Monday, December11, 2017 L-36.com


Marine Weather and Tides
Watch Hill, RI

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 7:02AMSunset 4:19PM Monday December 11, 2017 4:25 AM EST (09:25 UTC) Moonrise 1:23AMMoonset 1:59PM Illumination 45% Phase: Third Quarter Moon; Moon at 23 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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ANZ237 Block Island Sound- 403 Am Est Mon Dec 11 2017
.small craft advisory in effect through this afternoon...
Today..W winds 5 to 10 kt with gusts up to 20 kt. Seas 3 to 5 ft. Scattered showers this morning.
Tonight..W winds around 5 kt, becoming S 10 to 15 kt after midnight. Seas 2 to 4 ft.
Tue..S winds 15 to 20 kt with gusts up to 30 kt. Seas 4 to 6 ft. Patchy fog. Rain. Vsby 1 nm or less.
Tue night..W winds 10 to 15 kt, increasing to 15 to 20 kt after midnight. Gusts up to 30 kt. Seas 5 to 7 ft. A chance of rain and snow showers. Vsby 1 to 3 nm.
Wed..W winds 20 to 25 kt with gusts up to 35 kt, increasing to 25 to 30 kt with gusts up to 45 kt in the afternoon. Seas 6 to 9 ft. A chance of snow showers. Vsby 1 to 3 nm.
Wed night..W winds 25 to 30 kt, diminishing to 20 to 25 kt after midnight. Gusts up to 45 kt. Seas 6 to 9 ft.
Thu..W winds 15 to 20 kt with gusts up to 30 kt. Seas 4 to 6 ft.
Thu night..NW winds 5 to 10 kt with gusts up to 20 kt. Seas 2 to 4 ft. A chance of snow. Vsby 1 to 3 nm.
Fri..NW winds 5 to 10 kt with gusts up to 20 kt. Seas 2 to 4 ft. A chance of snow. Vsby 1 to 3 nm.
Fri night..NW winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 4 ft. A chance of snow. Vsby 1 to 3 nm. 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 403 Am Est Mon Dec 11 2017
Synopsis for massachusetts and rhode island coastal waters.. High pressure will briefly build across the waters today. Low pressure will approach from the west tonight, moving offshore and becoming a potential gale Tuesday into Wednesday. Another low pressure system will approach the waters on Friday. 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 Watch Hill, RI
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location: 41.31, -71.86     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 110904
afdbox
area forecast discussion
national weather service taunton ma
404 am est Mon dec 11 2017

Synopsis
Mainly dry today after early showers or snow showers. A mixed
wintry precipitation event begins early tomorrow morning and
continues into tomorrow evening, with many areas changing to all
rain. A shot of arctic air follows Wednesday and Thursday with
a period of strong winds and bitterly cold wind chills. Another
low pressure system may bring more snow to the region sometime
in the Thursday night to Friday night timeframe, if it tracks
close enough to the coast. Somewhat milder weather will arrive
by the end of the upcoming weekend.

Near term until 6 pm this evening
Wv imagery suggests upper lvl wave is sliding through pa ny at
this time, and should push across new england during the mid
morning hours. Dwpts and soundings suggest a slight increase in
area moisture this morning, which has led to light echos on
radar falling out of a mid-upper deck of sc. Pops associated
with the frontal passage will be focused mainly across SE ma ri
and offshore, where moisture peaks and there is an every so
slight increase in lower lvl instability which would enhance
precip potential. Elsewhere, have highlighted a risk for
flurries or sprinkles based on sfc temps until the wave fully
clears the region. Any accums of either liquid or snow would be
light.

After the passage, sc clears as a weak ridge of high pres moves
through the area. In spite of an increase in lower lvl mixing,
the lingering snowpack will keep highs mainly in the mid and
upper 30s. Raw 2m temps were best in this case, so leaned most
heavily on these numbers.

Short term 6 pm this evening through 6 pm Tuesday
*** mixed wintry precip event late tonight into tomorrow ***
setup...

dual, unphased shortwaves will generate double barreled low
pres situation late Mon night into tue. The leading wave is
currently sliding from saskatchewan into the N plains, while the
secondary wave slides out of manitoba into N ontario. The fact
that these remain unphased, allows the initial parent low pres,
developing the great lakes to transfer energy to a secondary
warm frontal low pres which will slide across central new
england or along gulf of maine. In either case, developing 40+
kt h92 LLJ will push fully into S new england Tue morning,
allowing a nose of warm air between 975-900hpa. This allows the
+2c isotherm to reach near the nh ma border, using an average of
available guidance, with slightly cooler temps along the ma vt
border. Given this, precip onset within overrunning ahead of the
warm front should start as mainly sn, but then gradually give
way to liquid precipitation from SE to nw, with a low risk for
mainly sn especially extreme NW ma and into the berkshires.

