Marine Weather and Tides
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
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.
|Sunrise 6:24AM||Sunset 5:31PM||Tuesday February 25, 2020 4:04 AM EST (09:04 UTC)||Moonrise 8:36AM||Moonset 8:24PM||Illumination 3%|
7 Day Forecast for Marine Location Near Siasconset, MAHourly EDIT Help
Area Discussion for - Boston, MA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS61 KBOX 250827 AFDBOX
Area Forecast Discussion National Weather Service Boston/Norton MA 327 AM EST Tue Feb 25 2020
SYNOPSIS. A weak cold front will drop south across the region today with a wind shift to northeast but it will be another mild day. Other than a period of light rain this morning over Nantucket, mainly dry conditions are expected today. The front will settle south of New England tonight and Wednesday with a moist northeast flow bringing patchy light rain and drizzle at times. A stronger frontal system Wednesday night into Thursday should produce a period of steady rain for most, with a potential for light accumulating wintry mix in the higher terrain of northwest Massachusetts. Turning colder and blustery late in the week into the weekend.
NEAR TERM /UNTIL 6 PM THIS EVENING/. Mid level shortwave passage this morning combined with deep moisture lifting north from the ocean will bring a period of rain to mainly Nantucket this morning. Hi-res and global guidance are indicating a few hours of rain here which may also briefly impact portions of the Cape. The rain which impacts Nantucket is developing off NJ coast and lifting NE. Otherwise, weak subsidence behind the shortwave and subtle drying in the column should result in a mainly dry day although can't rule of some light rain/drizzle late in the day south of the Mass Pike as moisture returns from the south and west. 925 mb temps remain mild today and with a bit of sunshine possible, highs should reach into the mid 50s away from the coast with some upper 50s possible, except cooler northern MA as weak cold front drops south across SNE with a wind shift to NE. This wind shift will result in temps falling through the 40s along east coastal MA during the afternoon.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/. Tonight .
Weak front sets up south of New Eng with a sfc wave tracking along the boundary to the south. Weak warm advection and deep moisture through the mid levels should bring some light rain/drizzle to the region, which may mix with some snow late tonight and Wed morning over the higher elevations in far northern MA where the column is marginally cold enough. Little or no accum is expected. Lows will range through the 30s with light NE winds.
Mid level trough amplifies from the Gt Lakes to the Ohio valley with downstream ridge building over New Eng. Mid level drying from the south moves up across SNE during the day. Low levels will be rather moist so low clouds expected with some patchy light rain/drizzle at times but most of the day should be mainly dry. Leading edge of steadier rain will be approaching from the west but should hold off until Wed night. Low clouds and NE wind will result in cooler temps with highs upper 30s to mid 40s.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/. Highlights .
* Strong frontal system may bring a period of light accumulating wintry wx to the higher terrain in the Berkshires Wed night into early Thurs. Mainly steady rains elsewhere with strengthening E winds.
* Cold frontal passage Thurs with falling temperatures and blustery W winds.
* Below-avg temps and cold wind chills late in the week into the weekend. Coldest conditions Sat and Sun.
Wednesday night and Thursday .
A quick hitting but potent rain system will bring gusty winds, widespread rain, and potential for high elevation snow/wintry mix late Wednesday night into early Thursday. A mid level trough over the Great Lakes becomes negatively tilted Wednesday night as its attendant sfc low moves up into eastern Canada and a secondary low forms along the frontal boundary. Out ahead of the digging trough a plume of subtropical moisture (PWATS >1") is pulled north over the region. This is coincident with warm frontal isentropic lift, diffluent flow at 500mb, a 50-60 kt LLJ, and placement beneath the left exit region of a strong upper jet. The combination of moisture and lift will bring widespread locally heavy rain to much of the region starting Wednesday night and ending sometime Thursday morning or early afternoon. Winds may be gusty as some of the strong LLJ has potential to be mixed down in heavy precip. How quickly the rain ends on Thursday will depend on timing the cold frontal passage and arrival of the mid level dry slot (sometime Thursday morning).
