Wednesday, January23, 2019 L-36.com


Marine Weather and Tides
Nahant, 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 7:04AMSunset 4:47PM Wednesday January 23, 2019 5:13 AM EST (10:13 UTC) Moonrise 9:00PMMoonset 9:57AM Illumination 94% Phase: Waning Gibbous; Moon at 17 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- 344 Am Est Wed Jan 23 2019
.gale watch in effect from Thursday morning through Thursday afternoon...
Today..SW winds 5 to 10 kt, increasing to 10 to 15 kt this afternoon. Gusts up to 25 kt. Waves around 2 ft.
Tonight..S winds 10 to 15 kt with gusts up to 25 kt. Waves around 2 ft. Patchy fog. A chance of rain in the evening, then rain likely after midnight with vsby 1 to 3 nm.
Thu..SW winds 15 to 20 kt with gusts up to 40 kt. Waves around 2 ft. Patchy fog. Rain. Vsby 1 to 3 nm.
Thu night..W winds 10 to 15 kt, diminishing to 5 to 10 kt after midnight. Gusts up to 25 kt. Waves around 2 ft. A chance of rain in the evening.
Fri..W winds 5 to 10 kt. Gusts up to 20 kt in the afternoon. Waves around 2 ft.
Fri night..W winds 10 to 15 kt with gusts up to 25 kt. Waves around 2 ft.
Sat..SW winds 5 to 10 kt. Waves 1 foot or less.
Sat night..W winds 5 to 10 kt. Waves 1 foot or less, then around 2 ft after midnight.
Sun..SE winds 5 to 10 kt with gusts up to 20 kt. Waves around 2 ft. A chance of snow showers. A chance of showers in the afternoon. Vsby 1 to 3 nm.
Sun night..S winds around 10 kt, becoming W after midnight. Gusts up to 20 kt. Waves around 2 ft. A chance of snow and rain showers in the evening. Vsby 1 to 3 nm. 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 344 Am Est Wed Jan 23 2019
Synopsis for massachusetts and rhode island coastal waters.. An area of low pressure tracks across the great lakes today. This will spread a soaking rain and strong south winds. Winds should reach at least gale force, and may reach storm force Thursday. Arctic high pressure follows with dry weather for Friday and Saturday. Another weather system brings a chance of rain and snow showers Sunday. 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 Nahant, MA
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location: 42.44, -70.94     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 230844
afdbox
area forecast discussion
national weather service boston norton ma
344 am est Wed jan 23 2019

Synopsis
Low pressure lifting across the great lakes into quebec will
result in considerably milder temperatures today. The risk for
showers will increase tonight and reach maximum strength on
Thursday. Heavy rainfall and possible flooding, strong coastal
winds and unseasonably mild temperatures are expected on
Thursday. Mainly dry and more seasonable temperatures follow on
Friday, then turning colder Saturday. Snow showers are possible
Sunday then another frontal system may impact the region
Tuesday.

Near term until 6 pm this evening
Upper trough over the plains with 170 kt jet feeding up over the
great lakes. This will bring a plume of moisture up through the
ohio valley into the eastern great lakes by this evening.

Satellite shows clouds spreading east toward new england. Expect
clouds increasing and thickening through the day. Southwest
winds will bring in milder air, and low level temps support
surface MAX temps in the low to mid 40s. Low level jet will be
increasing during the afternoon evening and may bring gusts 20
to 30 mph.

Overall, a dry day but note radar shows some very light pcpn and
temperatures are favorable initially for some light snow or
sleet, mainly in northwest ma, during the afternoon. We will
continue with a special weather statement for this possibility.

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

primary low pressure moves into canada. Precip water plume
increases overnight as it is drawn north, with values reaching
over 1 inch by Thursday morning. Upper jet shifts farther east,
and our area increasingly moves upper the right entrance region
of the jet, especially after midnight. Expect increasing
coverage of rain during the night.

Southerly flow will bring milder air into the region with higher
dew point values as well. Temperatures will slowly rise
overnight... Guidance suggests temperatures rising into the 50s.

Low level jet increases during the night, with speeds of 65 to
75 kt at 850 mb and 60 to 70 kt at 925 mb. Expect gust potential
overnight at 30 to 40 mph. Best chance for this wind will be
over ri and SE mass, and may extend into NE ct.

Thursday...

srn new england remains under the right entrance region, so
expect continued ascent combined with the well-above-normal
precip water values. Rain which increases overnight should fall
at its maximum rate during this time. Total amounts of 1-2
inches is favored, with small areas of 2-3" possible. K index
reaches 30+ over ri and SE mass during the afternoon, indicating
some instability that could generate isolated tstms during the
afternoon. This hold potential for urban and small stream
flooding, with focus over ct-ri and SE mass. We will issue a
flash flood watch for this area.

