Feb 27: Possible Late Winter Snow
Today we’ll be “getting there” but tomorrow will start a mild and sunny period through at least Tuesday. We’ll likely then see another interior low pressure system midweek bringing widespread rain to the region. The end of next week is starting to look interesting however. We’re now only 6 days away and model guidance is not backing off a potential east coast snow storm. Let’s look at some ensemble guidance.
GFS Ensembles (GEFS) for next Friday night:
Euro Ensembles (EPS) for next Friday night:
The biggest signals I see from this are one, an offshore low track and two, a favorably positioned high pressure to the north of the system. This combination, with a strong enough coastal low, could override the “sun angle too high” logic that naturally fights snow accumulations this late in the winter, especially if precipitation falls overnight with cold air in place.
The midweek interior low that I mentioned in the first paragraph will have a cold air mass behind it. This cold air should come at the courtesy of a sudden stratospheric warming event (SSWE) which should split the lower heights of the stratosphere between the N. Pacific and N. European regions. This should allow higher stratospheric heights to develop over E. Canada and NE US and therefore propagate down through the troposhpere as lower 500mb heights. This basically means there should be decent cold air available to tap.
Should all this come together (high position, coastal low track and colder air aloft), I see no reason why there couldn’t be a snow storm next Friday-Saturday-ish. As you can see, I’m mostly following ensembles for now but will begin considering surface solutions as we transition into the mid-range forecasting period this week (as we’re enjoying the milder conditions). This solution could easily drop off of guidance over the next few days in which case we can dismiss this threat. But for now, it’s still showing at day 6 and therefore we must track and discuss.
In English: Meh today. Nice and mild tomorrow through Tuesday. Rain midweek. Possible snow storm Friday-Saturday-ish. Discussion for now (not a forecast). Will take seriously if still modeled strong on Monday. Have a great weekend and be safe! JC