Thinking continues to be that most locations will remain warm enough for QPF to fall as rain (to the tune of 0.5 to 1"). However, the typically prone eastern slopes of the Berkshires will be the exception, likely changing to a wintry mix of snow, freezing rain, and/or sleet for a time. At this point, 60-72 hours out, there remains considerable uncertainty on the extent of the wintry precip based on how cold temperatures get in the low levels. The NAM continues to be the cold outlier, showing several inches of snow across northern MA while the GFS/EC has little to none outside of the northern Berkshires. Over the next 24 hours as we get into range of the hi-res guidance like the HREF and NAM-3k we'll have a better idea on chances for slick roads during the Thursday morning commute. Temperatures will have been so mild for many days, though, that impacts may be lessened when it comes to slick roads.
By Thursday afternoon the cold front swings through bringing in a colder and drier airmass. This pulls in colder air aloft, steepening lapse rates and mixing down some gusty winds. We're looking at wind gusts 20-30 mph, higher along the south coast. High temps will depend on how quickly the cold front arrives, but for now looking like we'll reach the upper 40s before temps plunge behind the front mid-late afternoon.
Friday through Monday .
This ushers in a pattern change bringing temps back down into the 30s for highs and teens/20s for lows. The cold pool aloft moves overhead Sat/Sun so these will be the coldest of the forecast. The upper trough lingers over the eastern seaboard through the weekend with moisture moving in and out of the column so expecting partly cloudy to mostly sunny skies, but no precipitation to speak of. By Monday temps should be on the rebound with continued dry weather under building high pressure.
AVIATION /09Z TUESDAY THROUGH SATURDAY/. Forecaster Confidence Levels .
Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.
Through 12z . VFR cigs, but MVFR/IFR cigs with a period of rain will overspread ACK 10-12z.
Today . Moderate confidence. IFR cigs ACK should improve to VFR by midday with rain exiting by 14z. Otherwise VFR cigs trending to MVFR south coast and Cape Cod toward evening. Light winds becoming NE
Tonight . Moderate confidence. Cigs becoming widespread MVFR with areas of IFR. Patchy light rain/drizzle and fog developing. Light NE winds.
Wednesday . Moderate confidence. MVFR/IFR cigs with patchy drizzle/fog at times. NE winds 5-15 kt.
KBOS Terminal . Moderate confidence in TAF.
KBDL Terminal . Moderate confidence in TAF.
Outlook /Wednesday Night through Saturday/ .
Wednesday Night: MVFR/IFR conditions possible. Windy with areas of gusts up to 30 kt. RA, patchy FG.
Thursday: Mainly VFR, with local IFR possible. Windy with gusts up to 35 kt. Chance RA, patchy FG.
Thursday Night: VFR. Windy with gusts up to 35 kt.
Friday through Friday Night: VFR. Breezy.
Saturday: Mainly VFR, with local MVFR possible. Breezy.
MARINE. Today . High confidence. Light SW winds turning NE across NE MA waters in the afternoon.
Tonight and Wednesday . High confidence. NE winds increasing to 10-20 kt late tonight into Wed with building seas. Gusts to 25 kt developing by late Wed.
Outlook /Wednesday Night through Saturday/ .
Wednesday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain, patchy fog.
Wednesday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 11 ft. Rain, patchy fog.
Thursday: Low risk for gale force winds with gusts up to 35 kt. Rough seas up to 12 ft. Chance of rain, patchy fog.
Thursday Night: Strong winds with gusts up to 35 kt. Rough seas up to 12 ft.
Friday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Local visibility 1 to 3 nm.
Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Areas of visibility 1 to 3 nm.
Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft.
BOX WATCHES/WARNINGS/ADVISORIES. CT . None. MA . None. RI . None. MARINE . Gale Watch from late Wednesday night through Thursday afternoon for ANZ250-254. Gale Watch from late Wednesday night through Thursday afternoon for ANZ251. Small Craft Advisory from 4 AM to 7 PM EST Wednesday for ANZ255-256.
SYNOPSIS . KJC NEAR TERM . KJC SHORT TERM . KJC LONG TERM . BW AVIATION . KJC/BW MARINE . KJC/BW
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|Nantucket, Nantucket Memorial Airport, MA||168 mi||71 min||SW 7||10.00 mi||Overcast||44°F||39°F||85%||1014.4 hPa|
Link to 5 minute data for KACK
Wind History from ACK (wind in knots)
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|2 days ago||W||W|
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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 (4,6,7,8)(on/off)  Help
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