Saturday, July22, 2017 L-36.com


Marine Weather and Tides
West Dennis, MA

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
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 5:25AMSunset 8:09PM Saturday July 22, 2017 4:40 PM EDT (20:40 UTC) Moonrise 4:32AMMoonset 7:30PM Illumination 1% Phase: Waning Crescent; Moon at 29 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
    EDIT      (on/off)   Help
ANZ232 Nantucket Sound- 359 Pm Edt Sat Jul 22 2017
Tonight..S winds 5 to 10 kt, diminishing to around 5 kt after midnight. Seas 1 foot or less.
Sun..NE winds 5 to 10 kt. Seas around 2 ft.
Sun night..E winds 5 to 10 kt. Gusts up to 20 kt after midnight. Seas 2 to 3 ft. A chance of showers.
Mon..E winds 5 to 10 kt with gusts up to 20 kt. Seas 2 to 3 ft. Showers likely.
Mon night..N winds 5 to 10 kt. Seas 2 to 3 ft. A chance of showers.
Tue..N winds 5 to 10 kt with gusts up to 20 kt. Seas 2 to 3 ft. A chance of showers.
Tue night..N winds 5 to 10 kt. Gusts up to 20 kt in the evening. Seas around 2 ft.
Wed..NE winds 5 to 10 kt. Seas 1 foot or less.
Wed night..S winds 5 to 10 kt. Seas 1 foot or less.
Thu..S winds 10 to 15 kt. Seas 1 foot or less. A chance of showers.
Thu night..SW winds 5 to 10 kt. Seas 1 foot or less. 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 359 Pm Edt Sat Jul 22 2017
Synopsis for massachusetts and rhode island coastal waters.. A frontal boundary will remain south of the waters tonight and Sunday, the coastal waters will be in between high pressure building from canada to northern new england and low pressure emerging off the mid- atlantic coast. The low will pass southeast of the waters Sunday night. Additional waves of low pressure will pass over the southern waters Monday...moving east of the region Tuesday. Strong high pressure will be centered over the waters Wednesday. 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 Dennis, MA
   Hourly   EDIT   Help
location: 41.67, -70.18     debug


Area Discussion for - Boston, MA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 kbox 222021
afdbox
area forecast discussion
national weather service taunton ma
421 pm edt Sat jul 22 2017

Synopsis
Showers and thunderstorms will pass to our south and west tonight,
with nothing more than a brief shower or two across the CAPE and
islands. It will be cooler across eastern new england Sunday, but
still warm in the connecticut valley. Cool, damp and unsettled
weather follows for Monday and Tuesday with improvement
Wednesday. Some showers and thundershowers possible again
Thursday and Friday.

Near term until 6 am Sunday morning
Southern new england will be in between a sprawling high pressure
over southeast canada and northernmost new england, and a low
pressure somewhere along the mid atlantic coast from nj to the
delmarva peninsula. This low pressure to our south will likely be
the remnants of a mesoscale convective system affecting that area
tonight. For us, winds will turn to a northeasterly direction. Skies
will be cloudy, and there is a chance of showers, mainly over
northern ct, ri, and southeast ma, closer to the low pressure. Lows
in the 60s.

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

low pressure will continue passing southeast of the region. It may
cause scattered showers, mainly along the south coast in the
morning. Then we should see a period of increasing sunshine
through mid afternoon. Light easterly wind flow will keep eastern ma
temperatures cool, in the low to mid 70s near the coast, but the
partial sunshine could allow the ct river valley to reach into the
80s. There is very little consensus on MAX temperatures for boston
tomorrow across the models. Given the easterly wind, it is likely
that boston will remain in the lower 70s for most of the day. The
gfs seems far too warm for the eastern coast, but could be correct
for the connecticut river valley where things will be able to heat
up a lot faster.

Sunday night...

skies will attempt to clear ahead of an approaching low pressure,
allowing for minimal radiational cooling. However, temperatures will
drop down into the low 60s, and even 50s in northern massachusetts.

Chances of showers increase again after midnight, mainly across
northern ct and western ma, ahead of advancing low pressure. The
main area of rain will likely not move into the region until
after 12z Monday. The NAM suggests that most of the area will remain
dry throughout the morning. However, guidance from the GFS and ecmwf
both agree on a late morning arrival. Opted to go more with the
gfs ECMWF timing, which was more in line with the previous forecast.

Areas of patchy fog are possible along the southern coast of new
england before midnight, and will likely persist and move northward
throughout the early morning hours.

Long term Monday through Saturday
Highlights...

* mon: below normal temps with some showers likely at times
* tue: a few leftover showers possible W below normal temps
* temps moderate mid to late next week but still below average
* another round of showers possible Thu thu night but not a washout
overview and model preferences...

synoptically there is little significant disagreement with the
mean jet remaining along the N conus, generally preventing
subtropical warmth moisture from reaching into new england
through the period. This suggests the continued thinking of
temperatures mainly at or below normal. Will be following this
trend with this update regardless of the preferred model
guidance. Initially weakening trof mon-tue will give way to
brief shortwave ridging as a second robust wave slides through
the mean jet from the pacnw later in the week. Therefore, an
unsettled start will give way to a brief dry period followed by
another short period of unsettled wx, pretty typical new england
summertime pattern when the mean jet rests this far s. Not
seeing significant enough differences in the overall pattern to
favor any one model. Therefore, will use a general consensus
blend for this update.

