Friday, May26, 2017 L-36.com


Marine Weather and Tides
West Yarmouth, MA

Version 3.4
What's New / NOTES
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 5:10AMSunset 8:06PM Friday May 26, 2017 8:33 PM EDT (00:33 UTC) Moonrise 6:12AMMoonset 9:04PM Illumination 2% Phase: Waxing Crescent; Moon at 1 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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ANZ232 Nantucket Sound- 716 Pm Edt Fri May 26 2017
Tonight..NW winds 5 to 10 kt. Gusts up to 20 kt this evening. Seas 2 to 3 ft. Scattered showers this evening.
Sat..N winds 5 to 10 kt...becoming ne in the afternoon. Seas 2 to 3 ft.
Sat night..E winds around 5 kt. Seas around 2 ft.
Sun..E winds around 5 kt...becoming se in the afternoon. Seas 1 foot or less.
Sun night..SE winds 5 to 10 kt. Seas 1 foot or less.
Mon..SE winds 5 to 10 kt...increasing to 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas around 2 ft. A chance of showers.
Mon night..E winds 5 to 10 kt. Seas around 2 ft. A chance of showers. Vsby 1 to 3 nm.
Tue..SE winds around 5 kt. Seas around 2 ft. Patchy fog. A chance of showers. Vsby 1 to 3 nm.
Tue night..S winds 5 to 10 kt. Seas 1 foot or less. A chance of showers. Vsby 1 to 3 nm.
Wed..SW winds 5 to 10 kt with gusts up to 20 kt. Seas around 2 ft. A chance of showers.
Wed night..SW winds 5 to 10 kt with gusts up to 20 kt. Seas 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 716 Pm Edt Fri May 26 2017
Synopsis for massachusetts and rhode island coastal waters.. Low pres will continue to head ne toward nova scotia tonight and behind it high pres will build across the waters. Anticipate quiet weather for the weekend with another frontal system expected to move through Mon and 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 Yarmouth, MA
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location: 41.6, -70.27     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 262301
afdbox
area forecast discussion
national weather service taunton ma
701 pm edt Fri may 26 2017

Synopsis
Low pressure moves offshore tonight followed by weak high
pressure this weekend which will bring mild days and cool
nights. Low pressure in the great lakes generates a coastal low
late Monday that passes off nantucket on Tuesday. This will
bring wet weather on memorial day. Daytime clouds and scattered
showers will pop up each day Tuesday through Friday.

Near term until 6 am Saturday morning
7 pm update...

a few comma head showers moving south and southeast, but most
have moved off the south coast headed toward sea. The remaining
showers look light. Expect the remainder to move offshore early
tonight.

As noted earlier, still a lot of moisture lingering overhead
tonight, so expect quite a few clouds lingering overnight.

Otherwise, a dry night. No significant changes to the forecast.

Previous discussion...

comma head showers continue to rotate south into sne, focused
mainly across central W ma into ct ri within defined trowal
signature. These showers will decrease toward evening as the low
pulls away but a few showers will likely linger into the early
evening.

Flow gradually becomes anticyclonic tonight as weak high pres
builds in from the west so expecting a mainly dry night. Plenty
of clouds will persist given presence of low level moisture
which will limit temp drop. Mins will range from the upper 40s
to lower 50s.

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

weak high pres builds across the region but low level moisture
remains abundant below the inversion which indicates clouds will
dominate with bkn-ovc cloud cover. Mid level shortwave
approaches from the west by late in the day which will also
bring increasing mid level clouds and can't rule out a brief
shower toward evening across ct. Soundings show mixing to about
925 mb with highs mostly in the 60s with a few lower 70s
possible lower ct valley. Seabreezes expected in the afternoon
which may hold temps in the upper 50s along east coastal ma.

Saturday night...

a brief shower possible from ct to southern ri in the evening
as shortwave passes to the south, otherwise dry weather as weak
high pres remains in control. Mostly cloudy skies persisting.

Mins mid 40s to lower 50s.

Long term Sunday through Friday
Big picture...

longwave scale maintains a ridge west trough east pattern for much
of the long term period. Shortwave scale shows a closed low slowly
moving from canada across the great lakes, eventually reaching new
england late in the week. Two jets in place for much of the period.

The northern jet sweeps around the closed low from western canada
across the northeast usa. The southern jet swings from baja into the
southern plains and southeast usa. The two streams interact over
the ohio valley and mid atlantic early next week.

Model mass fields are similar through Tuesday... The GFS and ecmwf
are similar through Thursday. GFS and ECMWF moisture and thermal
fields are similar during the same period while showing differences
in detail. This brings increased confidence in the overall pattern
through much of next week, although lingering uncertainty regarding
timing of individual shortwaves in the flow.

