Lexington, Massachusetts, USA
Point Forecast Updated Wed Mar 22, 2023 6:09am EDT
Continued mild and dry today, but cooling sea breezes along the eastern MA coast. A few showers possible tonight, especially across SE New England, then more showers Thursday as a cold front approaches. Drier and a bit cooler Friday behind the front. Active weather on Saturday into early Sunday with a wintry mix across the interior and higher terrain, while there is a cold rain elsewhere. Drier weather returns Sunday into early Monday. Unsettled once again late Monday into Tuesday.
Partly Sunny
Hi 51 °F
Partly sunny, with a high near 51. East wind 2 to 9 mph.
Mostly Cloudy then Slight Chance Rain Showers
Lo 42 °F
A slight chance of rain showers between midnight and 2am, then patchy fog and a slight chance of rain showers. Mostly cloudy, with a low around 42. Southeast wind 6 to 9 mph. Chance of precipitation is 20%.
Patchy Fog then Chance Rain Showers
Hi 60 °F
Patchy fog and a slight chance of rain showers before 8am, then a chance of rain showers and patchy fog. Cloudy, with a high near 60. South wind 6 to 16 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
Chance Rain Showers then Mostly Cloudy
Lo 41 °F
A chance of rain showers before midnight. Mostly cloudy, with a low around 41. West wind around 14 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
Partly Sunny
Hi 53 °F
Partly sunny, with a high near 53. Northwest wind 10 to 15 mph.
Mostly Cloudy
Lo 31 °F
Mostly cloudy, with a low around 31. North wind 8 to 13 mph.
Rain And Snow
Hi 41 °F
Rain and snow after 8am. Cloudy, with a high near 41. East wind 7 to 15 mph. Chance of precipitation is 80%.
Light Rain
Lo 37 °F
Rain. Cloudy, with a low around 37. Northeast wind 14 to 17 mph. Chance of precipitation is 90%.
Chance Light Rain
Hi 49 °F
A chance of rain before 5pm. Partly sunny, with a high near 49. Northwest wind 15 to 21 mph. Chance of precipitation is 50%.
Partly Cloudy
Lo 33 °F
Partly cloudy, with a low around 33. West wind 14 to 20 mph.
Mostly Sunny then Slight Chance Light Rain
Hi 49 °F
A slight chance of rain after 3pm. Mostly sunny, with a high near 49. Northwest wind around 13 mph.
Chance Light Rain
Lo 36 °F
A chance of rain. Mostly cloudy, with a low around 36. Northeast wind around 12 mph. Chance of precipitation is 40%.
Chance Light Rain
Hi 46 °F
A chance of rain. Mostly cloudy, with a high near 46. Northeast wind 9 to 15 mph. Chance of precipitation is 40%.
Chance Light Rain
Lo 33 °F
A chance of rain. Mostly cloudy, with a low around 33. Northwest wind around 17 mph. Chance of precipitation is 30%.
Updated Wed Mar 22, 2023 6:09am EDT
000 FXUS61 KBOX 221123 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 723 AM EDT Wed Mar 22 2023 .SYNOPSIS... Continued mild and dry today, but cooling sea breezes along the eastern MA coast. A few showers possible tonight, especially across SE New England, then more showers Thursday as a cold front approaches. Drier and a bit cooler Friday behind the front. Active weather on Saturday into early Sunday with a wintry mix across the interior and higher terrain, while there is a cold rain elsewhere. Drier weather returns Sunday into early Monday. Unsettled once again late Monday into Tuesday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 715 AM Update... No major changes in the latest update. Did bump up the cloud cover a bit from the previous forecast based on current mid/high clouds in place. Otherwise the forecast is on track. Previous discussion... Weak cold front moving south across the region will reach the south coast by daybreak, then it returns northward as a warm front today with a wind shift to south. This front will result in a tricky temp forecast, especially across portions of eastern and NE MA where the front may get hung up today. While there will be mid/high clouds around, the low levels are dry so expect at least partial sunshine today which will help to boost temps well into the 50s, with lower 60s in the CT valley. However, east winds may persist through the day across NE MA on the cool side of the boundary, holding temps in the upper 40s here, with lower 50s further south along the coast. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... Tonight... The warm front lifts to the north tonight with modest S/SW flow across the region tonight which will result in a milder night with lows upper 30s northern MA and low/mid 40s elsewhere. An area of higher PWATs and deep moisture plume over the ocean advect northward into SNE tonight aided by a modest low level jet which may bring a few showers to SE New Eng tonight. Some of the guidance is also suggesting a second area of scattered showers moving into western New Eng toward daybreak assocd with modest lift in the left exit region of an approaching upper jet. Otherwise, increasing low level moisture may result in areas of stratus and patchy fog developing overnight. Thursday... Northern stream shortwave passing well to the north will push a cold front southward through northern New Eng which will approach northern MA toward evening. Modest warm advection in the warm sector will result in scattered showers moving across the region, but not expecting a washout as the column does not fully saturate and forcing for ascent is not that strong. Rather mild low level temps will be advecting northward into region as 925 mb temps warm to 8- 10C from N to S by 00z Fri. Shallow mixing and cloud cover will limit full heating potential but still expect highs reaching the upper 50s to lower 60s, but cooler along the south coast. It will become breezy in the afternoon with pre-frontal gusts 20-30 mph developing as low level wind field increases. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Highlights... * Showers tapering off Thu night into early Fri. Cannot completely rule out a few rumbles of thunder along the south coast. * Dry weather returns for the rest of Fri. * Unsettled Sat into early Sun. Wintry mix of sleet/snow across the interior. Elsewhere will be a cold rain. Gusty winds at times. * Dry once again on Sun before the unsettled weather returns at some point early next week with wintry weather possible. Thursday night through Friday... A shortwave trough will initially be situated over northern New England/Upstate New York Thu night. The shortwave will dig offshore by early Fri AM. A ridge axis will build from the Mid Mississippi River Valley Fri AM into the central Great Lakes/OH Valley by Fri evening. A cold front will move through Thu night into the pre-dawn hours Fri AM. Behind the front, high pressure builds in from the the central Great Lakes/Ontario. Cold front will be working its way through southern New England late on Thu into very early Fri. As the front is moving through will have rain showers, which will gradually taper off as the night progresses. Does appear that there is the potential for a few rumbles of thunder along the south coast. Will have roughly 50-100 J/kg of MUCAPE available and K index values should be around 25-30 as the front is moving through. Other concern is immediately along/behind the front we may have a period of gusty winds. At this point looks like W to WNW/NW low level jet at 850 hPa with speeds of 30-40+ kts. At this point does appear we will have a better opportunity to tap into these stronger gusts per GFS/NAM Bufkit soundings, but the NBM still appearing a bit too strong. Knocked wind speeds/gusts down a bit per GFS/NAM soundings. After the frontal passage will see the gusts/winds come down during the day Fri and Fri night as the high relaxes the pressure gradient. Temperatures falling a bit closer to seasonable at 925 hPa temps fall to +/- 3 degrees Celsius. Given the NW flow should see some downsloping, so did nudge temps up a bit from the default NBM. Highs will generally be in the low/mid 50s outside of the higher terrain where readings will be in the 40s on Fri. Saturday into early Sunday... The ridge axis over the central Great Lakes late on Sat will build into New England by Sat AM and northeast of the region by late in the day. Behind the ridge axis a trough will lift from the Mid Mississippi River Valley into the central/eastern Great Lakes. The trough lifts into northern New England by early Sun. High pressure will be planted over Quebec on Sat and Newfoundland by late in the day. A low will deepen and become vertically stacked over the central Great Lakes late on Sat. The warm front associated with this system will lift into our region. A secondary low develops near/along the south coast late on Sat before moving into the Gulf of Maine by very early on Sun. Main concern during this period is the wintry mix anticipated across the higher terrain of the interior. Will note that deterministic/ensemble guidance has trended with less snowfall accumulation. This is largely a result of more a mixed bag of precip versus the colder solutions advertised yesterday. Have stuck with the NBM for now as it appears quite reasonable at this point in time for temps. Should start out as a mix of sleet/snow across the interior on Sat before gradually changing over to rain/sleet and potentially all rain other than the highest elevations. Will really struggle to accumulate much on Sat other than in locations where models prog 2M temps below freezing. This also a result of the late March sun angle and light precip rates. Thinking the best shot for accumulation comes late on Sat into early Sun as the secondary low is lifting across SE MA. This will also coincide with any wintry mix changing back over snow across the interior. Winds shift to the W, which will advect 0 to -2 degree Celsius air at 925 hPa across the higher terrain. Given there is still some uncertainty in the thermal profiles will really need to hone in on exact Ptypes to get idea on impacts expected. Will note that GEFS/EPS guidance have lowered probabilities of 24 hr 