Friday, September21, 2018 L-36.com


Marine Weather and Tides
Plymouth, MA

Version 3.4
What's New / NOTES
9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.

Sunrise 6:29AMSunset 6:42PM Friday September 21, 2018 8:40 AM EDT (12:40 UTC) Moonrise 5:19PMMoonset 2:48AM Illumination 88% 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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ANZ231 Cape Cod Bay- 716 Am Edt Fri Sep 21 2018
.gale warning in effect from this evening through late tonight...
Today..SE winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up to 25 kt this afternoon. Seas 2 to 3 ft.
Tonight..SW winds 15 to 20 kt with gusts up to 35 kt. Seas 3 to 5 ft. A chance of showers.
Sat..W winds 15 to 20 kt with gusts up to 30 kt, becoming N 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 4 ft.
Sat night..NE winds 5 to 10 kt. Seas 2 to 3 ft.
Sun..N winds 5 to 10 kt. Seas 1 foot or less.
Sun night..NE winds around 5 kt, increasing to 10 to 15 kt with gusts up to 20 kt after midnight. Seas 2 to 3 ft.
Mon..NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft.
Mon night..E winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft.
Tue..SE winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 3 ft. A chance of showers.
Tue night..SE winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 3 ft. 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 Edt Fri Sep 21 2018
Synopsis for massachusetts and rhode island coastal waters.. High pres moves east of the waters today. A cold front will sweep across the waters late tonight and early Sat with pre- frontal gale force s-sw winds tonight. High pres will build east from the great lakes this weekend with a reinforcing high pres building over quebec Mon, which will shift east toward nova scotia on Tue. 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 Plymouth, MA
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location: 42, -70.54     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 211133
afdbox
area forecast discussion
national weather service boston norton ma
733 am edt Fri sep 21 2018

Synopsis
High pressure will move slowly to the east today. A cold front
sweeps across the region late tonight with showers and a few
thunderstorms. Large high pressure will then bring dry but cool
conditions this weekend lasting into Monday. Another round of
scattered showers and a few thunderstorms are expected Tuesday
afternoon through Wednesday evening as a series of fronts move
across the region. High pressure will bring dry conditions
Thursday.

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

mid and high clouds tended to thin across portions of ri and se
mass during daybreak, though some low clouds lingered across
portions of CAPE cod at 11z as seen on latest observations. More
low and mid clouds remained across central and western areas,
and can see more clouds moving SE across the region on the
latest goes-east nighttime microphysics composite product.

Noting some showers across SW vt that may try to sneak briefly
into NW and N central mass ahead of the approaching warm front.

With a lot of lingering moisture as the warm front approaches,
clouds will continue through most of the morning if not into the
afternoon before breaking.

Have updated to bring conditions current, then incorporated
trends into the midday forecast. Not many changes beyond this.

Previous discussion...

high pres moves offshore today as cold front approaches the
eastern lakes toward evening. Considerable low level moisture
persists across the interior and especially western new eng
where lower clouds will likely remain. Less moisture further
east where partial sunshine expected to develop. There is a
good surge of warmer air aloft moving into sne today but this
will be above a shallow mixed layer so temps will remain on the
cool side. 925 mb temps only around 13c-14c so expect highs
upper 60s to lower 70s. Increasing southerly winds develop
this afternoon with gusts to 25 mph by mid late afternoon.

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

cold front moves across sne late tonight, mainly 06-12z and will
be accompanied by a weakening line of convection from new york
state, mainly after midnight. Surface instability is non
existent, but low level theta-e ridge and ki values into the mid
30s ahead of the front support a line of showers and possibly a
few t-storms. This activity will weaken as it approaches the
coast so best chance for thunder will be in western new eng.

Gusty S SW winds will continue tonight, especially near the
coast where gusts 25-35 mph likely. Dewpoints will be climbing
into the 60s with temps holding steady in the upper 60s ahead
of the front, but cooling interior northern and western ma late
tonight behind the front.