Details...

mon and tue...

early mon, will need to monitor the track of remnant
convection MCS which will moving ene from the oh valley into
ny pa. This convection looks to generate a weak cold pool low
pres which will slide near or just S of new england into early
tue. Given much of the initial convection will be driven by
mesoscale processes, confidence on how quickly any
precip storms associated will make it into new england. However,
with weakening shortwave moving in, the development of weak low
pres, as well as an increase in column moisture (pwats reach
1.25-1.50 inches), do expect to see on and off shra activity
much of Mon into early tue. E flow suggests sfc based convection
somewhat unlikely although as previous forecaster noted there
is modest instability aloft. Heights will be rising as the trof
weakens, which also may mitigate convective development.

Therefore, although unsettled, coverage will be showery with
breaks, with only a low risk for an isolated thunderstorm given
the mitigating factors. Otherwise, E flow and clouds will keep
highs mainly at or below normal, while overnight mins near
normal thanks to raised dwpts in the 60s.

Wed...

ridging will follow the exit of the weakened trof. As of now,
high pres associated with this ridging will have it's strongest
influence on wed, as it could give way enough to yield some
unsettled wx by thu. Subsidence and generally dry wx is
expected. Ridgeline is generally SW to NE oriented, suggest a
slight wedge of cooler air from the canadian maritimes.

Therefore in spite of more sunshine, highs will likely still
fall at or below normal.

Thu...

timing uncertainties for thu. As mentioned above, the weak
ridge and attendant sfc high pres will be sliding ene out of
the region, however the speed with which it does so will be
strongly dependent on how much deepening the approaching trof
undergoes. ECMWF is faster than the gfs, with ensembles on
either side. The faster solution would bring an afternoon cold
front through, with the possibility of showers and thunderstorms
while the slower solution favors a mainly dry forecast, keeping
the stronger forcing well upstream. Will feature some lower-end
pops for the possibility, but will need to monitor model shifts
temporally. Otherwise, a slight uptick in mid lvl temps, closer
to +13c or +14c at h85, suggest that with at least some sun
ahead of the approaching front, highs will reach near to
possibly even above normal in some spots.

Fri and sat...

cold front may linger fri, with the potential for
showers thundershowers remaining, however general consensus is
that it should be offshore by Fri night with a drier start to
next weekend. Temperatures near normal based on current forecast
mid lvl temp spread.

Aviation 20z Saturday 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 ... High confidence.

Tonight...

winds shifting to the northeast as high pressure builds to our north
and low pressure passes to our south. Winds gust to 20 kt,
especially from CAPE ann to mass bay and provincetown. Waves 1-3 ft.

Sunday...

northeast winds continue at 15-20 kts with seas building to 3-4 ft.

Small chance of showers along the CAPE and islands.

Sunday night...

northeast winds will turn due east late, with sustained winds at 10
kts. Winds will gust up to 20 kts across the waters. Waves 3-4 ft.

Kbos terminal...VFR. Sea-breezes forecast to move out around 00z
tonight.

Kbdl terminal...VFR.

Outlook Monday through Thursday ... Moderate confidence.

Mon into early tue... Moderate confidence.

Mix of ifr MVFR conditions in a mix of low CIGS occasional shra
and fog. E winds, gusting to 25 kt near shore but weaker
inland. Winds shift to the N early Tue and begin to subside.

Can't rule out a few breaks toVFR, especially inland, but lower
categories likely dominate.

Late Tue into wed... High confidence.

Improvement toVFR with drier weather to follow, weakened w-ne
winds.

Thu... Moderate confidence.

MainlyVFR. Afternoon showers thunderstorms possible. Winds s,
may gust to around 20 kt.

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.

Today... Light northwest winds allowing for daytime sea breezes.

Winds becoming south over the eastern ma waters this
afternoon evening. Seas 1-3 ft.

Tonight... Winds shifting to the northeast as high pressure
builds to our north and low pressure passes to our south. Winds
gust to 20 kt, especially from CAPE ann to mass bay and
provincetown. Chance of showers late. Local visibilities reduced
to 1-3 miles in fog late. Seas 1-3 ft.

Sunday... Northeast winds continue at 15-20 kt with seas building
to 3-4 ft. Chance of showers, especially south coast in the
morning.

Outlook Monday through Thursday ... Moderate confidence.

Mon and tue... Moderate confidence.

Low pres will be passing along the S waters late Mon into mon
night. Winds will shift from e, to NE then finally to N by tue.

Wind gusts during this time may gust to around 25 kt. Also, seas
mainly across the SE and E waters will reach about 5 ft as the
low pres passes. Therefore, small craft advisories may be
necessary. Showers and fog possible through the period.

Wed... High confidence.

Seas will subside, winds remain below 20 kt. Quiet boating
weather expected.

