Saturday, May25, 2019 L-36.com


Marine Weather and Tides
West Chatham, 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 5:11AMSunset 8:04PM Saturday May 25, 2019 11:52 PM EDT (03:52 UTC) Moonrise 1:01AMMoonset 11:09AM Illumination 54% Phase: Third Quarter Moon; Moon at 22 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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ANZ254 Coastal Waters From Provincetown Ma To Chatham Ma To Nantucket Ma Out 20 Nm- 954 Pm Edt Sat May 25 2019
.small craft advisory in effect from 2 am edt Sunday through Sunday evening...
Overnight..SW winds 5 to 10 kt, becoming S 15 to 20 kt with gusts up to 25 kt. Seas 4 to 5 ft. Showers likely.
Sun..SW winds 15 to 20 kt, diminishing to 10 to 15 kt in the afternoon. Gusts up to 30 kt. Seas 5 to 6 ft. Showers likely in the morning with vsby 1 to 3 nm.
Sun night..W winds 10 to 15 kt with gusts up to 20 kt, becoming nw 5 to 10 kt after midnight. Seas 4 to 5 ft.
Mon..NE winds 5 to 10 kt. Seas around 4 ft.
Mon night..SE winds 5 to 10 kt, becoming N after midnight. Seas around 3 ft.
Tue..NE winds 5 to 10 kt, becoming se in the afternoon. Seas around 3 ft. A chance of showers.
Tue night..S winds 10 to 15 kt with gusts up to 20 kt. Seas around 4 ft. Showers.
Wed..S winds 10 to 15 kt with gusts up to 20 kt. Seas around 5 ft. A chance of showers in the morning.
Wed night..S winds 10 to 15 kt with gusts up to 20 kt. Seas around 4 ft. A chance of showers.
Thu..SW winds around 15 kt with gusts up to 20 kt. Seas 4 to 5 ft. A chance of showers.
Thu night..SW winds around 15 kt with gusts up to 25 kt. Seas around 5 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 954 Pm Edt Sat May 25 2019
Synopsis for massachusetts and rhode island coastal waters.. A weak warm front moves into the waters late tonight followed by a cold front Sun evening. High pres builds across on Mon, with another system approaching 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 West Chatham, MA
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location: 41.73, -69.97     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 260215
afdbox
area forecast discussion
national weather service boston norton ma
1015 pm edt Sat may 25 2019

Synopsis
High pressure moves offshore, allowing a warm front to slip
through southern new england. This will bring mild night to our
area, along with a few showers and chance of a thunderstorm.

Southern new england gets a taste of summertime heat on Sunday
along with isolated thunderstorms. A cold front moves through
and brings moderating temperatures, but still pleasantly warm
air. High pressure pushes off the coast early Tuesday. Low
pressure then moves through Tuesday bringing cooler temps and
rain, followed by periodic unsettled weather through Thursday
night. A cold front pushes offshore late next week, with drying
conditions and mild temperatures.

Near term until 6 am Sunday morning
1010 pm update...

isolated showers moving into western ma while weakening line of
convection moves east from central ny. This area will
overspread sne overnight as the low level jet brings a burst of
moisture advection and decreasing stability aloft. Isolated
t-storms possible as soundings indicate a saturated column and
conditional instability above the inversion leading to mucapes
200-400 j kg. It will be a mild night with lows ranging from mid
50s to near 60. Increasing SW winds overnight as the low level
jet moves overhead. Inversion will prevent strongest winds from
mixing down but should see a period of gusts to 25 mph.

Short term 6 am Sunday morning through Sunday night
Sunday...

showers exit during the morning as the warm front moves off to
the north east. Southern new england will be in the warm sector,
with dew points in the upper 50s and lower 60s. Mixing is
expected to reach 800 mb, with temps at that level supporting
max sfc temps in the low to mid 80s. Winds in the mixed layer
have a potential for 25-30 kt.

Stability parameters linger at near unstable levels but drier
air moves in at all levels above 750 mb. The dryness suggests it
will be difficult to generate convection, but the parameters
suggest it is not out of the question. We will mention slight
chance pops in eastern mass for showers tstms.

Sunday night...

west-northwest winds bring lower dew points move in behind the
cold front. Overall a dry night with temps falling back into the
50s.

Long term Monday through Saturday
Highlights...

