Area Forecast Discussion
Issued by NWS Boston, MA

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932 FXUS61 KBOX 261052 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 652 AM EDT Sun Mar 26 2017 .SYNOPSIS... A front will remain stalled to our south today, then push north as a warm front late tonight into Monday. Another low pressure will move across southern New England Tuesday, bringing some rain showers. High pressure brings dry but cooler weather Wednesday and Thursday. Then more precipitation possible late Friday into Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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700 AM Update... Overall trend in the forecast is on track this morning. Have increased POPs across the southwest due to the quicker nature of precip moving into CT. If this precip moves in even quicker than there is a better shot for wintry mix/precip. Feel that the current SPS is still good so will hold off on issuing anything. Still this is something to watch. Otherwise, on and off showers for today as warm front to the south slowly begins its northward advancement. Previous Discussion... High pressure shifts east into the Maritimes. Ageostrophic winds remain from the north during the day. It will take some time for a front to our south to get close enough to southern New England before precipitation will be a risk. By that time, temperatures should have risen enough to minimize the threat of freezing rain or sleet across much of our region. The greatest risk for freezing rain and sleet will be towards the eastern slopes of the Berkshires. Due to the spotty nature of the freezing rain coverage, and limited amount of sleet, will not have a advisory in effect this morning. Will issue a Special Weather Statement instead. Increasing clouds will slow temperature rises into this afternoon. Max temperatures likely will be near or slightly below those from Saturday.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... Tonight... The stronger low level south winds shift farther east Sunday evening and bring a greater potential for lift and precipitation production through the night, especially after midnight. Temperature profiles showing a strong warm nose aloft. North ageostropic winds continue near the ground, which will set the stage for freezing rain across the higher terrain of central and western MA. Some freezing rain possible across northernmost Connecticut. However, thinking coverage is too limited at this time to warrant an advisory. This could change with later forecasts. Monday... Warm front finally moves north into southern New England. This will end the threat of any freezing rain across our region. However, that will not end the possibility for rain as a low pressure moves through our region. this rain could be moderate to heavy at times. Temperatures should be near normal. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Highlights... * Showery weather ahead of approaching cold front on Tuesday * Cooler but dry weather for mid-week * Active weather returns late in the week into the weekend Pattern Overview... 00z models and ensembles show fairly good agreement on the maintenance of a longwave trough over the western states with flat flow to moderate mean riding prevailing downstream over the East. A separate northern stream progresses along either side of the Canadian border. Within this consensus mean pattern models and ensembles have been showing a lot of spread for some of the embedded features. This is noticed as early as the Day 3 forecast. Both the GFS and GEFS are more amplified compared to the rest of model suite. However still anticipate open wave interacts with the northern stream bringing a shot of precip on Tuesday. Upper level trough with surface high pressure for the mid-week as another upper level closed low diffuses towards the region late in the week. Details... Monday night into Tuesday...Low confidence. Weak ridging in the mid-levels will result in a break in the precip Monday night into Tuesday morning. Focus then turns to the next open wave and how it will interact with the northern stream. The GFS is more amplified compared to the progressive EC with the remaining guidance inbetween. Used a model blend for this portion of the forecast. First wave will move offshore and with weak ridging aloft, anticipate a drying trend in the forecast. Timing issues for the next shot of precip on Tuesday, but feel there is enough of a chance to keep pops in the forecast ahead of approaching cold front. Thermal ridge over southern New England may help increase temps near or above seasonable. In fact, depending on mixing and cloud cover, we could see temps warm into the 60s. Southerly flow will help increase low level moisture and with approaching front, could see iso thunder as guidance hints at elevated convection. Cold front will sweep through during the overnight hours ushering in dry air and northwest flow Tuesday night. Wednesday into Friday...High confidence. Trough overhead as upper level low deepens as it moves towards the Canadian Maritimes. This puts the region in northwest flow through the period resulting in dry but breezy conditions. There might be a few showers across the northeast on Wednesday in cyclonic flow. Despite cold advection, the environment should be well mixed, so max temperatures will be close to normal. Northwest flow continues on Thursday with an area of high pressure building in New England. Anticipate increasing sunshine and lighter winds. Dry and seasonable conditions should persist through Friday with high pressure in control. Friday night into the weekend...Low confidence. Split flow remains over the region with the next southern stream wave interacting with the northern stream. Large model spread for the Friday night into the weekend time frame leading to a low confidence forecast. The GFS suppresses the system well to our south, with a dry northern stream flow dominating. However, the ECMWF and CMC continues to indicate the low opening into a progressive trough and tracking across the region. Overall this portion of the forecast will depend on the strength and timing of the upper level wave and thus surface reflections. Because of the large spread in the guidance will continue with low confidence forecast. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/...
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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 Monday/...Moderate confidence. Today...Mainly VFR. Areas of MVFR cigs/vsbys in possible precipitation, especially in CT and western MA. Patchy freezing rain or sleet toward the Berkshires from late morning into this afternoon. Tonight...Conditions lower to MVFR, with IFR in the Central Hills and the Berkshires. Increasing chance of precipitation through the night from southwest to northeast. Increasing chance of sleet or freezing rain in areas north and west of Boston- Providence. Greatest risk for precipitation will be late at night, as the Monday morning push starts to gear up. Monday...Any leftover -FZRA/-PL in the morning will end across higher terrain by mid morning. Otherwise, MVFR-IFR CIGS in rain. KBOS TAF...High confidence in TAF trends. Moderate confidence in timing. KBDL TAF...High confidence in TAF trends. Moderate confidence in timing. Outlook /Monday Night through Thursday/... Monday night...Moderate confidence. Improving conditions to VFR. Tuesday...High confidence. MVFR conditions within any passing rain showers with improving cigs to VFR. Low risk for thunder. Wednesday into Thursday...High confidence. Gusty N/W winds Wednesday with VFR conditions into Thursday.
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&& .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Monday/... Today...High confidence. East winds less than 20 knots. Seas less than 5 feet. Tonight...High confidence. Approaching low pressure from the west will spread rain across the waters from west to east. Winds will remain below 20 knots and seas below 5 feet through the period. Monday...Moderate confidence. Warm front with weak low pressure along it may kick up southeast to south winds to near 25 kt gusts and seas could build to 5-6 ft over the outer waters. Small Craft Advisories are likely for some of the outer waters. Outlook /Monday Night through Thursday/... Tuesday...Moderate confidence. Frontal system will pass over the waters increasing them to above 5 feet. SCA may be needed. Wednesday into Thursday...High confidence. Gusty NW winds near Gales on Wednesday will help increase seas. SCA will be needed at the very least. High pressure nosing in on Thursday will slowly relax seas. && .BOX WATCHES/WARNINGS/ADVISORIES...
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CT...None. MA...Freezing Rain Advisory from midnight tonight to 8 AM EDT Monday for MAZ002>004-008-009-012-026. RI...None. MARINE...Small Craft Advisory from 5 PM this afternoon to 8 AM EDT Monday for ANZ256.
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&& $$ SYNOPSIS...Belk/Dunten NEAR TERM...Belk/Dunten SHORT TERM...Belk LONG TERM...Dunten AVIATION...Belk/Dunten MARINE...Belk/Dunten

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