Thu... Moderate confidence.

S winds may gust to around 25 kt during the afternoon,
especially along the E coast. Small craft advisories may be
needed.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... None.

Synopsis... Belk doody correia
near term... Belk correia
short term... Belk correia
long term... Doody
aviation... Belk doody correia
marine... Belk doody correia


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44090 14 mi36 min 69°F1 ft
44020 - NANTUCKET SOUND 16 mi50 min 71°F1 ft1009.8 hPa (-1.0)
WAXM3 - Waquoit Bay Reserve, MA 19 mi55 min 1 78°F 1010 hPa66°F
NTKM3 - 8449130 - Nantucket Island, MA 27 mi40 min S 2.9 G 5.1 76°F 77°F1010.1 hPa (-1.2)
BZBM3 - 8447930 - Woods Hole, MA 28 mi40 min 77°F 74°F1009.9 hPa (-1.2)
BUZM3 - Buzzards Bay, MA 49 mi40 min S 2.9 G 2.9 74°F 1010.3 hPa (-1.3)

Wind History for Nantucket Island, MA
(wind in knots)    EDIT      (on/off)   Help
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
Last
24hr
SW6
G16
W9
G13
SW5
G13
SW6
G13
W6
G12
W5
G8
W6
G10
W7
G12
W6
G12
W7
G13
W5
G9
NW4
W4
SW5
W4
NW5
NW5
G8
N6
G9
N4
N4
E3
E3
SE4
S3
1 day
ago
SW10
G13
SW6
G11
SW6
G12
SW6
G11
SW6
G10
SW5
G10
SW5
G8
SW4
G9
W3
G6
SW4
W5
G8
W6
G10
W4
G8
W4
G7
W4
G9
NW8
G11
NW5
G11
W6
G9
NW7
G11
NW5
G8
SW7
G10
W6
G9
SW7
G10
SW7
G13
2 days
ago
SW11
G19
SW8
G13
SW7
G14
SW7
G11
SW6
G11
SW6
G12
SW5
G9
SW6
G15
W5
G9
SW5
G9
SW5
G10
SW6
W6
G10
W5
G8
W4
G7
W3
NW6
W4
SW5
G10
W8
G11
W7
G12
SW6
G12
SW6
G11

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hyannis, Barnstable Municipal-Boardman Airport, MA5 mi44 minSSE 510.00 miFair77°F66°F71%1009.6 hPa
Chatham, Chatham Municipal Airport, MA10 mi48 minSSW 310.00 miFair77°F66°F71%1010.4 hPa
Otis Air National Guard Base, MA18 mi45 minS 510.00 miFair77°F64°F65%1010.5 hPa
Provincetown Municipal Airport, MA24 mi44 minSSW 710.00 miFair80°F64°F58%1009.8 hPa

Wind History from HYA (wind in knots)
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
Last 24hrSW12SW8W16W11W6W6W5SW5W7W6W5NW7NW6NW3NW3NW6N8N7N5NW4S54S5S5
1 day agoSW14SW11SW10SW14SW13
G19
SW10SW8SW7CalmS4SW5W3W4W3NW7NW6NW6NW7NW5Calm6SW11SW10SW12
2 days agoSW12SW12
G20
SW14
G20
SW9SW12SW9SW9SW6W5W6W4W5CalmCalmCalmCalmNW4W3SE4SW6SW8SW12SW11SW13

Tide / Current Tables for South Yarmouth, Bass River, Nantucket Sound, Massachusetts
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
South Yarmouth
Click for Map
Sat -- 04:32 AM EDT     Moonrise
Sat -- 05:25 AM EDT     Sunrise
Sat -- 06:24 AM EDT     -0.49 feet Low Tide
Sat -- 12:38 PM EDT     3.09 feet High Tide
Sat -- 06:37 PM EDT     -0.23 feet Low Tide
Sat -- 07:29 PM EDT     Moonset
Sat -- 08:08 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
3.53.32.71.90.90.1-0.4-0.40.10.81.72.533.12.72.11.30.5-0.1-0.20.311.92.8

Tide / Current Tables for Pollock Rip Channel, Massachusetts Current
   EDIT      (on/off)   Help   One Week of Data
Pollock Rip Channel
Click for Map
Sat -- 02:21 AM EDT     0.00 knots Slack
Sat -- 04:31 AM EDT     Moonrise
Sat -- 05:25 AM EDT     Sunrise
Sat -- 05:54 AM EDT     2.22 knots Max Flood
Sat -- 09:06 AM EDT     -0.00 knots Slack
Sat -- 11:47 AM EDT     -1.77 knots Max Ebb
Sat -- 02:55 PM EDT     0.00 knots Slack
Sat -- 06:17 PM EDT     1.95 knots Max Flood
Sat -- 07:28 PM EDT     Moonset
Sat -- 08:07 PM EDT     Sunset
Sat -- 09:17 PM EDT     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-1.8-1.2-0.40.71.52.12.221.20.1-1-1.6-1.8-1.5-0.80.111.61.91.81.30.3-0.8-1.7

Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (16,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Boston, MA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.