Saturday, December14, 2019
Privacy Policy
L-36.com


Marine Weather and Tides
Nantucket, MA

Version 3.4
NOTICE
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 6:58AMSunset 4:12PM Saturday December 14, 2019 9:45 PM EST (02:45 UTC) Moonrise 7:43PMMoonset 10:11AM Illumination 88% Phase: Waning Gibbous; Moon at 18 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
ANZ255 Coastal Waters Extending Out To 25 Nm South Of Marthas Vineyard And Nantucket- 904 Pm Est Sat Dec 14 2019
.gale warning in effect through late Sunday night...
Overnight..SW winds 20 to 25 kt, becoming W 25 to 30 kt. Gusts up to 40 kt. Seas 10 to 15 ft.
Sun..W winds 25 to 30 kt with gusts up to 45 kt. Seas 10 to 15 ft.
Sun night..W winds 25 to 30 kt, diminishing to 20 to 25 kt after midnight. Gusts up to 40 kt. Seas 9 to 12 ft.
Mon..W winds 15 to 20 kt with gusts up to 25 kt, diminishing to 10 to 15 kt in the afternoon. Seas 5 to 8 ft. A chance of rain.
Mon night..S winds 5 to 10 kt, becoming se after midnight. Seas 3 to 5 ft. Rain. Vsby 1 to 3 nm.
Tue..S winds 10 to 15 kt, becoming W 5 to 10 kt in the afternoon. Gusts up to 20 kt. Seas 5 to 8 ft. Rain.
Tue night..NW winds 10 to 15 kt with gusts up to 20 kt. Seas 6 to 9 ft. A chance of rain.
Wed..NW winds 15 to 20 kt with gusts up to 30 kt. Seas 5 to 8 ft.
Wed night..NW winds 25 to 30 kt with gusts up to 35 kt. Seas 7 to 10 ft.
Thu..NW winds 20 to 25 kt with gusts up to 35 kt. Seas 6 to 9 ft.
Thu night..NW winds 15 to 20 kt with gusts up to 25 kt. Seas 4 to 7 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 904 Pm Est Sat Dec 14 2019
Synopsis for massachusetts and rhode island coastal waters.. Strong low pres will lift north of new england overnight, tracking up into quebec by morning. Westerly gales tonight through Sun night. High pres builds briefly over the waters on Mon, then is followed by a storm system approaching from the southwest Mon night. This low will lift northeast over southern new england early Tue. Westerly gales possible Wed into Wed 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 Nantucket, MA
   Hourly   EDIT   Help
location: 41.27, -70.06     debug


Area Discussion for - Boston, MA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS61 KBOX 150235 AFDBOX

Area Forecast Discussion National Weather Service Boston/Norton MA 935 PM EST Sat Dec 14 2019

SYNOPSIS.

Low pressure will lift north of the region this evening followed by drier but windy conditions. Dry and blustery conditions will continue Sunday. A frontal system passing just south of Southern New England may spread a period of snow to wintry mix Monday night into Tuesday. A strong Arctic front then ushers in a period of scattered snow showers and much below normal temperatures by mid to late week. Gradual moderation by the weekend, through temperatures should remain at below normal levels.

NEAR TERM /UNTIL 6 AM SUNDAY MORNING/.

935 PM Update .

Rapidly intensifying low pressure has lifted in Quebec and allowed for increasing SW flow. This has resulted in even most of the interior mixing out their inversion with most locations currently in the 50s. The fog has also pretty much scoured out, except for a bit of fog across the Cape/Islands which should improve soon.

Otherwise, dry weather prevails for the remainder of the night except for a few rain/snow showers along the east slopes of the Berks. Winds should increase after midnight as lapse rates begin to steepen with colder air working into the region aloft. Expect SW wind gusts of 25 to 40 mph to develop overnight, except gusts between 45 and 50 mph across the Islands where lapse rates will be maximized with the flow over the ocean. Therefore, wind advisories go into effect for the Islands after midnight.

While it will turn cooler, it will remain well above freezing in most locations overnight. Low temps will only drop into the upper 30s to lower 40s by daybreak.

SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/. Sunday .

Strong west winds will be the main story as deep low pres lifts north across eastern Canada. Steep low level lapse rates will promote a deep and well mixed boundary layer with soundings supporting gusts 40-50 mph. Strongest gusts expected over the higher terrain and Islands. We expanded the wind advisory across much of MA along and north of the Pike as well as east coastal MA and Cape Cod. Otherwise, a mainly dry day with sunshine becoming mixed with clouds as some low level moisture is present. However, can't rule out a few lake effect snow showers spilling across the Berkshires. Most cloud cover will be in the interior. Highs will range from upper 30s to mid 40s.

Sunday night .

Still gusty into the evening with potential for 35-45 mph gusts but winds will gradually diminish through the overnight as gradient relaxes and high pres approaches from the west. Mainly clear skies with lows dropping into the upper teens to mid 20s.

LONG TERM /MONDAY THROUGH SATURDAY/. Highlights .

* Increasing confidence for plowable snow, and/or snow and icy roads, Monday overnight into Tuesday across interior MA/CT into RI. Impact to the Tuesday AM commute from snow and/or mixed precip. Accumulations to depend on thermal structure and p-type changes, details on both are still uncertain. * Scattered snow showers and possible snow squalls Wednesday afternoon into early evening ahead of Arctic cold front.

* Well below normal temperatures, with single digit to below-zero wind chills, for Wednesday night into Thursday.

* Gradual moderation, though just less below-normal temps by Friday into the weekend. Details .

After a brief shot of colder air Sunday night, temperatures start to moderate somewhat with warm advection into the first part of Monday. GFS and ECMWF ensemble means then show a lead shortwave trough moving out from the Plains states into the Northeast states late Monday into Tuesday. This lead feature, with some interaction from a stronger polar trough digging SE from the northern Canadian Prairies into the Great Lakes, will spread a surface low/frontal system from the OH Valley to Southern New England and look to spread a period of wintry wx for Monday night into Tuesday. The polar trough mentioned then becomes the primary feature, with a shot of modified-Arctic air overspreading a good part of New England to end the workweek. Though there's greater spread in the guidance beyond Friday, the shot of well below normal temperatures looks generally short, with moderating temperatures for the weekend.

Monday:

Chilly start, though gradual warming through much of the day amid weak high pressure, modest warm advection and daytime sun becoming increasingly filtered moving through the day. BUFKIT soundings still show considerable dry air below 800 mb across much of the region so looking for a dry forecast through sunset; but the dry air from low- levels to sfc is an indication that temperatures may cool to wet- bulb values once steadier precip gets going later Monday night.

Monday Night Through Tuesday Night:

** Confidence on Wintry Weather Increasing for Monday Night thru Tuesday **

Warm front will begin to lift across coastal RI into southern CT early Monday night, with precip spreading northward across most of Southern New England late Monday night and into Tuesday. This again looks to be a mixed precip event with multiple p-types/changes for parts of the area, with greatest period of impact appearing to be Monday overnight into the first part of Tuesday.

Biggest sources of uncertainty on forecast accumulations and impact are from thermal structure, potential for bands and event total QPF. Wet-bulb temps look cold enough off most models to fall as frozen precip at least initially. Eastern/SE MA into central/southern RI should eventually see temps warming to near/above freezing levels. Models also continue to vary on how quickly to advance a warm nose northward into the colder air, which would affect precipitation types and changeovers even in the interior. The past few runs of the GFS have extended its warm nose further north the soonest; so the GFS would offer a somewhat shorter period of snow and a quicker transition to mixed precip and/or rain by Tuesday afternoon. ECMWF remains the coldest, and would keep snow hanging on longest at least into western/central and northern MA, and more of a snow to mixed- precip scenario across northern CT into central/northern RI. Canadian GEM is something in between when it comes to thermal structure. GFS does indicate a ribbon of 850-700 mb frontogenetic forcing, on the nose of 850 mb southerly speed convergence, lifting from S to N overnight into early Tuesday morning that may force steadier/heavier periods of precip in that period of time. While models have trended somewhat wetter compared to morning runs, I do note that synoptic features in mid-levels aren't closed off, giving an impression of a generally progressive system with (at least at the moment) a relatively short accumulation period.