Saturday...

the cold front moves south of the coast in the morning followed
by high pres and very dry air advecting into the region. Some
clouds may linger near the south coast early, otherwise lots of
sunshine expected. Gusty post-frontal NW winds expected in the
morning near the coast, then diminishing in the afternoon. Highs
upper 60s to lower 70s with dewpoints falling through the 50s
and into the 40s in the afternoon.

Long term Saturday night through Thursday
Highlights...

* large high pressure will bring dry, cool conditions late this
weekend into early next week
* a slow moving warm front brings scattered showers and a few
thunderstorms late Tuesday through Wednesday
* above normal temperatures briefly arrive Wednesday
* cooler temperatures return late next week as cold front passes
overview...

00z model suite continues trend of fast moving weather systems
into early next week thanks to a nearly zonal mid level
steering flow across the northern tier states. H5 begins to
amplify a trough as it moves out of the northern rockies mon
night Tue timeframe as the long wave ridge tends to suppress
south across the mid atlc and SE u.S. Some ridging does build
into quebec in response to the digging trough, which will allow
for a brief period of milder temperatures but will also see
scattered showers and isolated thunderstorms around the middle
of next week with an approaching frontal system. Noting a cold
front working SE by late next week, which should bring another
shot of cooler air, but there are timing issues in play amongst
the model suite, so have lower confidence during the later
timeframe.

With the approaching frontal system around the Tuesday
afternoon through Wednesday timeframe, noting marginal
instability with tq values in the upper teens and k indices in
the lower 30s. Have mentioned isolated thunderstorms through
this time, but will convection looks to be spotty at this
point.

Expect temperatures through most of this period running close
to or below normal. However, with the ridging that builds in
ahead of the tue-wed system, could see temps on Wed run 5 to 10
degrees above seasonal normals.

Aviation 11z Friday through Tuesday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday ...

through today... Moderate confidence.

MainlyVFR in the east with areas of MVFR CIGS persisting across
western new england. Increasing S winds this afternoon with
gusts to 20-25 kt developing after 21z.

Tonight... Moderate confidence.

Cigs lowering to MVFR with a band of sct showers and isold
t-storms moving west to east across sne 04-10z. Greatest
coverage across western new eng with activity weakening as it
moves east. S SW wind gusts to 20-30 kt, strongest near the
coast.

Saturday... High confidence.

Some lingering MVFR CIGS early CAPE islands, otherwiseVFR.

Gusty NW winds in the morning diminishing in the afternoon.

Kbos terminal... Moderate confidence in taf.

Kbdl terminal... Moderate confidence in taf.

Outlook Saturday night through Tuesday ...

Saturday night through Sunday:VFR.

Sunday night through Monday:VFR. Breezy.

Monday night:VFR. Breezy. Slight chance shra.

Tuesday: mainlyVFR, with local MVFR possible. Breezy.

Chance shra.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday ... High confidence.

Through tonight...

increasing S winds developing this afternoon and peaking
tonight as 45-50 kt low level jet develops. Given warm sst,
expect sufficient mixing to bring down some of this wind with
gale force gusts to 35-40 kt over eastern ma waters. Converted
gale watches to warnings for eastern ma waters with SCA for
south coastal waters and bos harbor. A few showers and perhaps
an isold t-storm is possible late tonight, after midnight.

Saturday...

w NW wind gusts to 25-30 kt in the morning diminishing rapidly
and becoming N NE in the afternoon as high pres builds over the
waters. Seas subsiding.

Outlook Saturday night through Tuesday ...

Saturday night through Sunday: winds less than 25 kt.

Sunday night: low risk for small craft advisory winds with
gusts up to 25 kt. Seas locally approaching 5 ft.

Monday: low risk for small craft advisory winds with gusts up
to 25 kt. Seas up to 5 ft.

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

Tuesday: moderate risk for small craft advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory from 8 pm this evening to 11 am edt
Saturday for anz232>235-237.

Small craft advisory from 5 pm this afternoon to 11 am edt
Saturday for anz230.

