Area Forecast Discussion
Issued by NWS Boston, MA
Issued by NWS Boston, MA
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677 FXUS61 KBOX 150636 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 236 AM EDT Thu Aug 15 2024 .SYNOPSIS... Scattered showers thunderstorms are expected this afternoon and evening. Dry weather returns Friday and may linger into Saturday, especially across RI and eastern MA. Then a frontal system may bring scattered showers and thunderstorms Sunday through Tuesday. Probably not a washout, with periods of dry weather too during this time. Meanwhile, Ernesto will track well southeast of New England, but it will bring rough surf and strong rip currents to south-facing ocean beaches of RI and MA this weekend. && .NEAR TERM /THROUGH TODAY/... Still expecting scattered showers and thunderstorms today as a cold pool aloft nudges closer to southern New England. Decent instability in most model outputs with most unstable CAPE values between 1,000-1,500 J/kg. Shear values of 20-30 kt and fairly straight hodographs suggest more of wind threat. Wet-bulb freezing level is projected to be less than 10 kft, which also suggests that some hail is a possibility. The lack of a major focus should lead to rapid weakening near and after sunset. Despite more clouds today, high temperatures should be near normal. Seabreezes develop once again, keeping the coasts cooler for a time this afternoon. && .SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/... High pressure moves in tonight into Friday. Once lingering evening convection has ended, expecting dry weather through Friday. Light winds will lead to another round of seabreezes Friday. Near normal temperatures should persist. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Highlights * Seasonable temperatures persist this weekend but with increased humidity * A slow-moving frontal boundary approaching from the west will result in increased rain chances Sunday and Monday * Cooler/drier conditions settle in behind a cold front by the middle of next week Saturday Latest suite of model guidance has slowed the eastward progression of an upper-level trough and associated surface cold front this weekend. This has resulted in a drier outlook for Saturday with low rain chances across southern New England. Deep southerly flow will continue to support seasonable temperatures in the low 80s, but with increased humidity as dewpoints rise into the mid to upper 60s. Ridging aloft should support a good amount of sunshine, but expect at least a mix of sun and clouds with the increased low-level moisture. Sunday and Monday Rain chances increase Sunday into Monday as a cold front approaches the region from the west. Guidance has been trending toward a later arrival of the front, thus at least some of Sunday could feature dry weather for portions of southern New England, mainly eastern MA and RI. Cloud cover will be driven by how far east the front progresses by Sunday afternoon, but generally expect more cloudiness further west with better chances for sunshine to the east. By Monday confidence increases in rain chances across the region as the aforementioned cold front should push through The Northeast Monday afternoon into Monday night. With PWATs up to 1.5", this should support a good soaking of rainfall with scattered to numerous showers and thunderstorms. Details in timing and precipitation amounts are vague at this time range, so stay tuned for further details. Next Week As the aforementioned cold front pushes through the region during the Tuesday/Wednesday time frame, we should trend toward drier/cooler weather as northwest winds usher a more early fall like air mass over The Northeast with highs/lows in the mid 70s/mid 50s respectively. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today...High Confidence. Mainly VFR. Winds light and variable. Seabreezes developing by this afternoon along both coasts. Risk for afternoon showers and thunderstorms with brief MVFR conditions. Smoke aloft may lead to visibility reductions and pseudo-overcast conditions around 4000 ft. Tonight and Friday...High Confidence. VFR. Winds light and variable. Seabreezes by late morning Friday. KBOS TAF...High Confidence KBDL TAF...High Confidence. Outlook /Friday Night through Monday/... Friday Night through Saturday: VFR. Saturday Night: VFR. Chance SHRA. Sunday: Mainly VFR, with local MVFR possible. Chance SHRA, isolated TSRA. Sunday Night: Mainly VFR, with local IFR possible. Chance SHRA, isolated TSRA. Monday: Mainly MVFR, with areas VFR possible. SHRA likely, isolated TSRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Through Friday...High Confidence. Relatively light winds and seas through Friday. Visibility should be quite good as well. Risk for scattered nearshore showers and thunderstorms this afternoon to just past sunset. Outlook /Friday Night through Monday/... Friday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday Night: Winds less than 25 kt. Local rough seas. Sunday through Sunday Night: Winds less than 25 kt. Areas of rough seas. Slight chance of rain showers. Monday: Winds less than 25 kt. Areas of rough seas. Chance of rain showers, isolated thunderstorms. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...Belk/RM NEAR TERM...Belk SHORT TERM...Belk LONG TERM...RM AVIATION...Belk/RM MARINE...Belk/RM