Monday, January21, 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 7:00AMSunset 4:43PM Monday January 21, 2019 1:23 PM EST (18:23 UTC) Moonrise 6:25PMMoonset 8:23AM Illumination 99% Phase: Full Moon; Moon at 16 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- 116 Pm Est Mon Jan 21 2019
.gale warning in effect through Tuesday morning...
.heavy freezing spray warning in effect through late tonight...
This afternoon..W winds 25 to 30 kt with gusts up to 35 kt. Seas 7 to 10 ft. Freezing spray. Widespread snow showers. Vsby 1 nm or less.
Tonight..NW winds 25 to 30 kt with gusts up to 35 kt. Seas 8 to 13 ft. Freezing spray. Numerous snow showers. Vsby 1 to 3 nm.
Tue..NW winds 20 to 25 kt with gusts up to 35 kt. Seas 7 to 10 ft. Light freezing spray.
Tue night..NW winds 10 to 15 kt, becoming sw 5 to 10 kt after midnight. Gusts up to 20 kt. Seas 3 to 5 ft.
Wed..SW winds 15 to 20 kt with gusts up to 35 kt. Seas 3 to 5 ft. A chance of rain.
Wed night..SW winds 15 to 20 kt with gusts up to 30 kt. Seas 5 to 8 ft. Rain. Vsby 1 to 3 nm.
Thu..S winds 25 to 30 kt with gusts up to 45 kt. Seas 7 to 10 ft, except 10 to 15 ft S and E of nantucket. Rain. Vsby 1 to 3 nm.
Thu night..W winds 20 to 25 kt with gusts up to 40 kt. Seas 6 to 9 ft, except 9 to 14 ft S and E of nantucket. Rain likely. Vsby 1 to 3 nm.
Fri..W winds 15 to 20 kt with gusts up to 25 kt. Seas 5 to 8 ft.
Fri night..W winds 15 to 20 kt with gusts up to 25 kt. Seas 6 to 9 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 116 Pm Est Mon Jan 21 2019
Synopsis for massachusetts and rhode island coastal waters.. Arctic air will spread across the waters through tonight on gusty nw gales, resulting in widespread areas of freezing spray. High pres builds over the waters Tue, then moves off the mid- atlantic coast Wed. Low pres will move E across nrn new england Wed and Wed night, and be trailed by another low pres lifting ne over srn new england Thu. High pres follows for Fri and Fri night. 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 211545
afdbox
area forecast discussion
national weather service boston norton ma
1045 am est Mon jan 21 2019

Synopsis
Arctic air pours into our region today behind the departing storm,
bringing dangerously cold wind chills. Moderating temperatures
Tuesday into Wednesday, then another storm brings a soaking rain
late Wednesday through Thursday night. Return of cold and mainly dry
conditions Friday into this weekend.

Near term until 6 pm this evening
1030 am update...

mid level vortex over vt and western ma this morning circulating
an arctic airmass across the region with 10 am temps from about
5 above to 5 below zero. This frigid temps combined with nw
winds 15-25g35 mph yielding dangerously cold wind chills as cold
as -30 at worcester! Speaking of worcester, they tied a record
low temp this morning of -6f, previously set back in 1970.

So wind chill warnings and advisories will remain posted today
given core of arctic airmass continues to overspread the region
with 1000-500 thickness falling below 500 dam!
a mix of Sun and clouds this afternoon but also some
flurries very light snow showers at times given cyclonic flow
aloft from mid level vortex combined with some upslope flow from
nw winds streaming across the high terrain.

Ocean effect snow showers continue for the outer CAPE given the
nw trajectory. Will be reviewing new model guid to see if extent
of accumulations if wind turns more to the nnw increasing the
fetch of cold air across the relatively warm waters. Speaking of
fetch, you know it's an extremely cold airmass when you have
ocean effect snow showers at nantucket with an extremely short
fetch across the sound. Also coastal web cams capturing arctic
sea smoke from extreme evaporation saturating the layer
immediately above the ocean surface.

Short term 6 pm this evening through 6 pm Tuesday
Overnight and Tuesday mid level heights are on the rise as a
high pressure ridge builds into the northeast. This will relax
our pressure gradient and bring down the winds by Tuesday as the
surface low moves over head. Overnight, skies clear rapidly
from the west as dry air moves in and plenty of Sun is in store
for Tuesday. Don't let the sunshine fool you, though, since
we'll remain locked in a very cold pattern until Wednesday. Lows
Tuesday morning in the single digits to below zero will rebound
to the mid 20s by Tuesday. It's not warm but compared to the
single digit highs of Monday, plus the lack of wind, Tuesday
will feel practically balmy.

