The outlook for next week continues to evolve and has gotten more interesting but we are not across the finish line yet. Tuesday's storm is a very close call right now and will need to be discussed in more detail in order to make sense of where we are at with this thing. There is also some new snow potential for the rest of next week and a better outlook as we head toward the month of February.
Our weekend forecast remains cloudy with somewhat less visibility than I advertised a few days ago. There is some very light rain or drizzle that is possible late in the day on Saturday along with temperatures at or slightly above the freezing mark. Sunday is more of the same, but any dampness should dry out later in the day.
We will indeed be provided with a needed bit of dry Canadian cold late Sunday into Monday. We discussed this in the last update as a necessary ingredient if we were to have any shot at snow on Tuesday. The jet streak in the Davis Straits will deliver on its part of the equation. We then have our monster weather system which will proceed from the Mississippi Valley to the Tennessee Valley on Sunday and strengthen as it does so. It will then transfer some of its energy to the Mid Atlantic coast and move toward coastal New England Monday. Precipitation will advance into New England late on Monday and continue into Tuesday with what looks to be extremely marginal temperatures. Models trended cooler for successive days but that trend stopped last night with the American GFS reverting back to a warmer storm. This might be why many of you are seeing the rain icon show up in your smartphone weather outlooks. These icons can be sensitive to changing GFS runs. What we are missing in this GFS forecast and a big reason as to why it went warmer is the lack of a coastal "bomb". The storm is shown to strengthen onshore, peak over the state of Tennessee but never restrengthen off the coast which a lot of big coastal storms do. The Euro model shows a bit more strengthening offshore but the intensification is not shown to follow through as the storm approaches Cape Cod. The Canadian is the best model for us and thus shows the most snow. Temperatures are close enough however to make for an elevation event. In addition, precipitation should stay snow as long as precipitation rates are moderate to heavy. Lighter precipitation is more likely to fall as rain. Also, unless the outlook turns cooler, snowfall will be wet except for perhaps the highest 1000 feet (above 3,000 feet). Right now, I would expect a gloppy 4-8 inches at the base and a slightly less wet 8-12 at the summit. Valley locations will not perform especially well and will receive nothing more than 1-3. The Champlain Valley probably gets next to nothing. Precipitation begins sometime on Monday and is likely heaviest Monday night or Tuesday.
Wednesday looks like a dry and somewhat mild day but by Thursday, another system will approach. There is some speculation about where this storm will track and it is not expected to strengthen as it proceeds by us on Thursday. It will however provide us with some limited moisture for snowfall and help to usher in colder more winter-like Temperatures in its wake. Lingering instability will enhance the window for new show through much of Friday making new snow very likely as we head toward the last weekend of February.
The big weapon we have in our favor very late in January and moving into February is the weakened jet stream in the Pacific or the negative EPO. A large ridge in the jet stream will temporarily position itself over western North America but we never get a needed high latitude block or a fully negative Arctic Oscillation (AO) to ensure successive weeks of cold weather. It looks instead like a decent burst of cold toward the end of the month into early February and then a pattern that looks closer to normal as we move later into February. This still constitutes a much better outlook compared to what we've experienced over the last 10 days, it just doesn't guarantee that every storm will come up roses for us.