457 FXUS61 KBOX 170834 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 434 AM EDT Thu Apr 17 2025 .SYNOPSIS... Continued dry weather today into Friday, along with a warming trend. Low risk for some showers Friday afternoon across northern MA. Breezy and warm weather expected Saturday, along with scattered showers ahead of an approaching cold front. Drier and mild behind the front Sunday. Weather pattern turns more unsettled early next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Key Messages: * Dry and breezy Low pressure moves farther away from the Maritimes today, relaxing the pressure gradient a little. While still gusty, thinking it will not be quite as strong as yesterday. Expecting near normal high temperatures today. Favored the lowest dew point guidance, as cases of west winds with deeper mixing tend to come in with lower humidity than guidance would otherwise suggest. This could lead to some fire weather concerns, if fuels can sufficiently dry out. Minimum relative humidity across the interior should be between 20-30 percent, but could be lower if temperatures overachieve the current forecast. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Key Messages: * Dry conditions continue * Low risk for showers across northern MA Friday High pressure moves from the central Appalachians to the Mid Atlantic coast tonight. With diminishing winds and mainly clear skies, good radiational cooling should result. That said, still thinking low temperatures will be near normal. Increasing southwest winds Friday should lead to above normal temperatures. Plenty of sunshine to start the day, with a mid level shortwave moving across northern New England in the afternoon. That could lead to some showers across northern MA during the afternoon. There should at least be some clouds. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Key Messages: * Widely scattered shower chances return Friday night and Saturday, dry on Sunday. * Above normal temperatures Saturday with highs in low-mid 70s, with potential for upper 70s in spots * Mainly dry Monday with showers arriving early evening. Friday Night through Weekend: The weak lift with the warm front coupled with a plume of above normal moisture will support scattered showers Friday night and Saturday. Continued warm advection into Saturday will support a warm day Saturday even despite the cloud cover and showery conditions. 850mb temperatures warm to 12-14C and with afternoon mixing will likely support highs in the 70s for much of southern New England. There are even ensemble members that display the potential for upper 70s and a few 80s in spots, mainly within the GFS ensemble. It will likely come down to how many breaks in the cloud we get. A tightened pressure gradient/LLJ present will support stronger southerly flow with gusts 25-35 mph, perhaps a few gusts up to 40 mph for the higher elevation spots. The cold front swings through by Saturday night switching winds to the NW. Conditions gradually dry out into early Sunday morning. A cooler airmass advects in behind the front overnight Saturday into Sunday supporting a cooler day with highs in the 50s for the Cape/Islands and low-mid 60s elsewhere. Breezy conditions continue, but out of the NW with gusts 20-35 mph. Early Next Week: A brief upper level ridge shifts over southern New England Monday yielding light NW winds and dry conditions for much of the day. Temperatures trend slightly cooler than Sunday with highs in the 50s to near 60. There is a general consensus among model guidance for our next system to moves through sometime in the late Monday-Tuesday timeframe. There are notable differences in timing of the system which in the grand scheme will impact the timing of precipitation. Some solutions develop showers as early as late afternoon Monday while others show showers arriving Monday night. When with a mean for now with low chances for isolated showers developing from west to east late afternoon and increasing chances for early evening and onward. This will be finer tuned as we get closer. Overall, precip looks to be light. Tuesday likely stays unsettled for the AM as the remaining showers exit off to the east followed by gradually drying conditions behind it. Highs trend around normal. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. High confidence for the entire period. VFR for the next 36 hours. Only scattered clouds expected today. Gusty surface winds again today before diminishing tonight. KBOS TAF...High confidence. KBDL TAF...High confidence. Outlook /Friday Night through Monday/... Friday Night: VFR. Breezy. Saturday: VFR. Windy with local gusts up to 30 kt. Slight chance SHRA. Saturday Night: Mainly VFR, with local MVFR possible. Breezy. Slight chance SHRA. Sunday through Sunday Night: VFR. Breezy. Monday: VFR. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Overall high confidence in the forecast. Key Points: * Gusty winds to continue today, but slowly diminishing Winds and seas gradually diminish across the waters late today into tonight as high pressure moves across the waters. Outlook /Friday Night through Monday/... Friday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Local rough seas. Saturday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 9 ft. Saturday Night: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Slight chance of rain showers. Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. Sunday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Monday: Winds less than 25 kt. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 10 AM EDT this morning for ANZ250. Small Craft Advisory until 1 PM EDT this afternoon for ANZ254- 256. Small Craft Advisory until 7 PM EDT this evening for ANZ255. && $$ SYNOPSIS...Belk/Mensch NEAR TERM...Belk SHORT TERM...Belk LONG TERM...Mensch AVIATION...Belk/Mensch MARINE...Belk/Mensch