Area Forecast Discussion
Issued by NWS Boston, MA

Current Version |  Previous Version |  Graphics & Text |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
236 FXUS61 KBOX 090453 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1153 PM EST Fri Nov 8 2024 .SYNOPSIS... A dry cold front will usher in a chilly and blustery airmass tonight into Saturday. High pressure then quickly follows Saturday night, before moving east of the region Sunday. Low pressure system brings light rain Sunday evening and wrapping up during the overnight. Low chance for shower early morning of Veterans Day, otherwise dry conditions into mid week. && .NEAR TERM /THROUGH SATURDAY/... 10PM Update: Only change to the forecast was to add slight chance pops across southern CT, RI, and MA as showers associated with the cold front are reaching the ground. These showers are however very light and will likely not add up to more then a trace of QPF. Previous discussion: A dry cold front will cross southern New England and move offshore by late this evening. Besides the wind shift to the northwest, this is when the colder air will start to arrive. Despite the clear skies, not expecting much radiational cooling. The cold advection will be strong enough to maintain gusty winds all night. Below normal low temperatures, mainly in the 30s away from the immediate coast. && .SHORT TERM /SATURDAY NIGHT/... High pressure arrives from the west during the day Saturday, then offshore Saturday night. Gusty northwest winds expected to continue through the morning hours, then diminishing into afternoon hours. Dry weather and below normal temperatures continue through Saturday night. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Highlights: * Dry for much of Sunday, but a low pressure system moving across northern New England will bring light rain during the evening and overnight hours. * Drying trend for Veterans Day through mid-week. Mild temperatures Monday afternoon, but a cold front on Tuesday will bring a change in airmass and cooling trend for the rest of the week. * Signs for unsettled conditions towards the end of next week, but there remains a lot of uncertainty. High pressure drifts offshore on Sunday, but a dry day is expected with increasing clouds. Still breezy, southwest wind gust around 20 mph. Given the dry spell and MIN RH values 30 to 40 percent across a large portion of the CWA may need another headline for elevated fire weather concerns. Overall a seasonable afternoon, highs in the middle to upper 50s. Heading past sunset, chances for rain start to increase, with the 08/12z run of the NAM 3KM, light rain could arrive as early as 00z/7pm for far western MA. But think for much of our CWA it will be closer to 03z/10pm. This is associated with our a system coming out of the Great Lakes. Mid-level ridging aloft deamplifies as a broad trough brings our next rain chances. While there is sufficient PWATs, 1.2" to 1.5", which is 250+ percent of normal for the day, the best forcing is across northern New England. Would like to see better forcing near us for a good widespread soaking of rain, am thinking the rain we get Sunday night into Monday morning will be showery. 08/12z ensemble probabilites show a spread in precipitation, the ECMWF ENS gives 80-90% of 0.1" across all of southern New England through 12z Monday. While the GEFS ENS is less optimistic with 60-80% along and east of I-95 and areas northwest are 20-50%. Thinking areas long the south coast will have the best potential for wetting rain and less chance the further north you go. Drying conditions for Veterans Day, with highs slightly warmer than Sunday in the low and middle 60s. Surface high pressure builds in Tuesday and Wednesday with mid- level ridging into the northeast. A weak frontal boundary moves through on Tuesday, bring a reinforcement of cooler air. This will set the stage for cooler conditions, highs on Tuesday in the upper 50s and low 60s. And for Wednesday highs are on either side of 50F. Late next week there are signs in a pattern shift in the mid- levels and the next chance for precipitation and/or snow showers in the higher elevation of northern New England. There are still unknowns at this point given the variations among the deterministic models, but something to keep an eye on heading Thursday into Friday. Nevertheless, the cooler temperature trend continues late week as high temperatures remain in the upper 40s and low 50s. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Through Saturday Night...High Confidence. VFR. Gusty W to NW winds through Saturday morning at 20-30 knots. Gusty NW winds diminish some Saturday afternoon to 15-25 knots then Saturday night. Scattered cloud bases down to 040-060 with the passage of a cold front late this afternoon and evening. KBOS TAF...High Confidence in TAF. VFR with gusty W to NW winds at 25-30 knots through saturday morning, dropping to 20-25 knots in the afternoon. KBDL TAF...High confidence in TAF. VFR with gusty W to NW winds at 20-25 knots. Outlook /Sunday through Wednesday/ Saturday Night through Sunday: VFR. Breezy. Sunday Night: MVFR/IFR conditions possible. Breezy. RA. Veterans Day: Mainly VFR, with local MVFR possible. Breezy. Chance RA. Monday Night through Tuesday: VFR. Breezy.
-- End Changed Discussion --
&& .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Gale Warnings and Small Craft Advisories continue into Saturday morning as a cold front crosses the waters this evening and overnight. Winds and waves will gradually diminish Saturday afternoon with Gale Warnings transitioning to Small Craft Advisories at that time. Outlook /Sunday through Wednesday/... Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Sunday: Winds less than 25 kt. Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Rain. Veterans Day: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Rain. Monday Night: Winds less than 25 kt. Local rough seas. Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft. && .FIRE WEATHER... The prolonged period of dry weather coupled with a very dry ground will continue to result in elevated fire weather concerns through Saturday. Plenty of sunshine is expected. Afternoon high temperatures Saturday in the 40s to lower 50s. Northwest wind gusts up to 35 mph are expected. Minimum afternoon relative humidity values Saturday are expected to range between 25 and 40 percent. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Red Flag Warning until 6 PM EST Saturday for CTZ002>004. MA...Red Flag Warning until 6 PM EST Saturday for MAZ002>024-026. RI...Red Flag Warning until 6 PM EST Saturday for RIZ001>008. MARINE...Small Craft Advisory until 10 AM EST Saturday for ANZ230- 233>237. Gale Warning until 1 PM EST Saturday for ANZ231-232-250-251- 254. Gale Warning until 10 AM EST Saturday for ANZ255-256. && $$ SYNOPSIS...Belk/Dooley NEAR TERM...Belk/KP SHORT TERM...Belk LONG TERM...Dooley AVIATION...Belk/Dooley/KP MARINE...Belk/Dooley FIRE WEATHER...Belk/Dooley