Thermal profiles are tricky, with more on that below. Latest
trends are also slower as the unphased wave takes on a negative
tilt and low dwpt depressions take time to overcome tonight,
suggesting overall lower QPF than previous runs.

Thermal profiles...

while soundings mainly h85 and above remain below 0c, the nose
of warm air associated with the LLJ falls mainly in the lower
100hpa. Mean temps in this layer rise above 0c to about route
+2c between 12z and 15z tue. Given the dwpt depressions, wet-
bulbing would suggest light sn at precip onset, sfc temps are
likely to warm slower, thanks to a lingering snowpack. Areas
closest to coastlines could start as a frozen mix.. Not a
classic damming signature, but low lvl mass fields do show some
weak inverted ridging and mesoscale guidance does have light
drainage flow particularly in the ct valley and worcester hills.

In any case, this is a typical scenario where guidance warms
the sfc 2m temps too quickly. The transition to all liquid
should generally occur no later than mid day, except in the
higher terrain of NW ma, which could remain cool enough for
sn frozen precip.

Qpf snowfall ice...

as mentioned above, thanks to a dry column initially overnight,
timing of precip onset have slowed and the resulting overall
qpf is lower, totaling around 0.30-0.50 given this, there may
be less sn at onset with some areas starting as ra fzra. The
warm influence also favors lower ratio snows, therefore, have
lowered expected snowfall through. The fzra sn thinking with
this update is backed up by latest wpc day 2 data. Ice accums
would be light as the warm air should translate to the sfc
mainly a tenth or so at best, as sfc temps are not expected to
be marginal, and not in the 20s, in which ice accumulation is
more efficient. Snowfall totals are now lighter, with the best
chance for advisory lvl snowfall in the high terrain of NW ma,
where the low lvl warm air will be slowest to arrive, if it even
ever shifts above 0c. 3-6 inches is the latest forecast for nw
ma but with another set of guidance still to come, these are
still likely to change a bit.

Timing impact...

precip, likely mainly in the form of light snow, gradually
transitioning to a mix of fzra and ra begins mainly after 1am
from W to E during the early morning hours tue, with widespread
precipitation likely between 7am and 1pm, and continuing to
change form wintry precip to then gradually ending from s-n
mainly after 3pm through 7pm. The Tue am commute has the highest
risk for impact, as sn or even a wintry mix could impact
portions of the commute as the warm air build in aloft.

Untreated sfc could become slippery thanks to a light sn accums
and or light icing. By the afternoon commute, precip still
occurring, but mainly rain outside of the higher terrain of ma
particularly.

With all these factors, will hoist winter weather advisories
for portions of western and central massachusetts, where
confidence is highest in snowfall totals in the realm of
advisory levels, and the best chance for cold air damming
supporting some ice accumulations. These may need to be expanded
based on new data today.

Long term Tuesday night through Sunday
Highlights...

* low risk for a few brief snow squalls late Tue night wed
* arctic air Wed into Thu W strong winds and bitter cold wind chills
* period of snow possible sometime in the Thu night-fri night period
* milder weather by the end of the weekend
details...

Tuesday night through Thursday..

An arctic cold front will move across the region Tue night wed
accompanied with impressive shortwave energy. A few brief passing
snow showers are likely to impact the region with the arctic front.

The bigger question is do we see a few localized intense snow
squalls. The shortwave energy is pretty dynamic with some steep 1000
to 700 mb lapse rates. However, moisture is the wild card and it is
usually a limiting factor for this activity making it over the
berks. We do think there is at least a low risk for a couple.

The other issue will be a period of strong winds. Bufkit indicates
very deep mixing with steep lapse rates and an impressive 850 mb
westerly jet. This will bring the potential for westerly wind gusts
of 40 to 50 mph Wed into Wed night and wind headlines may eventually
be requited.

Lastly... Very cold air will be ushered into the region with highs
wed and Thu mainly in the 20s to around 30. Lows Wed night early
thu am should be well down into the teens with some single digit
readings possible across western ma. This should result in wind
chill values between 5 above and 5 below zero.