10:1 SLR snow accumulations AOA 3 inches into roughly the 10-40 percent range. The GEPS has also retreated with these probabilities as well, likely a result of the stronger surge of warmer air aloft and more mixed ptypes. Risk is highest along roughly the Route 2 corridor. Not completely out of the question Winter Weather Advisories may be needed, but at the moment impacts appearing less likely. Elsewhere will have a cold rain. Also anticipating gusty winds as the system moves through. Should see 925 hPa jet of roughly 30-40+ kts out of the S/SE initially and shifting to the W late on Sat into early Sun as the secondary low lifts into the Gulf of Maine. Thinking that the wind risk is greater late Sat/into early Sun as we get into the W flow. May be difficult to mix down the SE/S winds given the warmer air advecting in and inversion in place per GFS Bufkit soundings. Have stuck with the NBM for now, but may need to be lowered a bit in future updates especially during the day Sat. Sunday into early Monday... A ridge axis builds into the central/eastern Great Lakes from the Mississippi River Valley on Sun. High pressure will nudge into southern New England behind the departing system on Sun into early Mon. This will result in another period of dry and quiet weather Sunday into early Monday with more seasonable temperatures. Late Monday through Tuesday... Next window for potentially impactful winter weather. Lots of uncertainty with timing, track and intensity of this system as guidance is all over the place. At this point have just stuck with the NBM, which features chances of precipitation. Depending on the exact track/intensity of a low moving through offshore there could be accumulating snow. Ensembles featuring low probabilities (10-30 percent chance) of 10:1 SLR 24 hr snow accums of 1" and 3" per the GEPS/GEFS and EPS guidance. && .AVIATION /11Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Today...High confidence. VFR with light and variable winds to start. Will gradually shift to the E/SE later this morning and S approaching 10 kts this afternoon. The only exception is across NE MA where E/SE winds persist. Mid/high clouds increasing as the day progresses. Tonight...Moderate confidence. VFR to start, but cigs lowering to MVFR overnight with pockets of IFR possible. Areal extent of lower cigs is uncertain. Scattered showers developing across eastern New Eng. Winds out of the S at 5-10 kts. Thursday...Moderate confidence. Areas of MVFR/IFR in the morning expected to improve to MVFR/VFR in the afternoon. Scattered rain showers. S winds around 5-10 kts in the morning shifting to the SSW/SW and increasing to 10-15 kts with 20-25 kt gusts during the afternoon. KBOS Terminal...High confidence in TAF. VFR into this evening, then potential for MVFR cigs overnight. Could perhaps see some localized IFR toward the Thu AM push. KBDL Terminal...High confidence in TAF. VFR into this evening, then potential for MVFR cigs overnight. Outlook /Thursday Night through Sunday/... Thursday Night: Mainly VFR, with local MVFR possible. Windy with gusts up to 35 kt. Chance SHRA. Friday: VFR. Windy with local gusts up to 30 kt. Friday Night: VFR. Breezy. Chance FZRA. Saturday: Mainly VFR, with local IFR possible. Windy with gusts up to 35 kt. RA, chance PL, chance FZRA. Saturday Night: MVFR/IFR conditions possible. Windy with gusts up to 35 kt. RA, FZRA, chance SN. Sunday: VFR. Windy with gusts up to 30 kt. Slight chance RA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Today through Thursday...High Confidence. Winds turn southerly today less than 20 kt across the south coastal waters, with mainly easterly winds over NE MA waters. S/SW winds 10- 20 kt tonight, increasing Thu with 25-30 kt gusts developing during the afternoon over the south coastal waters with building seas as a low level jet approaches from the south. Scattered showers tonight into Thu. Outlook /Thursday Night through Sunday/... Thursday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain showers, isolated thunderstorms. Friday: Winds less than 25 kt. Local rough seas. Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Seas up to 5 ft. Rain. Saturday Night: Low risk for gale force winds with gusts up to 35 kt. Rough seas up to 8 ft. Chance of rain. Sunday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 9 ft. Slight chance of rain. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...None. && $$ SYNOPSIS...KJC/BL NEAR TERM...KJC/BL SHORT TERM...KJC LONG TERM...BL AVIATION...KJC/BL MARINE...KJC/BL
Point forecast:
https://api.weather.gov/gridpoints/BOX/65,93/forecast
Zone forecast:
https://api.weather.gov/zones/forecast/MAZ014/forecast
Hourly forecast:
https://api.weather.gov/gridpoints/BOX/65,93/forecast/hourly
Hourly detail:
https://api.weather.gov/gridpoints/BOX/65,93
Point detail:
https://api.weather.gov/points/42.4399,-71.2405
Alerts:
https://api.weather.gov/alerts?active=1&point=42.4399,-71.2405