Gale warning from 8 pm this evening to 5 am edt Saturday for
anz231-251.

Small craft advisory from 8 pm this evening to 8 am edt
Saturday for anz236.

Gale warning from 8 pm this evening to 8 am edt Saturday for
anz250-254.

Small craft advisory from 8 pm this evening to 2 pm edt
Saturday for anz255-256.

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


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44090 16 mi41 min 67°F1 ft
44013 - BOSTON 16 NM East of Boston, MA 25 mi51 min SE 9.7 G 12 63°F 65°F5 ft1025.6 hPa (+0.8)51°F
44018 - SE Cape Cod 30NM East of Nantucket, MA 25 mi51 min ESE 7.8 G 9.7 63°F 5 ft1026.3 hPa (+0.5)48°F
WAXM3 - Waquoit Bay Reserve, MA 29 mi56 min Calm 59°F 1026 hPa53°F
BZBM3 - 8447930 - Woods Hole, MA 34 mi41 min 64°F 71°F1026 hPa (+0.9)
44029 - Buoy A0102 - Mass. Bay/Stellwagen 36 mi97 min SE 12 G 14 63°F 64°F5 ft1024.2 hPa
BHBM3 - 8443970 - Boston, MA 37 mi47 min 61°F 1026.4 hPa
44020 - NANTUCKET SOUND 38 mi31 min ESE 5.8 G 9.7 63°F 71°F1026.4 hPa52°F
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 39 mi41 min 63°F 1026.3 hPa (+0.7)
FRVM3 - 8447386 - Fall River, MA 39 mi47 min 62°F 71°F1026.7 hPa
FRXM3 40 mi41 min 63°F 51°F
CPTR1 - 8452944 - Conimicut Light, RI 47 mi41 min 62°F 71°F1026.4 hPa (+0.8)
PVDR1 47 mi41 min 62°F 1026.5 hPa (+0.9)56°F
FOXR1 - 8454000 - Providence, RI 48 mi47 min 61°F 69°F1025.9 hPa
BUZM3 - Buzzards Bay, MA 49 mi41 min ESE 7 G 8 63°F 1026.8 hPa (+0.9)
NAXR1 - Narragansett Bay Reserve, RI 49 mi56 min SE 2.9 63°F 1026 hPa56°F
PTCR1 - 8452951 - Potter Cove, Prudence Island, RI 49 mi47 min 63°F 1026.3 hPa

Wind History for Borden Flats Light at Fall River, MA
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NE14
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NE16
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S19
G25
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NW4
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N8
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NE1
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NE7
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G14

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Marshfield Airport, MA10 mi46 minSSE 310.00 miFair63°F51°F68%1026.4 hPa
Plymouth, Plymouth Municipal Airport, MA12 mi49 minN 010.00 miA Few Clouds59°F55°F87%1026.6 hPa
Provincetown Municipal Airport, MA18 mi45 minSE 310.00 miOvercast60°F54°F80%1026.7 hPa
Otis Air National Guard Base, MA24 mi46 minENE 410.00 miA Few Clouds59°F51°F77%1026.7 hPa

Wind History from PYM (wind in knots)
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Last 24hrNE9N11N9NE9NE11
G17
NE11NE10NE10NE8E8E6E6NE4N3E3CalmCalmCalmCalmCalmCalmCalmCalmCalm
1 day agoN15
G23
NE13NE12
G19
NE12
G18
NE12
G18
NE12NE12NE11
G17
NE11NE9
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NE9NE8NE10NE9NE14
G25
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NE11N7NE9
2 days ago--SW12
G20
S11
G23
SW13
G24
SW17
G26
SW12
G20
SW7CalmNW5N7NE4CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmE5NE4N9

Tide / Current Tables for Gurnet Point, 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 Cape Cod Canal, Massachusetts Current
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Tide / Current data from XTide NOT FOR NAVIGATION
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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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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Boston, MA (8,2,3,4)
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Ground Weather Radar Station Boston, MA
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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.