Ensemble probabilities of "plowable" snow (> 3 inches) are around 60- 70 percent across interior MA into northern CT/northern RI on the ECMWF ensemble; the more warmer GFS shifts this axis more into interior New England. Think this does convey the forecast uncertainty especially hinging on thermal structure and p-type transition zones.

In terms of accumulations, a first shot would be something in the 3- 5" range along the Route 2 corridor into NE MA away from the coast, amounts then may look like a 2-4" with a bit of freezing rain from the Mass Pike/I-95 southward through Bristol County MA into the Hartford/Providence corridor (with a transition from less snow and more PL/FZRA accretions further south one goes). Slushy C-2" and mainly cold rain along the E/SE MA coast into coastal S RI. Above initial scenario more closely follows the international guidance than the milder GFS. Uncertainties stated earlier may increase or decrease those totals, perhaps by a few inches. It is possible that some areas could see marginal warning-criteria accumulations towards northern MA though see this as being at least an Advisory event for the interior; given questions on p-types throwing a monkey wrench into accumulations, confidence wasn't high enough to hoist Watches.

Confidence is increasing on the overnight into the Tuesday AM commute being adversely impacted with snow and/or iced up roads, especially areas near/north of Route 6 in CT-RI and near/NW of I-95. Snow and/or sleet should be mixing in Tuesday across northern into central/west-central MA, with sleet/freezing rain transition zone trudging northward. Coastal MA/RI into part of SE MA may only see a shorter period of wintry weather before changing to a cold rain, with mild water temps resulting in warmer 2-m temps that may switch p-type from wintry to rain sooner. All areas change back to a brief bit of snow as surface low pulls away from the coast by Tuesday evening.

Wednesday:

Cold advection plunges in on NW winds on early Wednesday, as we await the strong northern stream trough and sharp Arctic cold front for the second part of the day into early evening. BUFKIT soundings show steep low-level lapse rates and shallow wintertime convective instability during the mid-aftn to early evening hrs with some shallow moisture. That could open the door for scattered snow showers or even some snow squalls with the frontal zone. Timing this front through will be critical and there exists the potential for low-visibility snow bursts/snow squalls during the Wednesday PM commute.

Wednesday Night into Thursday Night:

Core of the Arctic air plunges into Southern New England behind the Arctic front Wednesday evening. GFS/ECMWF differ on how cold low- level temperatures get, but there's multi-model signal for -15 to - 18C 850 mb air invading a large part of Southern New England Wednesday night. With lows in the single digits to low teens and winds 15-20 mph Wednesday night, likely looking at a period of sub- zero wind chills by early Thursday morning from the I-95 corridor, and wind chills around 0-5 above towards the E/SE Mass coast into southern RI.

Although Thursday looks dry as ridging builds into the region, it still looks quite chilly with highs only in the teens to low 20s and wind chills around 0-10 above. Winds slacken into Thursday night as high pressure centers itself over western New England, with good radiational cooling bringing single digit to mid teens lows.

Friday into the Weekend:

Does look like the period of well below normal temperatures is pretty short-lived. While still below normal, slow/gradual moderation in temperatures then looks to prevail Friday into Saturday. Compared to the -15 to -18C 850 mb temps from Wed nite into Thurs, these are around -3 to -6C by 12z Sunday. This part of the forecast is overall on the dry side, with the next chance for precip coming from a Clipper system by the end of the weekend.

AVIATION /03Z 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/ .

00z TAF Update:

Rest of tonight . High confidence in trends, moderate confidence on timing. Mist/fog should become less prevalent early, through IFR conditions due to low ceilings should continue until overnight. Gradual improvement in cigs to MVFR-VFR levels by morning. Winds to become SW/WSW with developing gusts 25-35 kts, nearing 40 kts towards eastern MA, the Cape and Islands by sunrise.