Long term Tuesday night through Sunday
* highlights...

- soaking rains late Wednesday through Thursday night
- return cold air Friday into the weekend
- watching a following early week storm system
* discussion...

21 00z guidance remains in rather good overall agreement through
Wednesday, then differences start to amplify through early next
week. Will prefer a consensus approach to this forecast to smooth
over the less predictable details through Wednesday, and to minimize
the timing and amplitude differences for the second half of this
forecast period.

In general, broad mid level ridge over the eastern usa shifts over
the north atlantic Wednesday, while a trough dominates much of the
central usa. This configuration should result in a potent SW flow.

This will not only track a low pressure our way toward mid week, but
also raise temperatures where mainly rainfall is expected. Decent
signal for low level temperatures to be about 1 standard deviation
above normal. Also looking like another moisture-rich system, with
precipitable water values about 3 standard deviations above normal.

Have high confidence in a period of wet weather sometime Wednesday
into Thursday. Depending upon timing, looking like snow to start
with a transition to all rain by late Wednesday afternoon. Small
risk for precipitation to end as snow towards NW ma Thursday
afternoon.

Once this low pressure departs our region, we should have another
period of very cold weather heading into this weekend. This could
set the stage for another winter storm early next week. Still lots
of moving parts with that storm, so not much confidence in the
details at this time.

Aviation 15z Monday through Friday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Tuesday ... High confidence
1030 am update...

mainlyVFR but occasionally marginal MVFR in scattered
flurries snow showers. Also MVFR just offshore including cape
cod and islands with scattered snow showers. Previous discussion
below.

=================================================================
today...

mainlyVFR cigs, but areas of MVFR across eastern ma
and CAPE islands. Sct flurries or snow showers possible. Nw
gusts to 30 to 35 kt with isolated 40 kts across SE coastal
terminals.

Tonight and Tuesday...VFR.

Kbos terminal... High confidence in taf.

Kbdl terminal... High confidence in taf
outlook Tuesday night through Friday ...

Tuesday night:VFR. Breezy.

Wednesday: mainlyVFR, with local ifr possible. Windy with local
gusts to 30 kt. Ra or fzra, with a chance of sn or pl.

Wednesday night: mainlyVFR, with areas ifr possible. Windy
with gusts to 30 kt. Ra or fzra.

Thursday: mainlyVFR, with local ifr possible. Strong winds
with areas gusts to 40 kt. Chance ra.

Thursday night:VFR. Windy with gusts to 35 kt. Slight chance
ra.

Friday:VFR. Breezy.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Tuesday ...

1030 am update...

expanded heavy freezing spray for all eastern ma waters.

Otherwise no changes. Previous discussion below.

===========================================================
nw gales persist through today in the strong cold advection.

With the arctic air pouring into the region and rough seas,
widespread moderate freezing spray will develop on all open
waters, with pockets heavy freezing spray.

Tuesday NW winds come down through the day, gusting 20-25 kts by
early afternoon. Seas start 5-7 ft with 9-11 ft on the outer
waters. By evening 2-4 ft for coastal waters and 5-8 ft outer.

Outlook Tuesday night through Friday ...

Tuesday night: winds less than 25 kt. Seas locally approaching
5 ft.

Wednesday: moderate risk for small craft advisory winds with
areas of gusts up to 30 kt. Areas of rough seas. Chance of
rain.

Wednesday night: low risk for gale force winds with gusts up to
30 kt. Areas of rough seas. Rain.

Thursday: moderate risk for gale force winds with gusts up to
40 kt. Rough seas up to 14 ft. Rain.

Thursday night: low risk for gale force winds with gusts up to
40 kt. Rough seas up to 13 ft. Chance of rain.

Friday: moderate risk for small craft advisory winds with gusts
up to 25 kt. Rough seas up to 11 ft.

Tides coastal flooding
1030 am update...

still running about a 0.3 ft surge in response to leftover
easterly swells precluding water from draining seaward. Given
high astro tide of 11.9 ft at boston total water levels will top
off just over 12 ft. So most prone areas will see very minor
water inundation along the eastern ma coastline. Previous
discussion below.

==================================================================
Monday morning astronomical high tides are a
few tenths higher along the east coast. While both seas and
surge will have subsided, there is a lingering easterly swell
and wave action offshore to lead to an additional 0.1-0.3 foot
surge.