* dry and mild conditions for memorial day
* low pressure bring showers and cooler temps Tuesday
* a front lingers across the region Wed and Thu with unsettled
conditions and warming temperatures
* rain ending Friday with dry and seasonable conditions toward
the weekend
overview...

progressive pattern in the extended forecast, with a persistent
subtropical ridge over the central southern u.S. Directing a
series of shortwaves through sne during the workweek. This will
lead to periodic shower thunderstorm chances with a bit of a
roller coaster of high temperatures, warmer Monday and even
moreso Thursday. By next weekend we see indications of a drier
regime with high pressure in the vicinity.

Details...

memorial day...

a cooler and drier post frontal airmass will be in place for
memorial day as high pressure builds in to the north.

Temperatures top out around 10 degrees cooler than Sunday,
in the mid 70s (near 80 for ct valley), while dewpoints in
the 40s and low 50s mean less humidity. The exception will
be along the immediate coast, where high pressure and light
winds will allow for light onshore flow, keeping temps in
the 60s.

Tuesday through Thursday...

showers return early Tuesday with cooler temperatures as a
surface low pressure system approaches and crosses the region
from the west. Still some uncertainty on the track and
magnitude of this system. The ec has consistently brought
a stronger ~1004mb low directly over sne while the GFS keeps
it weaker and further south. Given the associated greater
forcing at 925 in the ec solution, it paints a far wetter
picture as well. For now, sticking with a blend of synoptic
guidance brining rain on Tuesday. Instability, though, looks
poor, so not expecting thunderstorms. Either way flow remains
onshore Tuesday keeping high temps in the upper 50s and low
60s... Mid to upper 60s inland.

Rain clears out briefly early Wednesday before the next
system approaches Wednesday night into Thursday. This one with
several hundred j kg of CAPE so we could see some thunderstorms
overnight into early Thursday. A brief break in the rain
follows, early-mid day Thursday, before the approaching cold
front brings more widespread rain and potential for
thunderstorms to all of southern new england late Thursday into
early Friday.

Wednesday and Thursday we'll see increasing temperatures each
day as a warm front slowly makes its way north on southerly
flow, placing southern new england fully in the warm sector by
Thursday. This is associated with a surface low over the great
lakes moving into southeast canada. Cloudcover will limit solar
insolation Wednesday but temps manage to get into the 60s-70s.

Thursday is our warmest day of the week, with 850mb temps
approaching 16-18c, leading to surface highs in the 80s. Some
deterministic model runs continue to predict even hotter temps
Thursday, but for now keeping things in the low to mid 80s.

Glancing at the eps, only 1-2 of the 50+ members want to bring
90+ highs to pvd or bdl Thursday (even less for bos). This of
course depends on the timing of the approaching cold front which
if it were to speed up could limit our warming.

Friday and Saturday...

the cold front passes sometime around late Thursday night early
Friday morning, bringing showers to an end as pwats drop to
<0.5" and cooler NW winds return. Under large scale troughing
but generally zonal flow, things look to dry out as we head into
the weekend under high pressure. Seasonable temperatures are
expected, in the mid to upper 70s for most with increasingly
clear skies.

Aviation 02z Sunday through Thursday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Sunday night ...

tonight... Moderate confidence.

Vfr, at least for the first half of the night. Potential that
oncoming showers will lower CIGS vsbys to MVFR during the night.

In addition to showers, expect widely scattered thunderstorms.

Sunday... Moderate confidence.

Showers move offshore in the morning with partial clearing
taking place. Lingering instability hints at potential for
midday afternoon thunderstorms, but with the air drying out this
will be difficult to accomplish. We will expect isolated
shower t-storm in eastern ma. West winds gusting to 25 kt.

Sunday night... High confidence.

Vfr with clearing skies and diminishing wind.

Kbos terminal... Moderate confidence in timing of lower
conditions in showers tonight. Otherwise high confidence.

Kbdl terminal... Moderate confidence in timing of lower
conditions in showers tonight. Otherwise high confidence.

Outlook...

memorial day through Monday night:VFR.

Tuesday:VFR. Breezy. Chance shra.

Tuesday night: mainlyVFR, with local ifr possible. Breezy.

Chance shra.

Wednesday: mainlyVFR, with local ifr possible. Breezy. Chance
shra, isolated tsra.

Wednesday night: mainlyVFR, with local MVFR possible. Breezy.

Chance shra, isolated tsra.

Thursday:VFR. Breezy. Chance shra, isolated tsra.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Sunday night ... High confidence.

Tonight... Increasing SW winds as a low level jet moves across
the waters. Gusts to 25 kt possible after midnight with building
seas. A small craft advisory is being issued with this forecast.

Showers move through, mostly during the overnight, with reduced
vsbys.

