Weather: Significant Snow Accumulation Possible Throughout Region Saturday
PHILADELPHIA (CBS) -- Saturday's storm is getting more and more interesting as the days go on. This is a storm we've been monitoring all week long, but for most of the week it appeared as though it would either miss off the coast or brush the coast with some snow. But as last night's system departed and we got a better read on the storm, it's looking more and more likely that it will bring significant accumulations to parts of our area.
This is not an easy storm to forecast. The reason being that the track is so crucial to the positioning of snowfall totals, and these can be messed with by the formation of mesoscale bands of snow that like to form when an energetic low is moving along the coast and tapping into the maritime temperature gradient.
I am a bit concerned that this storm will perform toward the high end of our current snowfall ranges, and perhaps even exceed them in spots.
It's also tough when one storm follows another so closely. Yesterday most of the region was hyper-focused on last night's snow, and this was a secondary thought in most people's minds. It concerns me that maybe this will make people take it less seriously.
Here's the breakdown:
- snow begins down the shore and DE beaches around 5am, spreads north to Philadelphia around 8am
- height of the storm is 9am - 2pm
- snow will gradually taper from west to east between 2 and 5pm
- looking at a coating to 2" in near NW suburbs of Philadelphia, 2-4" from the city into nearby NJ suburbs, 4-6" across much of interior South Jersey, and a narrow band of 6-8" possible along the immediate coast. I wouldn't be shocked to see even higher totals the closer you head toward the Delmarva region (i.e. SE corner of Delaware).
- wild card? exact track. a shift east of only 20-30 miles can shift all these totals downward. a shift east could increase them.
- wild card? position of mesoscale banding. if a band sets up inland, snow totals will overachieve.
- wild card? temperatures and snow ratios. temps in the 20's during the height of the storm means the snow ratios will be quite high, on the order of 15:1. translation? light fluffy snow that likes to pile up quickly. i.e. 3" in temperatures near freezing could be closer to 5" with tomorrow's temps.
Please be very safe and plan your day accordingly Saturday. Snow will stick to the roads quickly, especially down the shore where it's falling at a good rate. Roads will be a mess and winds can whip the snow around. The lucky part is that this storm is arriving on a weekend when the roads won't be full of commuters.