Thursday night into Friday night..

This portion of the forecast remains uncertain. Another piece of
shortwave energy swings down from the northwest and allows for an
areas of low pressure to develop over the ocean. The ensembles
differ considerably as to where this low develops. Some solutions
depicted are fairly close to our region, while others are further
south and east. This will determine if we see a period of snow
sometime in the Thursday night to Friday night time range or
precipitation remains out over the ocean. Will just have to wait
this one out and see how models trend over the next few days.

Saturday and Sunday...

the upper trough lifts out of our region allowing more west to
southwest flow aloft. If guidance stays the course most of the
weekend will feature mainly dry weather with moderating temperatures
by Sunday.

Aviation 09z 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 ...

through today... High confidence.

MainlyVFR except brief MVFR CIGS mainly across CAPE island
terminals this morning. Occasional very light shsn shra through
mid day. W winds gradually shift to the sw.

Tonight... Moderate confidence.

Vfr to start, will give way to MVFR then ifr early am Tue as
cigs lower and light sn fzra moves in mainly after 06z from w-e.

Sn accums would be light. Winds shift around to the e-ne.

Tomorrow... Moderate confidence.

Mixed MVFR and occasional ifr conditions in a mix of sn fzra
giving way to all ra through sunrise into mid day tue. Risk for
nw ma to remain sn long enough for accums to exceed reach 3-6
inches with generally less further se. Low risk also for a
period of fzra before the change to ra. Conditions improve after
20z from s-n.

Kbos terminal... High confidence in taf, lower categories don't
move in until after 06z tonight.

Kbdl terminal... High confidence in taf.

Outlook Tuesday night through Friday ...

Tuesday night: MVFR ifr conditions possible. Windy with local
gusts to 30 kt. Chance shsn, slight chance shra.

Wednesday: MVFR ifr conditions possible. Strong winds with
gusts to 45 kt. Chance shsn.

Wednesday night:VFR. Strong winds with gusts to 40 kt.

Thursday:VFR. Windy with areas gusts to 30 kt.

Thursday night: mainlyVFR, with areas ifr possible. Breezy.

Chance sn, slight chance shsn.

Friday: MVFR ifr conditions possible. Breezy. Chance sn.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Tuesday ...

today and tonight... High confidence.

Winds will continue to diminish through the day today, and seas
will also recede. Current small craft advisories will be able to
be dropped through the day, with mainly quiet boating weather
thereafter.

Tomorrow... Moderate confidence.

Winds gradually shift around to the e. Gusts 25-30 kt expected
on the S waters with 35-40 kt possible on the E waters. Gale
watches will be issued, with the need for small craft advisories
where gales are not observed. Otherwise, rainy conditions
expected on the waters.

Outlook Tuesday night through Friday ...

Tuesday night: moderate risk for small craft advisory winds
with gusts up to 30 kt. Rough seas up to 12 ft. Chance of rain
showers, chance of snow showers. Local visibility 1 to 3 nm.

Wednesday: moderate risk for gale force winds with gusts up to
45 kt. Rough seas up to 15 ft. Chance of snow showers.

Visibility 1 to 3 nm.

Wednesday night: moderate risk for gale force winds with gusts
up to 40 kt. Rough seas up to 16 ft. Local visibility 1 to
3 nm.

Thursday: moderate risk for small craft advisory winds with
gusts up to 30 kt. Rough seas up to 12 ft.

Thursday night: winds less than 25 kt. Areas of seas
approaching 5 ft. Chance of snow, slight chance of snow
showers. Visibility 1 to 3 nm.

Friday: winds less than 25 kt. Areas of seas approaching 5 ft.

Chance of snow, chance of rain. Visibility 1 to 3 nm.

Box watches warnings advisories
Ct... None.

Ma... Winter weather advisory from 4 am to 4 pm est Tuesday for
maz002>004-008>012-026.

Ri... None.

Marine... Small craft advisory until 1 pm est this afternoon for
anz231>234-250.

Small craft advisory until 6 pm est this evening for anz235-
237.

Gale watch from Tuesday morning through Tuesday evening for
anz250-251-254.

Small craft advisory until midnight est tonight for anz254>256.