Sunday... Low level jet exits SE waters early with diminishing
winds. Another pulse of west gusts to 20-25 kt may develop in
the afternoon over boston harbor and narragansett bay. Also some
concern for a second round of showers t-storms along the eastern
ma coast, but important conditions for shower growth are not
showing in our data. We will forecast isolates showers thunder
along the north shore and south shore waters.

Sunday night... Diminishing northwest wind and diminishing seas
as high pressure builds from the west.

Outlook...

memorial day: winds less than 25 kt. Seas locally approaching
5 ft.

Monday night: winds less than 25 kt.

Tuesday: winds less than 25 kt. Rain showers likely.

Tuesday night: winds less than 25 kt. Areas of seas approaching
5 ft. Rain showers likely.

Wednesday through Wednesday night: winds less than 25 kt. Areas
of seas approaching 5 ft. Chance of rain showers, isolated
thunderstorms.

Thursday: winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers, isolated thunderstorms.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory from 2 am to noon edt Sunday for
anz231>235-237.

Small craft advisory until 8 am edt Sunday for anz230.

Small craft advisory from 2 am to 5 pm edt Sunday for anz250.

Small craft advisory from 2 am to 10 pm edt Sunday for
anz254>256.

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


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44090 20 mi52 min 53°F1 ft
44020 - NANTUCKET SOUND 23 mi32 min SSW 14 G 16 56°F 56°F1019.1 hPa49°F
NTKM3 - 8449130 - Nantucket Island, MA 31 mi40 min SSW 4.1 G 8 55°F 60°F1019.9 hPa
WAXM3 - Waquoit Bay Reserve, MA 31 mi67 min WNW 2.9 59°F 1020 hPa50°F
44018 - SE Cape Cod 30NM East of Nantucket, MA 34 mi62 min SSW 12 G 14 55°F 4 ft1018.4 hPa (-0.8)45°F
BZBM3 - 8447930 - Woods Hole, MA 40 mi34 min 56°F 58°F1019 hPa

Wind History for Nantucket Island, MA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chatham, Chatham Municipal Airport, MA2 mi60 minSW 610.00 miMostly Cloudy57°F50°F78%1019.7 hPa
Hyannis, Barnstable Municipal-Boardman Airport, MA17 mi56 minSW 1410.00 miOvercast59°F45°F60%1018.5 hPa
Provincetown Municipal Airport, MA23 mi56 minSSW 1210.00 miMostly Cloudy56°F48°F75%1018.6 hPa

Wind History from CQX (wind in knots)
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Last 24hrN4N5CalmNW3NW3NW3CalmNW6NW6NW8N8NW955NE7653S74SW6SW4SW5SW6
1 day agoSW9
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2 days ago4SW4SW5SW4SW5SW6SW6SW5SW7SW8
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Tide / Current Tables for Pleasant Bay, Quonset Pont, Massachusetts
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Pleasant Bay
Click for Map
Sat -- 01:00 AM EDT     Moonrise
Sat -- 01:48 AM EDT     0.59 feet Low Tide
Sat -- 05:11 AM EDT     Sunrise
Sat -- 07:02 AM EDT     3.20 feet High Tide
Sat -- 11:09 AM EDT     Moonset
Sat -- 02:24 PM EDT     0.26 feet Low Tide
Sat -- 07:40 PM EDT     2.85 feet High Tide
Sat -- 08:02 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.10.70.60.91.52.22.93.232.52.11.71.20.70.30.30.71.42.22.72.82.62.21.9

Tide / Current Tables for Pollock Rip Channel, Massachusetts Current
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Pollock Rip Channel
Click for Map
Sat -- 01:00 AM EDT     Moonrise
Sat -- 02:55 AM EDT     -0.00 knots Slack
Sat -- 05:12 AM EDT     Sunrise
Sat -- 05:37 AM EDT     -1.52 knots Max Ebb
Sat -- 08:45 AM EDT     0.00 knots Slack
Sat -- 11:09 AM EDT     Moonset
Sat -- 12:26 PM EDT     1.92 knots Max Flood
Sat -- 03:36 PM EDT     -0.00 knots Slack
Sat -- 06:18 PM EDT     -1.48 knots Max Ebb
Sat -- 08:01 PM EDT     Sunset
Sat -- 09:29 PM EDT     0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.61.40.8-0.1-0.9-1.4-1.5-1.2-0.60.211.61.91.91.40.6-0.4-1.1-1.5-1.4-1-0.40.41.1

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 (23,6,7,8)
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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.