Thursday, March21, 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 6:44AMSunset 6:58PM Thursday March 21, 2019 6:19 PM EDT (22:19 UTC) Moonrise 7:51PMMoonset 7:27AM Illumination 99% Phase: Waning Gibbous; Moon at 16 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- 324 Pm Edt Thu Mar 21 2019
.gale warning in effect from late Friday night through Saturday afternoon...
Tonight..SE winds 10 to 15 kt with gusts up to 20 kt, becoming E 15 to 20 kt with gusts up to 30 kt after midnight. Waves around 2 ft. At the outer harbor entrance, waves around 3 ft, building to 5 ft after midnight. A chance of rain this evening. Rain after midnight. Patchy fog after midnight with vsby 1 to 3 nm.
Fri..E winds 15 to 20 kt, becoming W 10 to 15 kt in the afternoon. Gusts up to 25 kt. Waves around 2 ft, except up to 6 ft at the outer harbor entrance. A chance of rain in the morning, then scattered showers in the afternoon. Patchy fog in the morning. Vsby 1 to 3 nm.
Fri night..W winds 15 to 20 kt with gusts up to 35 kt. Waves around 2 ft, except up to 5 ft at the outer harbor entrance. Numerous showers. Scattered snow showers after midnight.
Sat..W winds 15 to 20 kt with gusts up to 35 kt. Waves around 2 ft, except 4 to 5 ft at the outer harbor entrance. Scattered snow showers in the morning.
Sat night..NW winds 10 to 15 kt. Gusts up to 30 kt. Waves around 2 ft.
Sun..W winds around 10 kt. Waves around 2 ft.
Sun night..W winds 5 to 10 kt. Waves 1 foot or less.
Mon..W winds around 5 kt. Waves 1 foot or less. A chance of showers in the afternoon.
Mon night..NW winds 5 to 10 kt. Waves 1 foot or less, then around 2 ft after midnight.
Tue..N winds around 10 kt. Waves 1 foot or less, then around 2 ft in the afternoon.
Tue night..N winds around 10 kt. Gusts up to 20 kt after midnight. 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 324 Pm Edt Thu Mar 21 2019
Synopsis for massachusetts and rhode island coastal waters.. Low pres will lift ne across the mid atlc coast this evening, passing across ri and eastern ma Fri morning. The low will intensify Friday night as it tracks up along coastal maine. This powerful storm lingers near nova scotia Sat before finally exiting ne Sat night. High pres builds across the mid atlc waters Sun, shifting offshore Sun night. A cold front will drop S across the waters Mon. 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 212026
afdbox
area forecast discussion
national weather service boston norton ma
426 pm edt Thu mar 21 2019

Synopsis
Intensifying low pressure will bring a period of heavy rain
overnight, which will taper off to scattered showers Friday morning
and afternoon. Scattered showers should change to a period of snow
Friday night with some accumulations expected in the high terrain
and it will become windy across the entire region. The strong
winds will continue into Saturday, but it will be dry. It turns
milder Sunday and Monday, a return to colder than normal
conditions is expected Tuesday in mid next week.

Near term until 6 am Friday morning
* heavy rain overspreads the region but not until after 10 or 11 pm
deeper moisture forcing will remain west of our region during the
early to mid evening hours. The result will be just a few spot
showers across western ma ct during this time.

Things will change during the late evening and overnight hours as an
intensifying low pressure system approaches the southeast new
england coast. Although the storm system is quite progressive, a
925 mb easterly jet 3 to 4 standard deviations above normal along
with pwats of 1+ above normal will result in a period of heavy rain.

The bulk of the steady heavy rain will arrive after 10 or 11 pm and
be over by 5 or 6 am. Most locations should receive rainfall amounts
on the order of 0.50 to 1", but some locally higher totals are
possible.