Sunday . High confidence. VFR with sct-bkn cigs 4-5k ft developing. West wind gusts 35-40 kt, with 40-45 kt possible over higher terrain and Cape/Islands.

Sunday night . High confidence. VFR. Gradually diminishing wind but reaming gusty.

KBOS Terminal . Moderate to high confidence in TAF.

KBDL Terminal . Moderate to high confidence in TAF.

Outlook /Monday through Thursday/ .

Monday: Mainly VFR, with local IFR possible. Breezy. Chance SN.

Monday Night: Mainly IFR, with areas MVFR possible. RA, PL, chance SN, FZRA.

Tuesday: Mainly IFR, with areas MVFR possible. Breezy. RA likely, FZRA, PL likely, chance SN.

Tuesday Night: Mainly VFR, with local IFR possible. Breezy. Slight chance SN.

Wednesday: Mainly VFR, with areas IFR possible. Windy with local gusts up to 35 kt. Slight chance SHSN.

Wednesday Night: VFR. Strong winds with areas of gusts up to 45 kt.

Thursday: VFR. Strong winds with local gusts up to 40 kt.

MARINE. Short Term /through Sunday Night/ .

Gale warnings in place for all waters tonight into Sunday evening. Expect increasing SW winds tonight with gusts 35-40 kt after midnight, and 40-45 kt west gusts over open waters on Sunday. Winds slowly diminish during Sunday night. Generally improving visibilities through sunrise Sunday.

Outlook /Monday through Thursday/ .

Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain, slight chance of snow.

Monday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Rain, snow likely, freezing rain. Local visibility 1 to 3 nm.

Tuesday: Winds less than 25 kt. Areas of rough seas. Rain.

Tuesday Night: Winds less than 25 kt. Rough seas up to 10 ft. Slight chance of rain, slight chance of snow. Local visibility 1 to 3 nm.

Wednesday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Slight chance of snow showers. Visibility 1 to 3 nm.

Wednesday Night: Moderate risk for gale force winds with gusts up to 35 kt. Rough seas up to 11 ft. Slight chance of snow showers. Local visibility 1 to 3 nm.

Thursday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 11 ft.

BOX WATCHES/WARNINGS/ADVISORIES. CT . None. MA . Wind Advisory from 1 AM to 9 PM EST Sunday for MAZ023-024. Wind Advisory from 7 AM to 7 PM EST Sunday for MAZ002>016-018- 019-021-022-026. RI . Wind Advisory from 1 AM to 9 PM EST Sunday for RIZ008. MARINE . Gale Warning until 1 AM EST Monday for ANZ231>234-251-255-256. Gale Warning from 1 AM to 10 PM EST Sunday for ANZ230. Gale Warning from 7 AM to 7 PM EST Sunday for ANZ236. Gale Warning until 11 PM EST Sunday for ANZ235-237. Gale Warning until 4 AM EST Monday for ANZ250-254.

SYNOPSIS . KJC/Loconto NEAR TERM . Frank SHORT TERM . KJC LONG TERM . Loconto AVIATION . KJC/Loconto MARINE . KJC/Loconto


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
NTKM3 - 8449130 - Nantucket Island, MA 2 mi46 min SSW 8 G 15 54°F 44°F990.5 hPa (-1.3)
44020 - NANTUCKET SOUND 19 mi56 min 21 G 27 50°F 3 ft49°F
WAXM3 - Waquoit Bay Reserve, MA 33 mi61 min S 8 990 hPa
BZBM3 - 8447930 - Woods Hole, MA 37 mi46 min 51°F 43°F989.9 hPa (-0.4)
44090 42 mi16 min 45°F3 ft

