Our snow is now underway across the state and will continue to pick up in intensity during the rest of the morning into early afternoon. There will be a period during the 11 a.m. to 4 p.m. time frame when the snow will come down at its hardest.
Roads that are not treated will be slippery but passable. After 7 p.m. or 8 p.m. the crews should have had a chance to clear much of the snow.
The heaviest snow is going to fall south of the Mass Pike and especially over portions of Cape Cod, Connecticut and Rhode Island. Generally, we are looking at 1-3 inches north and 3-5 inches south. However, just like in the summer when some areas get a heavier rain shower, the same thing can happen today in the form of heavier snow showers. These heavier snow showers can add one or two inches of snow to totals in a few localized areas. These are tough to predict, but that is one of the reasons snowfall can be so variable from town to town.
Another aspect of this storm is that the cold temperatures will affect the amount of snow we measure. When meteorologists look at computer models we see how much liquid precipitation the storm is forecast to produce. We then have to convert that liquid to snow. When temperatures are around freezing, the ratio of liquid to snow is one to ten. In other words, if the models forecast two-tenths of an inch of melted precipitation, I would then convert that to 2 inches of snow. Today’s storm is happening in colder air, especially Boston and north. The ratio of liquid precipitation predicted for this storm, will be one to fifteen or even one to twenty along the New Hampshire border. Therefore, the small amount of liquid forecast will amount to higher amounts of snow in today’s cold air. One model I use is predicting .15 inches of melted and thus my forecast for up to 3 inches of snow. Now you know what that whole “fluff factor” is all about.
On Sunday, warmer air starts to move back into the region. When you have warm air replacing cold air in winter it can often lead to some light freezing drizzle or rain. This will be the case late Sunday night and could impact the Monday morning commute.
Speaking of storms, there was just a major storm on the Sun when a solar flare erupted yesterday. Now that energy is heading towards Earth. These eruptions, can, if conditions are right, give us quite a show of the aurora borealis. If the aurora happens, our best shot to see them will be late Saturday night. We will also have to clear out clouds as well. Check out the flare as it happened. (see image below)