Another concern is the wind. The low level jet continues to
increase Thursday, with speeds of 95 kt at 850 mb and 70-80 kt
at 925 mb. Cold water temps may attempt to stabilize the
surface layer but warm advection pushing land temps into the 50s
may be enough to draw strong winds to the surface, especially ri
and SE mass. We will issue a high wind watch for this area, and
anticipate wind advisories will eventually be issued over a
broader area.

Tides coastal flooding:
astronomical tides were elevated yesterday, which is cause for
concern along the south coast, but strongest winds and surge
expected to occur after the Thu morning high tides which will
minimize risk.

Long term Thursday night through Tuesday
Highlights...

* mainly dry and turning colder Fri into sat
* snow showers possible Sunday
* another round of snow rain showers possible mid week
overview and model preferences...

as noted yesterday, long range ensemble guidance continues to
favor predominantly negative nao ao and epo setup. This pattern
favors a broad, longwave trof settling across the E third of the
conus through much of the long term, and both operational and
ensemble guidance support this. With this trof in place, lobes
of the arctic vortex will be shifting S and e, impacting new
england with modified arctic air, and robust upper lvl energy.

While there remains some uncertainty in the sfc reflections of
these features, given they are not currently well sampled, a
general blend of guidance will be used as a baseline, giving a
rough outline of the potential impacts.

Details...

thu night...

lingering precip as low pres moves toward labrador. Timing
dependent, as both cold and dry air will be filtering through
the column. Low risk for some sn, especially across W ma ct
during the evening before the drier air cuts erodes the
remaining moisture. Gradual clearing overnight, with mins
falling into the 20s by early am fri. With mins below freezing,
damp sfcs may have ice by am.

Fri...

secondary arctic front introduces the coldest of the modified
arctic air mass late fri. Highs slightly colder than normal as
the strongest cold advection does not arrive until late fri. The
cold FROPA is mainly dry per latest soundings, but a few shsn
cannot be ruled out thanks to some lower lvl instability and
moisture pooling along the bl.

Fir night into sat...

as previous forecaster noted, modified arctic airmass in place.

H85 temp anomalies run about -10c. Lows Sat morning and highs
sat below normal as a result.

Sat night into Sun night...

first lobe of the arctic vortex rotates through the great lakes
and ontario with a sfc low pres in tow. Warm advection results
across the NE CONUS along with a modest pwat plume. A period of
shsn possible, and will need to monitor the potential
development of an inverted trof linked to this low pres inland
which could provide a focus for locally heavier sn. Most keep
this to the n, but something to watch.

Mon...

modest ridging ahead of a second lobe of the vortex suggests a
brief dry period.

Mid next week...

secondary vortex rotates to the s, however the longwave trof
has will have also shifted somewhat e. Suggesting that the final
track of any sfc low pres is further E than the inside runner
from the weekend. Again, given the time period, low confidence
in any one solution, but something to watch.

Aviation 09z Wednesday through Sunday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Thursday ...

today... High confidence.

Vfr most of the day. MVFR CIGS possible toward evening as rain
moves in from the southwest. Some rain snow sleet mix possible
in northwest ma. SW wind gusts of 20 to 30 mph develop during
the afternoon.

Tonight... Moderate to high confidence.

Conditions lower to ifr most areas during the night. Rain
develops as milder air moves into southern new england. High dew
points will also contribute to fog formation during the night.

Strong winds at 2000 feet will generate southwest wind gusts of
40 to 45 kt. The winds at 2000 feet will also generate low level
wind shear
Thursday... Ifr CIGS vsbys with areas of MVFR in rain and fog.

Strong wind gusts of 45 to 50 kt possible, as well as low level
wind shear. A cold front swings through later in the day,
and may generate isolated thunder to go along with the rain.

Kbos terminal... High confidence in taf.

Kbdl terminal... High confidence in taf
outlook Thursday night through Sunday ...

Thursday night through Friday:VFR. Windy with local gusts to
30 kt.

Friday night:VFR. Breezy.

Saturday:VFR.

Saturday night and Sunday: mainlyVFR, with areas ifr 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 Thursday ...

today... High confidence.

High pressure moves offshore, bringing a southwest flow of air
up across the waters. Winds should increase during the day,
although the stronger winds are just approaching our southern
waters late in the day.

Tonight... Moderate confidence.

Strong low level southwest winds above the surface will continue
to increase during the night. Winds in the jet will reach 60-70
kt and should support gale force gusts during the night. These
winds and the long fetch will build seas to 5-10 feet.

