Cold air remains entrenched over the region but the strong, warm March sun will combine with lighter winds today to make for a decent start to the weekend. Expect a good deal of sunshine through the day, with just an increase in high level cloudiness as we move into the afternoon hours. Temperatures will peak in the upper 30s and lower 40s – which is still a bit below average – but it will feel a bit more comfortable than recent days thanks to less wind.
Clouds will thicken tonight as low pressure advances into the region and gradually begins to impact our weather…setting the stage for a much less pleasant second half of the weekend.
A storm center will organize south and east of the Cape tonight and lift very slowly northeastward through the day on Sunday and into Sunday night, spreading its shield of wind and precipitation onto the Cape as it does so.
The result will be a nasty weather day on Sunday as periods of snow – perhaps mixed with some rain at times – combine with strong gusty northeast winds to 40 to 50 mph at times and temperatures in the 30s to produce a raw stay-inside-and-watch-a-movie kind of day.
The snowfall forecast is tricky as the ability for the snow to accumulate (and not melt on contact) will be dependent upon the temperature, which will be highly dependent upon the intensity of the precipitation. As mentioned yesterday, if precipitation is intermittent and lighter in intensity, temperatures are likely to be in the lower and middle 30s and the snow will have a tough time accumulating on much other than cold, grassy surfaces and car-tops etc. The end result would be a very low impact event, other than an ugly raw day.
However, if bands of heavier, steadier snow develop and pivot over the area, temperatures will drop to the freezing mark and the combination of slightly cooler air and heavier snow will overcome the marginal environment and allow snow to stick to just about everything and accumulate with ease. Such a scenario would increase the odds for tree and limb damage and subsequent power disruptions.
Added to the uncertainty is the fact that the Cape will be RIGHT ON THE EDGE of the precipitation shield. It’s quite likely that heavy precipitation will be lurking nearby but EXACTLY how far north and west it gets is virtually impossible to say. Relying on model guidance doesn’t provide too much help in this case as some products suggest it stays just east and very light precipitation falls on the Cape…while other products produce nearly an inch of total precipitation on the Outer Cape. From a big-picture perspective guidance is in good agreement…but from a finer details perspective there is a huge discrepancy over a very short distance.
The forecast at this point leans toward a glancing blow from the storm and keeps the worst of the system just to our south and east…but it’s a close call.
Also of note, most folks tend to not notice (or care) when 3/10ths of an inch of rain falls versus 7/10ths of an inch – either way it’s just raining. However, in this type of winter/early spring set-up that difference in total precipitation can literally be the difference between no snow accumulating and plowable amounts.