Details...

Sunday...

high pressure is in control Sunday with subsidence and light wind
flow. Moisture fields show an area of higher rh below 800 mb and
suggests a cloud Sun mix with the fair weather. Temperatures in the
mixed layer are equiv to 5-8c, suggesting MAX temps upper 60s to mid
70s. Sea breezes along the coast will hold temps there in the 60s.

Fair skies linger early in the night, but the next approaching
shortwave supports increasing clouds... Expect this overnight. Dew
points will be roughly 45-50 which with light flow and initial fair
skies should allow temps to reach the lower 50s and possibly the mid
40s.

Monday-Tuesday...

interaction between the northern and southern streams leads to a 120-
knot jet over the ohio valley which races east ahead of northern
stream shortwave during Monday. This crosses the surface cold front
and generates a triple-point low as it crosses the mid atlantic
coast. This in turn spins up a weak southerly low level jet that
aims for SRN new england during the afternoon evening. Precipitable
water values reach 1.0-1.2 inches which is above normal but not
excessive.

Model consensus slows some slowing of the onset of measurable
pcpn in southern new england. The GFS holds off on measurable
until after 12z Monday while the ggem and ECMWF bring it to the
ct valley by 12z and possibly a little farther. We opted to slow
pcpn onset to a compromise time with chance pops to the ct
valley around 09z and to worcester and the ri hills 12z... Then
to most of eastern ma by 14z.

We will bring likely pops to the western sections for late
morning early afternoon and for eastern sections for the afternoon.

Stability parameters are somewhat favorable for convection, with
totals around 50 while surface LI values will be near zero. We will
include scattered to isolated tstms Monday afternoon evening.

The coastal low passes offshore Tuesday morning. Expect leftover
showers diminishing Tuesday morning, then expanding again as another
shortwave moves through.

Wednesday through Friday...

upper low slowly sweeps across eastern canada during the period,
with shortwaves moving through the flow across new england. Cold
pool advection aloft will destabilize the airmass and support
scattered daytime showers, especially in areas north of the mass
pike. Temperatures in the mixed layer will support MAX temps upper
60s to mid 70s each day. Fair skies and dew points in the 50s will
support mins in the 50s each night... Possibly cooling to mid 40s to
low 50s late in the week.

Aviation 23z Friday through Wednesday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday night ... Moderate confidence.

Tonight... Mostly MVFR CIGS linger in the east, but improve to
vfr in central and western new eng. Diminishing NW winds.

Saturday and Saturday night... Mix ofVFR MVFR cigs. Seabreezes
developing late morning into the afternoon. Low risk for a brief
shower late Sat sat evening south of the mass pike.

Kbos taf... Moderate confidence.

Kbdl taf... Moderate confidence.

Outlook Sunday through Wednesday ... Moderate confidence.

Sunday... VFR. Light south wind becoming onshore on the mass east
coast by midday.

Monday... VFR at first, lowering to MVFR in the afternoon and
ifr lifr at night. Southeast winds less than 20 knots. Rain showers
developing during the morning and midday, with potential scattered
tstms in the afternoon evening. Areas of fog at night.

Tuesday-Wednesday...

ifr Tuesday morning, improving toVFR Tuesday afternoon through
Wednesday. Scattered showers, mostly during the daytime. Light east
wind Tuesday becoming south in the afternoon, then west-southwest
Wednesday. Speeds less than 15 knots.Moderate confidence.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday night ... High confidence.

Tonight... Winds will diminish but southerly swell will maintain
5-7 ft seas over the south coastal waters with seas subsiding
below 5 ft over eastern waters. Will allow CAPE cod bay and
nantucket sound headlines to expire, but keep mass ipswich bay
headlines to continue to 10 pm.

Saturday... Winds becoming E SE with speeds below 15 kt. Seas
will subside below 5 ft over southern waters.

Saturday night... Quiet weather with light winds and seas below
sca.

Outlook Sunday through Wednesday ... Moderate confidence.

Winds less than 20 knots and seas less than 5 feet through the
period. Showers and isolated tstms Monday, showers and fog Monday
night and early Tuesday.