While rain is on tap for the vast majority of the region, it is
possible that areas of the highest terrain in northwest ma see a
period of wet snow with a slush inch or two of accumulation. The
nam indicates that it will be too warm for this to occur, but other
guidance indicates that strong forcing dynamic cooling may allow for
ptype to be in the form of wet snow for a period of time. If this
were to occur, it would be confined to mainly elevations over 1500
feet in far northwest ma.

Short term 6 am Friday morning through Friday night
* accumulating snow expected Friday night in the high terrain
* windy later Friday and especially Friday night in all locales
Friday...

while the steady heavy rain will be over by early Friday morning,
scattered showers are expected at times through the afternoon along
with rather cloudy skies. This a result of cyclonic flow around the
mid level closed low. High temperatures should be in the 40s, so
ptype will mainly be in the form of rain showers. However, it is
possible that it becomes marginally cold enough for some wet snow in
the high terrain along the east slopes of the berks especially by
late in the day.

Friday night...

a second piece of vigorous shortwave energy will drop south of new
england Friday night. The result will be an increase in areal
coverage intensity of the precipitation. Thermal profiles will be
cooling... So any rain will quickly flip to snow in the high terrain
and eventually even the lower elevations. In addition... Strong winds
will develop as low pressure lifts into eastern maine. Some
locations may be near wind advisory criteria, but given this is a
3rd and 4th period marginal event, opted to hold off on any wind
headlines at this point.

With that said though, the westerly flow coupled with deep
moisture forcing will result in some enhanced upslope snowfall in
the berkshires. A few inches of snow seem likely in northwest ma,
but the highest terrain may see a swath of 4 to 8" above 1500 feet.

Will have to watch this region for a few power outages given the
snow coupled with gusty winds. We may also see an area of 1 to 3
inches of snow across the higher terrain of the worcester ct hills,
especially in the western hills where upslope flow will result in
some enhancement. Elsewhere in the lower elevations... A dusting
to 1 inch of snow is certainly possible, but we can not rule
out the low risk of some location seeing 2 inches. Overall
though the main impacts appear to be in the high terrain and
especially in the berkshires. Given that we have issued a winter
weather advisory for western franklin western hampshire county.

Snow amounts may vary quite a bit in this region too, highly
dependent on elevation.

Long term Saturday through Thursday
Highlights...

* windy Saturday, then milder Sunday.

* cold front brings rain showers Monday, possibly starting as snow
showers inland.

* colder weather follows through midweek.

Closed low exits new england this weekend as it heads into
maritimes. Colder air aloft coupled with steep lapse rates will
promote diurnal clouds and gusty NW winds of 35-45 mph Saturday,
before skies clear and winds diminish Saturday night.

Milder weather arrives Sunday as upper flow becomes more zonal and
high pressure off carolinas results in SW flow across region.

Blended guidance yields highs well into 50s away from colder ocean
influence (south coast, cape, and islands) but with plenty of sun
it's possible we reach lower 60s in some interior locations.

Ensembles in good agreement on timing of cold front through sne
Monday which should reach south coast around 18z before slowing down
a bit, as weak wave of low pressure may form along it as mid level
short wave approaches. Most of forcing and deeper moisture should be
located along and south of boundary, so while most of rainfall
(light) will be focused south of mass pike, we can't rule out some
showers farther north as well. Should they occur it's possible to
see some wet snow at start across NW ma where temperature profiles
support snow at least initially. Not looking for any real
accumulation at this point however.

Beyond Monday, broad upper trough remains in place for much of week
which will result in below average temperatures, at least through
Wednesday. High pressure will dominate with dry weather before
heading offshore later next week, so warmup appears more likely by
then.

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 ...

tonight... Moderate to high confidence. VFR conditions early this
evening deteriorate to low end MVFR-ifr thresholds late this evening
and through the overnight hours. This a result of steady rain
working into the region, which will be heavy at times. A period of
easterly wind gusts to 30 knots are expected for a time overnight on
the CAPE islands with the low level jet. Llws of 40 to 50 knots will
also be a concern overnight for all locations.