Synopsis... Frank doody
near term... Doody
short term... Doody
long term... Frank
aviation... Frank doody
marine... Frank doody


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LDLC3 - New London Ledge CT - Ledge Light Weather 12 mi26 min WNW 14 G 18 36°F 1011.3 hPa (-0.5)22°F
NLNC3 - 8461490 - New London, CT 13 mi38 min W 5.1 G 7 35°F 52°F1014.4 hPa
MTKN6 - 8510560 - Montauk, NY 19 mi38 min 38°F 47°F1014.6 hPa
QPTR1 - 8454049 - Quonset Point, RI 31 mi44 min WSW 8.9 G 12 36°F 46°F1014.5 hPa
NWPR1 - 8452660 - Newport, RI 31 mi38 min W 7 G 12 36°F 46°F1014.2 hPa
PRUR1 36 mi38 min 36°F 21°F
NAXR1 - Narragansett Bay Reserve, RI 36 mi101 min W 5.1 35°F 995 hPa22°F
PTCR1 - 8452951 - Potter Cove, Prudence Island, RI 36 mi44 min W 6 G 8.9 35°F 1014.2 hPa
CPTR1 - 8452944 - Conimicut Light, RI 39 mi38 min SW 9.9 G 14 35°F 46°F1014.2 hPa
PVDR1 41 mi38 min WSW 6 G 8 35°F 1014.2 hPa22°F
FOXR1 - 8454000 - Providence, RI 42 mi38 min W 5.1 G 7 34°F 46°F1013.7 hPa
44039 - Central Long Island Sound 44 mi71 min W 19 G 25 39°F 4 ft
BUZM3 - Buzzards Bay, MA 44 mi26 min W 21 G 24 37°F 1014.6 hPa (-0.7)
44097 - Block Island, RI (154) 45 mi43 min 53°F8 ft
FRXM3 45 mi38 min 37°F 23°F
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 45 mi38 min WSW 14 G 17 37°F 1013.5 hPa
FRVM3 - 8447386 - Fall River, MA 46 mi44 min 36°F 46°F1014.7 hPa

Wind History for New London, CT
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Westerly, Westerly State Airport, RI4 mi33 minW 410.00 miOvercast36°F21°F55%1014.7 hPa
Groton / New London, Groton / New London Airport, CT10 mi30 minWNW 1010.00 miOvercast36°F19°F52%1014.4 hPa
Montauk, Montauk Airport, NY16 mi32 minW 10 G 18 mi39°F24°F55%1015 hPa

Wind History from WST (wind in knots)
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Last 24hrNW4NW4NW3NW34W66W4W5W7W8W7W4W55W4CalmW546W4W6W54
1 day agoN3N3N3N4N5N9N5N5N6N6N6N7N11N8
G15
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2 days agoW44W3CalmNW3NW3W3W34SW7W7W7W3CalmCalmCalmCalmCalmNE3CalmCalmCalmCalmCalm

Tide / Current Tables for Watch Hill Point, Rhode Island
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Watch Hill Point
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Mon -- 12:22 AM EST     Moonrise
Mon -- 02:45 AM EST     2.50 feet High Tide
Mon -- 07:03 AM EST     Sunrise
Mon -- 09:38 AM EST     0.20 feet Low Tide
Mon -- 12:59 PM EST     Moonset
Mon -- 03:10 PM EST     2.39 feet High Tide
Mon -- 04:18 PM EST     Sunset
Mon -- 10:01 PM EST     0.11 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.31.92.42.52.21.81.30.80.50.20.20.40.91.62.12.42.31.91.40.90.50.20.10.2

Tide / Current Tables for The Race, Long Island Sound, New York Current
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The Race
Click for Map
Mon -- 12:23 AM EST     Moonrise
Mon -- 02:30 AM EST     2.68 knots Max Flood
Mon -- 05:54 AM EST     -0.00 knots Slack
Mon -- 07:03 AM EST     Sunrise
Mon -- 08:52 AM EST     -2.92 knots Max Ebb
Mon -- 12:16 PM EST     0.01 knots Slack
Mon -- 01:00 PM EST     Moonset
Mon -- 03:06 PM EST     2.35 knots Max Flood
Mon -- 04:19 PM EST     Sunset
Mon -- 06:19 PM EST     -0.00 knots Slack
Mon -- 09:16 PM EST     -2.79 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.61.92.62.62.21.2-0.2-1.6-2.6-2.9-2.5-1.6-0.4122.32.21.60.4-1-2.2-2.8-2.6-1.9

Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
east_satellite

GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (4,6,7,8)
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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.