Developing rain will reduce vsbys to 1-3 miles at times. The
increasing low level moisture will also help generate areas of
fog, which will also reduce vsbys.

Thursday... Moderate confidence.

Strong low level jet... About 2000 feet up... Will continue much
of the day with winds reaching 95 kt at about 5000 feet and
70-80 kt at 2000 feet. This will support southwest gales and may
support low-end storm force gusts. We have bumped the gale
watch up to a storm watch on most waters. Boston harbor and
narragansett bay will remain at a gale watch.

The strong winds will build seas especially across the southern
waters where heights may reach 15-17 feet. Rain and isolated
tstms will reduce local visibility to 1 to 3 nm.

Outlook Thursday night through Sunday ...

Thursday night into Friday night: moderate risk for small craft
advisory winds with gusts up to 30 kt. Rough seas up to 15 ft.

Saturday and Saturday night: winds less than 25 kt. Local rough
seas.

Sunday: low risk for small craft advisory winds with gusts up
to 25 kt. Seas up to 5 ft. Chance of rain showers, chance of
snow showers. Areas of visibility 1 to 3 nm.

Box watches warnings advisories
Ct... Flash flood watch from Thursday morning through Thursday
afternoon for ctz002>004.

Ma... High wind watch from Thursday morning through Thursday
afternoon for maz007-019>024.

Flash flood watch from Thursday morning through Thursday
afternoon for maz013-015>022.

Ri... High wind watch from Thursday morning through Thursday
afternoon for riz007-008.

Flash flood watch from Thursday morning through Thursday
afternoon for riz001>007.

Marine... Storm watch from Thursday morning through Thursday afternoon
for anz231>235-237-250-251-254>256.

Gale watch from Thursday morning through Thursday afternoon
for anz230.

Gale watch from late tonight through Thursday afternoon for
anz236.

Synopsis... Wtb kjc doody
near term... Wtb
short term... Wtb
long term... Doody
aviation... Wtb doody
marine... Wtb doody


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 8 mi44 min 21°F 1030.9 hPa
44013 - BOSTON 16 NM East of Boston, MA 17 mi84 min S 12 G 14 27°F 40°F1 ft1031.2 hPa (-2.0)14°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 21 mi70 min SW 14 G 18 29°F 40°F1 ft1030.2 hPa
IOSN3 - Isle of Shoals, NH 40 mi74 min SW 13 G 14 25°F 1030.3 hPa (-2.4)4°F
BGXN3 - Great Bay Reserve, NH 43 mi89 min Calm 8°F 1032 hPa-1°F
44018 - SE Cape Cod 30NM East of Nantucket, MA 45 mi84 min SW 12 G 14 28°F 2 ft1031.8 hPa (-1.9)5°F
44098 - Jeffrey's Ledge, NH (160) 48 mi66 min 41°F2 ft

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA6 mi20 minS 710.00 miOvercast22°F9°F57%1030.3 hPa
Beverly, Beverly Municipal Airport, MA10 mi21 minS 410.00 miFair19°F6°F57%1029.9 hPa
East Milton, MA18 mi18 minS 14 mi17°F6°F62%1030.4 hPa
Laurence G Hanscom Field Airport, MA19 mi78 minN 010.00 miFair14°F1°F56%1032.1 hPa
Norwood, Norwood Memorial Airport, MA21 mi21 minN 010.00 miFair18°F10°F74%1030.4 hPa
Lawrence Municipal Airport, MA22 mi20 minWSW 410.00 miFair17°F1°F49%1030.4 hPa

Wind History from BOS (wind in knots)
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Last 24hrW14
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W10W7W4W8NW7W7W6SW7SW8S7S5S6S7
1 day agoW15W14
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2 days agoNE20NE17N16
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N12NW9N10N7E8NW8NW19
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Tide / Current Tables for Lynn, Lynn Harbor, Massachusetts
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Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Wed -- 03:26 AM EST     -1.32 knots Max Ebb
Wed -- 06:27 AM EST     0.00 knots Slack
Wed -- 07:05 AM EST     Sunrise
Wed -- 08:56 AM EST     1.42 knots Max Flood
Wed -- 08:56 AM EST     Moonset
Wed -- 12:13 PM EST     -0.00 knots Slack
Wed -- 03:48 PM EST     -1.40 knots Max Ebb
Wed -- 04:46 PM EST     Sunset
Wed -- 06:55 PM EST     0.00 knots Slack
Wed -- 08:00 PM EST     Moonrise
Wed -- 09:37 PM EST     1.41 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.1-0.7-1.1-1.3-1.3-1.1-0.50.61.31.41.310.2-0.6-1.1-1.3-1.4-1.3-0.90.111.41.41.2

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 (5,6,7,8)
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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.