Tides coastal flooding
Still observing a 0.5 to 1 ft surge along both coasts which
estofs and etss guidance is underestimating. Surge expected to
diminish to around 0.2 to 0.5 ft at the time of high tide later
tonight as winds and swell diminish. High tides this evening are
quite high (boston 12.41 feet around 1230 am, providence 6.45
feet around 930 pm), even with minimal wave action, total water
level above 12.5 ft in boston typically produces very minor
inundation for the notorious low-lying locations (i.E, morrissey
boulevard in boston). In addition, minor inundation possible
along the south coast if surge still around 0.5 ft. We will
issue a coastal flood statement to address these concerns.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory until 10 am edt Saturday for anz235-237.

Small craft advisory until 6 am edt Saturday for anz250.

Small craft advisory until 10 pm edt this evening for anz251.

Small craft advisory until noon edt Saturday for anz254>256.

Synopsis... Wtb kjc
near term... Wtb kjc
short term... Kjc
long term... Wtb
aviation... Wtb kjc
marine... Wtb kjc
tides coastal flooding...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44020 - NANTUCKET SOUND 12 mi43 min 54°F1 ft1004.4 hPa (+2.7)
WAXM3 - Waquoit Bay Reserve, MA 14 mi108 min 1 56°F 55°F
44090 17 mi59 min 51°F3 ft
BZBM3 - 8447930 - Woods Hole, MA 22 mi45 min 57°F 57°F1004.3 hPa
NTKM3 - 8449130 - Nantucket Island, MA 24 mi45 min WSW 2.9 G 5.1 55°F 58°F1004.7 hPa
BUZM3 - Buzzards Bay, MA 43 mi33 min SW 9.9 G 9.9 55°F 1004.9 hPa (+1.6)
FRVM3 - 8447386 - Fall River, MA 48 mi45 min 58°F 57°F1004.8 hPa
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 48 mi45 min SW 2.9 G 4.1 58°F 1003.5 hPa
FRXM3 49 mi45 min 58°F 56°F

Wind History for Nantucket Island, MA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hyannis, Barnstable Municipal-Boardman Airport, MA6 mi37 minNNE 310.00 miOvercast54°F51°F90%1004.4 hPa
Otis Air National Guard Base, MA14 mi38 minno data4.00 miFog/Mist55°F55°F100%1005.1 hPa
Chatham, Chatham Municipal Airport, MA16 mi41 minNNE 310.00 miOvercast54°F52°F93%1004.9 hPa
Vineyard Haven, Marthas Vineyard Airport, MA23 mi40 minN 010.00 miOvercast57°F55°F93%1004.5 hPa

Wind History from HYA (wind in knots)
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Last 24hrCalmE3SE54S8S10
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CalmS6S7S6S7S11
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SW10SW11NW8NW10
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NW5W8W9W9NW6NE4NE3
1 day agoN5N5NE5CalmNE3NE4NE5NE5NE6E7E8NE8
G16
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2 days agoSW3SW4S5S3S4CalmCalmCalmCalmCalmCalmNE4N6E66
G14
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G17
E7E7N9NE4

Tide / Current Tables for Hyannis Port, Nantucket Sound, Massachusetts
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Hyannis Port
Click for Map
Fri -- 12:41 AM EDT     3.97 feet High Tide
Fri -- 05:12 AM EDT     Sunrise
Fri -- 06:12 AM EDT     Moonrise
Fri -- 06:46 AM EDT     -0.80 feet Low Tide
Fri -- 01:19 PM EDT     3.56 feet High Tide
Fri -- 07:01 PM EDT     -0.47 feet Low Tide
Fri -- 08:04 PM EDT     Sunset
Fri -- 09:03 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
3.83.93.52.61.50.3-0.6-0.8-0.30.51.42.33.13.53.42.91.90.8-0.1-0.5-0.10.71.72.6

Tide / Current Tables for Pollock Rip Channel, Massachusetts Current
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Pollock Rip Channel
Click for Map
Fri -- 12:35 AM EDT     -2.17 knots Max Ebb
Fri -- 03:45 AM EDT     0.00 knots Slack
Fri -- 05:11 AM EDT     Sunrise
Fri -- 06:11 AM EDT     Moonrise
Fri -- 07:05 AM EDT     2.41 knots Max Flood
Fri -- 10:26 AM EDT     -0.00 knots Slack
Fri -- 01:06 PM EDT     -2.07 knots Max Ebb
Fri -- 04:15 PM EDT     0.00 knots Slack
Fri -- 07:26 PM EDT     2.16 knots Max Flood
Fri -- 08:02 PM EDT     Sunset
Fri -- 09:02 PM EDT     Moonset
Fri -- 10:40 PM EDT     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-2.1-2.1-1.7-0.80.31.42.12.42.21.60.6-0.7-1.7-2.1-1.9-1.2-0.30.81.72.12.11.70.8-0.4

Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (20,4,5,8)
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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.