Greg

It also has to do with the intensity of the precipitation. Vertical vorticity can't really occur with only light precip falling.

I knew someone would say that with the early observations but our snow for Eastern/Northeastern Mass comes a little later.

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Key Points *Winter Storm Headlines remain in effect for tonight *6-8 inches, with localized 10 inches NW of I-95 *3-6 inches, with higher uncertainty SE of I-95 *0-2 inches across the Cape and the Islands An area of low pressure strengthens as it makes a close pass offshore, with the center near the Cape and Islands. Model guidance remained consistent with this path today. Thus, confidence continues to increase for widespread accumulating snowfall across the region tonight. Precipitation moves in SW to NE tonight between 4 pm - 7 pm, with a mix of rain/snow possible with onset due to above- freezing temperatures around the region. Temperatures should drop below freezing from NW to SE between 4 pm and 8 pm, allowing any rain-snow mix to change to snow. The heaviest snow and best potential for banding will occur between 6 pm to 1 am, where 0.5 inch/hr snow rates are likely, with a low to moderate chance for 1-2 inch/hr snow rates. The latest 12z Hi-res guidance favors SE of the I-95 corridor from Boston to Providence for the heaviest QPF and snow rates due to the close offshore track of the low. However, SE MA and RI is the area of highest uncertainty because temperatures will take longer for temps to drop below freezing. If temps stay above freezing after 7-8pm, then snow totals likely remain in the 3-6 range, but if they drop quicker, then 6-8 inches with localized 10 inches will be possible. As for north and west of I-95, colder temps and higher snow-to-liquid ratios will make up for less QPF. Widespread of 6-8 inches is expected, with localized areas of up to 10 inches possible. As for the Cape and Islands, Temps should stay above freezing until after midnight; by this point, the heaviest QPF will have moved off to the northeast. We did bump up snow totals with the slight shift south in the Hi-res guidance. Expect anywhere from 0-2 inches, with localized 3-4 inches if colder temps move in quicker than expected.

Mid-levels may be slightly colder than forecasted. This will help with those transitioning to snow quicker.

You do know you are under a Winter Weather Advisory not a Winter Storm Warning. Down there the temp and mix are what will be precluding you from accumulating initially.

True, very true. 12 Hour vs 24 Hour. Just wanted to post it to keep expectations in check. Again, my forecast still mostly stands from earlier.

As some of you just stated, the main show is not in the mountains of PA. It's developing right now as we speak over the coastline "ESE" of The DC area.

It seems to sound like he's taking that from the HREF mean that was posted.

Here is the latest HREF Ensembles for snow lovers out there. The one the top is the "Mean" and the one on the bottom is the "Max".

My call for 4-7" still holds with CT, the Central and Southern Berks with only 7-10" lollies highest elevation (Not widespread). The other will be with the classic synoptic scale east around the Boston and Northshore area where a 7-10" concentrated band will generally set up. The SouthShore 4-7" with the far SouthShore, extreme inner Cape 1-4". The rest outer Cape C-1". Generally, the forecast looks relatively on track.

Highly unusual for the Euro of to fall apart so close in.

I happen to like the majority of this model suite so far. Just waiting for the 0Z to make a final forecast.

This is starting to look better and better especially at this time frame in the game.

Same thinking here. Definitely down to Scott to the Brockton area on the Southshore and also to Northern Rhode Island. Only thing left is were exactly the heaviest band sets up. Will be interesting to say the least.

Where the 850 tacks in this will probably be the key.

More like the Marshfield Hills area in that to be exact if one looks very closely.

Probably not, but a small chance of this could actually happen if the track and the dispersement of the banding held like this. However, this is the 18Z model suite. The 0Z will be very important to see how tight these goal posts really are.

Actually, it's not bad but take the lower range of that. That's all. It's not wrong, it's just a range.

I'll try to explain. If one gets .4-.7 with about 1:10 ratios only and with a 9–10-hour window then it's about 4-7" of snow. If one has everything going for them, such as ratios 13:1 with the best omega banding, elevation, then the roof would be about a 10-12". Generally, that's what we have here. It's not going to be a widespread situation.

The center is staying offshore. It's not going over the cape at all. The real question now is where does the heaviest banding show-up and what will be the ratios when and if it does. As stated, that will determine the final heaviest possible accumulations of this storm.

Was it a burp, hiccup, or fart?