rough seas, areas of light
freezing spray are likely along the nearshore waters of the ma
coast into this evening.

Outlook Wednesday night through Saturday ...

Wednesday night through Thursday: winds less than 25 kt.

Thursday night: low risk for small craft advisory winds with
gusts up to 30 kt. Rain.

Friday: low risk for gale force winds with gusts up to 35 kt.

Areas of rough seas. Rain.

Friday night: moderate risk for small craft advisory winds with
areas of gusts up to 30 kt. Rough seas up to 12 ft. Rain
likely.

Saturday: moderate risk for small craft advisory winds with
gusts up to 30 kt. Rough seas up to 12 ft. Slight chance of
rain.

Tides coastal flooding
South to southeast winds Friday will come as astronomical tides
are trending higher. The winds will build seas offshore to 12-14
feet. Forecast guidance also shows a zone of 15-second wave
periods extending from the gulf of maine into massachusetts bay.

All of this shows a potential for building seas along the south
coast Friday, where the flow is onshore, and into parts of the
mass east coast.

This is still a ways in the future, but it will bear watching
for potential coastal splashover or minor flooding Friday.

Box watches warnings advisories
Ct... None.

Ma... Wind advisory until 1 pm est this afternoon for maz007-015-016-
019-022>024.

Ri... None.

Marine... Gale warning until 10 pm est this evening for anz232>235-237-
255-256.

Gale warning until 9 pm est this evening for anz230.

Gale warning until 11 pm est this evening for anz231.

Gale warning until 1 pm est this afternoon for anz236.

Gale warning until midnight est tonight for anz250-251-254.

Synopsis... Wtb belk
near term... Belk
short term... Belk
long term... Wtb
aviation... Wtb belk
marine... Wtb belk
tides coastal flooding...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 1 mi51 min 26°F 1005.5 hPa
44013 - BOSTON 16 NM East of Boston, MA 22 mi85 min WNW 31 G 39 29°F 45°F7 ft1002.8 hPa (+3.2)17°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi71 min NW 39 G 45 28°F 44°F6 ft1002 hPa
FOXR1 - 8454000 - Providence, RI 43 mi51 min N 21 G 26 27°F 46°F1006 hPa
PVDR1 44 mi51 min NW 20 G 32 27°F 1006.4 hPa11°F
FRVM3 - 8447386 - Fall River, MA 46 mi51 min 29°F 44°F1006.3 hPa
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi45 min NW 20 G 29 30°F 1006 hPa
FRXM3 47 mi45 min 30°F 18°F
IOSN3 - Isle of Shoals, NH 47 mi75 min WNW 34 G 39 25°F 1002.2 hPa (+2.5)12°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi45 min NW 35 G 38 28°F 45°F1005.9 hPa
BGXN3 - Great Bay Reserve, NH 49 mi90 min WNW 9.9 25°F 11°F

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi21 minWNW 20 G 3510.00 miMostly Cloudy and Breezy26°F9°F48%1006.1 hPa
East Milton, MA11 mi19 minWNW 18 G 37 miBreezy20°F10°F65%1006.2 hPa
Norwood, Norwood Memorial Airport, MA14 mi22 minNW 20 G 319.00 miLight Snow and Breezy26°F9°F48%1006.7 hPa
Laurence G Hanscom Field Airport, MA14 mi19 minNW 16 G 3110.00 miOvercast24°F8°F50%1008.4 hPa
Beverly, Beverly Municipal Airport, MA16 mi22 minNW 20 G 3610.00 miOvercast and Breezy25°F7°F46%1005.1 hPa

Wind History from BOS (wind in knots)
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1 day ago----E17E14E17E19E15NE16NE14NE15
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2 days ago----SW7SW8--W6--3N5N9NE7NE11NE10NE7NE6N7NE6N8NE12NE13
G19
NE16NE15
G22
NE9NE14

Tide / Current Tables for Charlestown Bridge, Charles River, Massachusetts
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Charlestown Bridge
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Tue -- 12:58 AM EST     1.06 feet Low Tide
Tue -- 02:12 AM EST     Moonset
Tue -- 07:08 AM EST     Sunrise
Tue -- 07:15 AM EST     9.57 feet High Tide
Tue -- 01:33 PM EST     0.90 feet Low Tide
Tue -- 01:42 PM EST     Moonrise
Tue -- 04:13 PM EST     Sunset
Tue -- 07:42 PM EST     8.96 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.71.11.73.256.98.69.59.38.16.34.42.41.112.13.75.57.48.78.98.16.54.7

Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Tue -- 01:03 AM EST     0.00 knots Slack
Tue -- 02:12 AM EST     Moonset
Tue -- 03:25 AM EST     1.15 knots Max Flood
Tue -- 06:52 AM EST     -0.00 knots Slack
Tue -- 07:07 AM EST     Sunrise
Tue -- 11:16 AM EST     -1.14 knots Max Ebb
Tue -- 01:34 PM EST     0.00 knots Slack
Tue -- 01:42 PM EST     Moonrise
Tue -- 04:12 PM EST     Sunset
Tue -- 04:22 PM EST     1.11 knots Max Flood
Tue -- 07:16 PM EST     -0.00 knots Slack
Tue -- 11:20 PM EST     -1.09 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.8-0.10.81.11.110.6-0.1-0.6-0.9-1.1-1.1-1.1-0.50.411.11.10.80.2-0.4-0.8-1-1.1

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 (6,6,7,8)
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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.