wxsniss

updated KBOS 1.9" for last night I believe that brings season total to 41.4" (normal to date 30.2") With the sustained deep cold and massive piles, what an unmitigated stretch of yore since the Jan SWFE, nothing close since 2015

KBOS event tonight 1.6” season 41.1” Feels good to be back

~Providence to Plymouth line looks great for 2"+ Mostly stopped here for now... 1.2" near Coolidge Corner in Brookline Maybe we can tack on another 0.5" with cell currently near Worcester

Heavy snow! Good flakes Roads completely white Coolidge Corner

Was gonna post you a headsup earlier... I'm located maybe ~15-20 min ahead of you? 2z HRRR dries up the stuff after 5z (prior runs had continued snowfall 5z-8z)... even if correct, 2 hours of this and we can get 2"+

Sidewalks covered in 10 min, roads starting to whiten 2 hours of this should get us to 2"+

Borderline heavy here near Fenway

Near Fenway: Nice moderate snowfall with great dendrites for 20 min with that band earlier, put down a fresh coating Radar looking not meager over eastern NY, expecting ~2-3" here

6z NAM / RGEM solid 2-4 / 3-6 east RGEM has been pretty good this winter and relatively steady for Tuesday

6z NAM says let’s refresh again

4.5” near Coolidge Corner Loving the fresh powdery white piles and deep tundra feel What a great event in an increasingly respectable winter … a mix of cool rare meso processes … a widespread refresher for the region … a fraud five actually delivering Along with the broad brush positive bust Jan 25 with its massive dendrite finale, this winter’s got some character

Awesome hoping that swings east more than south

I’m in Brookline just west of city, finally heavy snow gotta be 1-2”/hr at least Hoping we can benefit from the N-S orientation of this band whipping through city

Some 35-40 dbz stuff approaching south shore

@CoastalWx

100% Good Harbor Beach should be epic right now… very jealous but I’ll take the great refresher Hopefully metro area fills in 12-3p

Congrats @Ginx snewx@mattm4242folks RI/Orh/North shore getting absolutely crushed! Awesome event so many mesoscale processes HRRR has more filling in metrowest 12-3pm let’s hope we get better rates and growth

RAPs 0z-1z-2z also ticked west

A museum exhibit... I think I've seen something like this during a Dec 17 2020 WAA event:

What's also amazing is it's not just a passing hour... like 15z-21z

This is peak, but close to this for hours 15z-20z

KBOS from 0z HRRR...

Nice AFD, not a mundane setup: -AO and -NAO teleconnections yielding a very suppressed polar jet this period, with storm track well south of New England. However, this supports a potent, high latitude closed low to descend from James Bay into New England this weekend. This feature will be accompanied by an arctic front Sat, which will yield a complex snow event for SNE. This vigorous closed low induces cyclogenesis well southeast of the 40N/70W benchmark Sat. However, such strong forcing for ascent results in an inverted/Norlun trough from the offshore low extending northwest into SNE Sat. This will result in narrow bands of snow Sat moving west to east across CT/MA/RI. Model data reveals a combination of steep low level lapse rates (up to 9C/km in 0-2 km layer), deep saturated layer, strong convergence and at least modest omega in the snow growth region, will yield a 2- 4 hr period of moderate to perhaps heavy snow at times, from late Sat morning into the afternoon. The snow squall parameter ramps up rapidly between 18-22z across eastern MA Sat afternoon. 12z NAM bufkit for KBVY, indicates up to 20 u/bars of lift in the -10C to - 15C layer 15z-18z. This should yield favorable SLR and low vsbys. This is also supported by HREF offering 30-50% probs of hourly snowfall rates exceeding 1" and 20-30% for greater than 2" per hour, with these high rates focused across eastern MA westward into RI and the Worcester Hills. Duration of strong lift, deep saturation and steep low level lapse rates is brief (2-4 hr window) and this will limit accumulations to mainly 2 to 4 inches, with highest amounts across RI and central-eastern MA. This boundary becomes more enhanced as it enters eastern MA, with multiple models generating over 0.50 inches of qpf across Essex county, with some ocean effect enhancement contributing to the higher totals. In addition, the 13z NBM (v5.0) snow probs have 20- 30% probs of 8+ inches across Essex county, esp the Cape Ann area, and 50% prob of 6+ inches of snow. Given multiple models have strong low level convergence, steep low level lapse rates, a deep saturated layer and at least modest forcing for ascent in the snow growth region, will hoist a small winter storm watch area for Essex county. Snowfall projections here will be for 4-8", with even a low prob of isolated higher amounts pending the evolution of this mesoscale snow band associated with the inverted/Norlun trough. Keep in mind, these mesoscale snow bands are very difficult to forecast and this is a situation where snowfall amounts can vary greatly over short distance. Thus, continue to check back and monitor our updated forecast. For the remainder of coastal eastern MA, given the OES component, isolated amounts of up to 6 inches is possible.

12z GFS and RGEM also like RI, soundings there looked good too They're probably accounting for ocean enhancement for higher confidence to warning amounts North Shore

Box adjusted, appropriately imo... This is pretty close to HREF... some guidance had another max in south RI but not enough support: