If you have been following our blog or our on-air coverage, you will notice there are no significant changes to the weekend forecast.
There is good news / bad news in terms of the timing. The good news is the Saturday daylight hours should remain rain and snow-free; so we are looking good for the Providence St. Patrick’s Day Parade! The bad news is Sunday outdoor plans may not be so great with periods of snow falling.
Below is a 500mb chart which shows the weather pattern high above our heads (15 to 20 thousand feet). This particular snapshot shows Sunday evening as predicted by the European model.
Notice the big circle just offshore; this is an upper level low. In certain parts of the upper level low, there can be quite a bit of lift which can help produce heavy bursts of snow. The upper level lows can be tricky to forecast because instead of generally moving along from west to east, they can slow down, stall, and sometimes even back up. While much of this energy from this upper level low looks like it will stay offshore, it’s certainly close enough to leave in the possibility of some higher amounts of accumulating snow.
Below is the European model forecast for snowfall accumulation.
It has most of this falling from early Sunday morning to early Monday morning. Notice that it has about 1-2” for Providence, but then quickly increases totals to the east. Just east of Little Compton, Rhode Island, it has 4-5” totals.
It’s a little too early in the game to lock onto specific accumulation forecasts, but I do like the trend of lighter amounts 1-3” for most of our viewing area, and slightly higher amounts 2-4” from the southern RI coast into eastern Massachusetts. Higher amounts (4-6”), are not completely out of the question, but it looks like the most likely location for that would be out towards Cape Cod.
Big Difference Between Grass and Road Accumulation Possible
The European model (not the only model we use, but it has a good track record) is bringing in the bulk of snow accumulation from early Sunday morning into Sunday afternoon. Interestingly, here is what the European model is showing for surface temperatures on Sunday early afternoon.
Notice how these temperatures are several degrees above freezing. In reality, these temperatures often end up being cooler than predicted when snow is actually falling. However, it suggests a borderline situation in which the grass may be cold enough to collect snow, but the roads may be too warm for much of the snow to stick. Keep in mind that we are going into the 2nd half of March, that’s when it is common to get daytime snowstorms that have a hard time sticking to the pavement. Of course, if it’s snowing hard enough, the snow can pile up anywhere, so we still need to watch the weekend system carefully. –Pete Mangione