Friday... Moderate to high confidence. The steady rain should come to
an end early Friday morning, but scattered showers will remain
possible through the afternoon. Ifr conditions should improve to
mainly MVFR levels in most locations by mid afternoon. Winds shift
to the west by afternoon with gusts to 30 knots expected to develop.

Friday night... Moderate to high confidence. Scattered showers will
become more numerous and quickly flip to snow in the high terrain
during the evening with a few inches of accumulation expected. In
the lower elevations, scattered showers should change to a period of
snow showers but accumulations should generally be a dusting to an
inch with mainly wet runways. MVFR to ifr conditions anticipated
along with westerly wind gusts of 30 to 40 knots.

Kbos terminal... Moderate to high confidence in taf.

Kbdl terminal... Moderate to high confidence in taf.

Outlook Saturday through Tuesday ...

Saturday: mainlyVFR, with local MVFR possible. Strong winds
with gusts up to 40 kt.

Saturday night:VFR. Windy with local gusts up to 30 kt.

Sunday:VFR. Breezy.

Sunday night:VFR. Slight chance shra, slight chance fzra.

Monday:VFR. Chance shra.

Monday night:VFR. Breezy. Slight chance shra, slight chance
shsn.

Tuesday: mainlyVFR, with local MVFR possible. Breezy. Slight
chance shsn.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Friday night ...

tonight... High confidence. Intensifying easterly low level jet will
bring a period of easterly wind gusts of 25 to 35 knots from south
to north. Seas will build to between 5 and 9 feet across the open
waters by daybreak Friday with the long easterly fetch. Rain
overspreads the region and will be heavy at times
overnight, reducing vsbys for mariners at times.

Friday and Friday night... High confidence. Winds will slacken for a
time Friday morning as low pressure tracks across the region.

However... As the strong low lifts to the northeast of our area the
pressure gradient will increase. Westerly winds will increase to
between 35 and 45 knots later Friday and especially Friday night.

Gale warnings are posted for all our waters.

Outlook Saturday through Tuesday ...

Saturday: moderate risk for gale force winds with gusts up to
45 kt. Rough seas up to 15 ft.

Saturday night: moderate risk for small craft advisory winds
with gusts up to 30 kt. Areas of rough seas.

Sunday: low risk for small craft advisory winds with gusts up
to 25 kt. Local rough seas.

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

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

Chance of rain showers.

Monday night: winds less than 25 kt. Areas of rough seas.

Slight chance of rain showers.

Tuesday: winds less than 25 kt. Areas of rough seas. Slight
chance of rain showers, slight chance of snow showers.

Tides coastal flooding
The strongest winds seas will arrive after the overnight high tide.

Therefore... Worst case scenario appears to be some very minor splash
over during the 1 am high tide. The next high tide occurs early
Friday afternoon, but by that time winds will have diminished.

Nonetheless... Enough pressure falls lingering seas and relatively
high astro tide will likely result in pockets of splash over and
minor coastal flooding in the typically most vulnerable areas along
the eastern ma coast. We hoisted the coastal flood advisory for the
eastern ma coast with the greatest risk along the north shore, where
winds will be slowest to slacken. Nonetheless, not expecting any
property damage or significant impacts anywhere in our region.

Box watches warnings advisories
Ct... None.

Ma... Coastal flood advisory from 11 am to 3 pm edt Friday for
maz007-015-016-019.

Winter weather advisory from 11 pm this evening to 8 am edt
Saturday for maz002-008.

Ri... None.

Marine... Gale warning from 2 pm Friday to 4 pm edt Saturday for
anz232>235-237-254>256.

Gale warning from midnight Friday night to 4 pm edt Saturday
for anz230-236.

Gale warning from 8 pm Friday to 4 pm edt Saturday for anz231-
250-251.

