Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 260820 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 320 AM EST Sun Feb 26 2017 .SYNOPSIS... High pressure centered south of New England brings dry weather today and Monday. Cold air briefly visits for today, then milder air moves back in on Monday. A couple of weather systems will bring periods of wet weather Tuesday into Thursday. Colder air returns late next week. && .NEAR TERM /THROUGH TODAY/... Upper shortwave moves east of our area this morning. Colder drier air moves in on northwest winds. There is sufficient cold advection to support mixing up to 850 mb. Winds in this layer reach 30 knots, so expect gusts of 25-30 knots during the day. The mixing diminishes toward sunset, by which point winds will diminish. Dry air through most of the airmass today. Cross sections do show lingering moisture 850-900 mb, which should be enough to form some diurnal clouds. Expect partly to mostly sunny skies. Temperatures at 850 mb cool to -8C over the Southeast and -10C over northern and western MA. This supports max sfc temps in the upper 30s to mid 40s. With enough sunshine, mixing may extend a little higher than 850 mb and allow sfc temps to reach the upper 40s in some spots. && .SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/... Tonight...High Confidence. Surface ridge remains in place to our south. A shortwave moving across Canada pushes a weak cold front to the Canadian border and tightens the pressure gradient over New England, especially northern New England. The gradient over Southern New England will be lighter, and more conductive to radiational cooling. With dew points in the teens, min temps in the coldest spots will likely nudge into the teens, while the remaining areas will have mins in the 20s. Monday...High Confidence. High pressure remains to our south, with surface winds trending west-southwest. Diurnal heating will again create a mixed layer to around 850 mb. Winds in this layer reach 30 knots, and GFS suggests some potential for 35 knots just above the layer. Expect gusty WSW winds. Temperatures at 850 mb are forecast at -3C to -5C, which would support max sfc temps in the 50s. The WSW wind may keep temps a little cooler atMuch, if not all, of our snowpack has, or will have, melted. There is still much more snowpack upstream, over northern new England, that will push into the headwaters and head downstream. Some river levels could approach action stage. the south coast. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Highlights... * Above average temperatures for next week * Widespread showers possible Wednesday/Thursday * More seasonable conditions return Friday Overview... 25/12Z guidance remains in rather good agreement through this period. Mainly a nearly zonal flow aloft near New England, while a deeper mid level trough develops over the western USA. This would favor above normal temperatures, as well as a storm track to our north and west. Eventually, this mid level trough will move east, reacquainting our region to winter. Favored a consensus approach to smooth over the less predictable details. Timing the arrival of the aforementioned trough is not yet set in stone, and could change with later forecasts. Details... Tuesday...High confidence. High pressure continues to move east, as a second, more potent, shortwave arrives later in the day. Southwest flow aloft will help saturate the profile. Depending on when this occurs, we could see a few flakes north of the Pike early in the day. However, confidence remains low on any snow occurring. Will continue the forecast of clouds and showers. Wednesday into Thursday...Moderate confideMuch, if not all, of our snowpack has, or will have, melted. There is still much more snowpack upstream, over northern new England, that will push into the headwaters and head downstream. Some river levels could approach action stage.nce. Main weather producer for this portion of the forecast still anticipated to impact our region sometime between early Wednesday morning and Thursday afternoon. The low pressure should stay well to our north and west, so we`re looking at a more wet than white forecast. South to southwest winds will maintain temperatures well above average for late February. Moisture content with this system is above normal for this time of year. However, this system is progressive, so still not expecting a large amount of rain. Very strong low level jet may impact our region, if it comes farther north. Any heavy rainfall could produce strong gusts. Some weak instability, so thunderstorms are possible. Still a lot of details to work out, but a system to watch in the coming days. Friday and beyond...Moderate confidence. As the cold front with the mid week low pressure passes through our region, west to northwest winds take a hold across our region. Mainly dry weather with a return to more wintry temperatures. Can see a scenario where ocean-effect clouds and snow could develop, if temperatures get low enough. