Area Forecast Discussion
Issued by NWS Boston, MA

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168 FXUS61 KBOX 180136 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 936 PM EDT Tue Oct 17 2017 .SYNOPSIS... High pressure will maintain dry weather and warmer than normal temperatures through the weekend. && .NEAR TERM /THROUGH WEDNESDAY/... 935 PM Update... Despite clear skies and light winds, temperatures have not been dropping as rapidly as guidance (including MOS) suggests, as both sources have been verifying too cold (temperature) and too dry (dewpoint). Low level SW flow and warming aloft seem to be preventing a free-fall. Adjusted hourly trends and overnight lows to reflect more of a consensus blend of high-res guidance, which is matching up much better. This means lows have been nudged upward into the upper 30s and lower 40s for most of SNE, with mid to upper 40s along immediate coast and in larger cities. As a result, threat of frost remains isolated at best so there is no need for any advisories. && .SHORT TERM /WEDNESDAY NIGHT/... Wednesday... With high pres to the south, W/SW flow will bring milder airmass into SNE. Airmass remains very dry through column so plenty of sunshine will push afternoon high temps into the upper 60s to lower 70s. Wednesday night... Another clear night with light winds, but airmass is moderating so not as cool with low temps mostly in the 40s. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Highlights... * Above average temps and dry conditions lasting into the weekend * Next shot for precip appears to be around Tuesday Pattern Overview/Confidence... 12z guidance is in good agreement for the long term. Upper level shortwave will move through the flow on Thursday. Behind this wave, anomalous ridging will develop across the East Coast. Heights and temperatures will rise to 2-3 STD above normal. This strong ridge will last into early next week before a pattern change appears to take hold of the area. This switch will be associated with the digging trough across the eastern half of the CONUS by the Tuesday timeframe. Details... Temperature Forecast... Overall trend in the forecast is for above average temperatures through the period. Thursday`s breezy southwest flow combined with 850 mb temps near 10-12C will result in highs in the low to mid 70s. Cool front will sweep through the region Thursday night leading to a cooler day on Friday. Anomalous ridge will begin to build for the weekend into Monday resulting in high temps into the mid 70s. Tuesday`s temperature forecast is a bit trickier as it is dependent on the timing of the front. Thus will trend towards a model consensus until guidance gets a better handling on the FROPA. Precipitation Forecast... Frontal system on Thursday will pass through, but lack of moisture with the front will lead a dry passage. High pressure will take over the area on Friday through Monday leading to dry weather. Next chance or precipitation will be around the Tuesday timeframe when a potent trough will dig into the Ohio Valley and towards the East Coast. Several waves of low pressure will ride along this through resulting in a more unsettled weather pattern Tuesday and beyond. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday Night/...High confidence. VFR through Wed night. Localized late night river valley fog possible. SW winds may gust to 20 kt over the outer Cape tonight. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Thursday through Sunday/... High Confidence. VFR. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday Night/...High confidence. Shortwave passing well to the north will bring a period of increasing W/SW winds tonight as high pres settles to the south. A few gusts to 25 kt possible across mainly eastern MA waters with building seas so will issue SCA for these waters. Gusts to 20 kt elsewhere. Winds diminish Wed through Wed night. Outlook /Thursday through Sunday/...High confidence. High pressure prevails through the upcoming weekend with sub SCA conditions. The only exception is that SCA conditions may be approached Thursday night ahead of a passing front as SW winds could gust up to 25 kts. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 11 AM EDT Wednesday for ANZ250-254. Small Craft Advisory until 7 AM EDT Wednesday for ANZ231-251. && $$ SYNOPSIS...KJC/Dunten NEAR TERM...JWD SHORT TERM...KJC LONG TERM...Dunten AVIATION...KJC/Dunten MARINE...KJC/Dunten is the U.S. government's official web portal to all federal, state and local government web resources and services.