Synopsis... Frank jwd
near term... Frank
short term... Frank
long term... Jwd
aviation... Frank jwd
marine... Frank jwd
tides coastal flooding... Frank


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 1 mi37 min 43°F 1017.3 hPa
44013 - BOSTON 16 NM East of Boston, MA 22 mi29 min ESE 9.7 G 9.7 40°F 39°F2 ft1017.7 hPa (-1.7)37°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi75 min SE 12 G 16 39°F 39°F2 ft1017.2 hPa
FOXR1 - 8454000 - Providence, RI 43 mi37 min S 12 G 17 45°F 40°F1016.4 hPa
PVDR1 44 mi37 min ESE 11 G 14 46°F 1016.9 hPa35°F
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi31 min ESE 12 G 13 45°F 1016.9 hPa
FRVM3 - 8447386 - Fall River, MA 46 mi31 min 46°F 42°F1017.1 hPa
FRXM3 47 mi37 min 46°F 35°F
IOSN3 - Isle of Shoals, NH 47 mi79 min SE 17 G 18 40°F 1017.8 hPa (-2.4)32°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi31 min E 13 G 16 44°F 42°F
BGXN3 - Great Bay Reserve, NH 49 mi94 min SE 5.1 44°F 1019 hPa29°F

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi2.4 hrsS 1010.00 miMostly Cloudy51°F23°F33%1018.6 hPa
East Milton, MA11 mi83 minSSE 8 mi45°F25°F46%1017.9 hPa
Norwood, Norwood Memorial Airport, MA14 mi26 minSSE 710.00 miFair49°F32°F52%1016.9 hPa
Laurence G Hanscom Field Airport, MA14 mi83 minESE 810.00 miOvercast49°F25°F39%1018.2 hPa
Beverly, Beverly Municipal Airport, MA16 mi26 minSE 1010.00 miA Few Clouds42°F30°F65%1017.1 hPa

Wind History from BOS (wind in knots)
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1 day agoNW7N3N4NE3CalmCalmN3W4W5W5W4NW5CalmSW4CalmSE5SE7SE8E12--E18E14S12S14
2 days agoNW10NW8W7NW5W7W5W6NW5W7W6W9NW7W9W10W9NW11W10NW7
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Tide / Current Tables for Charlestown Bridge, Charles River, Massachusetts
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Charlestown Bridge
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Thu -- 06:03 AM EDT     -1.47 feet Low Tide
Thu -- 06:46 AM EDT     Sunrise
Thu -- 07:26 AM EDT     Moonset
Thu -- 12:17 PM EDT     11.81 feet High Tide
Thu -- 06:30 PM EDT     -1.73 feet Low Tide
Thu -- 06:57 PM EDT     Sunset
Thu -- 07:50 PM EDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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11.210.48.35.52.3-0.4-1.5-0.61.64.67.810.411.711.49.66.93.70.5-1.5-1.50.22.96.19.1

Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Thu -- 03:30 AM EDT     -1.50 knots Max Ebb
Thu -- 05:57 AM EDT     0.00 knots Slack
Thu -- 06:45 AM EDT     Sunrise
Thu -- 07:25 AM EDT     Moonset
Thu -- 09:07 AM EDT     1.50 knots Max Flood
Thu -- 11:50 AM EDT     -0.00 knots Slack
Thu -- 03:47 PM EDT     -1.54 knots Max Ebb
Thu -- 06:21 PM EDT     0.00 knots Slack
Thu -- 06:57 PM EDT     Sunset
Thu -- 07:50 PM EDT     Moonrise
Thu -- 09:32 PM EDT     1.58 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.3-0.9-1.3-1.5-1.5-1011.41.51.30.7-0.1-0.8-1.2-1.5-1.5-1.3-0.40.71.41.51.51.1

Weather Map and Satellite Images
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wmap_A
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 (18,4,5,8)
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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.