With an astronomical tide around 11.9 at boston at 11am, there is
the risk for some spotty minor coastal flooding. Overall, the
flooding risk is lower, and will likely be limited to the typically
prone locations.

A coastal flood statement has been issued.

Box watches warnings advisories
Ct... Wind chill advisory until 8 am est Tuesday for ctz002>004.

Ma... Wind chill advisory until 8 am est Tuesday for maz005>007-
010>021.

Wind chill warning until 5 am est Tuesday for maz002-008-009.

Wind chill warning until 8 am est Tuesday for maz003-004-026.

Ri... Wind chill advisory until 8 am est Tuesday for riz001>007.

Marine... Heavy freezing spray warning until 6 am est Tuesday for anz231-
232-250-251-254.

Gale warning until 7 am est Tuesday for anz232>234.

Freezing spray advisory until 11 am est Tuesday for anz233>235-
237-255-256.

Gale warning until 9 pm est this evening for anz230.

Gale warning until 6 am est Tuesday for anz231-251.

Gale warning until 10 pm est this evening for anz236.

Gale warning until 5 am est Tuesday for anz235-237.

Gale warning until 10 am est Tuesday for anz250-254>256.

Synopsis... Belk sipprell bw
near term... Belk nocera bw
short term... Bw
long term... Belk
aviation... Belk nocera bw
marine... Belk nocera bw
tides coastal flooding... Nocera


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44020 - NANTUCKET SOUND 23 mi33 min WNW 18 G 25 8°F 35°F2 ft1008.3 hPa-0°F
NTKM3 - 8449130 - Nantucket Island, MA 31 mi35 min WNW 8.9 G 17 8°F 36°F1008.6 hPa
WAXM3 - Waquoit Bay Reserve, MA 31 mi98 min W 7 8°F 1009 hPa-5°F
44018 - SE Cape Cod 30NM East of Nantucket, MA 34 mi33 min W 23 G 31 8°F 7 ft1006.7 hPa (+0.6)4°F
BZBM3 - 8447930 - Woods Hole, MA 40 mi35 min 35°F1008.8 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 mi31 minW 10 G 198.00 miOvercast9°F0°F%1008.2 hPa
Hyannis, Barnstable Municipal-Boardman Airport, MA17 mi27 minW 12 G 1710.00 miPartly Cloudy9°F-6°F50%1007.6 hPa
Provincetown Municipal Airport, MA23 mi27 minW 17 G 270.75 miLight Snow Fog/Mist7°F3°F84%1007.4 hPa

Wind History from CQX (wind in knots)
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1 day agoNE10NE10E9E10E11E14E9
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2 days agoE4CalmCalmCalmCalmCalmW3CalmSW3W3CalmCalmCalmCalmCalmCalmN4N333NE9NE7NE7NE10

Tide / Current Tables for Pleasant Bay, Quonset Pont, Massachusetts
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Pleasant Bay
Click for Map
Mon -- 12:17 AM EST     Full Moon
Mon -- 01:14 AM EST     3.37 feet High Tide
Mon -- 07:01 AM EST     Sunrise
Mon -- 07:22 AM EST     Moonset
Mon -- 07:56 AM EST     -0.14 feet Low Tide
Mon -- 01:30 PM EST     4.04 feet High Tide
Mon -- 04:41 PM EST     Sunset
Mon -- 05:25 PM EST     Moonrise
Mon -- 08:35 PM EST     -0.65 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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2.93.43.22.721.40.70.1-0.10.21.12.23.33.943.42.61.80.90.1-0.5-0.6-00.9

Tide / Current Tables for Pollock Rip Channel, Massachusetts Current
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Pollock Rip Channel
Click for Map
Mon -- 12:17 AM EST     Full Moon
Mon -- 02:41 AM EST     0.00 knots Slack
Mon -- 05:54 AM EST     1.94 knots Max Flood
Mon -- 07:01 AM EST     Sunrise
Mon -- 07:22 AM EST     Moonset
Mon -- 09:01 AM EST     -0.00 knots Slack
Mon -- 11:48 AM EST     -2.05 knots Max Ebb
Mon -- 02:57 PM EST     0.00 knots Slack
Mon -- 04:41 PM EST     Sunset
Mon -- 05:26 PM EST     Moonrise
Mon -- 06:24 PM EST     2.37 knots Max Flood
Mon -- 09:44 PM EST     -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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-1.8-1.4-0.60.31.21.81.91.71.10-1.1-1.9-2-1.7-101.11.92.32.31.80.9-0.3-1.4

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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Wind Forecast for Boston, MA (13,3,4,5)
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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.