The 4 Seasons

What is considered the fraud 5? 1. Inverted trough 2. Anafrontal snows 3. Wrap-around snows 4. Snow Squalls 5. Clipper redevlopment ??? I'm just guessing

plenty of model cycles to go...

Quickly, after reviewing the 12Z/18Z runs and checking out bufkit/soundings this is what i think is most likely at the moment. There are some positives such as good growth in the DGZ, model continuity amongst GFS/EC/GEM but also some red flags such as the dry air depicted in the GFS soundings and some mesos cutting way back and shifting SE. First call map, we are still about 36 hours away from the meat of it, final call issued tomorrow afternoon/evening before any snow begins.

EC slightly improved from 12Z not too much change but it went in the right direction.

18Z GEM/RGEM/HRGEM all in agreement with about 4-7 statewide. Here is the 18Z GEM

Light snow accumulation means sub advisory for that forecast period i.e. around 1", 1-2, 1-3, 2-3 Moderate means advisory for that period Heavy means warning for that period Adding an inch to say 1-3 yields about 2-4ish. That's generally how that works in my experience. @OceanStWx can correct me if im wrong. Light, moderate, heavy are the three categories and its usually stated outside of a time when exact numbers come into play.

Hi? Not sure how to interpret this, but i've been on the 2-4 range since the start, not flurries not 4-8 either. Nothings changed, map coming shortly. And no, there is no chance of WSWs (if you mean Winter Storm Watch or Warning) in the AM package (tomorrow) and i'm willing to be money on that. I'd say they will hoist advisories statewide in the AM package but its also possible they may hold off to PM with boarderline totals and low confidence. But most likely think well see advisories across the state tomorrow morning.

Yea, i posted that earlier...they bumped up while BOX bumped down and ALY went wayyyyy down.

Even some 7,8" lollis

HERPES gone wild

BOX cut totals a bit, now more realistic with widespread 3-4 rather than 4-6. ALY pretty much cancelled the storm, they really slashed totals less than 1/4 of what it was.

Clown map. I'll take my 6.0" of digital snow

18Z GFS actually ticked up a bit on the qpf side. Soundings still look fugly tho.

Where is he, still at work?

BOX PM UPDATE: Both ensemble data sets from the EC and GFS including deterministic guidance from the NAM/HREF/GFS/EC suggest heaviest qpf will be confined to the south coast of MA/RI/CT. Ensembles offering 0.25 to 0.33 in this area and obviously deterministic guidance higher with 12z NAM showing a stripe of 0.75+ inches from Cape Cod to MVY. 12z HREF ends 12z Wed but also has some members supporting higher qpf 06z-12z Wed. In fact the 12z ECENS has over 30 of its 50 members supporting at least 2 inches of snow for much CT/RI and MA! At this model time range (42+ hrs) typical model error for a frontal boundary is probably in the +/- 50-100 miles range. Thus this heavier qpf band could shift and verify offshore but also could shift inland to perhaps HFD-ORH-BOS. So there remains a range of possibilities. Tracing back the short wave that will enter the Great Lakes early Wed that will back the mid level flow across southern New England and impact our forecast, this feature traces back to the Arctic circle this afternoon. Obviously this is a data sparse area so expecting models to initialize this feature differently/better once it reaches lower latitudes with more data. Typically these arctic short waves verify stronger/more robust given poor model initialization at higher latitudes in data sparse regions. In addition this approaching arctic short wave will be accompanied by an anomalous upper level jet streak across northern New England into southern Quebec Tue ngt/Wed with speeds of 180+ kts! Thus a lot of jet dynamics to watch unfold. So at this early stage our preliminary snowfall forecast could range as little as a coating to an inch (our 10% percentile snow forecast) to possibly 2-4 inches (50% percentile snow forecast) if arctic short wave verifies stronger with mid level flow backing more to the SSW and with longer duration yielding higher qpf. Also can`t completely dismiss the more extreme NAM/HREF solution with 4+ inches, albeit a low prob but within the envelope of solutions. Nevertheless will need to watch this portion of the forecast given its potential impact to the Wed morning commute. @weatherwiz ha! Not sure why they are talking about NAM as the extreme solution when it appears to be on the lighter side of the envelope atm, at least comparing it to GEM/RGEM/UKMET.

RGEM still looks like a good hit, this is all i have to go off so far thats updated. Looks like it'll be a little toned down from 12Z but still probably .3-.5 qpf for most i would guess. Here's the link. https://collaboration.cmc.ec.gc.ca/cmc/cmdn/pcpn_type/pcpn_type_gem_reg.html

This isn't looking good but i still think a low end advisory snowfall is still in the cards for some.

I'll await the entire 18Z suite and make a first call map. We still have the 00Z runs overnight 6Z, 12Z tomorrow 18Z tomorrow and 00Z tomorrow night before anything starts anywhere.

Never said or impied they were. The last forecast was 7:15AM so they didn't get a chance to see any of the 12Z runs yet. The PM shift, this map, would be based off the entire 12Z suite probably not taking into account the 18Z NAM at all.

aaaand NWS OKX bumps up ???

Well overall i guess its better than the 12Z run but not good.

Not that i give it much weight but NAM is ugly. Literally yesterday it had warning snows now it's like what snow? Unreal, that model.

Not what you want to see.

NAM looks very dry so far.

NAM 12Z, is not nearly as dry but putting out less qpf than GFS. 18Z is rolling now out to 30 will see if it comes back up