Wind History for Nantucket Island, MA
(wind in knots)    EDIT      (on/off)   Help
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
5
PM
6
PM
7
PM
8
PM
9
PM
Last
24hr
SE14
G18
SE12
G17
SE12
G22
SE14
G21
SE17
G24
E18
G26
E17
G23
SE14
G22
SE9
G19
S8
G15
S9
G17
SE9
G25
S17
G27
S13
G25
S10
G17
S10
G18
S8
G17
S7
G13
S11
G21
S10
G18
S10
G16
S12
G21
SW10
G21
SW8
G15
1 day
ago
--
--
--
S1
SE1
G4
S2
SE2
SE2
G5
SE6
G10
SE8
G14
SE12
G15
SE11
G20
SE12
G17
SE11
G18
SE11
G18
SE13
G18
SE12
G17
SE10
G15
SE9
G17
SE9
G16
SE13
G20
SE12
G20
SE11
G19
SE10
G17
2 days
ago
W9
G16
NW8
G18
NW12
G17
NW13
G22
NW13
G25
NW13
G21
NW9
G22
NW9
G22
NW11
G20
NW9
G19
NW12
G19
NW12
G18
N10
G18
NW11
G15
N10
G13
N9
G12
N7
G11
N6
G9
N5
N4
G7
N3
N3
--
--

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Nantucket, Nantucket Memorial Airport, MA1 mi53 minSSW 18 G 230.75 miFog/Mist and Breezy53°F51°F93%990.6 hPa

Link to 5 minute data for KACK

Wind History from ACK (wind in knots)
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
5
PM
6
PM
7
PM
8
PM
9
PM
Last 24hrE13
G23
E15SE14E16
G23
E18
G26
E20E23
G35
E22
G30
SE12SE13
G21
S14S16S22
G33
S24
G32
S17S15S12S11S18S15S15S15S21
G27
S18
G23
1 day agoNE3E4E4E5E6SE5SE7SE11SE13SE13SE18SE18
G25
SE16
G23
SE14SE13SE15SE12E11SE9E12SE16SE16
G23
SE14SE15
2 days agoW6NW9NW9NW18
G24
NW17
G24
NW20
G27
NW10
G23
NW15
G22
NW17
G25
NW18
G24
NW15NW16NW18
G25
N15
G21
N14N14N10N10N7CalmN3CalmN3N4

Tide / Current Tables for Nantucket, Nantucket Island, Nantucket Island, Massachusetts
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Tide / Current Tables for Nantucket Harbor Entrance Channel, Massachusetts Current
   EDIT      (on/off)   Help   One Week of Data
Nantucket Harbor Entrance Channel
Click for Map
Sat -- 12:06 AM EST     -0.00 knots Slack
Sat -- 05:26 AM EST     -1.28 knots Max Ebb
Sat -- 06:58 AM EST     Sunrise
Sat -- 07:36 AM EST     0.00 knots Slack
Sat -- 09:10 AM EST     Moonset
Sat -- 09:33 AM EST     1.26 knots Max Flood
Sat -- 11:56 AM EST     -0.00 knots Slack
Sat -- 04:11 PM EST     Sunset
Sat -- 05:40 PM EST     -1.25 knots Max Ebb
Sat -- 06:43 PM EST     Moonrise
Sat -- 07:50 PM EST     0.00 knots Slack
Sat -- 10:00 PM EST     1.53 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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
5
pm
6
pm
7
pm
8
pm
9
pm
10
pm
11
pm
0-0.3-0.5-0.6-0.9-1.2-1.2-0.60.41.11.20.6-0-0.5-0.7-0.8-0.9-1.2-1.2-0.80.21.11.51.2

Weather Map
       (on/off)   Help Weather Map
wmap_A
GEOS 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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Boston, MA (21,6,7,8)
      (on/off)   Help

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

Ad by Google

Cookie Policy:
This webiste uses cookies to save your settings. No personal information is saved. You can disable cookies in your browser if you like but it is not recommended for this site. I do not sell cookies. Go to a bakery for that. In fact I do not sell anything. To disable cookies from L-36.com, please refer to the Help button in your browser.
Privacy Policy:
I do not sell or share any user data or anything else for that matter. I do not keep site logs longer than I need to to keep bad actors off the site. Basically, I delete them after looking at them. If you are subject to CCPA, Google ads on this site will not be based on your past behavior so you will likely not see an ad for a lawn mower just because you looked for one at a big box website. I do not believe this site is subject to CCPA but I am doing what I can to follow the guidelines anyway.
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.