Snow Increases With Intensity Throughout Day

Light snow has broken out across Southern New England and so far the storm is on schedule

NWS Boston local radar (512 AM)

The Cape and Islands are Rain (denoted by the red line) while everything west is falling as snow.  The regional radar shows plenty of storm to go

NWS Northeast Regional Radar 458 AM

The water vapor satellite shows a healthy storm off the Mid Atlantic coast

415 am Water Vapor Satellite (NOAA)

So far the dreaded dry slot has worked into Worcester County and Northern RI.  Lets call it the Cantore effect, since the Weather Channels Jim Cantore has moved from DC (where a lot of meteorologists busted) to Worcester to cover the storm.  This morning the NWS has expanded Winter Storm Warnings to the east

NWS Boston Watches/Warnings

I've enjoyed the back and forth between the midday NWS shift and the overnight crew.  The overnight crew is more bullish that the region sees over 6 inches of snow.  The midday has high doubts about the storm!  I noticed the same thing with the Weather Prediction Center (formerly HPC).  Here is the 3 day precipitation totals from the WPC

WPC 3 day precipitation totals

That's over an inch of precipitation from Worcester east, with more in SE MA.  So we know there will be a good slug of precipitation...how much falls as snow?  We'll have to look at the temperatures at several levels.

Current temps

5 am Regional  2 m Temps (image weatherbell)

At 5000 feet

850 mb temps, heights, wind

This image shows temperatures are -4 C to -5 across a lot of MA or 23-25 F.  One can also see the piece of energy moving through Northern Michigan which will really energize our ocean storm this afternoon.  These temperatures at 850 not only support snow, but during the day if surface temperatures are not to warm and precipitation is heavy enough it will accumulate.  According to the latest RAP (a super short range model) we will not see anything accumulate in MA today

10z RAP 2 m T 1 PM (image weatherbell)

Surface temperatures of 37 across much of SE New England will allow for slushy accumulation on the grass but will keep pavement wet, not white.  Interesting enough there is plenty of cold air in Northern New England.  As soon as the wind turns to the north (which may not happen until early evening) everyone will turn to accumulating snow.  The Cape will likely see little to no snow, but the coast has a MAJOR flooding event underway.  This is, has been, and will be the major story from this storm.  Here is a look at winds

10z RAP 900 mb winds 7 am (image weatherbell)

Those winds are at 3000 feet or so.  At the surface they will be howling at 60-70 over the water.  High tide is around 7 so you can see the issue.  High winds, large fetch, slow moving storm will mean several cycles of flooding.  Inland once the snow starts to accumulate on trees the winds will be gusting 30-40 mph inland, 45-55 along the coast.  I can't rule out 60+ because Nantucket has already reported one.

I like my snowfall map from yesterday and I do not like to flip/flop.  

Snow forecast

Can I see more in the Connecticut Valley? I sure can, especially in Southern CT.  Can I see more in Fall River and New Bedford? I can definitively see that.  The jackpot may well extend towards Norfolk and Foxboro.  In my hometown of Northbridge I like around 9 or 10.  I think Logan Airport measures 3.5 inches   The 6-10 may be pushing it in Providence.  I like the lower end of 5 or 6 there.  

So to recap it will snow today but will struggle to accumulate unless it is heavy.  It really picks up overnight as a system in the Great Lakes interacts with the storm and enhances precipitation rates.  Temperatures aloft look plenty cold enough so tonight we will see a good thump of snow.  It pulls away by early afternoon Friday.  The weekend has a warm up!  I don't see this as a flip to spring unfortunately; its just a tease.  More this afternoon if needed.  Watch out for falling branches it only takes two inches of heavy wet snow and 40 mph winds to cause problems.