Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 221354 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 954 AM EDT MON AUG 22 2016 .SYNOPSIS... High pressure will bring beautiful late summer weather today and Tuesday with low humidity. Warmer and more humid weather is expected Wednesday through Friday along with a low risk of showers and thunderstorms Thu night into Friday. Dry and less humid weather may return next weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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950 am update... Cold front and showers have moved offshore with drier air overspreading the region. OKX/ALY soundings are rather dry throughout the column and expect abundant sunshine through the afternoon. Becoming much less humid as dewpoints fall through the 50s with some 40s this afternoon as good mixing develops in cold advection pattern. Northwest winds will gust to 25 mph at times. High temps will range from the mid to upper 70s across the higher terrain, to the lower 80s on the coastal plain. Damage Survey This Morning... Earlier this morning, roughly between 3 and 4 am a localized area of significant tree damage/power outages occurred in the Marlborough and especially Concord MA areas. KBOS and TBOS radar showed a strong gate to gate couplet for a time, so some of this damage may have been tornadic. A damage team will be headed out to the region this morning.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Tonight... High pressure building in from the west will result in mainly clear skies and diminishing wind. Given the dry airmass behind this morning`s cold front, it will be an ideal setup for radiational cooling. Expect the normally coolest outlying locations to bottom out in the middle to upper 40s, while the urban heat island in Boston will be the warm spot only dropping to around 60. Tuesday... Another beautiful day for southern New England, but with less wind with high pressure in control. Mostly sunny skies will result in afternoon high temps in the upper 70s to the lower 80s, but with low humidity. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Highlights... * Warmer and more humid Wed thru Fri * Dry much of this week except a risk of T-storms Thu ngt/Fri * Dry and less humid weather may return next weekend Overview and model preferences... After a brief cool down Tue night the subtropical ridge builds northward up the eastern seaboard resulting in a warming trend and more humid conditions Wed through Friday. Good model agreement on next northern stream trough arriving around Fri. This trough will erode the northern edge of the subtropical ridge over the area resulting in lowering heights and a return to less humid weather and near seasonable temperatures next weekend. Details... Wed and Thu ... high pressure moving offshore with return flow yielding low level warm advection. This will result in highs warming into the mid and upper 80s...possibly touching 90 Thu with warmest readings away from the south coast given onshore winds. Humidity still comfortable Wed with dew pts in the 50s but rising into the 60s by Thu. Fri ... Good model agreement on next northern stream short wave traversing the region during this time...Thu night into Fri. Forcing for ascent appears weak along with marginal shear and instability. Thus for now at this time range slight chance and chance pops seems reasonable. It will be warm and humid ahead of the frontal passage. Saturday and Sunday ... Good agreement among the ensembles /both EPS and GEFS/ high pressure building into the northeast. Thus at least avg forecast confidence on this portion of the forecast. So trend here is for temps not as warm as Wed - Fri timeframe along with less humidity. && .AVIATION /14Z MONDAY THROUGH FRIDAY/...
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Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/... Today...High confidence. VFR conditions with northwest wind gusts of 20 to 25 knots. Tonight and Tuesday...High confidence. Winds diminish this evening and VFR conditions persist tonight and Tuesday. KBOS Terminal...High confidence in TAF. I KBDL Terminal...High confidence in TAF. Outlook /Tuesday Night through Friday/... High confidence in a stretch of mainly dry VFR weather. Sea breezes most likely mid-late week.
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&& .MARINE...
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Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Tuesday/... 950 am update... Expanded the SCA to include BOS harbor, Mass Bay and Narragansett Bay where nearshore gusts will be strongest. A few gusts to 25 kt likely. Today and tonight...High confidence. Near shore northwest wind gusts of 20 to perhaps close to 25 knots expected today. Opted to leave the near shore waters out of any headlines, but day shift will likely have to re-evaluate. We did hoist small craft headlines for our outer eastern MA waters, where northwest 25 knot wind gusts and 3 to 5 foot seas may develop for a time late this afternoon and evening. Tuesday...High confidence. High pressure building in from the west will keep winds and seas below small craft advisory thresholds along with excellent visibility. Outlook /Tuesday Night through Friday/...High confidence. Tuesday night through Thursday ... High confidence. Quiet boating weather as slow moving high pressure builds over the waters. By Thu SSW winds will likely become gusty near shore. Friday...Moderate confidence. Increasing SSW flow and seas, may just touch small craft criteria. Otherwise, late day risk of showers and thunderstorms over the waters.
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&& .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 2 PM this afternoon to 2 AM EDT Tuesday for ANZ250-254. Small Craft Advisory until 7 PM EDT this evening for ANZ230- 236-251.
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&& $$ SYNOPSIS...Frank/Doody NEAR TERM...KJC/Frank SHORT TERM...Frank LONG TERM...Nocera AVIATION...Frank/Nocera MARINE...KJC/Frank/Nocera

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