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Monday/...High confidMuch, if not all, of our snowpack has, or will have, melted. There is still much more snowpack upstream, over northern new England, that will push into the headwaters and head downstream. Some river levels could approach action stage.ence. Today... High Confidence. VFR through the period. Enough moistuMuch, if not all, of our snowpack has, or will have, melted. There is still much more snowpack upstream, over northern new England, that will push into the headwaters and head downstream. Some river levels could approach action stage.re at 4000-5000 feet to support scattered to broken cigs at that level. Winds up to this level will reach 30 to 35 knots, supporting surface gusts to those speeds during the day. Expect winds to diminish by late in the day. Tonight... High Confidence. VFR with diminishing wind. Trend to light winds in the interior overnight. Monday... High Confidence. VFR with WSW winds gusting to 30 knots. KBOS TAF...VFR. Gusty NW winds to 30 knots. High confidence in TAF. KBDL TAF...VFR. Gusty NW winds to 25 knots. High confidence in TAF. Outlook /Monday Night through Thursday/... Tuesday...Moderate confidence. Generally VFR, with MVFR conditions possible south of the Pike in showers. Wednesday into Thursday...Moderate confidence. MVFR to possible IFR in -SHRA/-RA. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Monday/...High confidence. Today...NW winds gusting 30-35 knots, slowly diminishing in the afternoon. Seas linger at 5 to 8 feet on the exposed waters most of the day. A Gale Warning is in effect for most of the waters, and we will maintain this. Small Craft Advisory in effect for Boston Harbor, Narragansett Bay, and Block Island Sound. Tonight... Diminishing winds turning West and possibly SW overnight. Gusts near 20 knots. Diminishing seas overnight with lingering 5 foot heights on the outer waters. Monday... WSW winds with gusts 25 to 30 knots. A Small Craft Advisory will be needed on at least some of the waters. Outlook /Monday Night through Thursday/... Tuesday...High confidence. Relatively quiet boating weather during the day. Seas build late Tuesday night Wednesday into Thursday...Moderate confidence. More widespread rainfall with lower vsbys possible. Increasing south to southwest winds with building seas. Small Craft Advisories likely, with a low risk for gale force gusts. && .HYDROLOGY... Rising water levels, partly from rain overnight but also from snowmelt in Northern New England. A couple of rivers in the CT River Valley rose above alert stage during the night, but crested below warning stage. Others crested below alert stage. There is still plenty of water moving downriver from the snowpack. We will need to monitor water levels across southern New England for a while this week. && .CLIMATE... RECORD HIGH TEMPS FOR YESTERDAY BOS 69 * breaks old record 65/1930 PVD 63 * no record BDL 70 * tied old record 70/1976 ORH 65 * breaks old record 64/1976 RECORD HIGH MIN TEMPS FOR YESTERDAY BOS 49 * breaks old record 46/1891 PVD 47 * breaks old record 45/1930 BDL 41 * no record ORH 40 * breaks old record 37/1996, 1984, 1976 DEW POINTS OF NOTE FOR YESTERDAY BOS Max Dew Point 56 is highest for date. Previous high 52/1985 PVD Max Dew Point 54 is highest for date. Previous high 51/1965 BDL Max Dew Point 58 is highest for date. Previous high 48/1984 ORH Max Dew Point 55 is highest for date. Previous high 47/1985 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Gale Warning until 11 AM EST this morning for ANZ231>235-251. Small Craft Advisory until 7 PM EST this evening for ANZ230- 236. Small Craft Advisory until 10 PM EST this evening for ANZ237. Gale Warning until 2 PM EST this afternoon for ANZ250-254>256. && $$ SYNOPSIS...WTB/Belk NEAR TERM...WTB/Belk SHORT TERM...WTB LONG TERM...Belk AVIATION...WTB/Belk MARINE...WTB/Belk HYDROLOGY... CLIMATE...

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